Mitigating solid waste accumulation through composting process in Jaffna Peninsula, Sri Lanka

Abstract

Disposal of solid waste is a major environmental problem globally, at present. Solid waste accumulation in the environment is contentiously increased because of the population development and globalization. In Jaffna, disposal of municipal solid waste has become a serious problem and high portion of solid waste comes from domestic sector of the Jaffna peninsula. Hence, an attempt was taken to justify the nature of waste collection annually and its composition thus to develop centrally aerated compost digester with all facilities to convert the decomposable fraction of house hold waste into good quality compost with an intention of mitigating waste accumulation in the environment. The composition ratio of the waste from the municipal council was 79% of organic compounds, 11% of paper, 2% of plastic, 1% of glass, 1% of metal and 6% of others (sand, small stones) and there were no significant differences in collected waste among months of a year and in between years. Designed compost digester was compared with peripherally aerated digester and evaluated for its efficiency by fitting a model for oxygen consumption during decomposing process and maturity was determined by sieving through 4mm sieve. Maximum oxygen consumption rate in mg/hr per gram of solid waste in the digester was recorded for centrally aerated with water spraying unit, and peripherally aerated as 5.11 mg/hr/g, and 3.89 mg/hr/g respectively. This higher oxygen consumption rate in designed digester was due to the higher aerobic decomposition by the aerobic microbes inside the digester and 80% of decomposition was achieved by 35 days and 65 days for centrally aerated compost digester and peripherally aerated compost digester respectively. Therefore, this is the best option to dispose Municipal solid waste in an eco-friendly manner in Jaffna peninsula.