Impact of Rainfall and Meteorological Factors on Wastewater Treatment in Palm Oil Mills

Abstract

This study investigates the influence of rainfall and meteorological factors on wastewater treatment performance in a palm oil mill, recognizing that CPO processing requires large volumes of water and generates complex liquid waste. The objective is to analyze how rainfall affects wastewater volume, characteristics, and treatment efficiency, and to evaluate the effects of temperature, humidity, and wind speed on the performance of the wastewater treatment plant (WTP). A case study approach was applied at a palm oil mill in Nagan Raya Regency. Primary data were collected by sampling wastewater at critical points in the open pond system and WTP unit, while secondary data were obtained from operational reports and meteorological records from the Cut Nyak Dhien Meteorological Station. Laboratory analysis was conducted to measure parameters such as BOD, COD, TSS, pH, and oil and grease content, aiming to assess the fluctuation in waste quality influenced by weather variables. The study also reviewed the management of hazardous emissions—methane, CO₂, ammonia, and hydrogen sulfide—to evaluate their environmental impact. Results indicated that increased rainfall led to higher wastewater volumes and altered pollutant concentrations, reducing treatment efficiency. Other meteorological factors, particularly temperature and wind speed, also influenced the biological decomposition process in open ponds. These findings highlight the need for adaptive treatment strategies to enhance resilience, improve system performance, and support sustainable operations in the palm oil industry.