基于生物沸石复合滤料的间歇式脱氮水处理

Denitrification Water Treatment with Zeolite Composite Filter by Intermittent Operation

以粒径0.15～0.18 mm的天然沸石粉为主要原料,水泥为黏结剂,制备出粒径4～8 mm的沸石复合滤料(ZCF).对制备的材料进行了空隙率、表观密度、强度等性能测试.优化出复合滤料中m(沸石粉):m(水泥)=7:3,自然条件下养护15 d.利用该ZCF装填实验柱,完成硝化微生物挂膜培养,然后进行间歇式脱氮水处理动态实验,间歇式运行周期分为吸附、生物再生、淋洗共3个阶段.采用上流式进水吸附脱氮,以NH4+-N浓度低于2 mg·L-1为出水标准,出水超标后,排空实验柱中水,鼓风生物再生,用水淋洗滤料后重复沸石吸附-生物再生循环,淋洗液单独进行反硝化处理.结果表明,在模拟实验条件下间歇式运行最佳的周期为:吸附5 d,鼓风生物再生24 h,NH4+-N平均去除率为87.7%,TN平均去除率达51.2%.

The zeolite composite filters（ZCF） with the size of 4-8 mm were prepared using raw zeolite（0.15-0.18 mm） as the main material and the cement as binder.After a combination of material characterizations,such as the void fraction,apparent density,compression strength and surface area,the optimal prepared conditions of composite filters were obtained as follow： weight ratio of m（zeolite）∶m（cement） =7∶3,curing for 15 d under the moisture condition and ambient temperature.Through upflow low-concentration ammonia nitrogen wastewater,ZCF filled in the experimental column was hung with the biological membrane.Thus,intermittent dynamic experiments were conducted,the intermittent operation cycle included adsorption,biological regeneration and drip washing.Until concentration of ammonia nitrogen was more than 2 mg·L-1 of effluent standards,water in experiment column was firstly emptied,and then blast biological regeneration was conducted.After the filters were bathed with water,the zeolite adsorption-biological regeneration cycle was performed repeatedly.The experimental results show that under conditions of 24 h blast and 5 d of continuous operation period,ammonia nitrogen removal rate is up to 87.6% on average,total nitrogen removal rate reaches 51.2% on average.