ABSTRACT

Studies on municipal solid waste generation, disposal, and management, and the effects on soil properties in the rainy and dry seasons of 2011 and 2012 at Warri and Ughelli, Delta State, Nigeria, were undertaken in three phases. Well- structured questionnaires were used to evaluate the current status and problems of waste generation, disposal and management. A 3 x 14 factorial experiment in a randomized complete block design (RCBD) with three replications was used to determine the quantities of 14 waste types in three major locations (Housing Estates, Residential Areas and Markets) in Warri and also in Ughelli. A 2 x 2 factorial experiment in RCBD was used to evaluate the physico-chemical properties oftwo soil depths (0-15 cm and 15-30 cm) in two locations; namely: a landfill waste dump site and a nearby bush fallow. Respondents to questionnaires stated the types of wastes available in their locations: kitchen wastes, waste papers and stationaries, household/farm yard manure, industrial effluents, garbage, polythene materials. Some of the factors militating against proper waste management in Warri and Ughelli were poor funding of waste disposal workers, inadequate infrastructures, such as waste receptacles and waste disposal trucks and non-payment/underpayment of the inadequate personnel/staff of Delta State Environmental Protection Agency (DELSEPA). Markets had significantly higher quantities of wastes at the rainy and dry seasons than Housing Estates and Residential areas in Warri and Ughelli. Vegetables followed by metal scraps, had significantly the highest quantities of wastes in Warri and Ughelli. The statistically similar quantities of wastes of plastics, water sachets, rubbers and aluminum had the least (p < 0.05) waste quantities in the two cities. The landfill site in Warri had significantly higher sand and silt contents than the bush fallow site. The Bush fallow site had higher (p < 0.05) clay content than the landfill site. In Ughelli, the landfill dump site had higher (p < 0.05) silt content than the bush fallow site. The bush fallow site had significantly higher sand and clay contents than the landfill site in Warri. The 0 - 15 cm soil depth had higher (p < 0.05) sand content than the 15 - 30 cm. The silt and clay contents ofthe 0 - 15 cm and 15- 30 cm soil depths were not significantly different. In Ughelli, the 15 - 30 cm soil depth significantly had higher sand content than 0-15 cm. The silt and clay contents ofthe 0-15 cm and 15 - 30 cm were statistically similar. In Warri, landfill site had significantly higher Organic Matter, Organic Carbon and pH than the bush fallow site. The bush fallow site had higher (p £ 0.05) exchangeable acidity (EA) than the landfill site. The Organic Matter and Organic Carbon contents of the 0 - 15 cm and 15 - 30 cm soil depths were statistically similar. The 0 - 15 cm soil depth had higher (p < 0.05) pH value than the 15 - 30 cm soil depth which had higher EA than the 0 - 15 cm soil depth. In Ughelli, the land fill dump site had higher (p < 0.05) Organic Matter and Organic Carbon than the bush fallow site. The bush fallow site had higher EA than the landfill site. The pH values ofthe landfill and bush fallow sites were not significantly different. The 15 - 30 cm soil depth had significantly higher Organic matter and organic carbon contents than the 0 - 15 cm soil depth. The pH values of 0 - 15 cm and 15 - 30 cm soil depth were not significantly different. The 0 - 15 cm soil depth had higher EA content than the 15 - 30 cm soil depth. In Warri and Ughelli, landfill sites had significantly higher N, P, K, Na, Ca and Mg contents than the bush fallow sites. In Warri t he 0 - 15 cm soil depth had higher N, Na, Ca and Mg than 15-30cm soil depth, while 15-30cm soil depth had higher P. K. than 0-15cm soil depth. In Ughelli 0-15cm soil depth had higher P. K. than 15-30cm soil depth. The 15- 30cm soil depth had higher N, Na, and Ca than 0-15 soil depth. Mg of the two soil depth were statistically similar. In Warri bush fallow had higher (p< 0.05) Cu and Zn contents than the landfill site. The landfill site however, had higher Fe and Cr contents than the bush fallow site. The 0 - 15 cm soil depth had higher Pb content than the 15 - 30 cm soil depth. The 15-30 cm soil depth had significantly higher Cu, Fe, Zn and Cr contents than the 0 - 15 cm soil depth. In Ughelli, the landfill site had higher (p < 0.05) Pb, Fe, Zn and Cr contents than the bush fallow site. The bush fallow site, however, had significantly higher Cu content than the landfill site