Effect of Co-composting Fish and Banana Wastes with Organic Municipal Solid Wastes on Carbon / Nitrogen Ratio

Abstract

This study seeks to assess the quality of co-composted shredded Municipal Solid Wastes (MSW) with fishery wastes, banana mulch wastes and aerobically composted slaughterhouse wastes. They are most common in Southern Lebanon and are likely candidates to investigate the carbon and nitrogen amendments to the MSW. The overriding goal of this study is to make the co-composting method as practical as possible for ordinary people to reproduce it in natural field settings by using a low cost technology and a good quality fertilizer. At a low maintenance cost, three initial trials were executed in this study to optimize the composting process of these waste ingredients.  The objective of the first two trials was to evaluate composting processes in two different bioreactors and using the two different mix ratios of co-composted waste material. However the third trial`s objective was to develop and validate the composting process of 4 different waste mix combinations  by using commercially available plastic barrels as self-heating bioreactors. The evaluations are focused on process indices during composting and chemical indices of carbon/nitrogen (C/N) ratio of the final compost. A mathematical optimization model is presented. Components of the composting are estimated in order to satisfy C/N ratio in the range between 20 and 30. The chosen ideal weight of the composting is 25 kg. Output data of optimization model, C/N ratio as a main parameter as well as secondary parameters components of composting are tabulated. A multiple regression analysis is performed to relate the main parameter to the secondary parameters. Finally, this study suggests that specific weights for fish and banana mulch wastes can be considered suitable for efficient composting with organic fraction of MSW. If implemented successfully at individual household or larger municipality level, it will contribute to the minimization of wastes.

Keywords: C/N ratio, municipal solid wastes (MSW), Fishery wastes, Agricultural solid wastes, Compost, Saida Solid Waste Management plant (SWM).