Food waste treatment

Food processing industries occupy an important position economically and generate large volumes of mostly biodegradable wastes

1. Food Waste Treatment Chapter 9

2. INTRODUCTION Food processing industries occupy an important position economically and generate large volumes of mostly biodegradable wastes. Wastes derived from food industries are categorized into three groups: (a) manufacturing losses, (b) food products thrown away as municipal solid waste (MSW), (c) discarded wrappers and containers. These groups may be further divided into liquid and solid wastes. .

3. LIQUID WASTES FROM FOOD INDUSTRIES Wastewater Treatment Systems for Food Processing Different sources contribute to the generation of wastewater in food processing industries, including meat processing dairy products seafood and fish processing fruits and vegetable processing starch and gluten products confectionery, sugar processing alcoholic/nonalcoholic beverages bean products.

4. Wastewater Treatment Systems for Food Processing Wastewaters released from these industries are turbid, with high concentrations of bio- chemical oxygen demand(BOD) Fats , oils and grease(FOG) Suspended solids(SS) usually nitrogen and phosphorus. Hazardous chemical content is generally low.

5. Wastewater Treatment Systems for Food Processing Other characteristics of food processing wastewater are large seasonal variation large hourly variation and concentration in daytime factories are often of small scale sometimes unbalanced ratio of BOD:N:P that induces the bulking of sludge colored effluent

6. Wastewater Treatment Systems for Food Processing wastewater can be grouped as high concentration, medium concentration, and low concentration. High-concentration wastewater may sometimes be concentrated further, treated, and recycled or disposed as solid wastes. Medium-concentration wastewater may be treated on site or discharged into public sewers. Low-concentration wastewater such as indirect cooling water may be discharged without any treatment.

7. Wastewater Treatment Systems for Food Processing Developed countries import processed raw materials or crude products for further refining or applications. The wastewater can be recycled after treatment, usually through oxidation ponds or stabilization ponds for irrigation on farms biomass wastes may also be used as fuel for factory operations. Labor-intensive industries such as sea-food processing also tend to shift to developing countries where cheap labor is available.

8. SOLID WASTES FROM FOOD PROCESSING Two groups of solid wastes are generated in food industries. One group is organic residual wastes such as sludge from wastewater treatment and food wastes or garbage accompanied with consumption. Another group is solid wastes such as vessels, containers, and wrappers. Among the wastes of this group, plastic wastes should be noted in particular.

9. Organic Residual Wastes For organic food wastes, the options of feedstuff use, composting, biogas then composting, and heat recovery are adopted for treatment and recycling. Feedstuff Use Industrial wastes from food processing are still recycled as feed or organic fertilizer to a fair extent feeding The rate of use is 77%. Other than that, rice bran, wheat bran, and plant oil residues and (best management practices) BMP, and others are used for general feedstuff products

10. Organic Residual Wastes Composting and Biogas Production Composting is a traditional, reliable method of recycling food wastes. This will be discussed later together with biogas production. Incineration with Energy Recovery Utilization of biomass as it relates to CO 2 reduction against global warming has been focused on recently. For this purpose, woody biomass is more suitable, and organic wastes including various minerals may not be appropriate for incineration.

11. Vessels, Containers, and Wrapping Wastes Another type of waste relating to food industries is the waste originating from containers, vessels, bottles, and wrapping materials. These wastes occupy a large portion of municipal solid waste (MSW). Among these wastes, plastic wastes in particular should be focused on from an environmental standpoint.

12. Vessels, Containers, and Wrapping Wastes Polyethylene terephtalate (PET) bottles are the most suitable wastes for material recycling. They can be recycled as polyester fiber products through PET flake and to raw chemicals through chemical recycling. However, the amount of incinerated PET bottles has still been increasing because the rate of consumption continues to exceed the recycling effort. Chemical recycling to obtain the monomer of dimethyl terephtalate (DMT) has been conducted successfully using recycled PET bottles collected by municipalities

13. Vessels, Containers, and Wrapping Wastes Recently, other plastic wastes used for wrapping and vessels have been recycled by means of gasification , liquifaction to oil, or heat recovery in the blast furnaces of steel industries (substituting cokes) and cement kilns (substituting coal). However, there are complicated arguments as to whether the direct incineration for heat recovery is more environmentally friendly than options through gas and oil

