MONITORING LEVEL OF POLLUTANTS IN NUST LAKES

Abstract

Water is a very important resource for life. It affects our public and environmental health. Water occupies approximately 71 % of the earth's surface in the shape of rivers, lakes, seas, oceans, glaciers, and ice caps. Both natural and anthropogenic activities have endangered this natural and precious resource. Pakistan is already a water stress country and now it has moved to a water scarce country. The three NUST lakes were constructed to store water and cope with water shortage but due to internal (NUST apartments, sports complex, hostels,

cafes, sports complex, saddle club and workshop) and external sources (wastewater from G- 13 and H-13), the quality of water present in lakes is deteriorating with each passing day. The

current study aimed to determine physicochemical parameters such as pH, total dissolved solids, turbidity, electrical conductivity, temperature, chemical oxygen demand, nitrate, nitrite, phosphate, total kjeldahl nitrogen, chlorophyll-a, b and c, chlorophyll content index and heavy metals in water, sediments and flora at NUST lakes. Samples were collected and analyzed according to the standard protocols. Algal species were also detected under compound microscope. Maximum chlorophyll content was observed in Stellaria graminea. Study revealed that contamination level at all sites was significantly high. Concentrations of four heavy metals (Cd, Cr, Zn and Pb) were observed. Higher concentration of Zn was found in water, sediments and plants of all lakes. The eutrophication levels were low making NUST lakes oligotrophic. Pearson correlation was used to identify the relationship among different parameters. Further studies should be conducted for better assessment of waste intrusion sources, nutrient release in lakes and dominant algal species.