Wastewater Treatment Plant for Food Industry

Introduction

India’s food and drink sector is the backbone of the country’s economy, yet like most others, it’s struggling to deal with the array of waste from its operations. It is one of the hardest and most high-strength industries in terms of effluent, largely because of its wide-ranging activity (food, brewery, dairy, meats). They are often have high organic materials, such as fat, oil, grease (FOG), and nutrients wastewater, if untreated can cause major disruptions in the municipal sewer systems and harm the aquatic environments.

Due to the increasing environmental concern, food processors have to establish suitable wastewater treating practice. This not only complies with regulations, but helps achieve sustainability, water conservation and facility profitability. An upgrade to an advanced food and beverage wastewater treatment system can help these manufacturers make an impact on their environmental footprint, minimize water use, and get a return on investment by strategically reclaiming wastewater resources.

Special Problems Of Wastewater In The Food Industry

Wastewater generated in the food industry is widely known for their diversity and complexity in treatment, which arise from a wide range of feedstock and manufacturing processes. Here are some of the common problems related to Food Processing wastewater.

High Organic Load

Biochemical and chemical oxygen demand are normally high in effluents from food industries. This pollutants come mainly from sugars, starches, proteins and alcohols of food waste. Elevated levels of BOD and COD are suggestive of the fact that the wastewater is oxygen demanding and can have grave impacts on receiving bodies of water if these are not treated adequately.

Fats, Oils, and Grease (FOG)

FOG is one of the most difficult compounds in wastewater of food industry to be degraded. Because these materials solidify when cooled, they can block pipes and machinery and create a thick sheet on the water's surface. This is an impediment to the transfer of oxygen; no less important, the treatment process is disrupted and the operation is inefficient.

Nutrient Loading

The high content of organic particles such as food solids and bacteria in the wastewater can lead to eutrophication of receiving waters. These nutrients can result in eutrophication within the recipient water bodies leading to overgrowth of algae interfering with water quality.

Seasonal Variations

The volume and the composition of the wastewater can widely vary along the processing cycle. These seasonal trends sometimes create times of high level effluent strength, or excess volumes, and it is important that such a system is flexible and can easily be expanded.

Biodegradability

Food industry effluent is generally biodegradable but may need constructive control of parameters such as pH and microbial activity for effective treatment. Moreover, the existence of biodegradable and nonbiodegradable is mixed with treatment.

Core Treatment Strategies

To solve these problems, the WWT (Wastewater Treatment) for the food industry is generally based on the use of multi-staged treatment. The following treatment methods are most frequently employed in order to guarantee a suitable treatment of food industry wastewater:

Pre-Treatment and Primary Removal

The primary treatment of wastewater refers to the removal of gravelsized and FOG that may interfere with subsequent treatment processes. Common pre-treatment methods include:

Pre Screen: eliminates large food particles and residue.

Sedimentation: Also used to enable heavier particles to settle to the bottom, separating the solids from the liquids.

DAF (Dissolved Air Flotation): An excellent solution to separating FOG and sludge. Microbubbles are added to bring the solids to the surface, where they can be skimmed away.

Biological Treatment (The Core Process)

At the core of wastewater treatment is bio-treatment, which uses microorganisms to convert organic pollutants into biological cells. There are mainly two biological treatments:

Anaerobic digestion: This process is best for high-strength food wastewater. Specialist bacteria decompose organic material in the absence of oxygen to provide biogas (a renewable energy source which is high in methane). The COD and BOD values are lowered by a large fraction in anaerobic digestion. Reactor UASB reactor are used in the food processing industry.

Aerobic processes such as activated sludge systems can be used for lower strength effluents. These systems use oxygen which assists in the growth of bacteria that feed on residual organic effluent and nutrients which process the effluent to make it cleaner.

Tertiary Polishing

The effluent was disinfected in the last unit to meet demanding discharge or reuse requirements. However, tertiary polishing further contains the following main processes:

Filtration Removes fine solids not eliminated during biological treatment.

Removal of Nutrients: Systems which reduce the amount of nitrogen and phosphorus (for example by biological nutrient removal (BNR) or chemical precipitation (e.g., phosphorous precipitation (Masutani et al., 1988))) are utilized.

Disinfection: The water is disinfected to ensure that all remaining pathogens are killed (e.g. with ultraviolet, UV, light or by ozonation) and that the water is safe to be discharged to the environment or used for another purpose.

The Value of Resource Recovery

Resource recovery plays a major role in contemporary wastewater treatment, which functions on the concept that wastewater is a valuable resource-stream rather than a by-product.

Biogas Production

Anaerobic digestion degrades organic pollutants while generating biogas that can be used as a renewable energy. This can be used to fuel the waste water treatment plant or manufacturing plant, saving on operating costs and need for external fuel supply.

Water Reuse

Treated water can be used for non-potable purposes within the building. To include; equipment wash (using water), cooling tower water, and even landscape irrigation. Recycling treated water enables food producers to rely less on freshwater sources, borrowing a leaf from water management practices, and to play a role in water conservation.

Nutrient Recovery

Phosphorus and nitrogen, both commonly found in food processing waste water, can be recovered and turned into fertiliser. This not only heals nutrient encroachments in water bodies, but it also loops closed waste byproducts into something useful for agriculture.

Conclusion

Food industry wastewater treatment is no small feat, but it is something that can be done. Using a customised treatment train consisting of pre-treatment, advanced biological processes and resource recovery in food-processing installations such can efficiently deal with their waste waters whilst making a contribution to environmental sus-tainability.

Explore more about our expertise at Amalgam Biotech now. And check out our Odour Abatement at Food Processing Facility case study.