vegetable waste management

treatment methods and potential uses of vegetable waste

1. Vegetable Waste Management : Treatment Methods and Potential Uses of Treated Waste Presented by Kulwinder Kaur

2. Overview This presentation reviews the three areas of waste management in vegetable‐processing operations: (1) waste generation; (2) waste management and treatment; and (3) value‐added utilization of vegetable wastess

3. Introduction India is the second largest producer of the fruits (97.97 million tonnes ) and vegetables (183.17 million tonnes ) in the world during 2019-20, has been bestowed with wide range of climate and physio -geographical conditions. Fruits and vegetables account for the largest portion of that wastage. About 30 % of the fruits and vegetables grown in India get wasted annually due to lack of proper cold storage infrastructure which is a cause of concern. ( Source: https://www.freshplaza.com/article/9184270/indian-horticulture-output-to-be-313-million-tons-in-2019-20 / ) .

4. Vegetable waste Vegetable waste is a biodegradable material generated in large quantities, much of which is dumped on land to rot in the open, which not only emits a foul odor, but also creates a big nuisance by attracting birds, rats, and pigs—vectors of various diseases. Vegetable wastes include the rotten, peels, shells, and scraped portions of vegetables or slurries.

5. Reasons of Vegetable Wastes

6. Life cycle of waste generation from vegetables

7. Types of waste generated from potato processing industry

8. Risks associated with vegetable waste Water pollution Solid or liquid waste pollutes aquatic life in rivers, lakes, and sea Soil pollution Solid waste Undesirable changes in soil composition Air pollution Malodorous compounds in air Unhygienic conditions Breeding of pathogenic microbes, flies, mosquitoes and rodents Unhealthy environment and spread of an epidemic Aesthetics Solid waste Loss of aesthetic value of an area

9. Waste management strategy The objective of any waste management plan and strategy should be twofold: (1) minimization of waste; and (2) selection of appropriate waste treatment and/or disposal strategies. The definition of waste minimization include three elements: preventing and/or reducing the generation of waste at source; improving the quality of the waste generated, such as reducing the hazard; and encouraging reuse, recycling, and recovery.

10. Basic consideration for implementation of management strategy

11. Characterization of waste: It is essential for deciding its application and determination of economic feasibility of the process as waste may contain materials that are hazardous or potentially hazardous to public health.

12. Flow measurements of waste Determine the volume of solid and liquid waste generated daily and annually. Segregation of highly contaminated waste : This initial determination is important because the volume of wastewaters requiring treatment determines the size of the treatment plant. Reduce Minimize solid waste production. Recover Reclaim waste utilization to produce byproducts/coproducts (e.g., nonfermented and fermented products).

13. Recycle The solid waste from vegetable processing contains nutrients that can be used as animal feed, bioenergy, and compost. Dispose There will always be some waste that would have no further use and thus will need to be disposed of away from the factory premises.

14. Existing Methods composting, landfill, Incineration or combustion, gasification , pyrolysis and Animal feed. Note: They are universally applicable but are wasteful of resources–neither recovers energy particularly efficiently .

15. Animal Feeding V egetable processing, packing, distribution and consumption generate a huge quantity of waste that is usually disposed of either by composting or dumping into landfills/rivers, causing environmental pollution. Such resources can act as an excellent source of nutrients due to enrichment of functional compounds, such as polyphenolics, carotenoids and dietary fibre . This has potential to be used in the production of animal feeds especially for cattle and dairy cows, and processing the waste into silage.

16. Landfill is the most economical, though not always environmentally safe, way of disposal where the waste is buried into the earth. In landfills, main macronutrients present in organic matter are hydrolyzed to soluble products and finally to biogas through methanogenesis . Application : production of electricity, hot  water, and steam as an energy source Disadvantages Traditional landfills were not managed in a scientific way. Landfill gases pollute the air and cause greenhouse effect, Leachate contaminates the ground water. Land Filling

17. Incineration Applications To preheat air and to power generation Ash can be used as construction material Drawbacks: Higher investment and operational costs Atmospheric Air pollution Low calorific content It is the controlled burning of waste at high temperatures in a facility designed for efficient and complete combustion ( Rhyner et al. 1995). This process generates carbon dioxide, water, sulfur dioxide, ash, gases, and heat energy.

