Optimasi Penggunaan Poly Aluminium Chloride dalam Menurunkan Total Suspended Solids Air Limbah Pertambangan Silica-Coal

Abstract

Tingginya nilai Total Suspended Solids (TSS) dari area tambang merupakan salah satu isu lingkungan utama yang dihadapi industri pertambangan, sehingga perlu dilakukan pengolahan menggunakan Poly aluminum chloride (PAC). Penelitian ini menentukan dosis optimum PAC melalui uji jar test pagi dan sore hari selama 30 hari sebagai representasi musim hujan yang dianalisis menggunakan regresi kuadratik. Hasil jar test dibandingkan dengan Permen LHK Nomor 5 Tahun 2022. Uji karakteristik awal diperoleh nilai TSS sebesar 931,47 mg/l (pagi) dan 941,30 mg/l (sore) belum memenuhi baku mutu, sedangkan nilai pH sebesar 6,64 (pagi) dan 6,61(sore) telah memenuhi baku mutu. Penambahan PAC menunjukkan hubungan positif terhadap penurunan TSS dengan dosis optimum sebesar 69,69 ppm (pagi) dan 134,18 ppm (sore) atau 195.131.00 ppm (pagi) dan 375.704.000 ppm pada skala konvensional. Dosis 20 ppm menunjukkan efektivitas terendah (34%), dosis 30 ppm dan 35 ppm sebesar 51% dan 58% (cukup efektif), dan efektivitas tertinggi pada dosis 50 ppm (76%). Kebutuhan PAC sebesar 3693,57 kg/hari dengan estimasi biaya Rp39.890.522/hari dan total biaya operasional mencapai Rp40.560.316/hari. Sistem pengaliran dirancang menggunakan IBC tank agitator yang terhubung dengan pompa dosing dan pipa penyalur sehingga distribusi tetap efektif pada kemiringan datar (1,44%).

The high level of Total Suspended Solids (TSS) from mining areas are a major environmental issue in mining operations, requiring treatment using Poly aluminium chloride (PAC) coagulant. This study determined the optimum PAC dose through 30-day morning and afternoon jar tests, analyzed using quadratic regression, then compared with the Ministry of Environment and Forestry Regulation No. 5 of 2022. The initial TSS values of 931.47 mg/l (morning) and 941.30 mg/l (afternoon) exceeded the standard, while pH values of 6.64 and 6.61 were within the limit. PAC addition was positively correlated with TSS reduction, with the optimum dosage determined at 69.69 ppm (morning) and 134.18 ppm (afternoon) or 195,131,000 ppm (morning) and 375,704,000 ppm (afternoon) at the conventional scale. The lowest effectiveness was observed at 20 ppm (34%), while 30 ppm and 35 ppm showed moderate effectiveness (51 and 58%). The highest effectiveness was achieved at 50 ppm (76%). The required amount of PAC was 3,693.57 kg/day with an estimated cost of IDR 39,890,522/day, resulting in a total operational cost of IDR 40,560,316/day. The distribution system employed an IBC tank agitator with a dosing pump and pipeline to ensure effectiveness under flat slope (1.44%).