MANAGEMENT OF URBAN ORGANIC WASTE INTEGRATING COMPOSTING, CIRCULAR ECONOMY AND SOCIO ECONOMIC

Abstract

This research focused on management of organic waste considering composting, circular economy and socio-economics. The study area was southern West Bank/Palestine, mainly Hebron and Bethlehem governorates. The study utilized data from the literature, data collection via questionnaire, and experimental part. The role of compost in the circular economy through the period extended from 2021 and up to 2035 was studied considering two scenarios: use of compost for agricultural purposes, and use as landfill cover materials. For agricultural purposes, and due to the strict restriction on access to high quality fertilizers by the Israeli Occupation, compost can be used as an alternative fertilizer where nutrients in compost can replace the existing chemical fertilizers available in Palestine such as humic acid (Iperen Humic 12+3 liquid) as source of carbon (C), Ammonium Sulphate (AS) source of nitrogen (N), Triple Super Phosphate (TSP) source of P, and Potassium Phosphate (SOP) source of Potassium (K). Replacement of chemical fertilizers can achieve financial benefit in addition to the environmental benefit through reduction of methane gas emissions and accordingly the saving as per the Clean Development Mechanism (CDM). Moreover, the tipping fees for waste landfilling are saved in addition to the landfill space. The socio-economic factors were also studied to assess the attitude of the local authorities (LAs) towards composting of organic waste through data collection via structured questionnaire from all LAs in the study area through face-to-face interview, through email and over phone. The data so obtained analyzed using descriptive statistics, bivariate analysis, and binary logistic regression model (LRM). The experimental part of the study focused on the design, test and evaluate two composting systems in two different climate regions, India and Palestine. A new composting forced-aerated device was designed and used in Palestine, and a steel mesh naturally-aerated composting bin was used in India. the operational parameters were monitored and controlled during the composting process, and physio-chemical and biological parameters were tested to evaluate the end quality of the produced composts. The results of the research on the compost’s role in the circular economy showed that the estimated revenue from compost use in agriculture is USD 194.8 million in 2021 and USD 369.8 million in 2035. The estimated saving from using compost as landfill cover is estimated USD 0.876 million annually, and USD 13.14 million during the 15 years’ study period. The use for agricultural purposes is preferred over the use as landfill cover because the savings are larger. Implementation of the circular economy principles in municipal solid waste management through composting can reduce many waste management problems by closing the materials recycling loop, generating extra income, and adding net revenue to the national economy. The results of the research on socio-economics showed that the LAs’ attitude toward organic solid waste (SW) composting is low and can be considered as dissatisfactory since only 36.5% of the LAs are planning for composting compared to 63.5% who are not. The output of the LRM showed LAs’ perception of compost contribution to SW reduction, availability of proper place, financial capacity, community awareness, and vi prevalent SWM bylaws are significant predictors of LAs’ attitudes toward organic MSW composting. The results of the research on design, test and evaluate two composting systems showed that both systems provide high efficiency in reducing the composting time (39-43 days in Palestine, and 31 days in India) although the aeration rate has no clear effect of the composting time. The physio-chemical analysis showed that most of the parameters comply with Palestinian Standards Institution (PSI) and Indian Fertilizer Control Order (FCO) except minor deviations. The volume reduction was 64.0,60.0, and 57.2 for experiments 1,2&3, respectively. Both systems also provided high fertility index (4.33, 4.73, & 4.8 for experiments 1,2&3, respectively), and high clean index (4.62, 5.00, & 4.69 for experiments 1,2&3, respectively). The biological parameters tests showed that all the experiments met PSI, but none of them met FCO, suggesting that the outer edges of the composting system didn’t heat enough to inactivate pathogenic microbes, therefore, developing the system by adding turning option could overcome this shortcoming. It was concluded that forced-aeration system is suitable for Palestine, while natural aeration system is suitable for India.