Shi Pengbo, Jiang Yingbo, Zhu Hongtao, Sun Dezhi
College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China E-mail:
Water Sci Technol. 2017 Jul;76(3-4):584-593. doi: 10.2166/wst.2017.232.
The CaO dissolution from slag, as well as the effects of influencing parameters (i.e. pH and Ca concentration) on the ammonium adsorption onto zeolite, was systematically studied in this paper. Modeling results of Ca and OH release from slag indicated that pseudo-second-order reaction had a better fitness than pseudo-first-order reaction. Changing pH value from 7 to 12 resulted in a drastic reduction of the ammonium adsorption capacity on zeolite, from the peak adsorption capacity at pH 7. High Ca concentration in solution also inhibited the adsorption of ammonium onto zeolite. There are two proposed mechanisms for steel slag inhibiting the ammonium adsorption capacity of zeolite. On the one hand, OH released from steel slag can react with ammonium ions to produce the molecular form of ammonia (NH·HO), which would cause the dissociation of NH from zeolite. On the other hand, Ca could replace the NH ions to adhere onto the surface of zeolite. An innovative substrate filling configuration with zeolite placed upstream of the steel slag was then proposed to eliminate the disadvantageous effects of steel slag. Experimental results showed that this novel filling configuration was superior to two other filling configurations in terms of ammonium removal.
本文系统研究了炉渣中CaO的溶解以及影响参数（即pH值和Ca浓度）对沸石吸附铵的影响。炉渣中Ca和OH释放的模拟结果表明，准二级反应比准一级反应具有更好的拟合度。将pH值从7变为12导致沸石对铵的吸附容量急剧降低，在pH 7时吸附容量达到峰值。溶液中的高Ca浓度也抑制了铵在沸石上的吸附。提出了两种钢渣抑制沸石铵吸附容量的机制。一方面，钢渣释放的OH可以与铵离子反应生成分子形式的氨（NH·HO），这会导致NH从沸石上解离。另一方面，Ca可以取代NH离子附着在沸石表面。然后提出了一种创新的基质填充配置，将沸石放置在钢渣的上游，以消除钢渣的不利影响。实验结果表明，这种新颖的填充配置在铵去除方面优于其他两种填充配置。
