厌氧条件下土壤中有机氯降解动力学模型及其参数优化──以五氯酚(PCP)为例

Kinetic modeling and parameter optimization for organochlorine degradation in anaerobic soil: A case study on pentachlorophenol(PCP)

研究厌氧条件下土壤中有机氯降解动力学模型及其参数优化方法,对阐明有机氯降解的动力学反应机制具有十分重要的理论意义。文章以厌氧条件下土壤中五氯酚(PCP)降解为例,归纳介绍了两类用于描述土壤中PCP降解动力学过程的模型:一类模型是不考虑微生物生长的基质降解模式,以一级动力学模型最有代表性,但这类模型多数情况下没有或没有完全体现环境因素对PCP降解的抑制作用;另一类模型是考虑微生物生长的基质降解模式,以Monod动力学模型使用最普遍,但这类模型只在微生物生长的指数期适用,对延迟期、稳定期和衰亡期需经扩展才可应用。logistic动力学模型可广泛用于以上两类模型,是可以近似地描述微生物经适应过程和共代谢作用而致有机氯降解的简单模型。文章还总结了有机氯降解非线性模型参数的优化方法,并对其优缺点进行了分析和比较。针对目前土壤中有机氯降解动力学模型及其参数优化研究中存在的问题,对今后的研究方向进行了展望。

Study on the kinetic modeling and parameter optimization for organochlorine degradation in anaerobic soil helps to eluci- date the kinetic mechanisms of organochlorine degradation in the environment. Here we introduce two types of kinetic models for organochlorine degradation in anaerobic soil through a case study on pentachlorophenol （PCP）. One type of the models exhibits sub- strate degradation patterns without considering microbial growth and is represented by the first-order kinetic model; in most cases, however, this kind of models does not fully reflect （or only partially reflects） the inhibitory effect of environmental factors on PCP degradation. The other type of models exhibits substrate degradation patterns by taking into consideration microbial growth and is represented by the Monod kinetic model; this type of models, however, is applicable only in the exponential phase of microbial growth and needs to be modified for application in the lag, stationary, and decline phases of microbial growth. The logistic kinetic model, which can be used widely in the above two types of kinetic models, provides a simple approach for approximately describing cometabolic degradation of organochlorine by microbial consortium after an adaptation period. Additionally, we summarize the methods for parameter optimization of nonlinear models for organochlorine degradation, and further discuss their advantages and disadvantages. Finally, we propose the research directions for studies on organochlorine degradation in soil related to kinetic model- ing and parameter optimization.