Daya Tampung Beban Pencemaran Nitrat dan Fosfat Sungai Brantas Ruas Sengkaling-Tlogomas, Kota Malang

Abstract

Abstrak: Sungai Brantas mengalir dan melintasi Kota Malang berpotensi mengalami degradasi kualitas air imbas dari transfigurasi tata guna lahan dan eskalasi penduduk di daerah Sub-Urban sepanjang sungai Ruas Sengkaling-Tlogomas, Kota Malang. Penelitian dilakukan pada bulan Februari-Maret-April tahun 2022 dengan sungai sepanjang ± 4,0 km. Penelitian ini bertujuan untuk mengidentifikasi kondisi eksisting kualitas air Sungai Brantas untuk mengitung beban pencemar, serta daya tampung beban pencemar pada Sungai Brantas dengan Qual2Kw. Parameter pencemar yang diteliti adalah Nitrat dan Fosfat. Kegiatan dan masalah di sekitar Sungai Brantas yang menjadi potensi pencemaran sungai pada bagian hulu adalah pertanian, serta menuju bagian hilir adalah domestik warga. Hasil dari penelitian ini kadar nitrat berkisar  antara 3,24-3,56 mg/l (tidak melampaui baku mutu kelas II). Demikian, sementara itu kadar fosfat berkisar antara 10,2-11.94 mg/l (melampaui baku mutu kelas II). Daya Tampung Beban Pencemar Nitrat 7,481 kg/hari dan Fosfat 1,359 kg/hari. Disimpulkan bahwa sungai masih mampu menampung beban pencemar harian Nitrat dan Fosfat.   Abstract: The Brantas River flows and crosses Malang City which has the potential to experience water quality degradation as a result of land use transfiguration and population escalation in Sub-Urban areas along the Sengkaling-Tlogomas River Section, Malang City. The research was conducted in February-March-April 2022 with a ± 4.0 km long river. This study aims to identify the existing condition of the water quality of the Brantas River to calculate the pollutant load, as well as the carrying capacity of the pollutant load on the Brantas River with Qual2Kw. The pollutant parameters studied were Nitrate and Phosphate. Activities and problems around the Brantas River that are potential for river pollution in the upstream part are agriculture, and towards the downstream are domestic residents. The results of this study ranged from 3.24-3.56 mg/l of nitrate (not exceed quality standards class II). While the phosphate levels ranged from 10.2-11.94 mg/l (over quality standards class II). The carrying capacity of the Nitrate Contaminant Load is 7.481 kg/day and Phosphate is 1.359 kg/day. It was concluded that the river is still able to accommodate the daily pollutant load of Nitrate and Phosphate