Zn-Al类水滑石吸附污泥脱水液中磷的研究

为了开发一种新型除磷吸附剂，将二价金属离子（Mg2+、Zn2+、Cu 2+、Ni2+、Co2+）和三价金属离子（Al3+、Fe3+）分别组合，用共沉淀法制备了不同金属组成的类水滑石，研究了类水滑石及其焙烧产物的磷吸附效果。结果表明:Zn/Al摩尔投料比为2∶1的类水滑石300℃焙烧4 h，得到的吸附剂对城市污水处理厂污泥脱水液中磷的吸附容量最高，约4077 mg/g；在pH中性和弱碱性条件下，Zn-Al-2-300对水中磷的吸附效果较好，吸附动力学符合假二级动力学方程，吸附等温线符合Langmuir吸附等温式；5%NaOH+10%Na2CO3溶液对载磷类水滑石的磷解吸效果最好，其解吸率约为91.17%。 

Phosphate adsorption from sewage sludge filtrate by Zn-Al hydrotacite-like compounds.

A series of hydrotalcite like compounds (HTALs) were made by coprecipitation with divalent ions (Mg^2+，Zn²⁺，Cu²⁺，Ni^2+ and Co²⁺) and trivalent ions (Al³⁺ and Fe³⁺)in order to be applied in phosphate adsorption as a new sorbent. With Zn Al molar ratio of 2∶1 and calcinations treatment at 300℃ for 4 hrs，Zn Al HTALs showed the most effective capacity as adsorbent to uptake phosphate up to 40.77 mg/g in sewage sludge filtrate with initial concentration of around 200 mg/L. Under neutral or weak base condition，Zn-Al-2-300 indicated higher stability and capacity of phosphate adsorption. The adsorption kinetics followed pseudo second order equation quite accurately and the isotherm was suggested as Langmuir type. In addition，the highest desorption rate of 9117% for phosphate from used HTALs was achieved when using 5% NaOH+10%Na2CO3 as the desorption solution.