Konsentrasi Logam Berat dan Bahan Organik dalam Sedimen di Teluk Jakarta

Abstract

C-Organik dan N-Total merupakan komponen penting yang mampu mengikat logam berat seperti As, Ni, Co, dan Cr, sehingga dapat memengaruhi distribusi logam. Informasi mengenai kandungan logam tersebut dalam sedimen di Teluk Jakarta dan korelasinya dengan C-Organik dan N-Total terbatas. Penelitian ini bertujuan mengidentifikasi sumber potensial logam As, Ni, Co, dan Cr dalam sedimen di Teluk Jakarta. Sampel sedimen diambil di 6 titik pengamatan untuk analisis logam, ukuran butir sedimen, dan bahan organik. Logam diukur menggunakan ICP-OES, sedangkan fraksinasi sedimen dengan metode dry sieving dan pippeting. C-Organik diidentifikasi dengan metode Walkley-Black, sedangkan N-Total dengan metode Kjeldahl. Konsentrasi logam Co>Ni>Cr>As secara berturut-turut 9.821–19.026 ppm, 9.769–14.350 ppm, 7.901–13.482 ppm, dan 4.092–9.917 ppm. Sedimen didominasi pasir 84.69–98.35% diikuti lanau 1.14–12.42% dan lempung 0.51–2.89%. C-Organik yang terukur sebanyak 0.97–3.34% dan N-Total sebanyak 0.08–0.26%. Rasio C/N menunjukkan sumber utama bahan organik berasal dari terestrial. Sumber potensial Co dan Cr berasal dari sumber yang sama dengan bahan organik, sedangkan As dan Ni berasal dari perairan.

C-Organic and N-Total are important components capable of binding heavy metals such as As, Ni, Co, and Cr, thus affecting the distribution of metals. However, there’s limited information on these metals in Jakarta Bay sediments and their correlation with C-Org and N-Total. This study aims to identify the potential source of As, Ni, Co, and Cr in sediments of Jakarta Bay. Sediment samples from 6 sites were analyzed for metals, grain size, and organic matter. Metals were measured using ICP-OES, while sediment fractionation was performed by dry sieving and pipetting. C-Org was identified using Walkley-Black, and N-Total by Kjeldahl. Metal concentrations Co>Ni>Cr>As were 9.821–19.026 ppm, 9.769–14.350 ppm, 7.901–13.482 ppm, and 4.092–9.917 ppm, respectively. Sediments were primarily sand 84.69-98.35% followed by silt 1.14-12.42% and clay 0.51-2.89%. C-Org ranged from 0.97–3.34% and N-Total from 0.08–0.26%. C/N ratios indicates that terrestrial as primary source of organic matter. Sources of Co and Cr likely originate from the same sources as organic matter, whereas As and Ni are more likely derived from aquatic sources.