How to Treat the Exhaust Air from Poultry and Meat Processing Companies?

Industries like poultry and meat processing companies causes odour nuisance to the neighborhood. There have been several technologies to tackle this situation. The requirement of an exhaust air treatment system is determined on the basis of the size of the facility, the specific processing operations involved, the exhaust air volume, and pollutant load to be treated, and the resulting nuisance potential. Elixir enviro Systems Pvt Ltd ( is a pioneer in odour control. Elixir Enviro Systems Pvt Ltd designs the required upstream and downstream processes for the effective odour control strategy. The strategies include appropriate ventilation design and pretreatment steps for the optimal operation of the Odour Control Unit(OCU).

What kind of exhaust air treatment system should be used in a slaughterhouse? It could vary for different facilities and is purely decided on case-by-case basis. Here are the commonly used exhaust air treatment systems for slaughterhouses:

Biological exhaust air treatment

Biological elimination of pollutants from air is the most environmental-friendly technique since it ensures minimal use of chemical agents and in many cases, it comes as the lowest lifetime cost alternative compared with other treatment technologies. In biological exhaust air treatment, microorganisms are used to convert odour components to CO2 and H2O.


Bioscrubbers are also called Bio-washers. In the Bioscrubber, absorption of air pollutants and the reaction or degradation of the pollutants occurs in two reactors. In the first stage the air is being washed or gets in contact with the air having the pollutant load and the absorbent or the liquid absorbs the pollutant from the air. In the second stage, this absorbent is treated biologically and circulated back to the washing stage. If you look in general, the Bioscrubbers are mainly employed for highly soluble and low volatile compound treatment.

Bio-Trickling filter

The contaminated air is passed through the packing media made of inert materials. In these filters, a liquid phase is trickled into the media. The pre-humidification can be avoided in the bio-trickling filters as the water phase can provide the moisture for the biomass activity. In Bio-Trickling filters inert materials with chemical stability, low weight and good mechanical properties are preferred. These filters are well aerated systems and the microorganism responsible for the degradation are usually aerobic but deeper into the bed, there is also anaerobic degradation. The flip side of this process is the requirement of micro and macro-nutrient supplementation to assure that the microorganisms are getting enough nutrients for the growth. If this nutrient supplementation is not properly regulated, this can lead to clogging of the unit.


What is biofilter? It is basically a porous layer made up of organic material. It supports the microbial population. The odorous air is forced into the porous layer where the biological degradation takes place. Odor emission is controlled to over 95 percent with biofilters. It should be noted that media moisture content affects the functioning of biofilters. The biofiltration technology is an entrenched odour pollution control technology in various parts of the world.

Chemical Absorption

The solubility behaviour of contents determines the absorption of gas in liquid. In absorption too, the efficiency is determined by adjusting the pH to acidic or alkaline. Hence the absorbers function as chemical scrubbers.

Process combination

Rather than limiting to one technique, usage of a combination of techniques has proven to be more efficient in slaughterhouse facilities. For example, combination of chemical and biological processes is mostly practiced.


Odor emission is an important measure that should be taken by slaughterhouse or meat and poultry processing facilities for the well-being of humans and environment. Elixir Enviro Systems Pvt Ltd is a pioneer in the field of odour control from such industries. Different kinds of cost-effective and highly efficient odor control systems are designed and implemented by the company all over India.

UASB – Back Flush (An advanced high-rate anaerobic reactor for complex wastewater)

Anaerobic treatment

Anaerobic digestion is a biological treatment where the degradation of the organic matter happens in the absence of oxygen and produces biogas as a by-product.  Anaerobic digestion of wastewater is the economic choice for the treatment of high-COD industrial effluents. High-rate anaerobic reactors extend the benefit of anaerobic treatment for medium and high strength effluent, substantially reducing the cost of effluent treatment plants. In an anaerobic digestion, a variety of micro-organisms have to work together to convert organic pollutants into biogas. Biogas contains 50 to 80% methane.

High-rate anaerobic reactors

High-rate reactors operate on the principle of decoupling biomass retention time from the hydraulic retention time. Examples of high-rate anaerobic reactors include the UASB (Up-flow Anaerobic Sludge Blanket) reactor and the Packed Bed Fixed Film reactor and the Fluidized Bed Fixed Film Reactor etc. The hydraulic retention time required for COD removal in high-rate reactors is small. This is important in reducing plant cost for the treatment of medium and high strength effluents which are usually discharged in large quantities.

