天然沸石颗粒对NH4^＋动态吸附过程中的离子交换特性研究

采用天然斜发沸石颗粒,进行了沸石吸附水溶液中NH4^＋的动态吸附实验研究。实验结果表明,沸石颗粒粒径、沸石床高度、上升流速、进水氨氮浓度、进水水质等因素对沸石颗粒吸附NH4^＋有着明显的影响,在工程实践应用时,要根据动态吸附实验结果选择合适的设计及运行参数。离子交换机理研究表明,Na^＋首先被交换出来,随着反应进行,Ca^2＋浓度逐渐增加,两者成为离子交换的主要对象。对于人工氨氮配水,整个运行期间金属阳离子液相增加量明显大于NH4^＋去除量,这与金属阳离子在固液两相间的再分配作用有关;对于厌氧工艺出水,在吸附初期,NH4^＋去除量大于金属阳离子液相增加量,随着反应进行,两者逐渐持平。

Study on ion-exchange characteristics in the dynamic adsorption process of NH4^＋ by natural granulated zeolite

Natural granulated clinoptilolite was adopted to investigate the dynamic adsorption characteristics of ammonium ions by zeolite.Test results showed that these factors such as zeolite particle size,bed height,up flow rate,ammonia nitrogen concentration and influent water quality had obvious effects on the adsorption of NH4^＋ by granulated zeolite.Proper parameters for design and operation in practical application should be selected according to the dynamic adsorption experiment.The results of ion-exchange mechanism experiment showed that Na＋ was firstly exchanged into liquid-phase,then the amount of Ca2＋ gradually increased with the reaction and both of them occupied the major part of the ion-exchange. For synthetic ammonia nitrogen wastewater,increasing amount of metal cations in liquid-phase was larger than decreasing amount of NH4^＋ in the whole operation,which can be attributed to the redistribution of the metal cations between the solid-liquid phases.For the effluent from anaerobic process,the removal amount of NH4^＋ was larger than the increasing amount of metal cations at the beginning of the adsorption and then gradually reached a balance.