Evaluasi Level Toksik Logam Berat pada Air, Sedimen Tersuspensi, dan Sedimen Dasar di Sungai Winongo, D.I.Yogyakarta

Abstract

Aktivitas manusia di sekitar Sungai Winongo dapat berdampak pada kontaminasi logam berat dari limpasan permukaan dan buangan langsung. Sifat toksik pada logam perlu diperhatikan karena dapat terakumulasi dalam waktu yang lama dan merusak lingkungan. Evaluasi logam berat dapat dilakukan dengan cara pemantauan kualitas air dan kualitas sedimen untuk mengetahui tingkat pencemaran suatu perairan karena logam berat dan distribusi logam berat itu sendiri. Penelitian ini bertujuan untuk mengetahui level toksik perairan dilakukan analisis hasil dengan berbagai indeks, yaitu Faktor Risiko Ekologis (Er) dan Indeks Beban Polusi (PLI). Sampel air, sampel sedimen tersuspensi (TSS), dan sedimen pada dasar permukaan diambil pada masing-masing titik untuk diuji laboratorium menggunakan alat AAS (Atomic Absorption Spectrophotometry). Hasil analisis menunjukkan bahwa logam Cu dan Cr paling banyak ditemukan pada sedimen dasar, sedangkan logam Pb paling banyak ditemukan terlarut dalam air. Logam pada sedimen tersuspensi ditemukan sangat kecil yaitu <0,031. Konsentrasi logam pada sedimen tersuspensi tertinggi adalah 0,043 mg/L pada titik T4.  Berdasarkan perhitungan Er dan PLI, potensi risiko ekologis terhadap logam di Sungai Winongo rendah (Er<40) dan tidak terdapat polusi karena logam berat (PLI<1). Namun, analisis kualitas air menunjukkan untuk nilai Cu dan Pb melebihi baku mutu kelas 2. Penelitian ini dapat dijadikan penelitian awal dalam kajian logam berat di Sungai Winongo secara historis.

ABSTRACT

The Increase of human activities around the Winongo River can have an impact on decreasing water quality due to pollution from household and small industrial waste. Metal contamination in the aquatic environment is an environmental issue that needs attention due to its toxicity. Moreover, it can be accumulated in aquatic environments for a long time. Monitoring water quality and sediment quality is important to determine the distribution of heavy metals sources and the level of pollution in the waters. This research aims to determine the water toxicity level. An analysis of the results was carried out with various indices, which are the Ecological Risk (Er) and Pollution Load Index (PLI) in the water samples, suspended sediment samples (TSS), and sediment at the bottom of the surface will be taken at each point for laboratory testing using AAS (Atomic Absorption Spectrophotometry). The concentration of heavy metals for Cu and Cr in the surface sediment respectively was found higher than its concentration in the river water. Meanwhile, Pb contents are found higher in river water. The contents of heavy metals are found less in the suspended sediment samples. The Er and PLI shows low pollution risk and low pollution status, respectively. It indicates that the Code River was still in low pollution status for Cu, Cr, and Pb contamination. On the other hand, the water quality analysis results Cu and Pb over the Water Quality Standard for Class 2. This study may serve as a useful reference and baseline for heavy metals research in Winongo River historically.