Absorption is a process in which one substance is taken up or dissolved into another substance. It commonly refers to the transfer of a gas or liquid into a solid or liquid phase. It occurs when molecules or particles are dissolved or incorporated into the bulk of a solid, liquid, or gas. Absorption is commonly used in various fields, including chemistry, environmental science, and pharmaceuticals, for separation, purification, or analysis purposes.
An accessor or panelist in odor measurement refers to an individual who participates in sensory evaluation panels to assess and rate odors. Panelists undergo training to develop their olfactory senses and use their expertise to detect, describe, and quantify odors using standardized methodologies. Their evaluations help in determining the intensity, character, and overall perception of odors in various applications, including environmental odor assessment and control.
A pollution control device used to remove acidic gases, such as sulfur dioxide (SO2) and hydrogen chloride (HCl), from industrial gas streams. It employs a chemical solution, typically an alkaline solution, to neutralize and absorb the acidic gases, reducing their emission into the atmosphere.
Rainfall with a pH lower than 5.6, caused by atmospheric pollution. Acid rain refers to precipitation, such as rain, snow, or fog, that is unusually acidic due to the presence of pollutants in the atmosphere. It is primarily caused by emissions of sulfur dioxide (SO2) and nitrogen oxides (NOx) from industrial activities, vehicle emissions, and combustion of fossil fuels. Acid rain can have detrimental effects on ecosystems, soil, water bodies, and infrastructure.
An acid scrubber generally use low pH and is used to remove alkaline gases. Generally dilute sulphuric acid is used as the absorbent. Alkaline gases such as Ammonia (NH3) is removed by acid scrubber.
An activated carbon filter is a filtration system that utilizes activated carbon as the primary filtering medium. It is designed to remove impurities, contaminants, and odors from air or water by adsorption. The activated carbon has a large surface area, which enables it to trap and retain a wide range of pollutants, providing improved air or water quality.
Activated sludge is a commonly used biological process in wastewater treatment plants. It involves the introduction of a mixture of wastewater and a microbial culture, known as the activated sludge, into an aeration tank. In this tank, air or oxygen is supplied to create an aerobic environment, promoting the growth and activity of microorganisms.
An active emission source refers to a specific and identifiable source or process that releases pollutants directly into the environment. Examples of active emission sources include industrial chimneys, vehicle exhaust pipes, power plant smokestacks, and other point sources where emissions are actively released.
Adsorption is a process where molecules or particles adhere to the surface of a solid or liquid. It occurs when the adsorbate is attracted to the surface of the adsorbent through intermolecular forces. Adsorption is commonly used in water treatment, air purification, and gas separation processes to remove contaminants.
An adsorbent is a material that has the ability to attract and retain molecules or particles from a gas or liquid onto its surface. It is commonly used in various applications, such as water and air purification, gas separation, and chemical processes, to remove impurities or target specific substances for purification or separation purposes.
Aerobic conditions refer to an environment or condition that has an adequate supply of oxygen. It is characterized by the presence of molecular oxygen, allowing aerobic organisms to thrive. Aerobic conditions are typically associated with processes such as aerobic respiration, where oxygen is utilized to generate energy through the breakdown of organic compounds.
Aerosols refer to particles or liquid droplets suspended in a gas, typically air. In the context of environmental engineering, aerosols are often associated with air pollution and can include various substances such as dust, smoke, pollutants, or even biological particles. These aerosols can be emitted from natural sources like volcanic eruptions or wildfires, as well as from human activities such as industrial processes, vehicle emissions, or aerosol sprays. Aerosols can have significant impacts on air quality, climate, and human health, making their measurement, monitoring, and control important aspects of environmental engineering.
Air pollution refers to the presence of harmful substances in the air that can pose risks to human health, the environment, and ecosystems. It is caused by various sources, including industrial emissions, vehicle exhaust, burning of fossil fuels, and agricultural activities. Common air pollutants include particulate matter, nitrogen dioxide, sulfur dioxide, ozone, and volatile organic compounds. Air pollution can lead to respiratory problems, cardiovascular diseases, climate change, and ecological imbalances. Effective measures are required to mitigate air pollution and protect public health and the environment.
Air stripping is a water treatment process that involves the transfer of volatile contaminants from water to the air. It is achieved by exposing water to air in a tower or column, allowing the contaminants to evaporate and be removed, resulting in purified water.
An air stripping column is a tower or column used in water treatment processes to remove volatile contaminants from water. Water is introduced at the top of the column and cascades down while air is passed through in a counter-current flow, facilitating the transfer of volatile compounds from the water to the air.
Alkali refers to a group of substances, typically hydroxides or carbonates of alkali metals, that have a high pH and exhibit basic properties. They are used in various applications, including pH regulation, chemical synthesis, soap production, and as cleaning agents due to their ability to neutralize acids.
An alkaline scrubber, is a pollution control device used to remove acidic gases from industrial gas streams. It operates by introducing an alkaline solution, such as sodium hydroxide (NaOH) or calcium carbonate (CaCO3), into the gas stream. The acidic gases, such as Hydrogen sulphide (H2S) react with the alkaline solution to form neutral or less acidic compounds, which are then collected and removed. Alkaline scrubbers are commonly employed in industries to reduce emissions of harmful acidic gases and comply with environmental regulations.
Ambient air refers to the air that surrounds us in our everyday environment. It is the air present in outdoor spaces, such as streets, parks, and open areas, without any specific confinement or enclosure. Ambient air composition can vary depending on location, weather, and human activities, and it serves as the baseline for assessing air quality.
Ambient conditions refer to the environmental factors and parameters that exist in a given space or area. These conditions include temperature, humidity, pressure, air quality, noise level, and lighting. Understanding and monitoring ambient conditions are crucial for various applications, including comfort, safety, and environmental assessments.
An ammonia scrubber, is a pollution control device used to remove ammonia gas (NH3) from industrial gas streams. It involves introducing an acidic solution, typically sulfuric acid (H2SO4), to react with and neutralize the ammonia gas, resulting in the formation of ammonium salts that are collected and removed. Ammonia scrubbers are commonly used in industries to mitigate ammonia emissions and ensure compliance with environmental regulations.
Anaerobic conditions refer to an environment or condition that lacks or has limited oxygen availability. It occurs in situations where oxygen is absent, depleted, or cannot penetrate the system. Anaerobic conditions are commonly found in oxygen-deprived environments, such as the bottom sediments of lakes, swamps, and within the digestive tracts of certain organisms. In anaerobic conditions, specific microbial processes occur, such as anaerobic digestion or fermentation, which have unique biochemical pathways compared to aerobic conditions. Anaerobic digestion is a biological process that converts organic materials, such as wastewater, sludge, agricultural waste, or food waste, into biogas and nutrient-rich digestate in the absence of oxygen. It is a sustainable method for energy production and organic waste management, reducing greenhouse gas emissions and providing renewable energy sources.
It is an advanced UASB reactor trademarked by Elixir Enviro Systems Pvt Ltd, Kerala, India. It is used for the treatment of Industrial Wastewater. The very advantage of the reactor is its ability to retain the floating and suspended COD and biomass and thereby yielding higher Biogas for the very same wastewater compared to the UASB reactors.
