层状双金属氢氧化物覆膜改性人工湿地无烟煤基质除磷

分别选取MgCl2、ZnCl2、CaCl2、CoCl3、FeCl3、AlCl3等6种金属化合物合成9种不同类型层状双金属氢氧化物(LDHs),利用其对垂直流人工湿地无烟煤基质进行LDHs覆膜改性;构建模拟基质试验柱,对改性前后的无烟煤基质进行模拟垂直流人工湿地净化污水试验.结果表明:相对于原始无烟煤基质,各种LDHs覆膜改性基质对总磷、溶解性总磷、颗粒态磷和磷酸盐的去除率均有不同程度的提高;Zn2+参与合成的改性基质对总磷、溶解性总磷、颗粒态磷和磷酸盐均有很好的去除效果,其中ZnCo-LDHs和ZnAl-LDHs改性基质对总磷和溶解性总磷的平均去除率超过95%,对磷酸盐平均去除率达到98%以上.

Removal rates of phosphorus by modified anthracite substrates coated with different layered double hydroxides reacted by different metal compounds in vertical-flow constructed wetlands

Nine different kinds of layered double hydroxides (LDHs) were co-precipitated synthesized under alkaline conditions using MgCl2, ZnCl2, CaCl2, CoCl3, FeCl3, and AlCl3. The simulated test columns were constructed using the modified anthracite substrates in-situ coated with the different synthesized LDHs to treat the urban sewage, and the control treatment (using anthracite as the substrates) was set up at the same time. Compared with control, the removal rates of total phosphorus, total dissolved phosphorus, particulate phosphorus and phosphate in the effluent were improved at different degrees after treating with the nine modified anthracite substrates: The modified anthracite substrates with Zn2+ showed good removal efficiency to total phosphorus, total dissolved phosphorus, particulate phosphorus and phosphate. In particular, the modified anthracite substrates coated with ZnCo-LDHs and ZnAl-LDHs showed average removal rates of 95% to total phosphorus and total dissolved phosphorus, and 98% to phosphate.