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研究论文

Basic research on the bioremediation of p,p'-DDT contaminated sediment by adding short chain organic substrate

摘要：考察了辽河沉积物中p,p'-DDT在无外加碳源和外加乳酸钠或丙酸钠情况下的缺氧生物降解行为、降解过程中体系的pH变化,并测定了p,p'-DDT的主要缺氧降解产物及其浓度变化.结果发现,p,p'-DDT的缺氧脱氯行为符合准一级反应动力学;无外加碳源,DDT的缺氧脱氯降解有近一个月的滞后期,降解速率为k_(无碳源)=0.0082d^-1;而外加碳源物质,大大缩短了DDT缺氧脱氯降解的滞后,降解速率分别为k_(乳酸钠)=0.0917d^-1,k_(丙酸钠)=0.1023d^-1.而且,p,p'DDT的缺氧还原脱氯行为主要发生在体系中pH上升的阶段.p,p'-DDT缺氧生物降解的主要产物是p,p'DDD,并有少量的p,p'DDE产生;p,p'DDD在后期有降解.

Abstract：The anaerobic dechlorination of p,p' DDT (2,2 bis(p-chlorophenyl) 1,1,1 trichlorothane) in the Liao River sediment under three conditions, simulating natural condition of the Liao River sediment, receiving sodium lactate or sodium propionate as carbon source, were investigated. Under the three conditions, the anaerobic dechlorination of p,p' DDT followed pseudo first order kinetics; however, the extents and rates of dechlorination were different, even the original concentration of p,p' DDT were the same. With the existence of sodium lactate or sodium propionate, the acclimation period was shortened obviously and the anaerobic dechlorination rate were improved to 0.0917 d^-1 and 0 1023 d^-1, respectively. While the acclimation period was almost one month, the dechlorination rate was 0.0082 d^-1 without additional organic substrate. The anaerobic dechlorination of p,p' DDT mostly happened during the period of pH rising, under the circumstance of sodium lactate or sodium propionate existing the faster pH increased, the faster p,p' DDT dechlorinated, which indicated that the existence with short chain organic substrate supplied sufficient donors for the dechlorination process. The main product of p,p' DDT anaerobic dechlorination was p,p' DDD, which transformed to other substance in the later phase. In addition, p,p' DDE was produced as a minor product.