18. The feasible alternative option to deal with the solid vegetable waste is to convert it into high-density briquettes, which give flexibility in storage, transportation as well as the use as per requirement. Briquetting of waste biomass can be done by bringing its moisture content to the specific level, pulverizing and mixing it with some kind of binder or by direct compacting. The briquettes can be easily adopted for gasification, pyrolysis and in other biomass-based conversions ( Kaliyan and Morey, 2009). Briquetting

19. Physical and thermal properties of briquettes

20. Gasification The gasification process breaks down the hydrocarbons left into a syngas using a controlled amount of oxygen at elevated temperatures 700°C. The gasification process occurs as the char reacts with carbon dioxide and steam to produce carbon monoxide and hydrogen. Syngas may be burnt directly for heating and/or electricity production or may be further converted to act as a substitute for almost any fossil fuel.

21. Gasification Gasification in conjunction with gas engines obtains higher conversion efficiency than conventional fossil-fuel energy generation. Advantages High temperatures required to break down any waste containing carbon. Not economically attractive. Disadvantages

22. Thermal decomposition of organic materials in an inert atmosphere or with insufficient oxygen to cause partial oxidation Endothermic process Involves the change of chemical composition Irreversible process Pyrolysis

23. Simple , inexpensive technology and environment friendly Reduce the country’s dependence on imported energy resources by generating energy from domestic resources Advantages Ineffective in destroying and physical separating inorganic compound from contaminated medium. Requires proper treatment, storage and disposal of hazardous wastes. Disadvantages Pyrolysis

24. Composting Composting is an old and inexpensive method that converts organic waste into useful compost that can be used as a soil conditioner and organic fertilizer. It is an exothermic biodegradation process that involves a complex web of bio- chemical reactions in which facultative and aerobic micro- organisms catabolize substrates to produce carbon dioxide (CO2) and heat , and finally transformed into stable composts

25. Novel or Emerging technologies Even though the above- described conventional techniques for managing food wastes have improved in recent years, only a little fraction of the residues generated can be valorized in some way ( Luque and Clark, 2013 )

26. Fluidized bed combustion Fluidized bed combustors can be designed to combust almost any solid, semisolid or liquid fuel without the use of supplemental fuel, as long as the heating value is sufficient to heat up the fuel, drive off the moisture and preheat the combustion air. W astes can also be co-fired with coal in many existing coal-fired fluidized bed combustion boilers. Advantages: compact furnace, simple design, effective burning of a wide variety of fuels, relatively uniform temperature reduced emission of nitrogen oxide and sulfur dioxide gases

27. Fluidized bed combustors

28. The combustion of three high moisture content waste materials (olive oil waste, municipal solid waste and potato) in a fluidized bed combustor was investigated by Suksankraisorn et al. (2003) and a comparison with co-firing of these materials with coal in the same combustor has been made.

29. Anaerobic Digestion Since the all stages of anaerobic digestion are controlled by bacteria, the product form varies with the type of bacterial population.

30. Increased reaction rates Less capital cost as a result of smaller digester size Highly efficient technologies for anaerobic digestion of FVW High stability , a high depuration rate and energy recovery with a good process economy Significant biogas productivity and better effluent quality from fruit and vegetable wastes anaerobic digestion Rapid acidification of fruit and vegetable wastes decreasing the pH in the reactor Larger volatile fatty acids production (VFA), which Stress and inhibit the activity of methanogenic bacteria Depression of the overall performance of the reactor by increasing the feed concentration

31. Biodiesel production By transesterification of vegetable oils with simple alcohols either using a catalyst or without it. By the fermentation of carbohydrate plants (sugar or starch based vegetable waste such as sugarbeet or potato peel ). Reaction temperature, alcohol to oil ratio, mixing speed, and purity of reactants are the other parameters which influence biodiesel production

32. Conversion of waste palm oil by transesterification to produce ethyl esters gives a product comparable to applying the process to neat VOs with properties comparable to those of the local diesel fuel Emission of less pollutants by biodiesel production Deterioration of biodiesel combustion performance at the higher energy input due to its high viscosity, density and low volatility

33. Vermicomposting Advantages : Rapid and Economical Environment friendly End product is disinfected and detoxified Vermicomposting technology, the bioconversion of organic waste into a biofertilizer through earthworm activity, is globally becoming a popular solid waste management technique ( Manyuchi et al., 2013; Thamaraj et al., 2011). The earthworms feed on the vegetable waste and their gut acts as a bioreactor whereby the vermicasts are produced.

34. Bioactive compound from vegetable waste

35. Conclusion Waste management in vegetable production is a tough problem and its optimum solution must foresee local factors to be taken into account. Waste treatment methods were divided in two categories : the currently employed and the novel ones. Although novel methods (bio active compound extraction , biofuel production etc ) appear to be promising and attractive alternatives, handicaps like high cost, requirements for trained personnel and high capital investment are still holding them back from widespread application in the vegetable waste industry.