Benzene is an organic chemical compound with the molecular formula C6H6. It is a colorless, flammable liquid with a sweet aroma. Benzene is a natural component of crude oil and is used as a starting material for the production of various chemicals, including plastics, synthetic fibers, dyes, and pharmaceuticals. It is known to be carcinogenic and toxic to human health.
Bellows are used as flexible connectors or expansion joints to accommodate the vibrations, thermal expansion and contraction. They help to absorb vibrations, compensate for misalignments, and reduce stress on the system components. Bellows in HVAC systems are commonly found in ductwork, fan assemblies, and piping systems to ensure proper operation and minimize the risk of damage due to temperature changes and mechanical stress.
BFBR is the abbreviation of Buoyant FIlter Bio Reactor, an invention of CSIR-NIIST, government of India. It is an advanced anaerobic reactor for complex wastewater treatment, basically for industrial applications. This is an advanced version of the UASB reactor.
Bioaccumulation refers to the gradual accumulation of substances, such as pollutants or toxins, in the tissues of living organisms over time. These substances are absorbed faster than they are eliminated, leading to their increasing concentration within the organism. Bioaccumulation can occur in various species and can have detrimental effects on ecosystems and human health.
Biodiversity refers to the variety of life forms, including plants, animals, microorganisms, and ecosystems, present on Earth. It encompasses the genetic, species, and ecosystem diversity. Biodiversity is crucial for maintaining ecological balance, providing ecosystem services, supporting human well-being, and contributing to the resilience of ecosystems in the face of environmental changes. Conservation efforts are necessary to protect and sustain biodiversity.
A biofilter is an air pollution control device that utilizes microorganisms to degrade and remove pollutants from gas streams. It consists of a bed or medium where the microorganisms reside, and as contaminated air passes through, the microorganisms break down pollutants, resulting in their conversion into harmless byproducts.
Biogas is a renewable energy source produced through the anaerobic digestion of organic matter, such as agricultural waste, food waste, specific industrial wastewater and sewage. It consists primarily of methane and carbon dioxide and can be used for heat, electricity, and as a vehicle fuel, providing a sustainable alternative to fossil fuels.
Biogas desulphurization refers to the process of removing sulphur compounds from biogas to reduce their harmful effects and comply with environmental regulations. Biogas, produced from organic waste through anaerobic digestion, contains various sulphur compounds, primarily hydrogen sulphide (H2S), which is known for its corrosive and odorous properties. Desulphurization is necessary to prevent equipment corrosion, minimize odour emissions, and ensure the safe utilization of biogas. There are different methods for biogas desulphurization, including biological, chemical, and physical processes. Biological desulphurization utilizes microorganisms to convert hydrogen sulphide into elemental sulphur or sulphate. Chemical desulphurization involves the use of scrubbing agents, such as iron oxide or activated carbon, to absorb and remove the sulphur compounds. Physical desulphurization methods, like adsorption or membrane separation, utilize specific materials or membranes to selectively capture sulphur compounds from the biogas stream.
A Biogas reactor, also known as an anaerobic digester, is a sealed vessel or system designed to facilitate the anaerobic digestion process. It provides an oxygen-free environment where organic waste is broken down by microorganisms, resulting in the production of biogas, primarily composed of methane and carbon dioxide. Biogas reactors are used for renewable energy generation, waste treatment, and nutrient recovery.
Biological Nutrient Removal (BNR) is a wastewater treatment process that uses microorganisms to remove nutrients such as nitrogen and phosphorus from wastewater. It typically involves two stages: nitrification, where ammonia is converted to nitrate, and denitrification, where nitrate is converted to nitrogen gas. BNR helps prevent nutrient pollution in receiving water bodies and promotes environmentally friendly wastewater treatment.
Bioremediation is a process that employs living organisms, such as bacteria, fungi, or plants, to degrade or remove pollutants from contaminated environments. These organisms break down or transform contaminants into less harmful forms, providing an environmentally friendly and sustainable approach to remediate polluted sites and restore ecosystems.
A Bioscrubber, also known as a bio-scrubbing system, is an air pollution control device that combines the principles of biological and chemical scrubbing to remove pollutants from gas streams. It uses a liquid solution containing microorganisms and chemical agents to absorb and break down pollutants, resulting in their removal from the gas stream. Bioscrubbers are commonly used for the treatment of odorous compounds and volatile organic compounds (VOCs).
Biosolids are nutrient-rich organic materials derived from the treatment of sewage or wastewater. After wastewater treatment processes, the residual sludge undergoes further treatment to reduce pathogens and stabilize the organic matter. The resulting biosolids can be beneficially reused as fertilizer in agriculture, land reclamation, or composting applications.
A Biotrickling Filter is an air pollution control system that utilizes a packed bed containing microbial biofilm to remove pollutants from gas streams. The biofilm on the packing material absorbs and metabolizes the pollutants, converting them into less harmful substances. Biotrickling filters are commonly used for the treatment of volatile organic compounds (VOCs) and inorganic gases.
A Carbon Credit is a tradable permit or certificate that represents the reduction or removal of one metric ton of carbon dioxide (CO2) emissions. It is a market-based mechanism used to incentivize and finance projects that reduce greenhouse gas emissions. Carbon credits are bought and sold to meet emission reduction targets and support sustainable practices.
Carbon footprint refers to the total amount of greenhouse gas emissions, primarily carbon dioxide (CO2), produced directly or indirectly by an individual, organization, or activity. It is a measure of the impact of human activities on climate change and is typically measured in terms of CO2 equivalent emissions, taking into account the global warming potential of different greenhouse gases.
A Carcinogen is a substance or agent that has the potential to cause cancer in living organisms. Carcinogens can be chemical compounds, such as certain pesticides or industrial chemicals, as well as physical agents like ionizing radiation. Exposure to carcinogens increases the risk of developing cancer over time.
A Chemical Scrubber, also known as a wet scrubber or gas scrubber, is an air pollution control device used to remove pollutants from gas streams through chemical reactions. It involves passing the gas stream through a liquid solution or slurry, where the pollutants are absorbed or chemically reacted with the scrubbing solution. This process removes the pollutants from the gas stream, resulting in cleaner emissions.
Climate change refers to long-term shifts in weather patterns and average temperatures on Earth. It is primarily caused by human activities, such as burning fossil fuels and deforestation, which release greenhouse gases into the atmosphere, leading to global warming. Climate change impacts include rising temperatures, sea level rise, extreme weather events, and ecological disruptions. Mitigation and adaptation strategies are crucial to address climate change and its consequences.
Cocofil Biofilters are proprietary trademarked Biofilter media made by Elixir Enviro Systems Pvt Ltd, Kerala, India. It can give odour efficiencies upto 99%. It comes in different series such as Cocofil 15, Cocofil 25, Cocofil 30 etc. It is widely used in many parts of India and in Sri Lanka.
