Department of Chemical Engineering, G H Patel College of Engineering and Technology, Vallabh Vidyanagar, Gujarat 399120, India.
Environ Sci Pollut Res Int. 2011 May;18(4):534-46. doi: 10.1007/s11356-010-0426-8. Epub 2010 Dec 9.
Regeneration of spent activated carbon assumes paramount importance in view of its economic reuse during adsorptive removal of organic contaminants. Classical thermal, chemical, or electrochemical regeneration methods are constrained with several limitations. Microbial regeneration of spent activated carbon provides a synergic combination of adsorption and biodegradation.
Microorganisms regenerate the surface of activated carbon using sorbed organic substrate as a source of food and energy. Aromatic hydrocarbons, particularly phenols, including their chlorinated derivatives and industrial waste water containing synthetic organic compounds and explosives-contaminated ground water are the major removal targets in adsorption-bioregeneration process. Popular mechanisms of bioregeneration include exoenzymatic hypothesis and biodegradation following desorption. Efficiency of bioregeneration can be quantified using direct determination of the substrate content on the adsorbent, the indirect measurement of substrate consumption by measuring the carbon dioxide production and the measurement of oxygen uptake. Modeling of bioregeneration involves the kinetics of adsorption/desorption and microbial growth followed by solute degradation. Some modeling aspects based on various simplifying assumptions for mass transport resistance, microbial kinetics and biofilm thickness, are briefly exposed.
Kinetic parameters from various representative bioregeneration models and their solution procedure are briefly summarized. The models would be useful in predicting the mass transfer driving forces, microbial growth, substrate degradation as well as the extent of bioregeneration.
Intraparticle mass transfer resistance, incomplete regeneration, and microbial fouling are some of the problems needed to be addressed adequately. A detailed techno-economic evaluation is also required to assess the commercial aspects of bioregeneration.
考虑到在吸附去除有机污染物过程中经济地重复使用，再生活性炭的再生具有极其重要的意义。经典的热、化学或电化学再生方法受到多种限制。微生物再生废活性炭提供了吸附和生物降解的协同组合。
微生物利用吸附的有机底物作为食物和能源来再生活性炭的表面。芳香烃，特别是酚类，包括其氯化衍生物以及含有合成有机化合物和爆炸物污染的地下水的工业废水，是吸附-生物再生过程中主要的去除目标。生物再生的流行机制包括外酶假说和吸附解吸后的生物降解。可以通过直接测定吸附剂上的底物含量、通过测量二氧化碳生成间接测量底物消耗以及通过测量耗氧量来定量生物再生的效率。生物再生的建模涉及吸附/解吸和微生物生长随后的溶质降解的动力学。简要介绍了基于传质阻力、微生物动力学和生物膜厚度的各种简化假设的一些建模方面。
简要总结了各种代表性生物再生模型的动力学参数及其求解过程。这些模型将有助于预测传质驱动力、微生物生长、底物降解以及生物再生的程度。
需要充分解决颗粒内传质阻力、不完全再生和微生物污垢等问题。还需要进行详细的技术经济评估，以评估生物再生的商业方面。
