Chemical and biological characterization of municipal solid waste at Chunga landfill for potential use as compost.

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Mkandawire, Dan
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The University of Zambia
The Chunga landfill located in the northern part of Lusaka city receives on a daily basis approximately 500 tonnes of comingled waste comprising mostly municipal solid waste (MSW). The MSW has being accumulating over the years within the limited space at the landfill without being recycled. Composting is one of the best methods of managing MSW because of the useful end product called compost. The application of compost to the soil has many benefits such as soil enrichment, fertility enhancement, and improvement of the soil’s physical and chemical properties. The current study was conducted to characterize MSW compost at Chunga Landfill for chemical and biological parameters to assess its potential to be used as compost so as to free up some space for the incoming MSW. The samples were taken from cell 2 where no fresh MSW was added for one year. Parameters used to assess the quality of the MSW were pH, EC, C:N ratio, OM, nitrogen, phosphorous, potassium, cadmium, lead, chromium, copper, nickel, zinc, presence of Salmonella spp. E. coli, feacal coliforms and viable Ascaris ova. Results indicated pH 7.94 ± 0.01, EC 6.46 ± 0.03 mS/cm, OM 6.76 ± 0.02 percent, C:N ratio 5.10, total nitrogen 0.77 ± 0.01 percent, phosphorous 0.53 ± 0.04 percent, potassium 0.88 ± 0.03 percent, copper 156.8 ± 5.52 mg/kg, zinc 207.83 ± 18.60 mg/kg, cadmium 4.63 ± 0.94 mg/kg, chromium 60.7 ± 0.57 mg/kg, lead 109.58 ± 8.92 mg/kg, nickel 28.75 ± 0.49 mg/kg, feacal coliforms >1,100 MPN/g, E. coli >1,100 MPN/g, Salmonella not detected per 25g and Ascaris was non-viable. Chemical characteristics with regard to pH, EC and heavy metals were within the stipulated values for matured compost and FAO standards while OM, biological characteristics and NPK were below. Therefore, the Chunga Landfill MSW may be applied as compost on low value crops and as a soil conditioner. It is recommended that the Chunga Landfill MSW compost must be sanitized to get rid of E. coli and feacal coliforms, material to be segregated at source or at the disposal site to boost OM and lower the heavy metal concentration, the chemical and biological characteristics of Chunga Landfill MSW compost be monitored on a monthly basis for one calendar year to check for variations in analytical data, a portion of the Chunga landfill be dedicated where only the degradable organic material will be disposed and Government to come up with chemical and biological guidelines on the utilization of MSW as compost. Keywords: MSW, compost, chemical, biological characteristics, Chunga Landfill
Municipal solid waste--Compost. , Solid waste management.