Cold Plasma technology is an innovative approach used for odour control in various applications. It involves generating a low-temperature plasma that creates highly reactive species capable of breaking down odorous compounds. By subjecting the air to the plasma, cold plasma technology can effectively neutralize and eliminate odours, offering a sustainable and efficient solution for odour control in various industries.
A combustible vapor mixture refers to a combination of flammable gases, vapors, or aerosols with air that has the potential to ignite and sustain a fire or explosion. These mixtures occur when a sufficient concentration of flammable substances is present in the air, creating a hazardous environment with the potential for rapid combustion if ignited.
Condensation is often used as a pretreatment method for odour control in certain applications. In this context, condensation refers to the process of cooling and condensing odorous gases to remove and collect the volatile compounds responsible for the odour, thereby the odour load as well as the temperature of the gas will become suitable for the Biological treatment. The condensed liquid, often referred to as condensate, can then be collected and treated further to remove or neutralize the odour-causing compounds or the COD. Condensation as a pretreatment for odour control can be effective in reducing the odour emissions from various sources, such as industrial processes and some waste/wastewater management facilities. However, it is important to note that condensation alone may not completely eliminate the odour, and additional treatment steps may be required depending on the specific odour sources and regulatory requirements.
Concentration refers to the amount of a substance present in a given volume or mass of a mixture or solution. It quantifies the relative abundance or density of a specific component within a system. Common units of concentration include mass/volume, moles/volume, mass/mass, and percentage, and they are used in various fields, such as chemistry, environmental science, and biology, to describe the composition of substances.
A contaminant refers to any substance or agent that is present in a material, system, or environment in an unwanted or harmful manner. It can include pollutants, toxic chemicals, microorganisms, or other substances that can cause adverse effects on human health, ecosystems, or the quality of air, water, soil, or food.
Consent to establish refers to the formal approval or authorization granted by a regulatory authority (generally Pollution Control Board) to an industrial or commercial entity for the establishment of a new project or facility. Consent to establish is typically obtained after submitting a comprehensive proposal that includes project details, environmental impact assessment, mitigation measures, and adherence to relevant laws and regulations. The approval process ensures that the proposed project is viable, safe, and environmentally sound before it can commence operations.
Consent to operate refers to the legal authorization (Generally the Pollution Control Board) or permission granted by a regulatory authority to an industrial or commercial entity to carry out its operations or activities. Consent to operate is typically obtained after fulfilling certain criteria, such as demonstrating compliance with emission limits, waste management practices, and other applicable regulations. It is an important regulatory requirement to ensure the safe and environmentally responsible operation of businesses.
Containment refers to the act of preventing the release or spread of hazardous substances or contaminants into the environment. It involves the use of physical barriers, enclosures, or control measures to confine and limit the movement or dispersion of pollutants, ensuring their isolation and minimizing potential risks to human health and the environment.
A corrosive chemical is a substance that can cause severe damage or destruction to living tissue or materials upon contact. It has the ability to corrode or erode surfaces, including metals, skin, eyes, and other materials. Examples of corrosive chemicals include strong acids (e.g., sulfuric acid) and strong bases (e.g., sodium hydroxide). Proper handling and protective measures are essential when working with corrosive chemicals.
Cumulative effect refers to the cumulative or combined impact of repeated or prolonged exposure to a substance or factor over time. It occurs when the effects of repeated exposures accumulate and produce a greater overall impact than single or isolated exposures. Cumulative effects can occur in relation to health, environment, or other areas and may lead to adverse outcomes or increased risks.
Deammonification is a biological process that involves the conversion of ammonium (NH4+) to gaseous nitrogen compounds, such as nitrogen gas (N2), without the intermediate formation of nitrite (NO2-) or nitrate (NO3-). This process is carried out by specific bacteria, such as anammox bacteria, and is used in wastewater treatment to remove nitrogen from effluent efficiently. Deammonification helps reduce the energy and chemical requirements associated with traditional nitrification and denitrification processes.
The Demineralization plants are two-column systems, where the water first passes through a cation exchange column and then next passes through an anion exchange column.The plants are used for many applications, including production of rinse water, process water, boiler water, and more.
Denitrification is a biological process in which certain bacteria convert nitrate (NO3-) to gaseous nitrogen compounds, such as nitrogen gas (N2) or nitrous oxide (N2O), under anaerobic conditions. It occurs in environments with low oxygen levels and serves as a natural mechanism for removing excess nitrate from soil, groundwater, and wastewater, thereby reducing nitrogen pollution.
Desorption is the process of releasing or removing adsorbed or absorbed substances from the surface or interior of a solid or liquid material. It involves the separation of molecules or particles that were previously attached or captured by the material, often through the application of heat, pressure, or chemical treatments. Desorption is commonly employed in various applications, such as in environmental remediation, gas separation, and purification processes.
The Detection threshold, also known as the detection limit or sensory threshold, is the lowest concentration or level at which a stimulus or substance can be perceived or detected by the human senses or an instrument. It represents the point at which the presence or intensity of a stimulus becomes noticeable or detectable above background noise or baseline levels. The term D/T is generally used in olfactometry.
Detention time refers to the period that a substance or fluid remains within a specific system or process. It is the duration for which the substance is retained or held in a reactor, tank, or channel, allowing sufficient time for desired reactions, settling, or separation to occur. Detention time is an important parameter in various processes, such as wastewater treatment, chemical reactors, and hydraulic systems, as it influences the effectiveness of the process and the desired outcomes.
Dewatered sludge refers to the solid residue obtained from the process of removing water from sludge, which is the semi-solid material generated during wastewater treatment. Dewatering processes, such as mechanical or chemical methods, are employed to reduce the moisture content of the sludge, resulting in a more concentrated and manageable solid material for disposal or further treatment.
Dioxins are a group of highly toxic chemical compounds that are formed as unintentional byproducts of various industrial processes, such as waste incineration and chemical manufacturing. They are persistent organic pollutants (POPs) and can accumulate in the environment and the food chain. Dioxins are known to have serious health effects, including carcinogenicity and disruption of the endocrine system.
A dry scrubber, also known as a dry scrubbing system or dry sorbent injection system, is an air pollution control technology used to remove pollutants from industrial exhaust gases. Unlike wet scrubbers that use a liquid solvent to capture and neutralize pollutants, dry scrubbers rely on a dry sorbent material to chemically react with and absorb the pollutants. The dry scrubbing process typically involves injecting a dry sorbent, such as activated carbon, lime, or sodium bicarbonate, into the exhaust gas stream.
A duplicate sample refers to a replicate or identical sample that is collected and analyzed alongside the original sample to assess the precision and accuracy of the measurement or analysis. Duplicate samples help identify any variability or inconsistencies in the results and ensure the reliability and quality of the data obtained. They are commonly used in scientific research, environmental monitoring, and quality control processes.
Dust Scrubbers, also known as dust collectors or particulate scrubbers, are air pollution control devices used to remove dust and particulate matter from industrial gas streams. They operate by using various mechanisms, such as impaction, interception, or absorption, to capture and collect dust particles, improving air quality and reducing emissions.
