Jelínek Ludek, Parschová Helena, Matejka Zdenek, Paidar Martin, Bouzek Karel
Department of Power Engineering, Institute of Chemical Technology, Prague, Czech Republic.
Water Environ Res. 2004 Nov-Dec;76(7):2686-90.
The process of selective nitrate removal from drinking water by means of ion exchange was studied. A commercial strong base anion exchanger with triethylammonium (-N+Et3) functional groups was used in the bicarbonate (HCO3-) and carbonate (CO3(2-)) form. The aim of this study was to optimize ion-exchanger regeneration in view of the subsequent electrochemical reduction of nitrates in the spent regenerant solution. The effects of ion-exchanger form, concentration of regenerant solution, and presence of nitrates, chlorides, and sulphates in the regenerant solution were studied. The strong base anion exchanger in HCO3- form that was investigated was able to treat 270 bed volumes of model water solution containing 124 mg dm(-3) nitrates. To achieve adequate regeneration of the saturated anion exchanger, it is necessary to use approximately 30 bed volumes of fresh 1-M sodium bicarbonate (NaHCO3) regenerant solution. The presence of residual 50-mg dm(-3) nitrates in the regenerant solution, treated by electrolysis, resulted in an increase in the dose of regenerant solution to 35 bed volumes and a decrease in the subsequent sorption run of approximately 13%. The volume of applied regenerant solution was high, but the consumption of NaHCO3 for regeneration was low.
研究了通过离子交换从饮用水中选择性去除硝酸盐的过程。使用了具有三乙铵（-N⁺Et₃）官能团的市售强碱性阴离子交换剂，其呈碳酸氢根（HCO₃⁻）和碳酸根（CO₃²⁻）形式。本研究的目的是鉴于后续对废再生液中硝酸盐进行电化学还原，优化离子交换剂的再生过程。研究了离子交换剂形式、再生液浓度以及再生液中硝酸盐、氯化物和硫酸盐的存在对其的影响。所研究的呈HCO₃⁻形式的强碱性阴离子交换剂能够处理270床体积含有124 mg dm⁻³硝酸盐的模拟水溶液。为使饱和阴离子交换剂实现充分再生，需要使用约30床体积的新鲜1 M碳酸氢钠（NaHCO₃）再生液。经电解处理的再生液中残留50 mg dm⁻³硝酸盐，导致再生液剂量增加至35床体积，后续吸附运行量减少约13%。所施加的再生液体积较大，但用于再生的NaHCO₃消耗量较低。
