ABSTRACT
This study was carried out on the analysis of some physicochemical and heavy metals of some pond in Bauchi metropolis. The level of Heavy metal in the pond was determined by measuring (As, Pb, Hg, and Cd) in the seepage and in the pond itself using Atomic Absorption Spectrometry methods. Heavy metal concentration upstream before contamination was low and within WHO limits. The mean concentrations of arsenic, lead, mercury and cadmium were 0.026mg/l, 0.957mg/l, 0.025mg/l and 0.005mg/l, respectively in the pond. Mean heavy metal concentration, two hundred metres downstream from the leachate discharge point was 0.008mg/l for arsenic, 0.393mg/l for lead, 0.001mg/l for mercury while cadmium was not detected. Lead exceeded the WHO acceptable limit of 0.01mg/l for drinking water. Mean levels in the corresponding sediment samples were 0.015mg/kg for arsenic, <0.001mg/kg for lead, 0.004mg/kg for mercury and cadmium 0.151mg/kg. Contamination factors computed were less than one (CF<1) for arsenic and lead in the sediments which imply low contamination and moderate contamination for cadmium (1 ≥ CF ≥ 3). Seepage of leachate from the landfill site into the pond must be monitored to ensure the quality of Zaki pond.
CHAPTER ONE
1.0 INTRODUCTION
Nigeria aims at achieving an efficient and effective management system for the sustainable development of water resources and to ensure full socio-economic benefits for present and future generations by 2025. However, water management is still a major developmental challenge as human activities have resulted in the dwindling of freshwater resources, increased pollution load, health and transportation problems and reduced ecosystem resilience which pose significant threat to sustainable development (Roosbroeck et al., 2006).
In Nigeria, technical, financial and institutional constraints have compounded this problem. Also, improperly designed solid waste disposal facilities and landfill sites have further contributed to contamination of surface and underground water resources. Akoteyon et al. (2011) investigated the heavy metal contamination of groundwater around a landfill site in Alimosho area of Lagos State, Nigeria and concluded that the leachates from the landfill have impacted on the groundwater resources of the sampled wells in the study area based on the direction of groundwater flow.
There are more than twenty heavy metals, but four are of particular concern to human health and the environment namely Lead (Pb), Cadmium (Cd), Mercury (Hg), and Arsenic (As), (ATSDR, 2011). They are toxic and can cause damaging effects even at very low concentrations. The Agency for Toxic Substances and Disease Registry
(ATSDR) in Atlanta, Georgia, (a part of the U.S. Department of Health and Human Services) compiled a Priority List called the “Top 20 Hazardous Substances.” The heavy metals arsenic (1), lead (2), mercury (3), and cadmium (7) appear on this list.