Complex wastewaters

Complex wastewaters are the wastewater with having high undissolved or particulate COD. High-rate reactors are successful only for the treatment of effluents containing COD in dissolved form. There are no high-rate reactors, in use, for the treatment of complex wastewaters, i.e., wastewaters containing undissolved COD.  The basic process of anaerobic degradation of complex effluent is:

1. Solubilization and hydrolysis:     Insoluble COD converted to soluble compounds of lower molecular weight such as long chain fatty acids by enzymatic reactions using enzymes secreted by microbes

2. Acidogenesis – reactions that result in the formation of volatile fatty acids from long chain fatty acids – these carried out by acidogenic bacteria

3. Acetogenesis – formation of acetic acid, hydrogen and carbon dioxide from volatile fatty acids

4. Methanogenesis – formation of methane by a) break up of acetic acid b) synthesis from carbon dioxide and hydrogen

In general, or in case of wastewater having high soluble COD, the Methanogenesis turns out to be the rate-limiting step in the anaerobic treatment of wastewaters. On the other hand, Solubilization and hydrolysis are rate limiting in the anaerobic treatment of wastewaters with insoluble COD.

Example:  Dairy wastewater and slaughterhouse wastewater are typical complex wastewater

Dairy wastewater is a high strength complex industrial waste. Untreated, the waste rapidly putrefies, causing severe odour. Conventional anaerobic reactors are unable to carry out biomethanation of fat in dairy wastewater. Therefore, many a times end up other removal steps for fats and suspended particles discharged along with the wastewater. The characteristics of dairy wastewater greatly depends on the products and dairy operation. For example: Milk effluent has characteristics different from that of cheese effluent or ice-cream effluent.  Special attention has to be given to the following aspects of process and reactor design when dairy wastewaters are to be treated


Hence, the anaerobic process for dairy wastewater is more effective when:

UASB reactor failure when applied for the treatment of some dairy wastewaters

The UASB reactor is an economical solution for the treatment of effluents which have substantially dissolved pollutants. It combines modern high-rate treatment technology with simplicity of design. In the UASB reactor, special gas-liquid-solid separators are mounted which enable collection of biogas and recycle of anaerobic biomass. The avoidance of internal packing in the reactor greatly reduces the cost of reactor construction. The UASB reactor works best when desirable micro-organisms are retained as highly active and fast settling granules. Granular seed sludge is required for quick start-up of such reactors.

But, when UASB is applied to dairy wastewaters, fat content of dairy wastewaters accumulates in the reactor adsorbed on methanogenic sludge and as scum on the gas-liquid interface. Eventually, sludge density is so reduced that catastrophic sludge washout occurs and reactor failure occurs.

The UASB – Back Flush

The UASB Back flush, is a unique solution to the high-rate anaerobic treatment of complex wastewaters. Anaerobic sludge, is retained in the reactor by a special low density granular filter system integrally provided in the reactor. Thus, the separation of sludge and its retention in the reactor is independent of the settleability of sludge.

UASB BackFlush– Principle of operation

The key feature of the UASB-BF is the granular bed filter, which retains sludge and effluent solids. The filter bed is kept free from choking by intermittent inverse fluidization, which backflushes retained solids into the reactor mixed liquor. The backflushing of filter bed is accomplished by a periodic release of gas accumulated in the reactor, thereby avoiding extra pumping systems and power consumption. The granular filter bed is constructed from non-degradable Plastic. Therefore, the UASB-BF is able to decouple both solids and biomass retention time from hydraulic retention time, while providing high mass-transfer conditions. The UASB-BF provides the performance of an anaerobic membrane bioreactor without the drawbacks of expensive systems and high-power costs. The UASB-BF retains all microflora – settling, dispersed and slow growing– enabling the development of high activity sludge.

Elixir Enviro Systems has designed several effluent treatment plants with UASB-BF based anaerobic digestion system. We do the process design, the operational optimization and effective implementation of Anerobic digestion of wastewater across the industries and are a market leader for effluent treatment plants. We have successfully implemented several effluent treatment plant with anaerobic digestion system, especially in ice-cream industries, rice-mill industries and dairy to name a few.

Benefits of Using Anaerobic Digestion for Industrial Waste Water Treatment

Industrial Revolution over the past few decades has led to the generation of large amounts of Industrial waste water that has the potential to pose huge threats to the environment & to the health of the living beings.  In order to avoid, prevent & control this, various industrial waste treatment and disposal methods are used. The method to process the Industrial waste water is generally based on utmost safety, minimum impact on the environment and to a larger extends on vaporization of the waste and possibility of final recycling of the end products.  Anaerobic digestion is the most suggested option for the treatment of high strength organic effluents. The presence of biodegradable components in the effluents along with the benefits of anaerobic process over other treatment methods makes it the most recommended & suitable option.

