Study On Additives For Food Waste Treatment In Fed-Batch Reactor

With the in-depth promotion of domestic waste classification,the resource utilization of food waste has increasingly become the focus of attention.Aerobic composting has the advantages of large-scale treatment and high technical maturity.It is one of the mainstream technologies to realize the resource utilization of organic waste.The addition of additives can adjust the moisture content and C/N and other physical and chemical properties of food waste materials,which is conducive to improving the composting efficiency and the quality of composting products.This paper uses fedbatch aerobic reactor to treat food waste,compares the effects of different additives on food waste composting process and products,and optimizes the fineness of the selected additives.The main work and achievements are as follows:(1)The effects of additives on the composting process of food waste were investigated.1000 g of green waste,wheat straw,sawdust and bamboo charcoal are added to the four reactors at one time as additives,and 500 g of food waste is added to each reactor every day.The weight and temperature of materials are measured regularly,and samples are taken to analyze the moisture content,p H,EC(conductivity),organic matter and C/N of materials in the reactor.The results show that except for the reactor with bamboo charcoal as additives,the reactors with the other three additives can operate stably in the composting cycle;the effect of food waste composting with green waste as additives is relatively better.After the composting is stable,the daily average values of weight loss rate,water content and carbon nitrogen ratio are 83.89%,3.46%and 16.21% respectively.Correlation analysis showed that green waste could be determined to be the best in the composting process by water content and C/N.(2)The effects of additives on food waste composting products were investigated.The physicochemical and biological characteristics of compost products were tested.The results showed that the relevant parameters of food waste compost products of the four additives met the requirements of 《 organic fertilizer 》(NY/T 525-2021);Compared with the other three kinds of additives,the quality of food waste compost with green waste as additives is relatively high,and its moisture content,organic matter content and C/ N are 3.16%,66.92% and 13.98% respectively.(3)The effects of the fineness of green waste on the process and products of food waste composting were investigated.1000 g of green wastes with fineness of 0 ～ 3 mm,3 ～ 6 mm,6 ～ 9 mm and 9 ～ 12 mm were added into the four reactors at one time,500 g food waste was added to each reactor every day,the weight and temperature of materials were measured regularly,the moisture content,p H,EC,organic matter and C/N of materials in the reactor were sampled and analyzed,and the physical,chemical and biological characteristics of composting products were tested.The relevant parameters of food waste compost products of 0-3 mm and 3-6 mm fineness green waste meet the requirements of《organic fertilizer》(NY/T 525-2021);compared with the other three kinds of fineness of green waste additives,the quality of food waste compost products with 3 ～ 6 mm fineness of green waste as additives is relatively high,and its moisture content,organic matter content and C/N are 3.12%,63.93% and 12.00%respectively.Correlation analysis showed that weight loss rate and C/N indexes could be used to determine the best performance in the composting process of green waste with 3-6 mm fineness.The research results provide a reference for the selection of additives in the process of aerobic composting of food waste.