Treatment of oil well “produced water” by waste stabilization ponds: Removal of heavy metals

• Published in: Water research (Oxford) Vol. 43; no. 17; pp. 4258 - 4268
• Main Authors: Shpiner, R., Vathi, S., Stuckey, D.C.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.09.2009; Elsevier
• Subjects: Applied sciences; Biological; biological treatment; Biological uptake; cadmium; carbonates; Chemical Precipitation; chromium; Exact sciences and technology; filters; Heavy metals; Hydroxides; Irrigation; irrigation water; Metals, Heavy - isolation & purification; nickel; Oil well; Oil wells; Osmolar Concentration; Other industrial wastes. Sewage sludge; Oxidation pond; Particle Size; Petroleum; pollutants; Pollution; ponds; Precipitation; Produced water; Sand; Sewage; sulfides; Sulfides - chemistry; Wastes; wastewater irrigation; wastewater treatment; Water Pollutants, Chemical - isolation & purification; Water treatment and pollution; Precipitation; Oxidation pond; Produced water; Oil well; Biological uptake; Heavy metals; Irrigation; Nickel II; Stabilization; Waste treatment; Biological purification; Sand filter; Water well; Anaerobe; Cadmium II; Oxidation; Biological treatment; Water resources; Organic compounds; Stabilization pond; Hydrocarbon; Chemical precipitation; Heavy metal; Trace element; Biosorption; Chromium III; Waste water purification
• ISSN: 0043-1354; 1879-2448
• DOI: 10.1016/j.watres.2009.06.004

Oil well produced water (PW) can serve as an alternative water resource for restricted halotolerant agricultural purposes if the main pollutants, hydrocarbons and heavy metals, can be removed to below the irrigation standards. In this work, the potential removal of cadmium(II), chromium(III) and nickel(II) from PW by chemical precipitation in biological treatment was evaluated. Precipitation as a sulphide salt was found to be a very effective mechanism, which together with biosorption, biological metal uptake, precipitation as hydroxides and carbonates could remove heavy metals down to below irrigation standards. The existence and capability of these various mechanisms was demonstrated in the performance of a continuous artificial pond followed by intermittent sand filter, achieving removals of around 95% for nickel(II) and even higher removal rates for cadmium(II), chromium(III) from artificial PW after the installation of an anaerobic stage. The treated effluent quality was higher than that required by current European standards.