Remediation and optimization of petroleum hydrocarbons degradation in contaminated water using alkaline activated persulphate

This study investigated the characterization of Nigerian crude oil using gas chromatography-mass spectrometry (GC-MS) and the efficiency of alkaline activated sodium persulphate in degrading petroleum hydrocarbons in crude oil-polluted water. Hydrocarbons (aliphatics and aromatics), non-hydrocarbons, and other constituents were characterized in crude oil samples. The ratio of hydrocarbons:non-hydrocarbons/others and aliphatics: aromatics is 86:14 and 45:55, respectively. Alkylated benzenes, toluene, o-xylene, fluorene, and naphthalenic compounds were the most common aromatic compounds. The majority of aliphatic compounds were n-alkanes and cyclic hydrocarbons, including cyclohexane and heptylcyclohexane. Degradation experiments were performed with different initial concentrations of sodium persulphate (0.3 M, 0.5 M and 0.7 M) with sodium hydroxide as an activator. Runs were carried out within 8 days. The total petroleum hydrocarbons (TPH) extraction was carried out and analyzed using gas chromatography flame ionization detector (GC-FID). From an initial TPH concentration of similar to 137 mg L-1 in water, near-complete degradation was achieved with 0.3 and 0.5 M oxidant dosage. With 0.7 M sodium persulphate, 76% TPH was degraded within 8 days. Radical quenching using sodium thiosulphate showed that the addition of the scavenger resulted in negligible changes in TPH concentration preand post-degradation using all three oxidant dosages. Thus, alkaline activated persulphate is effective for the remediation of petroleum hydrocarbon contamination.

Automated summary

This study characterized Nigerian crude oil using GC-MS and investigated the efficiency of alkaline activated sodium persulphate in degrading petroleum hydrocarbons. The research found that the alkaline activated persulphate was effective in degrading petroleum hydrocarbons in crude oil-polluted water.