Spectrophotometric Determination of Nitrate and Phosphate in Selected Water Sources of Tansen

Abstract

Direct human activities, such as washing and bathing in water sources, can contribute to nutrient  enrichment in surface waters. However, limited information is available on the contribution of local washing and bathing practices to nitrate and phosphate enrichment in spring water sources of Tansen, necessitating systematic monitoring. Elevated nitrate and phosphate levels in water sources may pose risks to human health and contribute to eutrophication of nearby aquatic systems. Therefore, this study aimed to assess nitrate and phosphate concentrations in some water sources in and around the urban area of Tansen, Palpa, Nepal, before and after such activities using spectrophotometric analysis. The results revealed a clear increase in nutrient levels, with nitrate concentrations rising from 10.54 ± 0.83 to 108.04 ± 1.67 mg L^-1 and phosphate concentrations increasing from 0.248 ± 0.007 to 1.085 ± 0.033 mg L^-1 across all sites. Phosphate levels exceeded the typical range for unpolluted waters (0.01–0.03 mg L^-1), indicating potential eutrophication risks. These elevated nutrient concentrations are attributed to detergent and organicmatter residues introduced directly into the water during washing and bathing, highlighting their role as diffuse, non-point sources of pollution in small urban water bodies. While this study is limited to selected water sources and a single sampling period, the results emphasize the importance of long-term and seasonal monitoring, regulation of phosphate-containing detergents, and public awareness initiatives to reduce nutrient loading and protect local water quality.