Effect of Wet Coffee Processing Industries Waste on Water Quality of Receiving Water Body and Its Trend on Downstream (Case Study of Gidabo Watershed in South Ethiopia)

Abstract

Environmental pollution is a worldwide problem, currently it is a challenge to keep environmental quality while achieving sustainable development. Wet coffee processing is one of environmental polluting anthropogenic activities in Ethiopia. The effluents are discharged irresponsibly into nearby surface water and it may also infiltrate into ground water and become main threat to both ground and surface water qualities. The main objective of this study was to investigate the impact of wet coffee processing effluent on nearby surface and ground water bodies and assess the seasonal load of pollution and its extent of ecosystem degradation. The study was carried out in the southern part of Ethiopia, Gidabo watershed. The concentrations of different parameters were collected for upstream, middle stream and downstream of the catchment for both surface (two seasons) and shallow well. Analysis of variance was carried out to study the interactions among different factors (location, Season). The mean values of studied parameters were used to assess the extent of pollution in ecosystem by comparing with the Ethiopian national discharge limit. The result of analysis reveals that during wet coffee processing (dry season) the organic waste effluent increases the BOD to 473.0 ± 179.61mg/l thus, DO value diminished to a level almost zero. Parameters: pH, TDS, EC, DO, BOD, COD, turbidity, nitrate and phosphate shows significant difference in different season. Turbidity, BOD, pH, COD, DO, nitrate and phosphate were above the limit. Significant difference was not observed for pH, BOD, COD and nitrate in location variation at (?= 0.05). Where, for shallow well the variation along the altitude is not significant for most of the parameters. The results concluded that, the intensity of effects is seasonal. Still it puts the recover capacity of river under question since; it is continues processes and it may alter the ecology in general. As a recommendation, appropriate technology input and community involvement is essential.