渗透反应格栅去除地下水中铵的化学生物联合柱研究

通过柱实验对比研究了天然河沙、沈阳沸石、复合介质(释氧材料和沈阳沸石)作为渗透反应格栅填料修复地下水中铵污染的可行性。结果表明:柱实验运行120孔隙体积(PV)期间,在进水流速为1.8 m/d,铵浓度为6.6~10.3 mg/L的条件下,实验设计的复合介质填充柱对铵去除率达到99%以上。沸石在吸附去除铵的同时,又可作为微生物生长的载体,使铵进一步通过生物硝化作用被去除,实现沸石的生物再生。释氧材料的加入保证了硝化细菌繁殖所需要的溶解氧条件,水经过释氧层后溶解氧含量由2 mg/L增加到6 mg/L以上(最高达到22 mg/L左右)。实验中通过硝化作用去除的铵量占总去除量的74%左右,实现了沸石吸附联合微生物共同作用去除铵,有助于保证反应柱长期高效地去除地下水中铵污染。

Laboratory Column Study for Evaluating a Bio-chemical Permeable Reactive Barrier to Remove Ammonium from Groundwater

A column study experiment was carried out to evaluate the performance of a fixed bed column made of river sand,Shenyang zeolite and the composite medium(O2 releasing material and Shenyang zeolite)which was to remove ammonium from the polluted groundwater.The result showed that removal of ammonium of the column was more than 99% and zeolite could play a role of the carrier onto which microorganisms were growing.Thus zeolite as the adsorbent could be biologically regenerated while O2 releasing material acted as a supplier of oxygen enough for microbial nitrification.Actually,the amount ammonium removed by nitrification accounted for 74% of the total.Consequently,composite medium of the column facilitated a joint action-zeolite adsorption and microbial nitrification-to remove ammonium,which could be run in a long-term and high efficient way.