CHARACTERIZATION OF METALLIC POLLUTANTS IN PAHARANG DRAIN, FAISALABAD

Abstract

Metals in the untreated combined wastewater pose a serious threat to the soil and water environment in general and to human health in particular. Samples from Paharang Drain, Faisalabad, one of the major carriers of combined industrial, predominantly textile, and municipal effluents, were collected from six different locations between July 2008 and December 2008. The objective was to examine the state of metallic pollution and its variation with time and space. Metal concentrations in separate industrial and municipal streams falling into the Paharang Drain, were also studied independently for the baseline development. Metals selected for scrutiny were Cr, Ni, Cd, Mn, Zn, Cu, Fe, Pb, As and Hg. Standard Methods were adopted for sample collection, preservation and analysis. Benthic zone soil samples were also analyzed for the same metals by using the Flame Atomic Absorption Spectrometer (FAAS) and X-ray Fluorescence technique. Concentrations of most of the metals were found below Pakistan National Environmental Quality Standards (NEQS) in the Paharang Drain wastewater. Effects of seasonal variations on metal concentration in the drain water have also been elucidated. In addition, correlation between metals concentration and other physicochemical parameters such as pH, total suspended solids and total organic carbon etc. were examined. Good exponential correlation was found between metal concentrations and total suspended solids (TSS). Metal concentrations were found to be more sensitive to temporal variations than spatial ones. The pollution load indices, bioaccumulation factors, enrichment factors and geoaccumulation indices of selected metals were also assessed for benthic soil of the drain.