Comparative Evaluation of Adsorption and Biodegradation Mechanisms in PMS-Contaminated Water Using Clay and Banana-Based Adsorbents

Abstract

The contamination of aquatic environments by petroleum hydrocarbons remains a major environmental challenge due to its adverse effects on ecosystems and human health. This study investigated the role of clay soil and banana-based adsorbent mixtures in the mitigation of Premium Motor Spirit (PMS)-contaminated aquatic systems, with particular emphasis on the contribution of hydrocarbon-utilizing bacteria (HUB) and adsorption mechanisms. Physicochemical properties of the clay soil, including particle size distribution, pH, conductivity, chlorides, sulphates, nitrogen, phosphorus, ferric oxide, silicon oxide, organic matter, organic carbon, and total hydrocarbon content, were determined using standard analytical procedures. Soil pH was measured using a calibrated pH meter, while total petroleum hydrocarbon (TPH) concentrations were determined through solvent extraction, sample clean-up, and analytical quantification procedures. The experimental setup involved the introduction of different clay-banana adsorbent mixtures into PMScontaminated freshwater and saltwater systems. Hydrocarbon-utilizing bacterial populations were monitored over time to evaluate their contribution to hydrocarbon degradation. The results revealed only slight increases in HUB populations throughout the experimental period. Growth patterns exhibited the typical microbial phases of adaptation, exponential growth, stationary phase, and decline phase. However, the observed microbial activity had minimal influence on TPH reduction. The reduction in hydrocarbon concentration was primarily attributed to adsorption processes occurring between the contaminants and the adsorbent materials. The findings demonstrated that adsorption was the dominant mechanism responsible for the removal of petroleum hydrocarbons from contaminated media, while biodegradation by indigenous hydrocarbon-utilizing bacteria contributed only marginally. Environmental factors such as pH, nutrient availability, temperature, and salinity may have limited microbial effectiveness during the study period. The results highlight the potential application of clay soil and banana-derived adsorbents as cost-effective and  Adsorbents for PMS Removal Ozioko Fabian Chidiebere et al. environmentally sustainable materials for the remediation of petroleum-contaminated aquatic environments. Furthermore, the study provides valuable insights into the interaction between adsorption and biological processes in hydrocarbon remediation systems and supports the development of integrated approaches for environmental pollution control.