The Study Of Municipal Solid Waste Sorting Behavior And The Following Food Waste Composting Degradation

Rapid growing rate of municipal solid waste has aroused substantial concern of Chinese government and researchers.Source-separated collection and integrated management are probably the key elements to solve the urban waste disposal problem.Since the study of waste classification in down-tier cities in Liaoning Province is not enough,this study carried out a household waste source-sorting pilot trial in a fourth-tier city,Panjin,in the northeast of China.Combining kitchen waste with poultry manure co-composting treatment,the pilot trial implements the source classification,reduction and recycling of household waste.This article includes three parts:(1)The study of waste sorting behavior.In order to investigate the feasibility of launching waste sorting program and to study the impact factors which can influence waste sorting behavior,we focused on food waste who has the biggest proportion and hard to be transported in waste management and conducted a two rounds(A & B)waste sorting pilot trial in a fourth-tier city,Panjin,in the northeast of China.Prior to Campaign A,questionnaire survey was conducted,paper bags were freely distributed to habitants for food waste collection only,and fine-sorted food,paper,plastic,metal and glass waste bins were installed at the center place of the residential area.Food waste sorting rate and purity,as well as other waste sorting rate were measured weekly/monthly on a wet weight basis.In the Campaign B,two modifications were made,that food waste bins were relocated from the center place to the front door of each building unit,and the propaganda of waste sorting campaign was carried out weekly instead of once in the beginning of campaign.We found that in the Campaign A,food waste sorting rate averaged at 19.4% and purity rate averaged at 41.5%,while other waste sorting rates varied in 0.7-4.7%.Whereas in the Campaign B,the mean food waste sorting rate increased to 49.7% with sorting purity raised to 90.0%,and other waste sorting rates varied in 14.8-28.8%.The questionnaire survey analysis showed there was considerable high intention(>96%)for waste sorting,which was opposite to the relatively low waste sorting behavior.Overall,our results suggest that it is feasible to launch waste sorting campaign in a medium developed city in China,improved facility convenience and detailed frequent propaganda are probably two key priorities to promote optimum waste sorting behavior.(2)The study of food waste and poultry manure aerobic co-composting in the compost reactor.In order to explore the co-composting optimal method and the structure of bacteria and fungi in the composting process,this study conducted multiple percentages of food waste aerobic composting reactor research,tested the physical and chemical properties of compost during the composting process(Temperature,MC,pH,EC,OM,TN,TC,C/N)and germination index(GI),analyzed microbial community structure(number of coli form,bacteria and fungi,RISA fingerprint).40% proportion of food waste compost had the best temperature performance,highest germination index(GI = 162.1%)and richest bacterial diversity(B-Bands = 86),met the maturity successfully and was to be considered as the best candidate.Correlation analysis and factor analysis between physical/chemical properties and microbial community structure were approached,the results showed that temperature and MC were two significant factors that influenced the amount of bacteria and fungi,however,the factors influencing the diversity of bacteria and fungi were quite different,we extracted two main factors which can explained 66.03% of the total inpact in the factor analysis.(3)The comparative study of poultry manure+ vegetable leaf and poultry manure+ meal leftover co-compost.In order to implement the compost treatment of kitchen waste,on the fundation of the composting reactor,we set up two compost with the same size(length * width * height = 1.5 * 0.8 * 0.8 m),compared the difference of physical and chemical properties of two pile body with 40% food waste reactor compost.The results showed that the poultry manure + vegetable leaf had better performance than another one and reached to manure earlier,the significant difference between pH and TC were observed,meal leftover's property — low pH,high C content contributed to the difference.