EVALUASI KINERJA INSTALASI PENGOLAHAN AIR LIMBAH PABRIK KARET PT. BKP KABUPATEN TANAH LAUT KALIMANTAN SELATAN DAN SIMULASI DAMPAK KERUSAKAN TERHADAP KUALITAS SUNGAI KARUH DENGAN QUAL2K

Muhammad Baehaqi, Dr. Dwi Siswanto

2012 | Tesis | S2 Ilmu Kimia

Telah dilakukan evaluasi terhadap kinerja IPAL untuk menurunkan kadar BOD, COD dan amonia total pada limbah cair pabrik karet PT. BKP dan simulasi dampak kerusakan IPAL terhadap penurunan kualitas air Sungai Karuh serta cara penanganannya menggunakan Model QUAL2K. Sampel air limbah IPAL diambil pada 5 macam kolam yaitu kolam penampungan awal, kolam equalisasi, kolam aerasi, kolam denitrifikasi dan saluran outlet. Parameter kualitas air yang dilibatkan dalam pemodelan meliputi: suhu, pH, DHL, TDS, TSS, DO, BOD,COD, amonia, nitrat, dan alkalinitas. Adapun parameter dampak yang dikaji yaitu BOD, COD dan amonia. Untuk validasi model yang dihasilkan, dilakukan analisis suhu, pH, DHL, TDS, TSS, DO, BOD,COD, amonia, nitrat, dan alkalinitas sampel air sungai Karuh pada 4 titik pada rentang jarak 4 km dari titik pembuangan limbah PT BKP. Hasil evaluasi terhadap kinerja IPAL PT. BKP, diketahui bahwa IPAL bekerja efektif untuk menurunkan kadar TSS (98%), BOD (97%), COD (98%) dan amonia total (90%).sebelum dialirkan ke sungai Karuh. Hasil validasi model dengan hasil pengukuran sampel air yang diambil pada 9 November 2011 menunjukkan kesesuaian yang tinggi dengan nilai statistik U untuk BOD, COD dan amonia total masing-masing sebesar 0,0979; 0,0580 dan 0,0403. Hasil simulasi dengan QUAL2K terhadap dampak kerusakan IPAL menunjukkan bahwa, apabila terjadi saat musim penghujan dengan debit 1,6 m3/s kadar COD diprediksikan mencapai 98,73 mg/L, melebihi baku mutu, sehingga diperlukan debit aliran sungai sebesar 5,4 m3/s untuk mengatasinya. Pada musim kemarau dengan debit 0,31 m3/s, kadar BOD dan COD diperkirakan mencapai 19,31 mg/L, 358,47 mg/L, keduanya melebihi baku mutu dan untuk mengatasi dampak keduanya diperlukan debit aliran sungai sebesar 4,8 m3/s.

An evaluation on the performance of wastewater treatment plant of PT. BKP Kabupaten Tanah Laut South Kalimantan to reduce levels of BOD, COD and total ammonia in the effluent of rubber factories PT. BKP has been conducted. The impact of the damage of WWTP to the decline of water quality of Karuh River as well as how to handle that impact has been simulated using QUAL2K. Wastewater samples have been collected from the initial holding pond, equalization pond, aeration pond, denitrification pond and outlet flow. Twelve water quality parameters, i.e. temperature, pH, DHL, TDS, TSS, DO, BOD, COD, ammonia, nitrate, and alkalinity has been included in the simulation. BOD, COD and ammonia were used as the indicator parameters for the impact. In order to validate the generated model, an analysis of Karuh river water samples quality parameters has been conducted at 4 points on the distance range of 4 km from the waste disposal point of PT BKP. The result of WWTP performance evaluation of PT. BKP showed that the WWTP works effectively to reduce the levels of TSS (98%), BOD (97%), COD (98%) and total ammonia (90%) before discharged into the Karuh river. Validation model based on the measurements of water quality parameters of samples taken on 9 November 2011 shows high conformity with the value of U statistics for BOD, COD and total ammonia were 0.0979, 0.0580, and 0.0403, respectively. The simulation on the WWTP damage showed that in case of rainy season with the river debit of 1.6 m3/s, the levels of COD reached 98.73 mg/L, which was exceeding the water quality standard. It need to increase the debit up to 5.4 m3/s in order to restore the water quality. In case of dry season at the river debit level of 0.31 m3/s, BOD and COD levels were estimated to reach 19.31 and 358.47 mg/L, respectively. Both parameters were exceeding the standard quality, and it was necessary to increase the river debit up to 4.8 m3/s to overcome the effects of WWTP damage on the decline of the river quality.

Kata Kunci : QUAL2K, kerusakan IPAL, kualitas air, limbah cair pabrik karet.