Xuan Zhao, Meng Zhang, Xuzhou Cheng
Division of Environmental Science & Technology, Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing, PR China.
Water Environ Res. 2009 Jan;81(1):69-75. doi: 10.2175/106143008x304631.
Water shortages lead to increasing attention to artificial groundwater recharge by reclaimed water. A new kind of approach, enhanced direct injection-well recharge (EnDir) consisting of short- and long-term soil treatment, is considered to be suitable for large cities in China. In this paper, EnDir was simulated by soil columns in the laboratory with the secondary effluent as raw water that was ozonated before EnDir. Laboratory-scale experiments demonstrate that the short-term part of EnDir can remove 47 to 60% dissolved organic carbon (DOC), convert 5 mg/L of ammonia-nitrogen to equivalent nitrate-nitrogen, and offer preferred removal of non-UV-absorbing organics. Soluble microbial byproducts and fulvic-acid-like materials can be ozonated and then partially biodegraded. The residuals of organic matter as a refractory fraction are biodegraded continuously during the long-term part. The DOC value of 1.8 to 2.5 mg/L can be reached, and 40% of organic matter with molecular weight less than 500 Da can be removed after full-term EnDir.
水资源短缺导致人们越来越关注利用再生水进行人工地下水回灌。一种由短期和长期土壤处理组成的新型方法——强化直接注入式回灌（EnDir），被认为适用于中国的大城市。在本文中，以二级出水为原水，在EnDir之前进行臭氧处理，通过实验室中的土柱模拟了EnDir过程。实验室规模的实验表明，EnDir的短期部分可以去除47%至60%的溶解有机碳（DOC），将5mg/L的氨氮转化为等量的硝酸盐氮，并能较好地去除非紫外线吸收性有机物。可溶性微生物副产物和类富里酸物质可被臭氧氧化，然后部分生物降解。作为难降解部分的有机物质残留，在长期部分会持续进行生物降解。经过完整的EnDir过程后，DOC值可达到1.8至2.5mg/L，分子量小于500Da的有机物可去除40%。
