Environmental impact of coffee processing effluent on the ecological integrity of rivers found in Gomma woreda of Jimma zone, Ethiopia

摘要

The physico-chemical parameters of coffee effluent consists of very high amount of BOD (2200 mg dm~(-3)), TDS (1810 mg dm~(-3)), NO_3 (26.4 mg dm~(-3)), NH_4~+ (12.6 mg dm~(-3)), low pH (4.3) and zero DO values. Despite the reduction of these values by dilution effect of river water, BOD values as high as 1900 mg dm~(-3) and 1700 mg dm~(-3) were found at the downstream sites of Bore and Fite rivers. For biological assemblage study, 6047 macroinvertebrates representing 27 different taxa were identified from riffle sampling sites. The average Shannon and equitability indices and total EPT taxa were reduced at the downstream sites. The habitat score of the study sites was in the range of 27% (very poor) up to 84% (excellent).