Physicochemical Evaluation of Palm Oil Mill Wastewater and Its Environmental Health Impacts in Umuapu, Ohaji, Imo State, Nigeria

Palm oil mill wastewater (POMW) represents a significant environmental challenge in many tropical agro-industrial regions, including rural Southeastern Nigeria. This study presents a comprehensive physicochemical evaluation of POMW from artisanal mills in Umuapu, Ohaji, Imo State, assessing key water quality parameters such as pH, turbidity, electrical conductivity (EC), total dissolved solids (TDS), total suspended solids (TSS), biochemical oxygen demand (BOD), and chemical oxygen demand (COD). Samples collected over six months revealed substantial deviations from Federal Ministry of Environment (F.MEnv.) and World Health Organization (WHO) permissible limits, with notably high organic and inorganic pollutant loads. pH values ranged from slightly acidic to highly alkaline (6.91–10.62), while turbidity, TDS, and TSS consistently exceeded regulatory thresholds, indicating heavy particulate and dissolved contaminant presence. Elevated BOD (288–389 mg/L) and COD (790–1200 mg/L) values suggest severe organic pollution and insufficient treatment of effluents, posing risks such as aquatic oxygen depletion, eutrophication, and ecological imbalance. Spatial variability across sampling sites reflects heterogeneous operational practices and inconsistent waste management. Complementary environmental health surveys within the affected community documented frequent waterborne illnesses, underscoring the public health implications of untreated POMW discharge. The study highlights the urgent need for tailored, integrated treatment technologies and strengthened regulatory enforcement to mitigate environmental and health risks. Furthermore, it advocates for adaptive, location-specific discharge standards and community engagement through education and monitoring programs. This investigation provides a critical empirical baseline for POMW pollution in Southeastern Nigeria, employing an integrated analytical and socio-environmental approach to inform sustainable management strategies and policy formulation in similar tropical agro-industrial contexts.