Impacts of effluent and particulate matter from Mukwano factory on the surrounding environment.

Abstract

Nakivubo Channel is the major recipient of runoff and a surrogate end point for organic substances in industrial and domestic effluents. However, the quality of the various effluents, like that of Mukwano industries, that end up in the channel is not known. This study was carried out to assess the impacts of effluents and particulate matter from Mukwano industries on the surrounding environment. The study was guided by the following objectives: to determine the physico-chemical characteristics (dissolved oxygen, temperature, conductivity, pH, and total dissolved solids (TDS) in effluents) from Mukwano factory, evaluate the impact of effluents on the quality of water in the Nakivubo channel, and lastly assess the air quality or particulate matter around Mukwano and the surrounding environment. Effluent discharge was sampled at four selected points of Nakivubo channel: point (A) upstream, point (B) discharge point, point (C) storm water, and point (D) downstream. Samples were collected at three different sampling days, twice in the wet season and once in the dry season. It was found that pH ranges from 6.73 to 9.24. The lowest pH value was 6.73 at point C and the highest pH value was 9.24, while electrical conductivity was within limits prescribed by WHO (1200 μS/cm) while other samples exceeded limits, especially at the point of Mukwano discharge (2620 μS/cm). Total dissolved solids concentration was 0.1 mg/L at the point of discharge, 0.18 mg/L upstream, and least downstream at 0.03 mg/L. It was found out that all the sites had BOD5 concentration above the NEMA standards of 50 mg/L, with the highest concentrations were found at the Mukwano discharge points, which recorded BOD5 of 202 mg/L. It was revealed that all study sites had COD above the stipulated NEMA standards of 100 mg/L. Total nitrogen concentration was 18.32 mg/L in the wet season and they were higher in the dry season. The results showed that PM2.5, PM10, hydrogen sulfide, sulfur dioxide, volatile organic compounds, carbon dioxide, and carbon monoxide were below the recommended standard exposure limit. The highest particulate matter concentrations were recorded at point D, a point downstream, and volatile organic compounds were detected at the point of discharge (B), while hydrogen sulfide was detected in the drainage channel. It can be concluded that upstream points sampled from Nakivubo channel water have higher concentrations of physico-chemical parameters such as pH, temperature, and total dissolved oxygen. The effluents from the Mukwano industry contain higher BOD5 and COD concentrations. It was from these findings that it was concluded that there is a need for the Mukwano industry to treat its effluents before they are discharged from the factory, and this can be done in collaboration with NEMA to ensure compliance with laws and discharge standards, particulate matter standards.