人工湿地中沸石对铵吸附能力的生物再生研究

利用铵吸附饱和的天然斜发沸石和沙质土壤作为基质,构建了沸石柱和芦苇、菖蒲沸石人工湿地试验系统,采用曝气供氧、自然复氧、植物根系输氧以及培养系统中基质上的硝化菌群的方法,研究了铵吸附饱和的沸石在沸石柱和湿地中的生物再生过程。结果显示,沸石在湿地中再生过程符合指数模拟,在试验周期内沸石在沸石柱中再生可以用指数和线性模拟。沸石在湿地系统和沸石柱中经过1个月的再生,交换容量分别恢复到了原来的60.3%~62.6%和11.8%,3个月后分别恢复到了原来的94.6%~94.8%和38.4%。试验证明,沸石在湿地中再生比在沸石柱中再生效果好,交换容量恢复率高出约50%~63%。根据试验结果,探讨了铵吸附饱和的沸石在人工湿地中的生物再生机理,证明了饱和沸石在湿地中生物再生的可行性。

Bioregeneration process of ammonium-saturated clinoptilolite in subsurface wetland systems

The laboratory scale wetlands planted Phragmites australis and Acorus calamus and zeolite column were constructed with ammonium-saturated clinoptilolite and sandiness soils substrate.Bio-regeneration process of ammonium-saturated zeolite in planted wetlands and zeolite column was studied through aeration,natural oxygen diffusion,oxygen transfer by plant roots and substrate inoculated with sludge of nitrifying bacteria.The kinetic models for biogengeration process of zeolite were evaluated.The kinetics of zeolite bioregeneration process in wetlands are subjected to power rate law model.The power rate law model and the linear model are both suitable to the zeolite bioregeneration process in column during bioregeneration period.After one month bioregenerating,the ion exchange capacity of zeolite in wetlands restored to 60.3%~62.6% and 11.8 % of the original respectively,and to 94.8%~94.6 % and 38.4% after three months respectively.The results denote that the zeolite in wetland had better bioregeneration effect than in column with ion exchange capacity recovery rate of 50%~63% net value added.According to the results,the mechanism of bio-regeneration process of ammonium-saturated zeolite in planted wetlands was pursued and feasibility of zeolite bioregeneration in wetlands was demonstrated.