Technical University of Berlin, 10623 Berlin, Germany.
Water Res. 2012 Nov 15;46(18):6059-68. doi: 10.1016/j.watres.2012.09.001. Epub 2012 Sep 11.
Pilot scale experiments using an 8 g/h ozonation unit and a 1.4 m(2) slow sand filter have demonstrated that the combination of ozonation and artificial groundwater recharge is suitable for efficient reduction of bulk and trace organics. The biodegradation of dissolved organic carbon (DOC) in the slow sand filter was enhanced from 22% without pre-treatment to 34% by pre-ozonation. In addition, realistic surface water concentrations of most investigated trace organic compounds (TrOCs) including carbamazepine, sulfamethoxazole, phenazone and metoprolol were reduced below the limits of quantification. Only a few TrOCs, e.g. primidone and benzotriazole, were not efficiently removed in both treatment steps and could be detected regularly in the filter effluent. For these compounds, enhanced treatment, such as advanced oxidation processes, needs to be considered. Testing for genotoxicity and cytotoxicity did not reveal any systematic adverse effects for human health. The formation of the by-product bromate from bromide was below the limit of the German drinking water directive of 10 μg/L. No removal of bromate was observed in the aerobic slow sand filter. Additional experiments with sand columns showed that operating a preceding bank filtration step to reduce DOC can reduce oxidant demand by approximately 20%.
中试规模实验采用 8 g/h 臭氧单元和 1.4 m²慢砂滤池，证明了臭氧氧化与人工地下水补给相结合适用于有效减少有机物总量和痕量有机物。预臭氧化可将慢砂滤池中溶解性有机碳（DOC）的生物降解率从无预处理的 22%提高到 34%。此外，大多数研究痕量有机物（TrOCs）的实际地表水中的浓度，包括卡马西平、磺胺甲恶唑、非那宗和美托洛尔，均低于定量限。只有少数 TrOCs，如苯巴比妥和苯并三唑，在两个处理步骤中均未被有效去除，且可定期在滤过水中检出。对于这些化合物，需要考虑增强处理，如高级氧化工艺。遗传毒性和细胞毒性测试未显示出对人类健康有任何系统的不良影响。溴酸盐（由溴化物形成）的生成量低于德国饮用水指令规定的 10 μg/L 限值。在好氧慢砂滤池中未观察到溴酸盐的去除。砂柱的进一步实验表明，运行前置的渗滤步骤以减少 DOC 可使氧化剂需求量减少约 20%。
