Comparative Evaluation of Physicochemical Parameter Dynamics during Crude Oil Degradation in Freshwater and Saltwater Media

Abstract

Crude oil contamination of aquatic environments presents serious ecological and environmental challenges, particularly in freshwater and marine systems. This study investigates the physicochemical behavior of crude oil degradation in freshwater and saltwater media under controlled laboratory conditions at a constant temperature of 15°C. Key physicochemical parameters—including total dissolved solids, conductivity, total hardness, sulphate, chloride, alkalinity, pH, nitrate, turbidity, oil and grease, dissolved oxygen, and iron—were monitored over increasing contact time. Results revealed slight but consistent variations in parameter concentrations with time in both media, indicating active degradation processes. Temperature was observed to play a critical role in influencing substrate availability and microbial activity, which subsequently affected degradation efficiency. Comparative analysis showed that both freshwater and saltwater systems respond differently to crude oil contamination due to variations in ionic composition and physicochemical stability. These findings highlight the importance of physicochemical monitoring in understanding petroleum hydrocarbon degradation and optimizing bioremediation strategies in aquatic environments.