Evaluation of Contaminated Irrigation Water Near The Metal Coating Industry

The irrigation water in Plosowahyu Village, Lamongan, East Java, Indonesia, was predicted to be low quality due to pollution from the metal coating industry. The purpose of this study was to evaluate the physicochemical quality of irrigation water. Water sampling was carried out in October 2021 at the irrigation canals, which served as outlets for the disposal of metal coating industrial waste. Several water parameters were measured, including the value of pH, conductivity, total suspended solids (TSS), dissolved oxygen (DO), biochemical oxygen demand (BOD), nitrate, orthophosphate, the concentration of copper (Cu), lead (Pb) and zinc (Zn). The parameter measurements were conducted in the Ecology and Chemistry Laboratory of Universitas Brawijaya. The results of this study indicated that the irrigation water had been polluted with organic matter and heavy metals. This pollution was shown by the value of BOD 15.8 mg/L, N Total 88.24 mg/L, P Total 39.34 mg/L, Cu 2.81 mg/L, Pb 101.47 mg/L, and Zn 18.82 mg/L that did not meet the quality standards according to Indonesian government regulations No. 22/2021. Other parameters include TSS 6.78 mg/L, the conductivity of 0.239 S/m, DO 4.98 mg/L, pH 7.25, nitrate 0.194 mg/L, and orthophosphate 3.462 mg/L have met the government quality standards set for agricultural use. The highest heavy metal content is lead, so further research is needed to reduce the lead level through phytoremediation technology.