Feedstock Amendment for the Production of Quality Compost for Soil Amendment and Heavy Metal Immobilisation

Abstract

Composting is a waste management technology for recycling organic waste. A compost without detectable of pathogens and heavy metals can act as a soil conditioner or organic fertilizer to promote plant growth. It provides the soil with organic matter and nutrients, improving soil texture and water holding capacity and suppressing plant diseases with the presence of beneficial microorganisms. Many researchers aim to improve the quality of compost at a reduced process cost and composting duration. Preferably the composting process also offers the co-benefits of reduced environmental impact. The quality of the compost is closely related to the feedstock used for the composting. The feedstock ranges from bio-waste, plant- and animal-based agricultural waste and sometimes the organic fraction in the municipal solid waste. This paper reviews a range of feedstock amendment methods including the addition of bulking agent or chemical additive, inoculation with earthworm or microbial inoculants, and the addition of the mature compost, that could influence the composting process and the end product quality. The potential of immobilisation of the heavy metals in the waste material through composting was also discussed.