氧化石墨烯-FeCl3改性沸石联合生物预处理对氨氮的强化处理研究

Study on enhanced treatment effect of ammonia nitrogen by graphene oxide-FeCl3 coated zeolite combined with biological pretreatment

以氧化石墨烯(GO)和FeCl3·6H2O为改性剂,制备GO-FeCl3改性沸石,与生物预处理技术结合,对含(2.98±0.38)mg/L氨氮的微污染水进行强化处理,探讨了GO-FeCl3改性沸石表面的挂膜性能以及GO-FeCl3改性沸石的表面特性,并对GO-FeCl3改性沸石、FeCl3改性石英砂(IOCS)和普通石英砂(RQS)3种滤料联合生物预处理的强化处理效果进行了比较分析。结果表明:(1)与RQS和IOCS比较,GO-FeCl3改性沸石表面生物量最高(17.26μg/cm^3);(2)GO-FeCl3改性沸石联合生物预处理,对氨氮的去除率最高(95.60%),出水中悬浮物粒径最小(由进水的458.70nm下降至1.49nm),生物安全性最高;(3)GO-FeCl3改性沸石比表面积最大,表面结构更加复杂且多孔,表面含有羟基、羧基等官能团,且煅烧过程形成的Fe3O4和α-FeOOH与GO结合,具有一定的可见光催化作用,因而强化处理效果最好。

Enhanced treatment of the micropollutant ammonia nitrogen with the concentration of (2.98± 0.38) mg/L was conducted by graphene oxide (GO)-FeCl3coated zeolite (GO and FeCl 3·6H2O as modifiers) combined with biological pretreatment. The biofilm formation performance on the surface of GO-FeCl3coated zeolite,and its morphological characteristics were investigated. The comparison of enhanced treatment effects were done by the combination of three filtration materials with the biological pretreatment. Three filtration materials were GO-FeCl3coated zeolite, FeCl3coated quartz sand (IOCS) and raw quartz sand (RQS). The experimental results were indicated that:(1) the biomass on the surface of GO-FeCl3coated zeolite was17.26 μg/cm3,which was higher than that on the surface of RQS and IOCS.(2) Combined with the biological pretreatment, GO- FeCl3coated zeolite had the highest removal rate of ammonia nitrogen (95.60%). The particle size of the effluent from the filtration column filled with GO-FeCl3coated zeolite decreased from 458.70 nm to1.49 nm,which meant the filtered water was the highest biosafety.(3) Compared with IOCS and RQS, GO-FeCl3coated zeolite showed the biggest specific surface area and the most complex and porous surface structure. GO-FeCl3coated zeolite had the best enhanced treatment efficiency for the adsorption of ammonia nitrogen,because there were special functional groups on its surface,such as hydroxyl,carboxyl. Meanwhile, GO-FeCl3coated zeolite had performed some certain photocatalysis behaviors based on the combination of GO with Fe 3O 4 and α-FeOOH coated on its surface.