Zilouei Hamid, Guieysse Benoit, Mattiasson Bo
Department of Biotechnology, Lund University, P.O. Box 124, 22100 Lund, Sweden.
Chemosphere. 2008 Aug;72(11):1788-94. doi: 10.1016/j.chemosphere.2008.04.035. Epub 2008 Jun 13.
An organic-aqueous two-liquid-phase partitioning system was developed to degrade high concentrations of pentachlorophenol (PCP). Dioctyl sebacate was selected among 12 non-aqueous phases as the most suitable solvent to control the delivery of PCP to the aqueous phase for being non-biodegradable and biocompatible. In shake-flask experiments, the two-phase system was able to support the removal of 1g PCP l(-1) of total liquid phase. The performance of the two-liquid phase partitioning system (TLPPS) in shake-flask was evaluated under different conditions. At the initial biomass concentrations of 7, 25, and 58 mg dry weight l(-1), the volumetric removal rates of PCP obtained were 25.7+/-0.5, 32.1+/-0.1, and 39.3+/-2.9 mg PCP l(-1)h(-1), respectively. Higher performance was observed at lower organic-aqueous phase ratios (16% and 28%) than higher ones (37% and 44%). In a 2-l TLPPS, the degradation of 10 g PCP was completed in less than 100 h at a total volumetric rate of 142 mg l(-1) h(-1). Kinetics study using Monod model showed that compared to monophasic systems, the biphasic system significantly enhanced the maximum specific growth rate and PCP removal rate. Results of this biphasic system showed no accumulation of unknown by-product(s) which has been reported for physical-pretreatment or high-performance biphasic systems of PCP degradation.
开发了一种有机-水双液相分配系统来降解高浓度的五氯苯酚(PCP)。在12种非水相中,癸二酸二辛酯被选为最合适的溶剂,因为它不可生物降解且具有生物相容性,能够控制PCP向水相的释放。在摇瓶实验中,该双相系统能够去除总液相中1g/L的PCP。在不同条件下评估了摇瓶中双液相分配系统(TLPPS)的性能。在初始生物量浓度分别为7、25和58mg干重/L时,获得的PCP体积去除率分别为25.7±0.5、32.1±0.1和39.3±2.9mg PCP/L·h-1。在较低的有机-水相比(16%和28%)下观察到的性能高于较高的相比(37%和44%)。在2L的TLPPS中,以142mg/L·h-1的总体积速率,在不到100小时内完成了10g PCP的降解。使用Monod模型的动力学研究表明,与单相系统相比,双相系统显著提高了最大比生长速率和PCP去除率。该双相系统的结果表明,没有出现物理预处理或PCP降解的高性能双相系统中报道的未知副产物积累。