An ecosystem is a dynamic and interconnected community of living organisms, including plants, animals, and microorganisms, interacting with their physical environment. It involves the exchange of energy, nutrients, and resources within a specific area or habitat. Ecosystems can range from small, localized habitats like ponds to vast biomes like forests or oceans, and they play a crucial role in maintaining ecological balance, supporting biodiversity, and providing essential services such as nutrient cycling, water purification, and climate regulation.
Effluent refers to any liquid or gaseous waste discharged from a process, system, or treatment facility. It commonly refers to wastewater or industrial discharge that is released into the environment or conveyed to a treatment facility. Effluent may contain pollutants, contaminants, or residual substances that require proper management or treatment to minimize their impact on the environment and public health.
An electrostatic precipitator (ESP) is an air pollution control device that removes particulate matter from industrial exhaust gases. It utilizes electrostatic forces to charge and attract particles onto collection plates, where they are later removed. ESPs are commonly used to reduce emissions of fine particles and improve air quality in various industrial processes.
Emission Control refers to the measures and techniques implemented to reduce or mitigate the release of harmful pollutants into the environment. It involves the use of technologies, such as air pollution control devices and emission reduction strategies, to minimize emissions from industrial processes, effluent treatment plants and other pollution sources. Emission control aims to improve air quality and protect human health and the environment.
EN 13725 is a European standard that provides guidelines for the measurement of odor concentration and odor intensity in ambient air. It outlines the procedures and requirements for conducting olfactometric assessments and sets criteria for the calibration and performance of olfactometers. The standard ensures consistent and reliable measurement of odors for regulatory purposes, environmental impact assessments, and odor control strategies.
An electronic nose, also known as an e-nose, is a device that mimics the sense of smell using sensor arrays and pattern recognition algorithms. It is designed to detect and identify odours or volatile compounds in a similar manner to human olfaction. The electronic nose consists of sensors that respond to various chemical compounds and generate a pattern of responses. These patterns are then analyzed by a computer algorithm to identify and classify different odours or detect specific target compounds. Electronic noses find applications in various fields, including food quality control, environmental monitoring, and industrial odor detection.
Enthalpy is a thermodynamic property that describes the total heat content of a system. It includes both the internal energy and the energy associated with the system’s pressure and volume. Enthalpy change (ΔH) is often used to analyze heat transfer in chemical reactions or phase changes, and it provides insights into the energy flow within a system.
Environmental footprint refers to the total impact of human activities on the environment, including the consumption of resources and generation of waste and emissions. It measures the ecological footprint left behind by individuals, organizations, or societies and encompasses factors such as carbon emissions, water usage, land use, and waste generation. The goal is to minimize the negative environmental impact and promote sustainable practices.
It is a process used to evaluate the potential environmental impacts of proposed projects or activities. EIA involves identifying, predicting, and assessing the likely environmental effects, considering alternatives, and proposing measures to mitigate or manage adverse impacts. It is a vital tool for sustainable decision-making and ensuring environmental protection.
Environmental Remediation refers to the process of addressing and mitigating contamination or pollution in soil, water, or air to restore environmental quality and protect human health. It involves various techniques such as excavation, soil vapor extraction, bioremediation, and chemical treatment, tailored to the specific contaminants and site conditions. The goal is to mitigate or eliminate the risks posed by pollutants and restore the affected area to its desired state.
Exergy is a thermodynamic concept that measures the maximum useful work that can be obtained from a system as it approaches equilibrium with its surroundings. Unlike energy, which represents the total quantity of work or heat, exergy represents the quality or available energy. It takes into account the differences in temperature, pressure, and chemical composition between the system and its surroundings. Exergy analysis is used to optimize energy conversion processes, identify inefficiencies, and improve overall system performance.
Extended Aeration Treatment Plants works by providing ideal conditions for aerobic bacteria and other microorganisms which provides sufficient oxygen to consume organic matter and to live and multiply within the system. In this way the aerobic bacteria and microorganism decompose organic matter into a stable form which will be odor free and nuisance free.
Exhaust refers to the gases, fumes, or air that is expelled from an engine, combustion process, or industrial operation. It is the result of the combustion or operation of a system and typically contains byproducts such as carbon dioxide, nitrogen oxides, particulate matter, and other pollutants. Proper exhaust management and control are essential to minimize environmental impacts and ensure air quality.
Ex-situ refers to a process or treatment that occurs outside of its original or natural location or setting. It involves removing or relocating a substance, organism, or environmental process to a controlled or engineered environment for remediation, management, or study. Ex-situ approaches are commonly used in environmental remediation, conservation efforts, and scientific research to address specific challenges or conditions.
A feasibility study is an assessment conducted to determine the practicality and viability of a proposed project or venture. It involves evaluating various factors, such as technical, financial, legal, and market aspects, to determine if the project is feasible and likely to be successful. The study helps stakeholders make informed decisions regarding project initiation and investment.
“FIDOL” stands for Frequency, Intensity, Duration, Offensiveness, and Location. FIDOL is a framework used to assess and characterize odor complaints or incidents. It involves considering the frequency of odor occurrences, the intensity or strength of the odors, the duration of odor events, the offensiveness or impact on individuals, and the specific location or source of the odors. The FIDOL framework helps in understanding and addressing odor-related issues and implementing appropriate mitigation measures.
Flammable refers to substances or materials that can easily catch fire and sustain combustion when exposed to an ignition source. These substances have low flash points, meaning they can vaporize quickly and form ignitable mixtures in the air. Flammable materials pose fire hazards and require proper storage, handling, and precautions to prevent accidents and minimize risks.
A fugitive emission refers to a source of pollutant emissions that is not well-defined or easily quantifiable. Unlike point sources that have a specific location and are regulated under emission standards, fugitive sources are diffuse and often arise from various activities or processes. Fugitive emissions can result from equipment leaks, open storage of materials, dust generation, or other uncontrolled releases. They are typically challenging to measure and control, requiring proactive strategies such as improved equipment maintenance, leak detection programs, and proper handling practices to minimize their impact on air quality. In case of Odour control fugitive emission capture and management is very important.
Gas purification involves the removal of pollutants from the exhaust gases emitted by the industrial facilities. This is typically achieved through the use of various technologies, including Biological systems such as Bioscrubbers, Biofilters, Biotrickling filters, particulate filters, thermal oxidisers, chemical scrubbers, chemical oxidisers, thermal oxidisers and selective catalytic reduction systems, to reduce harmful emissions and improve air quality.
Granular activated carbon (GAC) is a highly porous form of carbon that is used for adsorption and filtration purposes. It consists of granules or particles with a large surface area, which allows it to effectively adsorb contaminants from air or water. GAC is commonly used in water treatment, air purification, and industrial processes to remove organic compounds, odors, and impurities.
The trapping of heat in the Earth’s atmosphere due to the presence of certain gases, such as carbon dioxide and methane, which leads to global warming.
Waste materials that pose a substantial risk to human health or the environment due to their chemical, physical, or biological characteristics. Hazardous waste refers to any waste material that poses a substantial risk to human health, the environment, or both. It can be generated from various sources, including industrial processes, healthcare facilities, and household activities. Hazardous waste may contain toxic, flammable, corrosive, or reactive substances that require special handling, treatment, and disposal to prevent harm to people and the environment. Proper management and disposal of hazardous waste are essential to protect public health and the environment.
