Kehadiran Logam-Logam Berat (Pb, Cd, Cu, Zn) Pada Air dan Sedimen Sungai Lowatag, Minahasa Tenggara - Sulawesi Utara (The Occurrence of Heavy Metals (Pb, Cd, Cu, Zn) on Water and Sediment in the River Lowatag, Southeast Minahasa - North Sulawesi)

Abstract

Abstrak Kualitas air sungai yang baik dibutuhkan oleh makhluk hidup untuk keberlanjutan kehidupannya. Kehadiran logam-logam berat di air dan sedimen dapat menurunkan kualitas air sungai. Penelitian ini bertujuan menganalisis kehadiran logam-logam berat timbal (Pb), kadmium (Cd), tembaga (Cu) dan seng (Zn) di air dan sedimen Sungai Lowatag. Penelitian ini menggunakan metode purposive sampling pada tiga stasiun yang tersebar dari hulu ke hilir. Pengambilan sampel sedimen dilakukan secara komposit di tiap stasiun. Sampel air diulang sebanyak tiga kali di tiap stasiun. Kehadiran logam berat-logam  berat  pada sedimen dengan konsentrasi berbeda-beda yaitu Cu berturut-turut dari Stasiun I, II dan III yaitu 13; 17 dan 13 mg/kg dan Zn yaitu 73; 48 dan 56 mg/kg. Kehadiran logam berat Pb di sedimen dari Stasiun I, II dan III yaitu 28; 19,1 dan 28,2 mg/kg masih di bawah Nilai Ambang Batas (NAB) menurut RNO/1981 sebesar 10 mg/kg – 70 mg/kg. Kehadiran logam berat Cd berturut-turut 3,83;  2,69 dan 4,03 mg/kg telah melampaui NAB menurut RNO/1981 (0,1 mg/kg – 2,0 mg/kg). Kehadiran logam-logam berat Pb, Cd, Cu, dan Zn di air masih di bawah NAB menurut PP No.82/2001. Kata-kata kunci: logam berat, kualitas air, sedimen, Sungai Lowatag, Sulawesi Utara AbstractThe qualified river water is required by organisms for their sustainability. The occurrence of heavy metals in surface water and sediments can degrade the quality of river water. The aim of this study was to analyze the occurrence of lead metals (Pb), cadmium (Cd), copper (Cu) and zinc (Zn) in water and sediment of Lowatag River. The purposive sampling method was applied to survey three stations from upstream to downstream. Sediment sampling was collected compositely at each station. Water samples were collected three times in each station. The occurrence of heavy metals in the surface sediments with different concentrations of Cu were 13; 17 and 13 mg /kg and Zn were 73; 48 and 56 mg/kg respectively from Station I, II and III. The occurrence of heavy metal Pb in the sediments of Stations I (28 mg/kg), II (19.1 mg/kg) and III (28.2 mg/kg) were below the Threshold Limit Value (TLV) according to Du Reseau National D’ Observation (RNO) year 1981 (10 mg/kg-70 mg/kg). The occurrence of heavy metal Cd in the sediments of Stations I (3.83 mg/kg), II (2.69 mg/kg) and III (4.03 mg/kg) were exceeded TLV according to RNO/1981 (0.1 mg/kg-2.0 mg/kg). The occurrence of heavy metals Pb, Cd, Cu, and Zn in water were still in the standard range of Indonesia Government Regulation No.82 year 2001.Key words: heavy metals, water quality, sediment, Lowatag River, North Sulawesi