Wastewater Characterization of Chiniot Drain and Evaluation of Groundwater Contamination Using Water Quality Index (WQI) and GIS Techniques

Abstract

Groundwater pollution is considered a major concern in today’s world. Most industries in Pakistan produce untreated wastewater, extracting from and contaminating a nearby water source and the soil. This study was conducted in the Nithar Ke area of Chiniot District to assess the impact of the flow of wastewater over the area on groundwater quality. It aimed to: (1) investigate the conditions of industrial wastewater; (2) study the spatial variability of different parameters in groundwater using a GIS map; and (3) check the appropriateness of groundwater for drinking purposes using the water quality index (WQI). Physical and chemical characteristics, including pH, electrical conductivity, total dissolved solids, TSS, CO3, HCO3, chlorides, alkalinity, total hardness, Ca, Mg, arsenic, copper, chromium, nickel, iron, manganese, and sulfate, were tested using groundwater samples, and variance in groundwater was analyzed using a GIS (geographic information system). The water quality index (WQI) was developed for the Nithar Ke area to determine the appropriateness of the groundwater for drinking purposes. WQI values were determined within the range of 41 to 89.5, which showed a poor to good water quality. It was discovered that parameters such as BOD, COD, iron, and TDS had average concentrations of 192 mg/L, 264 mg/L, 2.62 mg/L, and 6039 mg/L, respectively, in the polluted water, which exceeded the permissible limit. Iron and manganese were the most common contaminants found in that area. The biplot and correlation circle showed that iron and turbidity had a positive relationship. Further study on soil stratification and soil characteristics is recommended in this area for a detailed analysis of the causes of metal contamination.

Keywords

• groundwater
• physiochemical parameters
• heavy metal
• iron
• manganese
• WQI