Anaerobic digestion for Industrial waste water treatment is an efficient and attractive waste treatment practice which focuses on both pollution control and energy recovery.  Since majority of agricultural and industrial wastes are composed of high levels of easily biodegradable materials, anaerobic digestion is considered the most suitable method.

Even though anaerobic technology dates back more than 100 years, the technology is still under development, adapting novel treatment systems to the needs of the modern society and life style.  It has been observed that most of the advances were achieved during the last three decades, when high-rate reactor systems were developed and a profound insight was obtained through research in the microbiology of the anaerobic communities.

Here are some advantages of using Anaerobic Digestion as the most trusted approach for Industrial Effluent Treatment. These are in comparison to the conventionally applied aerobic processes for removing Organic Pollutants from waste water based streams.

Anaerobic biological wastewater treatment is, in many cases, a highly attractive option for treatment of various chemical and petrochemical wastewaters. The full potential of anaerobic treatment has only in the past two decades begun to be recognized and a lot of work is being carried out in the field.

An Insight into Odour Control in Reclaim Rubber Factory


Odour emission from industrial and commercial establishment invariably attracts adverse public attention. Regulatory agencies have closed down industries because of odour complaints. Odour also affects worker health and labour relations. Until the development of gas biofilters, odour control system was expensive and inefficient.


Rubber reclaiming refers to the process of reclaiming rubber from scrap tyres. Tyres are ground to small particles and subjected to devulcanizing. After devulcanizing the rubber is soft and can be compounded with additives and rolled into sheets that can be used as a raw material in the manufacture of new tyres. Chemical reclaiming uses devulcanizing chemicals and high temperature and pressure (20-22 bar) to soften ground rubber. These chemicals are aromatic organic compounds. The reaction is carried out in autoclave as batches. At the end of the reaction, the devulcanized mash is discharged after autoclave pressure is released.


The autoclave pressure release contains a large amount of volatile organic compounds. Many of these are sulphur containing organic compounds formed from devulcanizing of rubber, which is essentially breaking of sulphur cross-linkages in vulcanized rubber.  If condensed, the condensates from autoclave steam release, is extremely foul smelling and hence is an effluent discharge issue. The soft rubber mash discharged from autoclave is hot and is a source of odourous vapours.  Another source is the handling and working of rubber during maceration and sheeting.
Reclaim rubber factory odour emissions

Figure 1: The orange upward arrow shows odour emission sources


Hot autoclave release emissions are treated separately by direct incineration in the factory boiler. Scientifically calculated and automatically controlled release of vapour ensures complete combustion while boiler firebox temperatures are unaffected.  The incineration system not only destroys odour but also eliminates effluent. The remaining low strength, low temperature vapour is better treated in the Biofiltration unit.

Biofiltration uses micro-organisms to remove undesirable components from industrial waste gases. Waste gases are forced through filter material on which micro-organisms are immobilised. After absorption in the filter material, micro-organisms break down the polluting components and transform them into harmless products such as carbon dioxide, mineral salts or acids and water. Biological waste air treatment processes offer a cost-effective solution for the treatment of large volumetric airstreams containing low levels of pollutants. They have found use in a broad spectrum of industries. Biofiltration is distinguished by its low operating costs, low maintenance requirements and low energy requirements. Properly designed biofilter achieve very high odorant removal efficiency (>99%).

Biofilters can be designed as low-cost open systems with single stage media. Where land is not available, biofilters can be provided as multi-storey units. Biofilters can also be located on roof of factory buildings to have maximum space savings.


EES undertakes careful study of customer requirements before design of the odour control system. The most important step in the design of a successful odour control system is that characterisation and estimation of quantity of odour emissions. In most cases, direct measurement of quantity of emissions is impossible. It requires considerable skill and creativity to make reasonable estimates required for design.

Pre-treatment requirements and media composition have to be selected to suit the emission characteristics. Hot gases have to be cooled and humidified before biofiltration. Elixir Enviro Systems Pvt Ltd ( designs the ventilation system required to collect odour from open spaces like dumps or sumps and closed spaces such as sheds. Gas biofilter are best suited for emissions with low VOC concentration. For high strength emissions such as pressure reactor release, EES designs incineration system for odour control.

EES is biofilter media is advanced proprietary development originally based on license from the patented biofilter media of CSIR-NIIST. The media marketed by EES is known for its high-performance, low-cost BIOFILTER MEDIA. It features

Guaranteed performance and life

very low pressure drop,

Plug and play start-up to maximum activity,

high water holding capacity

green eco-friendly material

This biofilter media has the ability to accommodate highly varying “puff” loads which is a common occurrence from may industrial sources.

