Ex situ remediation of polluted soils by absorptive polymers, and a comparison of slurry and two-phase partitioning bioreactors for ultimate contaminant degradation

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• 作者：M. Concetta Tomei ; Domenica Mosca Angelucci ; M. Cristina Annesini ; Andrew J. Daugulis
• 关键词：Ex situ soil bioremediation ; Absorptive polymers ; Two-phase partitioning bioreactors ; Slurry bioreactors ; Xenobiotics ; Polymer bioregeneration
• 刊名：Journal of Hazardous Materials
• 出版年：15 November, 2013
• 年：2013
• 卷：262
• 期：Complete
• 页码：31-37
• 全文大小：1135 K

文摘

The present study has provided a comparison between a conventional m>ex situm> method for the treatment of contaminated soil, a soil slurry bioreactor, with a novel technology in which a contaminant is rapidly and effectively removed from the soil by means of absorptive polymer beads, which are then added to a two-phase partitioning bioreactor (TPPB) for biodegradation of the target molecule. 4-nitrophenol (4NP) was selected as a model contaminant, being representative of a large class of xenobiotics, and the DuPont thermoplastic Hytrel鈩?8206 was utilized for its extraction from soil over ranges of soil contamination level, soil moisture content, and polymer:soil ratios. Since the polymers were able to rapidly (up to 77% and 85% in 4 and 24 h respectively) and selectively remove the contaminant, the soil retained its nutrient and microflora content, which is in contrast to soil washing which can remove these valuable soil resources. After 4 h of reaction time, the TPPB system demonstrated removal efficiency four times higher (77% m>vsm> 20%) than the slurry system, with expected concomitant savings in time and energy. A volumetric removal rate of 75 mg4NP h^鈭? L^鈭? was obtained in the TPPB, significantly greater than the value of 1.7 obtained in the slurry bioreactor. The polymers were readily regenerated for subsequent reuse, demonstrating the versatility of the polymer-based soil treatment technology.