From Food To Household Food Waste

Garbage classification is related to the people’s living environment and the economical use of resources.It is also an important embodiment of the level of civicmindedness."Household Waste Management Regulations of Shanghai" is implemented on July 1,2019,and the amount of household food waste increased from 4,400 tons per day in 2018 to 9,428 tons per day in 2020,accounting for 32% of the total domestic waste in Shanghai,marking the initial success of domestic waste classification.However,the data far exceeds the forecast in Shanghai’s planning,and there are also difficulties in disposing of household food waste.And this further reflects the food waste is widespread.Therefore,the systematic exploration of the process of "from food to household food waste" has good practical significance for reducing food waste,reducing the amount of household food waste,and promoting the utilization of household food waste.This article summarizes the work process and progress of the classification of domestic waste in Shanghai,and sorts out the source,output,and physical and chemical characteristics of household food waste in Shanghai by collecting,summarizing and analyzing the government,enterprises and other relevant data,visiting several garbage treatment plant in Shanghai.At the end of 2020,the total amount of household food waste in Shanghai was about 3.44 million tons,with a purity of more than 99%,of which 50.06% came from communities,36.67% came from restaurants,and 13.27%came from vegetable markets.The main physical and chemical properties are 76.85%moisture content,81.37% organic matter,14.10% fat and 18.20% protein.The results show that household food waste mainly comes from the food consumption process,and food waste as a breakthrough point for reduction can be further explored.In order to further sort out the ways and amounts of household food waste generated during the food consumption process,this article collates and summarizes relevant data such as "Shanghai Statistical Yearbook" and "China Statistical Yearbook",and investigates relevant domestic and foreign documents from the perspective of "from food to household food waste ".This article divides the food involved into 11 categories to build a Shanghai food consumption material flow model to calculate the amount of food consumption,the amount of household food waste and the amount of food waste in Shanghai.According to calculations,in 2019,Shanghai’s food consumption reached8.9 million tons,the edible part was 7.23 million tons,and the amount of household food waste generated during the food consumption process exceeded 2 million tons.In the material flow model,it can be found that food waste accounts for about 7%-11% of food consumption.In order to further explore the various types of food waste in Shanghai,this paper selects 385 catering units and 384 community household samples for research.According to calculations,the per capita food waste of the public in Shanghai is 93.72g/person,and the total amount of food waste in the year is 707,800 tons.Food waste is equivalent to wasting 328,000 mu of land resources,emitting about1.83 million tons of carbon dioxide,210,000 tons of nitrogen,and more than 1.44 billion tons of virtual water.This article explores whether the implementation of the mandatory classification of household waste will promote the public to reduce food waste.visits and surveys of more than 100 communities,interviews and surveys are conducted,and SPSS analysis is conducted.The results show that after Shanghai’s mandatory classification,the public’s acceptance of waste classification publicity and education,the level of waste classification management standards in the community,and other related policies,publicity have shown initial results in reducing food waste,reducing the amount of household food waste,and promoting the utilization of household food waste.When analyzing the relationship between food waste and garbage classification,it can be found that reducing food waste can achieve household food waste reduction.At the same time,if the management of some food waste is strengthened,the physical and chemical properties of household food waste can be changed by changing the composition of household food waste.The results of this paper show that the fat and protein content of household food waste produced by food waste is 21.25% and 12.78%,respectively.If all food waste is reduced,the protein content of household food waste in catering units will be reduced by 1.12% and the fat content will be increased by0.01%;the protein content of household food waste in community households will be increased by 0.09%,and the fat content will be increased by 14.53%.From the perspective of household food waste recycling,increasing protein content and reducing fat content are beneficial to the end treatment of household food waste.At the same time,considering the frequency of food waste and the amount of food waste in the public,with limited manpower and policy costs,we can focus on strengthening the control of staple food and meat waste,and propose feasible management and compulsory measures.This article was supported and sponsored by Shanghai Municipal Administration of Greening and City Appearance,Shanghai Environmental Sanitation Engineering Design and Research Institut,and Shanghai Feilin Public Welfare Development Center.Part of the research results of this article are written into the "Guidelines for Classification of Domestic Waste in Shanghai"(for middle school students,elementary school students,and kindergarten).