Heavy Metal Contents of Different Wastes Used for Compost

Abstract

A study was conducted to assess the heavy metal (As, Pb, Cd, Cr, Cu, Zn and Hg) contents of different sources of wastes generated in Dhaka city which was further used for a compost plant. The study consisted of both field survey and laboratory analyses. Relevant primary and secondary sources of data were collected to identify the source and nature of wastes generated near the compost plant. A total of eight households, ten officers and ten waste collectors were surveyed for data collection. For laboratory analyses, wastes from various socio-economic niches (lower, lower middle, middle and high) were collected. The result showed that wastes generated in the lower income niche contained the minimum contents of heavy metals compared to middle and high niches. The increasing trend of heavy metal contents of the wastes from lower to high income groups has been found to be linked to the life style, attitude, profession, culture and food habit. Most of the heavy metals did not meet the standard level for almost all the niches. Most of the correlations were found to be insignificant between the contents of nutrient element (C, N and P) and heavy metals (As, Pb, Cd, Cr, Cu, Zn and Hg).