Investigating the effect of leachate from solid wastes management plant on surface water quality in Mbale

Abstract

This study investigated the effect of leachate from solid wastes composite plant on River Namatala water quality in Mbale City. Data was collected on the amount of solid wastes generated per day within Mbale city. Concentrations of water pollutants in the leachate produced from the decomposed solid wastes were tested in the laboratory. Possibility of treating lead as a pollutant using low cost adsorbent was explored. The results indicated that 273.5 tons of solid wastes are collected per day and deposited at the wastes management plant. Of this total, biodegradable and nonbiodegradable wastes constituted 84.4% and 15.6%, respectively. The concentrations or values of water pollutants especially total phosphorus, chemical oxygen demand, total nitrogen, lead and electrical conductivity from the leachate were higher than the limits recommended by the World Health Organisation (WHO).The heavy metals such as copper, iron, nickel, silver, chromium had lower values compared to maximum acceptable limit set by WHO. However, heavy metals should not be ignored as they are potential sources of pollution to nearby environments. The differences in the means of upstream and downstream pH, iron, chromium, lead, copper, total nitrogen, total phosphorus concentration and electrical conductivity were statistically significant (p < 0.05) while nickel, silver chemical oxygen demand, biochemical oxygen demand were statistically not significant (p >0.05).Raw avocado seeds had a higher lead removal efficiency (93.97%) compared to activated avocado seeds (89.7%). The households in Mbale city should be sensitized on the need for separation of wastes into biodegradable and nonbiodegradable. Water from River Namatala should be first treated before its domestic use.