Refers to the subjective pleasantness or unpleasantness associated with a particular sensory experience, such as taste or smell. It represents an individual’s emotional response to a stimulus and is often described on a spectrum ranging from highly pleasant to highly unpleasant. In the case of odours, the hedonic tone reflects the perceived pleasantness or unpleasantness of a specific smell. Hedonic tone plays a significant role in shaping our preferences, perceptions, and overall sensory experiences.
The hydraulic gradient is a term used in fluid mechanics and hydrogeology to describe the change in hydraulic head per unit of distance in a groundwater or fluid flow system. It represents the driving force for fluid movement and is calculated by dividing the difference in hydraulic head between two points by the distance between those points.The hydraulic gradient is an important factor in understanding flow patterns and determining the direction and rate of flow of water or groundwater.
Hydraulic retention time (HRT) refers to the average time that water or wastewater remains in a treatment system or reactor. It is a critical parameter in determining the efficiency of the system in removing pollutants. A longer HRT allows more time for processes such as sedimentation, biological reactions, and filtration to occur, resulting in improved treatment performance.
Hydrocarbon refers to a compound composed of hydrogen and carbon atoms. They are the primary components of fossil fuels such as petroleum, natural gas, and coal. Hydrocarbons play a vital role in energy production and are used as fuels for transportation, heating, and electricity generation. They also serve as raw materials in various industries, including petrochemicals, plastics, and pharmaceuticals.
HCl emission control refers to the measures and technologies implemented to reduce or mitigate the release of hydrogen chloride (HCl) gas into the environment. This is typically achieved through the use of air pollution control devices, such as wet scrubbers or dry sorbent injection systems, which capture and neutralize HCl emissions before they are released into the atmosphere. The purpose is to minimize the environmental impact and potential health risks associated with HCl emissions.
Hydrogen Sulphide (H2S) is a colorless, highly toxic gas with a characteristic foul odor of rotten eggs. It is produced naturally by the decay of organic matter and is also emitted during various industrial processes, such as petroleum refining and wastewater treatment. Exposure to high concentrations of hydrogen sulfide can be deadly, causing respiratory and neurological effects. Proper monitoring and control measures are essential to mitigate the risks associated with hydrogen sulfide exposure.
Hydrogen sulfide (H2S) removal refers to the process of eliminating or reducing the presence of H2S gas from air or gas streams. This is typically done through various methods, including chemical scrubbing, biological treatment, and activated carbon adsorption, to effectively capture and remove the toxic and odorous H2S gas, ensuring improved air quality and safety.
Hyposmia is a medical term used to describe a reduced or decreased sense of smell. It refers to a diminished ability to detect or perceive odours. Individuals with hyposmia may have difficulty detecting certain scents or may perceive them as weaker or less intense compared to others. Hyposmia can be caused by various factors, including nasal congestion, sinusitis, neurological conditions, or certain medications.
HVAC stands for Heating, Ventilation, and Air Conditioning. It refers to the technology and systems used to control the indoor environment in buildings for comfort, health, and safety. Heating systems provide warmth during cold weather, ventilation systems supply fresh air, and air conditioning systems cool and dehumidify the air. HVAC systems play a crucial role in maintaining indoor air quality and creating a comfortable living or working environment.They are widely used in residential, commercial, and industrial buildings. A proper HVAC system is essential for air pollution control as well.
The study of industrial systems and their interconnections with natural systems, aiming to minimize waste and optimize resource utilization.
In situ refers to a process or treatment that occurs in its original or natural location or setting, without the need for removal or relocation. It involves addressing a problem or conducting a study directly at the site where it occurs, without disrupting or removing the materials or organisms involved. In situ approaches are commonly used in environmental remediation, habitat restoration, and geological studies to minimize disturbance and maintain the integrity of the natural environment.
A designated area for the disposal of solid waste, where waste is buried and covered with soil. It involves the controlled burial of waste in the ground, usually in layers, with appropriate engineering measures to minimize environmental impacts. Landfills are designed to prevent contamination of soil, water, and air, and to promote proper waste management and disposal practices.
Leachate treatment refers to the process of treating the liquid that is generated when from landfills or contaminated sites. Leachate contains various pollutants and contaminants that require treatment to prevent environmental contamination. Treatment methods typically involve physical, chemical, and biological processes to remove or neutralize the pollutants and ensure proper disposal or reuse of the treated leachate.
An analysis of the environmental impact of a product, process, or activity throughout its entire life cycle, from raw material extraction to disposal. LCA is a systematic evaluation of the environmental impacts of a product, process, or service throughout its entire life cycle, from raw material extraction to disposal. It considers the environmental burdens associated with resource use, energy consumption, emissions, and waste generation, providing insights for sustainable decision-making and product improvement.
A masking agent is a substance or chemical compound used to cover or mask unwanted odours or tastes with a more desirable scent or flavor. It works by chemically interacting with the odorous compounds, altering their perception and providing a more pleasant experience. Masking agents are commonly used in products such as air fresheners, perfumes, and flavored food and beverages. However, it’s important to note that masking agents do not eliminate or remove the odour-causing compounds; they simply provide a temporary solution by overpowering or masking the unpleasant odour.
Methane is a byproduct of the decomposition of organic matter in the absence of oxygen. It is produced by anaerobic bacteria during the breakdown of biomass, such as sewage sludge, agricultural waste, or food scraps. Methane generated in anaerobic digestion can be captured and utilized as a renewable energy source, reducing greenhouse gas emissions and providing a sustainable alternative to fossil fuels.
Mitigation refers to actions taken to reduce or prevent the adverse impacts of climate change or other environmental problems. It involves implementing measures to decrease greenhouse gas emissions, conserve resources, promote sustainable practices, and enhance resilience to environmental changes. Mitigation aims to minimize the severity and extent of environmental issues and their associated risks.
n-Butanol, also known as n-butyl alcohol, is a colorless, flammable liquid with a characteristic alcohol odor. It is commonly used as a solvent in various industrial applications, such as paints, coatings, adhesives, and cleaning products. n-Butanol, in odour measurement and control context, is used in the panelist screening of Odour assessment.
Nitrification is a biological process in which certain bacteria convert ammonia (NH3) into nitrite (NO2-) and further into nitrate (NO3-). It occurs in two steps: the first step is ammonia oxidation by ammonia-oxidizing bacteria (AOB) to produce nitrite, and the second step is nitrite oxidation by nitrite-oxidizing bacteria (NOB) to produce nitrate. Nitrification plays a crucial role in the nitrogen cycle and is commonly employed in wastewater treatment to remove ammonia and control nitrogen pollution.
Nitritation is a biological process in wastewater treatment that involves the conversion of ammonium (NH4+) to nitrite (NO2-) through the activity of specific bacteria known as ammonium-oxidizing bacteria (AOB). It is the first step in nitrification, which is followed by the conversion of nitrite to nitrate by nitrite-oxidizing bacteria (NOB). Nitritation plays a crucial role in removing nitrogen from wastewater and is often employed in biological nutrient removal systems.
