A mass transport model was developed to predict the transport rate of ions within biofilms, which was experimentally verified using the fluxes of NH4^＋ and Ca^2＋ through the heterotrophic biofilms with the thickness...A mass transport model was developed to predict the transport rate of ions within biofilms, which was experimentally verified using the fluxes of NH4^＋ and Ca^2＋ through the heterotrophic biofilms with the thickness varying from 230 to 1430μm under the effect of external field in the range of-20 V/m to 60 V/m. It is found that the result predicted by the model is in agreement with the experimentally obtained one, with the error less than 5 percent for the thin biofilms. The error increases with the increase of the biofilm thickness. The transport rate of ions caused by electric migration is affected by the charges, field strength, and biofilm thickness and so on.展开更多
A flexible fibre biofilm reactor was developed for treatment of organic wastewaters.The hydrodynamic characteristics and mass transfer coefficients of oxygen were studied and compared with those of the conventional ac...A flexible fibre biofilm reactor was developed for treatment of organic wastewaters.The hydrodynamic characteristics and mass transfer coefficients of oxygen were studied and compared with those of the conventional activated sludge processes.Tracer experiments were performed to obtain the residence time distributions of the reactors.The results indicated that both reactors could be treated as mixed flow reactors.The effects of flow rates of water and air on the overall mass transfer coefficient of oxygen were investigated,and the correlations between the mass transfer coefficient and the ratio of flow rates were obtained.Compared to the conventional activated sludge reactor,the mass transfer coefficients in the flexible fibre reactor were similar to but slightly lower,and less sensitive to the variation in the ratio of flow rates.It indicated that the fibre packing in the reactor hindered the oxygen transfer to some extent.展开更多
以连续流产氢为目标,采用高透光性弥散光纤作为导光介质和光合细菌吸附成膜的载体,构造了环流型光纤生物膜制氢反应器。在实验研究的基础上,根据传质原理和Monod生化反应动力学建立了描述连续流反应器中底物传输和降解的二维数学模型。...以连续流产氢为目标,采用高透光性弥散光纤作为导光介质和光合细菌吸附成膜的载体,构造了环流型光纤生物膜制氢反应器。在实验研究的基础上,根据传质原理和Monod生化反应动力学建立了描述连续流反应器中底物传输和降解的二维数学模型。以强化底物传输和提高底物降解效率为目标,对反应器的实际操作参数进行了优化。研究结果表明,反应器的底物传输特性对反应器的底物降解效率有显著影响。反应器的底物降解效率随进口底物质量浓度的增加呈现先增大后减小的趋势。反应器的底物降解效率随流速的增加呈现逐渐减小的趋势。当反应器的进口底物质量浓度为10 g/L,流速为100 m L/h时,底物消耗速率最大,底物降解效率达到43.5%。合理地控制反应器中的底物传输使得生物膜区域具有适合的底物质量浓度分布,是维持反应器较高底物降解效率的有效途径。展开更多
基金The National Natural Science Foundation of China (No. 40506028 30270258) the Encouraging Foundation for Outstanding YouthScientists of Shandong Province (No. 03BS120) and the China Postdoctoral Science Foundation (No. 2005037237)
文摘A mass transport model was developed to predict the transport rate of ions within biofilms, which was experimentally verified using the fluxes of NH4^＋ and Ca^2＋ through the heterotrophic biofilms with the thickness varying from 230 to 1430μm under the effect of external field in the range of-20 V/m to 60 V/m. It is found that the result predicted by the model is in agreement with the experimentally obtained one, with the error less than 5 percent for the thin biofilms. The error increases with the increase of the biofilm thickness. The transport rate of ions caused by electric migration is affected by the charges, field strength, and biofilm thickness and so on.
文摘A flexible fibre biofilm reactor was developed for treatment of organic wastewaters.The hydrodynamic characteristics and mass transfer coefficients of oxygen were studied and compared with those of the conventional activated sludge processes.Tracer experiments were performed to obtain the residence time distributions of the reactors.The results indicated that both reactors could be treated as mixed flow reactors.The effects of flow rates of water and air on the overall mass transfer coefficient of oxygen were investigated,and the correlations between the mass transfer coefficient and the ratio of flow rates were obtained.Compared to the conventional activated sludge reactor,the mass transfer coefficients in the flexible fibre reactor were similar to but slightly lower,and less sensitive to the variation in the ratio of flow rates.It indicated that the fibre packing in the reactor hindered the oxygen transfer to some extent.
文摘以连续流产氢为目标,采用高透光性弥散光纤作为导光介质和光合细菌吸附成膜的载体,构造了环流型光纤生物膜制氢反应器。在实验研究的基础上,根据传质原理和Monod生化反应动力学建立了描述连续流反应器中底物传输和降解的二维数学模型。以强化底物传输和提高底物降解效率为目标,对反应器的实际操作参数进行了优化。研究结果表明,反应器的底物传输特性对反应器的底物降解效率有显著影响。反应器的底物降解效率随进口底物质量浓度的增加呈现先增大后减小的趋势。反应器的底物降解效率随流速的增加呈现逐渐减小的趋势。当反应器的进口底物质量浓度为10 g/L,流速为100 m L/h时,底物消耗速率最大,底物降解效率达到43.5%。合理地控制反应器中的底物传输使得生物膜区域具有适合的底物质量浓度分布,是维持反应器较高底物降解效率的有效途径。
