Nitrate/Nitrite Contamination in Groundwater of Karachi and its Correlation with other Physicochemical Parameters

摘要

A study on the contamination of groundwater by nitrate and nitrite in residential areas of all the five districts of Karachi has been conducted.Samples have been analyzed for their different chemical constituents and nitrateitrite content.The mean concentration of all the major chemical constituents like calcium,magnesium,sodium,potassium,chloride and sulfate were found to be particularly higher in groundwater samples of district South.In the light of this study,groundwater samples of Karachi have been characterized as hard water.Nitrate contents were within the range of 0.4-44.5 ppm as nitrogen and 75% samples have been found to be within permissible limits of WHO guidelines for nitrate,whereas nitrite contents were found to be below detection limits in 31%(10 out of 32)of samples,however the maximum i.e.1.69 ppm as N was found in district South.Correlation coefficients have also been calculated,however no significant correlation has been found to exist between nitrate contents and other physicochemical parameters determined in this study.