Analisis Kualitas Air Anak Sungai Bedok Akibat Limbah Pabrik Gula Madukismo di Desa Tirtonirmolo Kecamatan Kasihan Kabupaten Bantul

Quality of river water was affected by several factors, especially human activity. Bedok River tributary was a waterway used by Madukismo sugar mill to drain its liquid waste. In every production season, water of the Bedok river tributary experienced physical changes because of the liquid waste. Purposes of the research were to know water quality of Bedok river tributary and to know self-cleaning point of the water. The research used field survey method. Sample was taken by using purposive sample method. Analysis of the research included Trend Analysis and descriptive analysis. Condition of water quality of the Bedok river tributary based on laboratory tests from point 1 to point 5 indicated a reduced quality. It can be seen from parameters (temperature, color, odor, TSS, BOD, COD and DO) exceeding quality standards. The reduced quality of the river water was caused by abundant content of organic materials of the sugar mill waste. Quality of the river water was gradually normal into downstream, because of decomposition process and oxygen addition from atmosphere. It indicated that the Bedok river tributary had self-cleaning, namely at point 5 marked by a reduced BOD and an increased DO (4 and 6.9 mg/l)