Distribusi Logam Berat (Pb dan Cd) Sedimen di Perairan Pantai Loji Pekalongan, Jawa Tengah

Abstract

Sungai Loji merupakan salah satu sungai di Kabupaten Pekalongan, Jawa Tengah, yang dipengaruhi oleh berbagai aktivitas manusia seperti industri, perikanan, dan pemukiman. Berbagai aktivitas tersebut dapat menghasilkan limbah, salah satunya adalah logam berat, Adanya aliran air dari daratan menyebabkan sebagian logam berat dapat masuk ke laut. Penelitian ini bertujuan  menentukan dan memetakan pola distribusi kandungan logam berat Timbal (Pb) dan Cadmium (Cd) di sedimen dasar dan keterkaitannya terhadap prosentase ukuran butir dan bahan organik sedimen. Pengambilan sampel pada 24 Agustus 2021. Analissis logam berat Pb dan Cd sedimen menggunakan metode SNI 4819:2013, bahan organik menggunakan loss of igniation (LOI), ukuran butir melalui pengayakan dan pemipetan. Hasil penelitian menunjukkan konsentrasi Pb antara 3,708 - 6,149 mg/kg dan Cd dibawah deteksi limit (≤0,003 mg/kg). Pola distribusi logam Pb tidak dipengaruhi oleh ukuran butir, namun dipengaruhi oleh prosentase bahan organik sebesar 43%. Konsentrasi bahan organik berada pada kisaran 28,5% - 53,29%. Konsentrasi logam berat sedimen masih berada di bawah baku mutu ANZECC dan perairan pantai Loji, Pekalongan ini masih dalam kondisi alami atau belum tercemar.

One of the rivers in Pekalongan Regency, Central Java, Loji River is affected by various human activities such as industry, fisheries, and settlements. These activities can produce waste, one of which is heavy metals. The existence of runoff from land causes some heavy metals to reach the marine environment. This study aims to determine and mapping the distribution patterns of the heavy metal content of Lead (Pb) and Cadmium (Cd) in bottom sediments and their relationship to the percentage of grain size and organic matter of sediments. Sampling was on 24 August 2021. Analysis of sediment Pb and Cd using the SNI 4819: 2013 method, organic matter using loss of igniation (LOI), grain size through sieving and pipetting. The results showed Pb concentrations between 3.708 - 6.149 mg/kg and Cd concentration below the detection limit (≤0.003 mg/kg). The distribution pattern of Pb metal was not influenced by grain size, but was influenced by the percentage of organic matter by 43%. The concentration of organic matter is in the range of 28.5% - 53.29%. The concentration of Pb and Cd in the sediment is still below the ANZECC quality standard, so the coastal waters of Loji, Pekalongan are still in an unpolluted condition.