Bacteria are at the heart of a successful biofilter and a key factor is the growth of suitable microbial population. EES (www.elixirenviro) brings experience of Odour Control system in different fields and internationally recognized competence in biological treatment systems to guarantee biofilter performance.

Things You Need to Know about Odour Control Systems Today

Air- without it, life is over in seconds. Air is the most consumed gift of nature by humans. Yet we pay too little attention to managing air pollution.

Odour is a serious inconvenience for humans and brings about great irritation and physical stress to our day to day lives. The air we breathe in, the water we drink should be odourless and tasteless. The presence of foul odour indicates something toxic. The right to clean odour free air is part of the fundamental right to life. Industries, commercial establishments, municipalities and housing establishments have a legal responsibility to ensure that their activities don’t cause odour pollution and have proper Odour control systems.


The common sources of odour are:

Since odour affects us and our fellow beings physically and mentally especially when exposed to it frequently or persistently, it is a growing concern at a humanitarian level, Hence the need of Odour control systems. This is why few skilled individuals devoted their time to find a solution for this inconvenience. Companies like Elixir Enviro Systems provide industries with technology to be environment friendly.

Why is it essential to have an odour control system in your industry?

1. To eliminate harmful health risks 
Odour control systems are set up for welfare of the employees and those who live in the neighbourhood. Odour can cause vomiting, nausea, headache and mental fatigue which will interfere with their day to day lives. We are liable to keep the impacts of our operations from harming others.
2. Control Air Pollution
It is popular knowledge that industries are the biggest contributors to air pollution. Children are cursing industries for taking away the quality of our environment and leaving them with no good air to breathe. Odour control systems remove odour due to harmful gases from the air. It’s high time industries act with responsibility.
3. Free of Complaints
Irritation caused due to odour can lead the nearby residents to file a complaint against your industries to the concerned officials. If the complaint is valid, you would be facing legal cases. Save yourself from such chaos by investing in an efficient odour control system.

How to control odour?

Odour emitted from industries contains complexes chemical compositions. The first and foremost thing about odour control is the effective capture of the odour from the factory. To capture the odour, a proper exhaust ventilation system has to be designed. Once the odour is collected, the next thing is the selection and careful implementation of the suitable odour control system. A wide range of odour abatement technologies is available including Biofilters, Bioscrubbers, physical adsorption, Chemical scrubbing and catalytic/thermal oxidation systems. Spraying “deodarants” are wrong practice and do not control or eliminate the odour from the exhaust gas. The choice of the treatment to be used depends on many factors including required odour removal efficiencies, flow rate & inlet odour concentration, type of chemical species in the odour, variability in flow and load, space requirements and infrastructure (power, drainage, etc). Biofilter is considered to be an ecofriendly and cost-effective technology to eliminate the volatile organic compounds (VOCs), H2S, Ammonia and other odorous gases from the exhaust gas stream.


Be a part of the movement to shift our industrial activities from non-ecological to environment friendly. Elixir Enviro Systems provide you with scientifically engineered technology-based Odour control systems to beat odour related issues.

An Introduction to Wastewater Treatment Plant Modelling

The Stringent Wastewater discharge limits made the process modelling software an inevitable asset to many process-engineering companies. Process modelling provides a better understanding of new plant designing, upgrading the plant, optimizing the existing plants, and improvements in process control. It also helps to select the lowest CAPEX-OPEX solutions, in troubleshooting, to train the stakeholders, and nowadays even used to predict the greenhouse gas footprint of a treatment plant.

The late 1970s to early 1980s can be considered as the golden era of wastewater treatment models. Several research groups worked independently to develop activated sludge process models, resulted in several models with different equations and notations. Initially, they were only steady-state models, which paved the stepping-stone for the development of dynamic models. The International Water Association (IWA) facilitated the acceleration of the model development by combining the models that existed and released the ASM1 (Activated Sludge Model 1). Later ASM1 got modified to ASM2, ASM2d, ASM3, and their modifications. These developments resulted in the birth of many commercial modelling software using these models as such or with some modifications and upgrades thereof. In general, for any wastewater treatment process simulators, the most important aspect lies in its Biological Model.

The wastewater treatment process is generally divided into the primary, secondary, and tertiary stages. The primary stage includes the mechanical systems; the secondary stage is the most important biological treatment stage. The tertiary is the polishing stage including the suspended solids removal, removal of residual organics from the secondary stage, disinfection, and removal of inorganic components.