14. HAZARDOUS WASTES FROM FOOD PROCESSING Hazardous wastes from food processing Accidentally Contaminated Food Wastes Incineration Ash of Food Wastes

15. HAZARDOUS WASTES FROM FOOD PROCESSING Emergency Planning and Community Right-to-Know Act (EPCRA) in the United States and the Pollutant Release and Transfer Register (PRTR) system was also enacted in Japan describes the use of chemicals in food processing Food that has been accidentally contaminated by pesticides, herbicides, or fumigants may also be treated as hazardous waste. Chlorine is frequently used for sanitary cleaning in food processing at the end of daily operations. Therefore chlorinated organic compounds should be noted in the wastewater treatment plants of food industries.

16. Chemicals commonly encountered in food processing

17. Possible release and other waste management types for epcra

18. b) Accidentally Contaminated Food Wastes Food products contaminated with pathogenic microbes or food poisoning sometimes result in hazardous wastes. Two recent examples discussed below include the treatment of contaminated milk products and the issues relating to the issues of ( Bovine Spongiform Encephalopathy ) BSE Contaminated Milk with Enterotoxin A Treatment of Bone and Meat Powder Suspicious of BSE

19. Contaminated Milk with Enterotoxin A Contaminated Milk with Enterotoxin A In June 2000, skim milk contaminated by Staphylococcus aureus led to a huge outbreak of food poisoning in Japan. The milk was contaminated in April because of an electricity outage that lasted several hours in the factory of Yukijirushi Co. Ltd. Afterwards, contaminated milk products were widely distributed and 14,780 persons exhibited food poisoning symptoms The milk products produced by the company were removed from market displays, and most of them were incinerated as hazardous wastes

20. Treatment of Bone and Meat Powder Suspicious of BSE The Japanese government has prohibited the import of bone powder from England since March 1996 and also from EU countries since January 2001 to prevent the introduction of Bovine Spongiform Encephalopathy (BSE), known as “mad cow” disease. After three infected cows were reported in Japan, bone and meat powder (BMP) rendered in domestic bone-boiling factories has been prohibited as use as feedstuff and also as fertilizer for a certain period. Although BMP is a good fertilizer, especially for fruit trees, consumers have avoided it because of the risk of BSE.

21. c) Incineration Ash of Food Wastes Incineration is the most popular method of disposing of combustible solid wastes in Japan, especially for MSW from restaurants, hotels, and supermarkets. For a long time incineration was perceived as a progressive method and the percentage of incineration of MSW was near 80%.

22. RECENT TECHNOLOGIES ON FOOD WASTES TREATMENT Waste Management in Fermentation Industries Agro-Industries in Tropical Countries UASB and EGSB Treatment Systems Zero-Emission in Beer Breweries Recycling of Garbage

23. Waste Management in Fermentation Industries Fermentation industries cover a wide range of food processing from the traditional industries of Breweries soy source Pickles Yeast Alcohol amino acids nucleic acids Antibiotics Enzyme

24. Waste Management in Fermentation Industries Usually, the harvest rate of these products is not high except for traditional fermentation, which typically has a large pollutant load. However, the possibility of resources recovery is also high because hazardous chemicals are rarely used. The wastewater comes from (a) the mother liquid after harvesting the products, (b) cleaning water of cells or reactors, (c) condensates from the evaporator, (d) spent eluting solution in purifying processes (e) ammonium sulfate, used in salt crystallization of enzymes, and others.

25. examples Alcohol Molasses Nucleotides Mono-Sodium Glutamate Bread yeast

26. Alcohol Molasses Alcohol Molasses and sweet potatoes are used as the raw materials for alcohol fermentation. In Japan, to improve wastewater quality, the trend of importing crude alcohol and refining it increased in the 1970s. Here the case of alcohol production using sugar cane molasses as raw material is introduced. It is also replaced for example by acetic acid.

