Analisis Chemical Oxygen Demand (COD) Pada Pengolahan Air Limbah (Wastewater Treatment Plant) dengan Metode Spektrofotometri UV-Visible

Abstract

Background: Wastewater from the oleochemical industry contains high levels of organic compounds, which pose a potential threat to the environment. Chemical Oxygen Demand (COD) is an important parameter for evaluating wastewater quality. COD testing using the UV-Visible spectrophotometry method with a closed reflux principle, based on SNI 6989.2:2019, offers an efficient and sensitive alternative for analyzing wastewater quality. Objective: This study aims to analyze the effectiveness of the wastewater treatment system at PT. Soci Mas in reducing COD levels and to evaluate its compliance with the wastewater quality standards of the oleochemical industry. Method: The testing was carried out using the UV-Visible spectrophotometry method at a wavelength of 420 nm for low-concentration samples and 600 nm for high-concentration samples. The tested samples included D1401, D1403, D1407, D1408A, D1408B, and D1408C1. Results: COD levels in samples D1401, D1403, and D1407 were 3089 ppm, 3160 ppm, and 3035 ppm respectively, meeting the required thresholds of <6000–5000 ppm. Samples D1408A (907 ppm), D1408B (900 ppm), and D1408C1 (760 ppm) were compared with the maximum limit of 900 ppm. Most samples met the standard, except D1408A, which exceeded the limit and requires retesting. Conclusion: The UV-Visible spectrophotometry method is effective for analyzing COD levels. In general, the wastewater treatment system at PT. Soci Mas complies with the quality standards for oleochemical industry wastewater.