title: Multivariate optimization for the simultaneous bioremoval of BTEX and chlorinated aliphatic hydrocarbons by Pseudomonas plecoglossicida.
abstract: This study aimed to evaluate the effects of some major parameters on the cometabolic removal of cis-1,2-dichloroethylene (cis-DCE) and trichloroethylene (TCE), mixed with benzene, toluene, ethylbenzene, and xylenes, by an indigenous bacterial isolate Pseudomonas plecoglossicida. Such statistical methodologies as hierarchical cluster analysis heat map and principal component analysis were applied to better evaluate the effects of major parameters (soil pH, temperature, moisture, and cis-DCE/TCE concentrations) on the biological process. The bioremoval experiments were carried out in microcosms containing soil slurry, and the headspace concentrations of contaminants were analyzed by gas chromatography. The optimal bioremoval conditions for the mixture were soil water content >110%, pH 8-9, and temperature 15-20°C, while the cis-DCE/TCE concentration did not significantly affect the mixture bioremoval within the tested range (∼10mg per kg soil). Under the optimal conditions, benzene (97.7%), toluene (96.3%), and ethylbenzene (89.8%) were almost completely removed, while cis-DCE (24.5%), TCE (29.0%), m,p-xylene (36.3%), and o-xylene (29.6%) showed lower removal efficiencies. The obtained results would help to better design a remediation technology to be applied to the sites contaminated with mixed wastes, and the statistical methodologies used in this study appear to be very efficient and could serve as a template for optimization.
authors.affiliation: College of Natural Resources and Environmental Science, South China Agricultural University, Guangzhou 510642, China; Department of Civil and Environmental Engineering, Faculty of Science and Technology, University of Macau, Macau SAR 999078, China; Key Laboratory of the Ministry of Land and Resources for Construction Land Transformation, South China Agricultural University, Guangzhou 510642, China; Guangdong Provincial Key Laboratory of Land Use and Consolidation, South China Agricultural University, Guangzhou 510642, China.
authors.forename: Junhui
authors.initials: J
authors.lastname: Li
authors.affiliation: Department of Civil and Environmental Engineering, Faculty of Science and Technology, University of Macau, Macau SAR 999078, China.
authors.forename: Renata Alves
authors.initials: RA
authors.lastname: de Toledo
authors.affiliation: Department of Civil and Environmental Engineering, Faculty of Science and Technology, University of Macau, Macau SAR 999078, China. Electronic address: hjshim@umac.mo.
authors.forename: Hojae
authors.initials: H
authors.lastname: Shim
mesh_terms: D000332:Aerobiosis; D001554:Benzene / Q000032:analysis; D001555:Benzene Derivatives / Q000032:analysis*; D001673:Biodegradation, Environmental; D016000:Cluster Analysis; D006843:Hydrocarbons, Chlorinated / Q000032:analysis*; D008962:Models, Theoretical; D025341:Principal Component Analysis; D011549:Pseudomonas / Q000378:metabolism*; D012989:Soil Pollutants / Q000032:analysis*; D014050:Toluene / Q000032:analysis; D014992:Xylenes / Q000032:analysis
chemical_list: D001555:Benzene Derivatives; D006843:Hydrocarbons, Chlorinated; D012989:Soil Pollutants; D014992:Xylenes; D014050:Toluene; D001554:Benzene; C004912:ethylbenzene
keywords: Aerobic bioremoval; Hierarchical cluster analysis; Mixture; Optimization; Principal component analysis