The effect of rice husk biochar on heavy metal content in compost derived from municipal waste.

Abstract

The heavy metals contained in the municipal wastes has been an issue when it comes to re-using of wastes. This study objectively studied the effect of rice husk biochar on lead and copper content of compost derived from municipal waste. Different waste materi-als comprising of municipal waste: 8kg, rice husk biochar: 2kg, Rice straw: 0.2kg, Eucalyptus green leaves: 0.5kg, decaying toma-toes: 1.5kg, Vegetable leaves (spinach): 0.5kg were composted. Three replications were made, one set with biochar and one set with-out biochar. The result showed that copper content only increased from 85.47 mg kg-1 to 99.60 mg kg-1 in the biochar pile, unlike the non-biochar pile, which increased to 105.43 mg kg-1. The reduction of lead was not as effective as that of copper as it is from 86.00 mg kg-1 to 138.35 mg kg-1 for non-biochar and with biochar is 111.33 mg kg-1. The non-effectiveness in reducing lead as compared to cupper is because of the inherent content in the biochar used. It was therefore concluded that rice husk biochar was more effective in removing Cu compared to Pb.