环境与分析毒理学

The Pollution Profile of Modjo River Due to Industrial Wastewater Discharge, in Modjo Town, Oromia, Ethiopia

Abstract

Amde Eshete Gebre, Hailu Fekadu Demissie, Solomon Tejineh Mengesha and Mesfin Tafa Segni

Introduction: Accelerated water quality change due to industrial pollution is one of the major environmental concerns throughout the world. In Ethiopia, Pollution of surface water is largely a problem due to rapid urbanization and industrialization. The main objective of this study was to determine the pollution profile of Modjo River throughout study sites.

Methods: A cross-sectional study was conducted to assess water pollution along Modjo River. Ten sampling sites were selected based on wastewater discharge, accessibility and pollution feasibility of river water. The sampling frequency was for two rounds composite sample taken from Modjo River. The chemical parameters were determined in the laboratory by using standard instrumental method AAS and UV-VIS.

Results: Temperature, Electrical conductivity, Turbidity and PH were within the acceptable limit of surface water standard. Ammonia Nitrogen (NH3-N), BOD, Phosphorous, Nitrate Nitrogen (NO3-N) was all above acceptable limit except for BOD and Ammonia Nitrogen in station 1 within acceptable limit. TDS above standard limit in Stations 5, 6, 7, 8, 10 were above acceptable limit. COD of station 2, 3, 4, 8, 9 and above the acceptable limit. For chromium stations 3, 6, 8, 9 and 10 above acceptable limit of surface water standards.

Conclusion and recommendations: The study result found that there was change on the physico-chemical parameters from upstream to downstream areas, which indicates an introduction of pollution load from industrial wastewater. It is recommended that National Environmental Quality Standard (NEQS) should be strictly enforced on all industries to install facilities and treat wastewater effectively.