Qualitative assessment of municipal solid waste compost by indexing method

Background A study was carried out to classify municipalsolid waste (MSW) compost produced in Delhi, Indiafor their marketability and use in different area with respectto physico-chemical properties, fertilizing and heavy metalpolluting potentials.Results The pH of the compost was slightly alkaline(8.4 ± 0.02) and C:N ratio (9.46 ± 0.91) was low ascompared to Fertilizer Control Order (FCO) Standard,Government of India, 1985. Sample analysis was carriedout using standard methods. The concentrations of someselected heavy metals, e.g., Zn, Cd and Ni were within thepermissible limit of FCO standard. However, the concentrationsof Cu, Pb and Cr exceeded (66.7 %) the permissiblelimit of FCO standard. Further, the compost wascharacterized to know the fertilizing potential and itspotential to contaminate the soil. Fertilizing index (FI) wascalculated from the values of TOC, TN, TP, TK and C:Nratio and clean index (CI) was also calculated using heavymetal concentrations. FI value of compost was varied from4.47 to 4.60, whereas CI value of compost was varied from2.33 to 2.87, respectively.Conclusions The study results indicated that majority ofMSW compost produced in Delhi failed to achieve qualitycontrol guidelines of FCO standard. The compost has fertilizingpotential, however, certain risk to the environment.Hence, the prepared compost in Delhi was not suitable forits intended purpose. Post-treatment of compost is requiredto improve the quality of compost, which can be utilizedfor agricultural purposes.