Odour, also spelled as odor, refers to the perception of smell or the sensation produced by certain substances or compounds in the air. It is a subjective experience that occurs when odor molecules come into contact with receptors in the nose, triggering a neurological response that results in the perception of smell. Odours can be pleasant or unpleasant and can vary in intensity. They can be emitted from various sources, such as natural substances, industrial processes, waste materials, or biological activities. Odour control and management are important in various contexts, including environmental, industrial, and public health, to address issues related to odor nuisance, air quality, and overall well-being.
An odorant refers to a substance or chemical compound that has a distinct odor or smell. Odorants are responsible for creating the sensory perception of odors. They can be naturally occurring compounds or synthetic substances. Odorants can be volatile and easily released into the air, allowing them to be detected by the olfactory system. They are often used in various applications, including perfumes, fragrances, food flavorings, and industrial processes. Odorants play a crucial role in our ability to detect and distinguish different smells and are often the target of odor control efforts in environmental engineering to mitigate unpleasant or harmful odors.
Odor concentration refers to the amount or intensity of an odor present in a given volume of air. It is a measure of the odor’s strength or potency and is typically expressed in terms of a unit of measurement, such as odor units per cubic meter (ou/m³) or parts per billion by volume (ppbv). Odor concentration is influenced by factors such as the emission rate of odorous substances, the distance from the odor source, atmospheric conditions, and the sensitivity of individuals’ olfactory perception. Monitoring and assessing odor concentration is important in evaluating odor impacts, implementing control measures, and determining compliance with odor regulations or guidelines.
Odor dispersion modeling is a technique used to simulate and predict the movement and spread of odorous substances in the atmosphere. It involves the use of mathematical models and computer simulations to estimate the concentration and distribution of odors emitted from a specific source or area. Various factors such as meteorological conditions, terrain features, source characteristics, and emission rates are considered in the modeling process. Odor dispersion models help in understanding how odors disperse, how far they travel, and where they may be detected, aiding in odor impact assessment, mitigation planning, and regulatory decision-making.
Odour fatigue is the phinominon of the inability or decreased ability of a person to perceive an odour when he/she is exposed to it for a long time. Odor fatigue, also known as olfactory fatigue or olfactory adaptation, refers to the temporary desensitization or diminished perception of an odor after prolonged exposure to it. When individuals are exposed to a particular odor for an extended period, their sense of smell becomes less sensitive to that odor, and they may no longer notice it or perceive it as strongly as they initially did. This phenomenon occurs due to the sensory receptors in the nose becoming less responsive over time. For example, fishermen will not smell fish after a while; that doesn’t mean that the smell is not there. The odour may be initially detectable but will diminish in a few minutes. This is the very reason for having the clean “air purge” of the panelist after every sample analysis. To avoid the odour fatigue issue, it is always advisable to have several pauses in between the odour measurement cycle. Odor fatigue can lead to a reduced ability to detect and evaluate odors accurately, which may have implications for odor assessment and control in various settings, including environmental and industrial contexts.
An “Odour-hour” is defined as the occurrence of a clearly identifiable odour, which is perceived for a minimum of 10% of the measurement interval. This translates to at least 6 minutes of distinctly recognizable odour within a one-hour timeframe.
Odour impact assessment is a process used to evaluate the potential effects of odours on the surrounding environment and human receptors. It involves measuring and analyzing odour emissions from a specific source or area, assessing the dispersion and concentration of odours in the vicinity, and determining the potential impacts on sensitive receptors such as residential areas, workplaces, or recreational spaces. Odour impact assessment typically includes field surveys, odour sampling, dispersion modeling, and odorant concentration measurements. The results of the assessment help in understanding the extent of odour impacts, identifying potential sources of odor nuisance, and guiding the development of appropriate mitigation measures to minimize or eliminate odour-related issues.
Odour intensity refers to the perceived strength or concentration of an odour sensation. It describes how strong or weak the smell is to an individual’s sense of smell. Odour intensity is subjective and can vary from person to person based on factors such as sensitivity to odours, previous exposure, and individual perception. It is often evaluated using standardized methods, such as odor intensity scales or panel assessments, where trained individuals rate the strength of an odour on a numerical or descriptive scale. Odour intensity is an important factor in assessing the impact of odours, determining the effectiveness of odor control measures, and understanding the level of odor nuisance experienced by individuals in a given environment.
Odour pollution refers to the presence of unpleasant or offensive odours in the environment that can cause annoyance, discomfort, and adverse health effects to individuals. It can arise from various sources, such as industrial activities, waste management facilities, agriculture, and transportation. Effective management and control of odour pollution are important to maintain a healthy and pleasant living environment.
Odour unit is a unit of measurement used to quantify the intensity of odors. It is based on the concentration of an odorant that elicits a specific intensity or response from a panel of trained assessors. Odour units provide a standardized measure for comparing and evaluating odors, helping in odor control and regulatory compliance.
Olfactometry is a method used to measure and assess odors objectively. It involves human assessors sniffing and evaluating odor samples using standardized techniques and scales. Olfactometry provides quantitative data on odor concentration and intensity, helping to assess odor sources, control measures, and compliance with odor regulations in various industries and environmental settings.
An Olfactometer is a device used in olfactometry to measure and quantify odors. It typically consists of a series of dilution systems that dilute an odor sample to different concentrations, allowing human assessors to sniff and rate the intensity of the odor. Olfactometers are important tools for odor analysis, research, and regulatory compliance.
Oxidizers, also known as oxidizing agents or oxidants, are substances that have the ability to accept electrons from other substances, resulting in the oxidation of those substances. They are typically involved in chemical reactions where they provide oxygen or other highly electronegative elements to facilitate the oxidation process. Common examples of oxidizers include oxygen (O2), hydrogen peroxide (H2O2), chlorine (Cl2), and potassium permanganate (KMnO4). Oxidizers are used in various applications, such as disinfection, combustion, and chemical synthesis. However, they can also be hazardous and should be handled with caution.
The ozone layer is a region in the Earth’s stratosphere that contains a high concentration of ozone (O3) molecules. It plays a crucial role in protecting life on Earth by absorbing a significant portion of the sun’s ultraviolet (UV) radiation. However, human activities, particularly the release of ozone-depleting substances, have led to the thinning of the ozone layer, resulting in the formation of the ozone hole. International efforts, such as the Montreal Protocol, have been successful in reducing the use of ozone-depleting substances and allowing the ozone layer to recover gradually.The thinning of the ozone layer in the Earth’s stratosphere due to the release of ozone-depleting substances, such as chlorofluorocarbons (CFCs).
A passive pollution source refers to a source of pollution that does not actively release pollutants but rather allows them to be emitted or dispersed naturally without any mechanical or intentional intervention. Examples: the release of gases from decaying organic matter. These sources contribute to environmental pollution without any human-driven activity.
Particulates, or particulate matter (PM), are small solid or liquid particles suspended in the air. They can originate from various sources and have detrimental effects on human health and the environment. PM10 and PM2.5 are of particular concern due to their ability to penetrate deep into the lungs. Effective mitigation strategies are necessary to reduce particulate pollution.
