层状材料对水中全氟化合物的富集与资源化利用研究

Because of perfluorochemicals (PFCs) of persistent, bioaccumulative, recalcitrance, endocrine toxicity and long-range environmental transport, causing harm to human and animal health, how to effectively remove PFCs from water is more urgent ever before.According to layered double hydroxides (LDHs) and its calcined materials(LDO) have layered structure, larger specific surface area, "memory effect" and other features,using its superior adsorption and ion exchange properties, the selective adsorption and resource utilization of PFCs from wastewater will be carried out. Around high capacity and selectivity of the adsorption process, QSAR related PFCs wastewater treatment involved,using LDHs controllable preparation by altering the composition, morphology and microstructure, and the adsorption kinetics and thermodynamics have been also studied. Combined with microstructure changes in the adsorption and regeneration of LDHs, using molecular simulation and quantum chemistry, calculated interaction PFCs with LDHs, adsorption-desorption behavior of LDHs surface, the driving force and adsorption sites, to reveal the mechanism of layered material effect on selection absorption and utilization of PFCs from wastewater.The final goal is to provide a theory and application basis for LDHs using treatment PFCs in wastewater.

由于全氟化合物（PFCs）的持久性、生物累积性、难降解性、内分泌毒性和远距离环境迁移，对人类和动物的健康造成了危害，如何有效去除水体中的PFCs非常迫切。课题根据层状双金属复合氢氧化物（LDHs）及其焙烧物(LDO)具有独特层状结构、较大的比表面积和结构"记忆效应"等特点，利用其优异的吸附和离子交换性能，开展PFCs废水的选择吸附及资源化利用研究。通过LDHs可控制备调变层板组成、形貌和微观结构，关联PFCs废水处理所涉及的构效关系，实现吸附过程的高容量和高选择性；结合吸附及再生循环过程中LDHs的微观结构变化，利用分子模拟和量子化学计算PFCs与层状材料的相互作用、LDHs表面的吸脱附行为、吸附过程的驱动力及吸附位点等，揭示层状材料作用于PFCs选择吸附与资源化利用的内在本质。课题研究为LDHs和LDO类层状材料在PFCs废水资源化处理中的推广奠定相关理论和应用基础。

根据层状双金属复合氢氧化物（LDHs）及其焙烧物(LDO)具有独特层状结构、较大的比表面积和结构“记忆效应”等特点，利用其优异的吸附和离子交换性能，对废水中PFCs的选择吸附及资源化利用进行了研究。通过LDHs的可控制备调变层板组成、形貌和微观结构，可实现吸附PFCs过程的高容量和高选择性。.（1）所制备的水滑石均具有典型水滑石的层状结构；在所制备的水滑石中，摩尔比（Mg:Fe）为4:1的MgFe-CO3-LDHs的比表面积相对较大。.（2）经焙烧后，水滑石转化为晶相的LDO，450℃下焙烧得到的摩尔比（Ni:Al）为4:1的NiAl-CO3-LDO具有最大的比表面积。.（3）硝酸根类LDHs的吸附性能优于未焙烧碳酸根类LDHs，但焙烧后碳酸根类水滑石的吸附性能大大超过硝酸根类水滑石，对PFOS、PFOA的去除率接近100%。.（4）在45oC下0.125g Mg/Fe=3:1的MgFe硝酸根水滑石与PFOA溶液振荡5h，对浓度为1.0036g/L PFOA的去除率为70.50%；以0.3g镍铝比为2:1的NiAl硝酸根水滑石处理浓度为0.4988g/L的PFHxA溶液，并在45oC的恒温摇床中振荡5h后得到的处理结果最好，去除率为73.48%；在55oC 下，焙烧后0.2g的Mg-Fe碳酸根水滑石与PFHxA溶液振荡4h，对浓度为0.6907 g/L PFHxA溶液的去除率分别达到99.90%、99.88%、99.91%；65oC 下，焙烧后0.2g的Ni-Al碳酸根水滑石与PFHxA溶液振荡4h，对浓度为0.6907 g/L PFHxA溶液的去除率分别达到99.73%、99.88%、99.62%。.（5）Mg/Al为3:1的MgFe-CO3-LDO对全氟辛酸、全氟丁酸、全氟己酸吸附的活化能Ea值分别为60.9kJ/mol，35.01kJ/mol，47.04kJ/mol。.（6）对LDO对全氟丁酸的吸附进行了热力学研究，得出ΔHɵ=49.593kJ/mol，ΔSɵ=210.5J/mol*K，ΔHɵ为正值证明吸附LDO对全氟丁酸的吸附是一个吸热过程，ΔSɵ为正值表明在固体/溶液界面处吸附过程的随机性变大。.上述结果表明，采用LDHs及其焙烧物LDO可以很好的从废水中去除PFCs，达到富集PFCs目标。