Experimental soil matrix, vortex and oil skimming technology as a tertiary treatment of wastewater effluent

Abstract

Water is a necessary resource that must be carefully managed. Hazardous chemicals are produced with increased industrial activities and contamination has been detrimental to both people and the environment. An experimental investigation was performed to evaluate the efficiency of vortex technology, soil matrices, and oil skimmer separately for combination as a tertiary wastewater treatment in the design of a phytoremediation system. The objective of the study is to evaluate the performance of each component in removing oil and grease, reducing the concentration of ammonia, nitrate, and phosphate; quality control measures for dissolved oxygen, total dissolved solids, and chemical oxygen demand. One-way ANOVA, kinetics analysis, and adoption isotherm analysis were applied to determine the significance of the parameters. Analysis of results for the oil skimmer exhibited an efficiency of 96% in removing oil and grease after 5 hours of treatment. The vortex technology results were fluctuating with percentage removal of nitrates at 11% while ammonia with an initial concentration of 5.24 mg/L was reduced to 4.12 mg/L. Phosphate decreased after treatment from an initial of 0.87 mg/L to 0.809 mg/L. The analysis of pollutant concentration in the soil matrix after a 5-day period indicated a greater efficiency compared to the vortex technology in the removal of ammonia and phosphate. The ammonia concentration decreased from 18.7 mg/L and 21.4 mg/L to <0.1 mg/L. Similarly, phosphate concentration decreased from 15.5 mg/L to 1.13 mg/L and from 32.5 mg/L to 0.948 mg/L. The research finding underscores the efficiency of the soil matrix in removing ammonia and phosphate but recommends the need for additional intervention to lower nitrate. Overall, the three technologies showed potential and greater efficiencies in mitigating wastewater streams resulting in a notable reduction in oil and pollutant concentrations.