Parts per million (ppm) is a unit of measurement used to express the concentration of a substance in a solution or mixture. It represents the number of parts of a particular substance per one million parts of the total solution or mixture. It is commonly used in various fields, such as environmental monitoring, water quality assessment, and industrial processes, to indicate trace amounts of substances.
Parts per billion (ppb) is a unit of measurement used to express extremely low concentrations of a substance in a solution or mixture. It represents the number of parts of a particular substance per one billion parts of the total solution or mixture. PPB is commonly used in environmental analysis, particularly for measuring trace levels of pollutants in air, water, and soil samples.
Petrochemicals are chemical compounds derived from petroleum or natural gas. They serve as the building blocks for various products and industries, including plastics, synthetic fibers, rubber, dyes, solvents, and fertilizers. Petrochemicals are produced through processes such as refining, cracking, and polymerization, and play a significant role in modern society’s manufacturing and consumer sectors.
pH is a measure of the acidity or alkalinity of a solution. It is based on the concentration of hydrogen ions (H+) present in the solution. The pH scale ranges from 0 to 14, where values below 7 indicate acidity, values above 7 indicate alkalinity, and a pH of 7 represents neutrality. pH is an important parameter in various fields, including chemistry, biology, environmental monitoring, and water treatment.
Phenols are a group of organic compounds that contain a hydroxyl (OH) group attached to an aromatic ring. They can occur naturally or be produced synthetically. Phenols have diverse applications, including use as disinfectants, antiseptics, and precursors for the production of plastics, pharmaceuticals, and dyes. Some phenols can be toxic and pose environmental and health risks when present in high concentrations.
A pilot project is a small-scale initiative or experiment designed to test and evaluate the feasibility, effectiveness, or viability of a particular concept, approach, or technology. It allows for testing and refining strategies before implementing them on a larger scale. Pilot projects help identify potential challenges, assess outcomes, and inform decision-making for broader implementation or further development.
In environmental engineering, a plume refers to a visible or invisible stream of gases, particles, or other substances that are emitted from a source and disperse through the surrounding air or water. Plumes can be observed in scenarios such as smokestack emissions, pollutant releases, or groundwater contamination, and their behavior is influenced by factors like wind direction, atmospheric conditions, and source characteristics.
Pollution prevention refers to the practice of minimizing or eliminating the generation of pollutants and waste materials at their source. It involves implementing strategies, technologies, and practices to reduce or eliminate pollution before it is produced, rather than relying solely on end-of-pipe treatments. Pollution prevention aims to conserve resources, protect the environment, and promote sustainable practices.
Polychlorinated Biphenyls (PCBs) are a group of synthetic organic compounds that were widely used in various industrial applications, such as electrical equipment, hydraulic fluids, and insulation materials. PCBs are persistent, bioaccumulative, and toxic, posing risks to human health and the environment. Their production and use have been largely banned or restricted due to their harmful effects.
Polyvinyl chloride (PVC) is a widely used thermoplastic polymer. It is known for its versatility, durability, and affordability, making it popular in construction, automotive, and consumer product industries. However, PVC production and disposal can release toxic chemicals, and proper handling and recycling are necessary to mitigate environmental and health impacts.
POP stands for Persistent Organic Pollutants, which are highly toxic chemical substances that persist in the environment for long periods, bioaccumulate in living organisms, and can travel long distances through air, water, and migratory species. Examples of POPs include dioxins, furans, polychlorinated biphenyls (PCBs), and certain pesticides. They pose significant risks to human health and the environment.
A pretreatment system in environmental engineering refers to a set of processes and equipment used to treat wastewater or pollutants before they enter the main treatment system. It aims to remove or reduce specific contaminants, solids, or toxic substances, improving the overall effectiveness and efficiency of the treatment process and protecting downstream equipment and ecosystems.
The Pressure Sand Filter consists of a multiple layer of sand with a variety in size and specific gravity. These Filters are designed to remove turbidity and suspended particles present in the feed water with minimum pressure drop. These Filters are custom designed to suit the process requirement.
Quality assurance and quality control (QA/QC) are processes implemented to ensure the consistency, reliability, and accuracy of data, measurements, and processes in environmental engineering. Quality assurance focuses on establishing procedures and standards, while quality control involves monitoring and evaluating performance to identify and rectify any deviations or errors, ensuring the reliability and validity of results.
Recognition threshold refers to the minimum concentration or level at which a stimulus, such as an odor or taste, is detectable by an individual. It represents the point at which a person can perceive the presence of a particular substance or sensory experience, often determined through sensory testing and analysis.
A remedial action plan (RAP) is a comprehensive strategy developed to address and mitigate the contamination or environmental damage at a specific site. It outlines the steps, techniques, and timelines for remediation activities, including site investigation, cleanup methods, monitoring, and long-term management. RAPs aim to restore the site to acceptable environmental standards and protect human health.
Renewable energy refers to energy derived from sources that are naturally replenished and have a minimal environmental impact. It includes solar, wind, hydroelectric, geothermal, and biomass energy. Renewable energy technologies harness these sources to generate electricity, heat, or fuel, offering sustainable alternatives to fossil fuels and reducing greenhouse gas emissions.
Residence time or residence time refers to the average amount of time that a substance or particle spends within a specific system, such as a water body or a reactor. It is calculated by dividing the volume of the system by the flow rate or the rate of input or removal of the substance, providing an indication of the system’s retention or turnover time.
Reverse osmosis is a water purification process that uses a semi-permeable membrane (synthetic lining) to filter out unwanted molecules and large particles such as contaminants and sediments like chlorine, salt, and dirt from drinking water. When pressure is added, to the higher level side, that is greater than the current osmotic pressure the flow will be reversed. This reversal allows the contaminant solution to be further concentrated and produces purified water. The adding of pressure to enact the reversal is called Reverse Osmosis or RO.
Risk assessment is a systematic process used to identify, evaluate, and quantify potential risks associated with a specific activity, project, or situation. It involves analyzing hazards, assessing their likelihood and potential impacts, and determining risk levels.The results inform decision-making, risk management strategies, and the development of measures to reduce or mitigate risks.
A sanitary landfill is a carefully engineered waste disposal facility designed to safely and effectively manage solid waste. It involves the systematic placement and compaction of waste into designated cells within the landfill, along with measures to control leachate and landfill gas. Liners, covers, and monitoring systems are employed to minimize environmental impacts and protect public health.
A scrubber, also known as a gas scrubber or air scrubber, is an air pollution control device used to remove harmful pollutants from industrial exhaust gases. It operates by introducing a liquid or solid scrubbing medium, such as water or chemicals, to capture and neutralize the pollutants before the gases are released into the environment.
Sedimentation is the process by which solid particles in a liquid or gas settle and separate from the fluid under the influence of gravity. It occurs when the velocity of the fluid decreases, allowing the heavier particles to settle to the bottom or form sediment layers. Sedimentation is commonly used in wastewater treatment, where it helps to remove suspended solids and pollutants from the water.
