Food processing industries consist of a variety of industries such as dairy, snacks, sweets, beverages, and distillery. Wastewaters from these industries come from different plant operations such as production, cleaning, sanitizing, cooling, and materials transport.
Methods of Treating Wastewater from Food Processing Industries
Discharging untreated wastewaters from food processing industries into rivers and other aquatic environment contribute to eutrophication by addition of phosphorus and nitrogen compounds. Hence, many food processing industries used a whole array of methods in treating their wastewater before the eventual disposal.
Biological treatment (bioremediation/biodegradation) of food processing industries wastewater
Biological treatment can be achieved by aerobic and anaerobic method. Various high rate reactors have been designed for the biological treatment at full-scale operation.
Advanced oxidation processes
These processes involve the production of highly free radicals (OH) through chemical, photochemical, and photocatalytic reactors. The methods include Fenton process, ultraviolet (UV) photolysis, sonication, ozonation, and electrochemical oxidation. This applies most especially to refractory organic pollutants.
This is referred to as the most simple and economical. It involves using a solution of some salts to precipitate dissolved organic compounds.
This is a natural process by which molecules of dissolved substance collect on and adhere to the surface of an adsorbent (solid). It occurs when the attraction force at the adsorbent surface overcome the attractive forces of the dissolved substance of the liquid.
Expected market growth for water treatment chemicals by 2024
The Indian food processing industry is one of the largest in the world in terms of production, consumption, export and growth prospects. Wastewater generated from this industry depicts wide variation in strength and characteristics due to variation in the type of products manufactured and also different fruits, vegetables and various raw materials that are used. The pollution load in food processing wastewater or effluent is due to the use of many preservatives, salts, color, fragrances, oil, sugar, gelatin etc. which are added as per the manufacturing requirement of the products.
Typical Effluent Characteristics
Waste waters from food processing industries are characterized by moderate to high BOD, high COD, high dissolved and suspended solids, very high nutrient content such as phosphorous, nitrogen , heavy oil and grease. This effluent is amicable to non-chemical biological treatment comprising of anaerobic treatment like Hybrid Upflow Anaerobic Sludge Blanket Reactor (HUASBR) followed by aerobic treatment. The HUASBR generates biogas for use in electricity generator which meets total captive requirement of Effluent Treatment Facility.
Aerobic biological treatment, either in the form of high rate trickling filters or activated sludge plant generally suffice for this industry. However, due to intermittent nature of wastewater discharge or due to higher shock loadings , advanced biological treatments such as moving bed bioreactor (MBBR), membrane bioreactor (MBR) are suggested instead of conventional activated sludge process (ASP).
The treated effluent can be recycled at par with food grade water by employing advanced treatment i.e. Ultrafiltration (UF) and Reverse Osmosis (R.O.) Alternatively, Membrane Bioreactor (MBR) can be used in place of MBBR which can yield industrial quality water and by additional R.O. food grade water could be generated.
The food processing industry contributes to economic growth and makes food more available. Wastewaters discharged from food industries need to be characterized often for their compliance to standards by regulatory authorities. In order to reduce environmental pollution, these industries use different treatment methods to treat their wastewater. Characterization of wastewater helps in developing various treatment methods among which are biological techniques, advanced oxidation process (AOP), and more recently adsorption. The biological treatment and AOP have undergone several investigations in the past few years and have advantages ranging from low operation cost to no waste product but not as efficient as adsorption which has low operation cost and high efficiency.
Though the Earth is covered in water, access to safe drinking water is harder to come by. In fact, around 844 million people around the globe don’t have access to safe water. Lack of surface and groundwater availability due to drought has caused many shortage issues. Chemical run-off has also contaminated a number of clean water sources.
To improve sustainability, many industries are looking into water recycling and reuse strategies. While water scarcity is a major threat to businesses in the food and beverage sector, water conversation methods can limit their water footprint and help them operate more efficiently.
Water is a necessary component of the food and beverage industry. With recent quality concerns, it’s more important than ever for manufacturers to treat water and ensure it is safe for consumption. Water treatment methods remove contaminants and particles to provide a high-quality end-product. Processors can also adopt water reuse and recycling techniques to reduce their water footprint and combat freshwater scarcity.