Sebaran Fosfor Anorganik Partikulat (PIP) di Muara Sungai Banjir Kanal Barat Semarang

Abstract

Muara Sungai Banjir Kanal Barat Semarang merupakan wilayah yang berpotensi mengalami eutrofikasi akibat buangan limbah rumah tangga dan industri. Sebagian besar penelitian sebelumnya lebih berfokus pada fosfor dalam sedimen dasar dan fosfat terlarut, sedangkan kandungan fosfor anorganik dalam total suspended solid (TSS) di perairan muara dan laut menerima lebih sedikit perhatian. Tujuan dari penelitian ini adalah mengetahui sebaran fosfor anorganik partikulat (PIP) di perairan sekitar muara Sungai Banjir Kanal Barat Semarang. Pengambilan sampel dilakukan pada lapisan permukaan (kedalaman 0,5 m). Analisis TSS dilakukan dengan metode gravimetri. Ekstraksi asam PIP dilakukan berdasarkan metodologi ekstraksi konvensional, menggunakan 1 M HCl, diikuti oleh prosedur untuk menurunkan keasaman dan dianalisis dengan metode spectrophotometric phosphomolybdenum blue pada panjang gelombang 880 nm. Konsentrasi PIP yang didapatkan berkisar antara 0,42 µmol/g – 1,28 µmol/g dengan nilai rata-rata sebesar 0,54 µmol/g. Sebaran PIP dipengaruhi oleh arus pasang surut, total suspended solid (TSS) dan salinitas. Sebaran PIP dominan ke arah barat – barat laut karena pengaruh arus pada saat pasang menuju surut. Konsentrasi PIP menurun seiring berkurangnya konsentrasi TSS dan meningkatnya nilai salinitas.

Banjir Kanal Barat estuary is an area that has the potential to experience eutrophication due to household and industrial waste disposal. Most previous research has focused more on phosphorus in basic sediments and dissolved phosphate, whereas the inorganic phosphorus content in total suspended solid (TSS) in estuarine and marine waters received less attention. The purpose of this study was to determine the distribution of particulate inorganic phosphorus (PIP) in the waters around the Banjir Kanal Barat estuary. Sampling was carried out on the surface layer (0.5 m depth). TSS analysis was performed using the gravimetric method. PIP acid extraction was carried out based on conventional extraction methodology, which required 1 M HCl, followed by a procedure to reduce acidity and analyzed by spectrophotometric phosphomolybdate blue method at a wavelength of 880 nm. PIP concentrations obtained ranged from 0,42 µmol/g – 1,28 µmol/g with an average value of 0.54 µmol/g. Distribution of PIP is influenced by tidal currents, total suspended solid (TSS) and salinity. Distribution of PIP is dominant to west – northwest direction due to the influence of currents at ebb current. PIP concentration decreases with decreasing TSS concentration and increasing salinity.