27. Nucleotides Through hydrolysis of RNA, nucleotides such as inosinic acid and guanylic acid are formed and used for seasonings. Ribo -nucleotides are produced by the combination of extraction fermentation, and chemical synthesis. During fermentation, yeast capable of accumulating RNA is cultured and forms ribonucleotides through enzymatic hydrolysis of extracted RNA from the yeast The spent cell of the yeast is utilized for feedstuff and the concentrated part of the wastewater from the purifying process is used as liquid fertilizer after further concentration

28. Mono-Sodium Glutamate Mono-sodium glutamate (MSG) is a product that originates from Japan, and is produced mostly by fermentation. Glucose, acetic acid, or molasses are used as the raw material for the source of carbon while ammonia and urea may be used as the source of nitrogen

29. Estimation flow of waste water in the production of msg

30. Bread yeast Bread yeast is still produced by fermentation using molasses this process includes cultivation, separation, pressurized filtration, and the addition of baking powder. Wastewater derives mainly from centrifugal supernatant and the cell-washing process The fraction of high concentration was further concentrated and dried to make organic fertilizer.

31. Agro-Industries in Tropical Countries Cassava is a key food product in many tropical countries. In 1997, 165 million tons were produced worldwide for food and feed. Cassava chips, pellet, and starch are major exports for Thailand Solid waste from the extraction process of cassava is known as cassava pulp Pulp is sun dried to reduce the moisture content and used as filler in animal feed.

32. Agro-Industries in Tropical Countries Environmental problems from the solid waste occur only if the storage of pulp is badly managed and it becomes exposed to rain. Utilization of pulp as a substrate for industrial fermentation has been investigated, but to date there has been no success. An attempt to extract the starch from the pulp by means of enzyme hydrolysis has been reported

33. UASB and EGSB Treatment Systems Anaerobic treatment, especially thermophilic treatment, offers an attractive alternative for the treatment of high-strength, hot wastewater. The thermophilic process, compared to the mesophilic anaerobic process, has the advantages of increased loading rate and the elimination of cooling before treatment. Furthermore, the heat content of the wastewater would be available for post-treatment

34. Zero-Emission in Beer Breweries Waste recycling systems in beer breweries are very complete. Kirin Beer Co. Ltd. has achieved zero-emission for its industrial wastes since 1998 Wastewater is treated by a UASB reactor and activated sludge method in 10 out of 12 factories in this company. In fact, 18,860x103 m3 of wastewater generate 4800 tons of methane gas from UASB reactors, corresponding to 5200 kL of oil. The biogas is used for the fuel of boiler and cogeneration systems

35. Recycling of Garbage It can be done by two methods Compositing Bio gas production

36. Composting Composting has long been a traditional technology, but new composting technologies have also been developed. Generally there are mainly two types of technology, both dependent on using microorganisms. One type uses a thermophilic bacillus, which is effective in enhancing the initial decomposing phase Another type of composting uses mixed culture mainly constituted by lactic acid bacteria(EM) under aerobic condition

37. compositing A combination of both types of composting has also been tested. In one case, relatively fresh fish refuse was preheated at 80ºC for several hours with the addition of a thermophilic bacillus, and then EM was added. In this case EM was expected to work after packaging in plastic bags. This product may be used as chicken feed.

38. Biogas Production This system also seems feasible, especially since the capacities of night soil treatment plants have become excessive accompanied by the spread of publicly owned sewerage systems. Therefore a part of these night soil plants have been reformed to treat night soil, sludge from septic tanks, and garbage together The energy efficiency of the biogas system is estimated to be better than that of an incineration system. If the heat value of garbage becomes higher, then incineration with power generation becomes advantageous

39. CONCLUSION As a main principle, the self-supply of food should be a goal for all countries. The local unbalance between food production and consumption makes food wastes hazardous and induces eutrophication of water bodies, nitrate pollution of groundwater, and ruins farmland soil because of limited recycling of minerals. Therefore, the free trade of primary products should be re- examined in light of environmental issues.

40. CONCLUSION Generally, food processing does not generate chemical hazards. However, attention should be given to chlorine used for cleaning and sanitation leading to chlorinated byproducts in wastewater. If contaminated by poisonous materials or pathogens, food may change to hazardous wastes. Treatment of BMP by cement kiln is a typical example of this.

41. CONCLUSION As previously discussed, incineration of food wastes together with other miscellaneous wastes is not a suitable solution because of the generation of hazardous ash containing DXNs and heavy metals doing so also threatens food recycling efforts. A recommended option would be composting followed by the combination of biogas production and composting of the sludge.

42. CONCLUSION Anaerobic treatment systems lost their popularity in wastewater treatment field for failing to meet strict environmental criteria. Recently, however, these systems have regained attention because of their ability to save energy and also reflecting the development of UASB or EGSB technology. However, zero emission should also cover all products, including containers and wrappers.

43. THANKS