From a layman’s point of view, a wastewater treatment model can be one or several equations that describe one or several processes that are being functional in a treatment plant. The model can be physical models such as Gravitational settling models (used for primary and secondary clarifiers), Chemical Precipitation models (important for chemical processes such as lime/alum/struvite precipitations), Biological Models (such as for aerobic, anaerobic biological processes), aeration models (important for mass transfer/mixing) or can be filtration models (such as the membrane filtration).

Wastewater usually is not homogenous, the flow (hydraulics) and the concentrations are many times inhomogeneous. wastewater treatment plants, especially the large ones, are not at the luxury to afford a large collection tank. The flow variations could be due to the diurnal changes or rain (monsoon) for instance, similarly, the concentrations load changes could be, due to an industrial discharge. The effect of this heterogenicity, in hydraulic and/or concentration loads, on the treatment plant efficiency can only be predicted using dynamic modelling. Using the model one could investigate the best alternative solution to the problem.

Control systems and control philosophies are absolutely essential in the operation of a wastewater treatment plant economically. When it comes to advanced biological processes, the odds are that the control system is “the heart” of the process. In case of the advanced biological processes, such as a combination of Nitrification-denitrification, Sequential Batch Reactors, granular sludge sequential reactors, Nitritation Deammonification treatment, Sulphur oxidation, Biological/chemical phosphorous removal, etc the treatment efficiency prediction becomes almost impossible without good modelling software. Technically, the simulator helps the process engineer to predict the treatment efficiency.

We at Elixir Enviro Systems Pvt Ltd are proficient in modelling the wastewater treatment plant. We are a distributor of EnviroSim Associates’ BioWin software for the wastewater treatment plants. We also have our own proprietary Anaerobic Digestion model (non-commercial) for the simulation of wastewaters generated from different industries

Should you have any queries, please do connect to us at


Odor can be defined as the perception of smell or the identity of a substance that can be sensed with our sensory organ, also known as olfaction. The substance that causes this reaction is commonly referred to as an odorant and consists of one or many volatilized compounds that can be organic or inorganic.

Odor affects human beings in several ways; pleasant smells can bring about a positive feeling whereas unpleasant smells can interfere with a person’s quality of life. Studies have shown that the prolonged exposure to odorous gases has adverse effects on human health and the complex nature of odor may result in air pollution. Continuous exposure leads to many health issues including stress, anxiety, and headache. With the growing population, industrialization, and urbanization, the odor pollution has increased manifolds.

Industries as a source of Odor

Industries flush out various odorous substances during their production processes. The most commonly reported issues related to odor include the odor note of rotten egg (Hydrogen sulfide), sharp pungent (ammonia), fishy (trimethylamine), and rotten vegetables (dimethyl sulphides). Based on the nature of the products, the emissions differ from each industry:

Fishmeal Industry
The odor emission from a fishmeal industry starts from the storage of the raw material and the quality of the fish processed at the plant impacts the nature of odor emissions. Further, the different stages of processing like the cooking and drying process also add to the release of ammonia and many other volatile organic compounds (VOCs).

Shrimp and Fish feed Industry
In the shrimp and fish feed industry, the major odor release starts from the storage of raw materials to palletization, cooking, and drying. Mostly the odor is of fishy note.

Slaughterhouses, Rendering & Bone Meal Industry
In these industries, the odor is emitted from the lairage, processing of the meat, byproducts handling facilities such as rendering units, and treatment of the wastewater. The bones from the slaughterhouse are often used for crushed bone and bone meal production. The emission from the cooking and drying processes are major odor sources in bonemeal & rendering industries and primarily consist of hydrogen sulphide, ammonia, VOCs, and different mercaptans.

Pulp and paper industry
The sources of odor in the paper industry are mainly from the pulping digesters, digester blowdown, Black Liquor Storage Tank, and Effluent Treatment Plants. The main odorous compounds released during the various processes include methanethiol, hydrogen sulphide, and dimethyl sulphide.

Sugar and Distillery Industry
In these industries, the molasses tank, spent wash handling step releases hydrogen sulphide. Also, the wastewater treatment plants, on many occasions, are considered as a major source of odor release and hence, need to be treated.

STP and MSW treatment plants
In the case of the Sewage Treatment Plant (STP), the major emissions happen during the preliminary treatment stages, whereas in the case of Municipal Solid Waste Treatment Plants (MSWTP), the odor emission starts right from the delivery point of the raw material, followed by almost all the processes practiced in the treatment processes.

Odor Control

Odor control is considered a growing concern across the world. Hence, efficient scientific and engineering design is required to address the odor issues posed by each industry.

Elixir Enviro Systems Pvt Ltd (EES) ( is involved in the design and installation of reliable environmental solutions in industries in India and abroad since its inception in 2014.

Should you require any further clarifications/assistance, reach out to us at Contact Us.