Sequential Batch Reactor (SBR) is a type of activated sludge process in which the treatment will be conducted in batch mode with several tanks. Each batch process includes fill, aeration, settle and decanting.
Semi-volatile organic compounds (SVOCs) are a class of organic compounds that have intermediate volatility, meaning they can exist in both the vapor and particulate phases. They have relatively higher molecular weights and tend to exhibit lower vapor pressures compared to volatile organic compounds (VOCs).
Skatole, also known as 3-methylindole, is a naturally occurring organic compound with a strong, unpleasant odor. It is commonly found in feces and is responsible for the characteristic smell of human and animal waste. Skatole is considered a volatile organic compound (VOC) and can contribute to odor pollution in certain environments.
A water softener plant is a device that is designed to remove positively charged ions of calcium and magnesium from water. It is essential to treat hard water in industries as it can cause expensive machinery and equipment to malfunction.The high synthetic resin is used to exchange Sodium ion with hardness forming Calcium and Magnesium ions.
Soil erosion is the process by which soil particles are displaced and transported by the forces of wind, water, or gravity. It can occur naturally or be accelerated by human activities such as deforestation and improper land management. Soil erosion leads to the loss of topsoil, reduced soil fertility, and environmental degradation, affecting agricultural productivity and water quality. Preventive measures such as erosion control structures and land conservation practices are implemented to mitigate soil erosion.
A solvent is a substance that has the ability to dissolve other substances, typically liquids, solids, or gases. It is used to create solutions by dissolving solutes into a solvent. Solvents are commonly used in various industries for processes such as cleaning, degreasing, extraction, and as a medium for chemical reactions. Examples of solvents include water, ethanol, acetone, and toluene.
Stabilization in environmental engineering refers to the treatment process that aims to reduce the reactivity or mobility of contaminants in soils, sediments, or waste materials. It involves techniques such as solidification, immobilization, or chemical reactions to transform or bind contaminants into a more stable and less hazardous form, minimizing their potential for migration and environmental impact.
A sump is a low-lying area or basin that collects and holds liquids, typically water or other fluids. In environmental engineering, a sump refers to an engineered structure or pit designed to collect and contain liquids, such as groundwater or wastewater. Sumps are commonly used in various applications, including stormwater management, industrial processes, and water treatment systems. They often incorporate pumps or drainage systems to facilitate the removal or transfer of the collected liquids.
Sustainable development refers to the practice of meeting the needs of the present generation without compromising the ability of future generations to meet their own needs. It involves balancing economic growth, social progress, and environmental protection. Sustainable development promotes responsible resource management, social equity, and environmental stewardship to create a more resilient and sustainable world.
Sludge Residence Time is the duration that sludge spends in a treatment system, allowing for the degradation, settling, and removal of solids. It is crucial for achieving effective sludge treatment and ensuring proper biological and chemical processes occur. The residence time is determined by factors such as flow rates, tank volumes, and treatment objectives. It is typically measured in days or hours and is an important parameter in determining the effectiveness of sludge treatment processes, such as digestion and stabilization.
Toluene is a volatile organic compound (VOC) and a colorless liquid with a sweet, pungent odor. It is commonly used as a solvent in various industrial processes, such as paint thinners, adhesives, and gasoline additives. Toluene has both industrial and commercial applications but should be handled with caution due to its flammability and potential health effects.
Toxicology is the scientific study of the adverse effects of chemical, physical, or biological agents on living organisms. It involves assessing and understanding the toxicity, mechanisms of action, and potential health risks associated with exposure to various substances. Toxicologists evaluate the dose-response relationship, toxicokinetics, and potential hazards to guide risk assessment and regulatory decision-making..
It is a Biofilter developed and trademarked by Elixir Enviro Systems Pvt Ltd, Kerala. It is used for low concentrated odour control for industries and municipal/corporations with limited space for the odour control unit installation. This is highly efficient especially for large airflow situations such as ventilation air odour control, shed ventilation from municipal Waste Treatment plants, grinder emissions from shrimp feed manufacturing facilities etc.
It is a type of anaerobic wastewater treatment process that utilizes an anaerobic sludge blanket to remove organic pollutants from wastewater. In a UASB reactor, wastewater flows upward through a column, and a dense sludge blanket is formed at the bottom of the reactor. The anaerobic microorganisms present in the sludge blanket break down organic matter, producing biogas (primarily methane). UASB reactors are commonly used in industrial and municipal wastewater treatment to efficiently remove organic pollutants and produce biogas as a renewable energy source.
VDI 3882 is a guideline published by the Association of German Engineers (VDI) that provides a framework for assessing odour emissions in various industrial and environmental settings. It outlines methods for measuring and evaluating odour emissions, assessing their impact on the surrounding environment, and establishing criteria for odour control and mitigation. VDI 3882 offers guidance on sampling techniques, laboratory analysis, dispersion modelling, and odour nuisance assessment. It serves as a valuable resource for industries, regulatory bodies, and consultants involved in managing odour-related issues.
A ventilation system plays a crucial role in odour control by effectively removing and diluting odorous air from an area. It consists of fans, ductwork, and air distribution devices that facilitate the movement of air. The system can be designed to exhaust odorous air to treat it using various odour control technologies before being discharged. Properly designed ventilation systems help maintain good indoor air quality and minimize odour nuisance in various industrial, commercial, and residential settings.
Virtual water refers to the hidden water embedded in the production and trade of goods and services. It represents the amount of water used throughout the supply chain of a product, including the water consumed in its production, processing, and transportation. Virtual water is used to analyze water efficiency, water scarcity, and the global water footprint of goods and services.
Volatile Organic Compounds (VOCs) are organic chemicals that easily evaporate at room temperature and can be released into the air from various sources such as paints, solvents, fuels, and consumer products. VOCs contribute to air pollution and can have harmful effects on human health and the environment, including respiratory issues and the formation of ground-level ozone. Proper management and control of VOC emissions are crucial in maintaining air quality.
Water pollution refers to the contamination of water bodies, such as lakes, rivers, oceans, and groundwater, by harmful substances or pollutants. These pollutants can include industrial chemicals, agricultural runoff, sewage, oil spills, and plastics. Water pollution can have detrimental effects on aquatic ecosystems, drinking water supplies, and human health.
The water table refers to the upper boundary of the underground zone where the soil and rock are saturated with water. It represents the level at which the ground is saturated and below which groundwater fills the available pore spaces. The water table can vary in depth depending on factors such as precipitation, groundwater recharge, and local geology.
Xylene is a volatile organic compound (VOC) commonly used as a solvent in industrial applications. It has a sweet odor and can be found in paints, coatings, adhesives, and gasoline. Xylene can pose health risks when inhaled or absorbed through the skin, including respiratory and nervous system effects.
Yes/No method in EN 13725 standard employs specific method wherein the The assessor is asked to evaluate gas presented from a specific port (one port out of two or three sampling port available) and will be asked to indicate whether an odour is perceived (YES/NO). The presented odour can be a blank (clean gas without-without any smell). A second port always presents neutral gas (blank) for the assessor to compare or for reference.
