分别利用3种二价金属化合物和3种三价金属化合物,采用水热共沉淀法在碱性条件下对人工湿地中常用的生物陶粒基质进行层状双金属氢氧化物(LDHs)覆膜改性,并将9种不同类型的LDHs覆膜改性生物陶粒基质和普通生物陶粒基质分别填充于10个垂直流人工湿地模拟实验柱中,进行除磷净化实验.结果表明,9种不同类型的改性生物陶粒基质均能有效提高磷素的净化效果;Zn系LDHs改性生物陶粒对总磷、溶解性总磷、磷酸盐均有很好的处理效果,其中Zn Fe-LDHs、Zn Co-LDHs和Zn Al-LDHs对总磷的平均去除率均在92%以上,对溶解性总磷和磷酸盐的平均去除率均超过95%;其对磷素的净化机理主要集中于物理化学作用,同时还应与其对微生物生长的促进作用有关。
Three kinds of divalent and trivalent metal compounds were used to synthesize layered double hydroxides( LDHs) on biological ceramsite by a hydrothermal co-precipitation method in alkaline conditions. The biological ceramsite( as the control),together with nine kinds of modified biological ceramsite,were applied in simulated vertical-flow constructed wetlands to study their effect of different substrates on phosphorus removal. The results showed that the removal rates of phosphorus could be enhanced by the nine kinds of modified biological ceramsite. In the case of Zn-type modified biological ceramsite,high removal efficiencies of total phosphorus( TP),total dissolved phosphorus( TDP) and phosphate( P) were observed. For the biological ceramsite modified with Zn Fe-LDHs,Zn Co-LDHs and Zn Al-LDHs,the average removal rates of TP,TDP and P were higher than 92%,95%and 95%,respectively. The P removal of Zn-type modified biological ceramsite were mainly due to the role of physical chemistry,together with the positive role in the enhancement for microbial growth.