Optimizing Composting Conditions of WetMarket Wastes

摘要

The solid wastes management in the Philippines is still plagued with problemson the choice of technology to handle the vast volume of wastes in the communities.Existing laws consider composting as the most logical solution to these problems. Thestudy utilized bioreactors to decompose wet market wastes and optimized by responsesurface methodology (RSM). Four-liter plastic bottles served as bioreactors for marketwastes, shredded to 1.0, 2.0 and 3.0 and above cm nominal diameter and treated withinoculants under ambient temperatures of 27 to 32°C to decompose in 7 days. Theresponse variables included pH, compost temperature, weight loss, moisture content,nitrogen, phosphorus, potassium, organic carbon, and C/N ratio to assess compostingrate at 5% level of significance. Inoculants, particle size, time of composting, andambient temperature significantly increased pH and weight loss. Time and ambienttemperature significantly decreased moisture content of composts while no factorssignificantly increased temperature. Inoculants and particle size significantly influencednitrogen levels but failed to show significant effects on phosphorus, potassium, and C/Nratio of composts after composting. Analyses resulted in optimum conditions forcomposting wet market wastes using inoculants in 5 days composting, 2.0 cm averageparticle size and 30oC ambient temperatures. At these conditions, the composts will havepH 6.5, 36°C temperature, 0.08 kg d-1 weight loss, and 63%wb moisture content.Composted wet market wastes have potential nutrients of 2.5% nitrogen, 6.6%phosphorus, 1.5% potassium, and 27% carbon content.