Impact of industrial effluents on water quality of receiving streams in Nakawa-Ntinda Uganda

Abstract

The impact of industrial effluents on water quality of receiving streams in Nakawa -Ntinda industrial area was assessed so that preventive measures may be taken. The streams pass through Kinawataka wetland that is being degraded thus increasing the degree of pollution into Lake Victoria. Water samples were taken from areas with active industrial activities and from an area where there is no industrial activity.

Both the effluents and the water samples at selected points in the stream were analysed for pH (ranged from 3.68±0.17 to 12.41±4.68 mg/l), EC (ranged from 212±51.31 to 4633±154.42 µScm-1), turbidity (ranged from 20.9±0.42 to 715.9±9.31 NTU), colour (ranged from 72±2.11 to 958±86.52 TCU), BOD (ranged from 16.4±0.45 to 325.5±40.32 mg/l), COD (ranged from 39±1.22 to 1351±321.04 mg/l), TN (ranged from 0.45±0.18 to 32.63±4.17 mg/l), TP (ranged from 0.078±0.01 to 1.674±0.22 mg/l), Na (ranged from 0.59±0.27 to 53.04±1.74 mg/l), Cl (ranged from 11.68±0.14 to 31.08±1.48 mg/l), Ca (ranged from 6.38±0.66 to 38.75±7.41 mg/l), Pb (ranged from 0.039±0.01 to 0.256±0.14 mg/l), Cu (ranged from 0.015±0.01 to 0.52±0.16 mg/l) and Cd . These were compared with the standards set by NEMA for waste water. Cadmium was below the detection limits at all sampling sites.

It was found that there is a high degree of pollution in the stream and recommendations on reduction of pollution in the streams were made. Sources of water pollution include effluents from a fish filleting industry (high TN), foam mattress manufacturing/metal fabricating industry (high Cu), soft drinks manufacturing industry (high pH), pharmaceutical industry (high Pb) and food processing industry (high EC and BOD)