季铵盐插层蒙脱土及其去除海洋卡盾藻的研究

利用插层法制备了5种季铵盐改性的蒙脱土,通过FTIR、XRD和DTG等表征表明5种季铵盐已成功插入蒙脱土中;随后以中国典型赤潮藻海洋卡盾藻(Chattonella marina)为研究对象,考察了5种季铵盐改性蒙脱土的除藻效果。发现以双溴化十四烷基二甲基乙基溴化铵改性的蒙脱土在用量为8mg·L-1时,24h内对海洋卡盾藻的去除率最高,可达100%,而未改性蒙脱土在相同条件下除藻率仅为5.64%;除藻效果与除藻剂的结构有密切关系,在官能团相同时,链长数为14的脂肪族季铵盐除藻率最高,24h可达67.03%;在链长数相同时,含吡啶官能团的季铵盐比脂肪族季铵盐除藻率高,24h为33.62%,且随时间延长明显提高。渗溢性评估实验显示,改性蒙脱土经72h浸泡后表观插层率从71.9%降低到69.6%,表明除藻剂在水体中基本不释放。

Quaternary Ammonium Salts Intercalated Montmorillonite for Removal of Chattonella Marina

Five quaternary ammonium salts were intercalated into montmorillonite(MMT) and the structures of organo-montmorillonite(O-MMT) were characterized. And then the performance of O-MMT was studied for the removal of Chinese typical HABs alga Chattonella marina. The results of FTIR, XRD and TGA show that the five ammonium salts have successfully intercalated into MMT. The removal rate of Gemini tetradecyl dimethylammonium ethyl bromide intercalated MMT(8 mg·L^-1) was 100 % in 24 h while that of unmodified MMT was 5.64% under the same condition, suggesting that the capacity of modified MMT for the removal of Chattonella marina is greatly enhanced. Furthermore, the removal effect is closely related to the molecular structure of the ammonium salts. With the same functional group, the removal efficiency of MMT modified by aliphatic quaternary ammonium salt with chain length of 14 is the highest(67.03% in 24 h); however, when the chain length is equal, the efficiency of MMT modified by quaternary ammonium salt with pyridine group is 33.62% in 24 h and increases with the extension of the time, which is higher than that of aliphatic quaternary ammonium salt. After 72 h soaking, the apparent intercalation ratio of O-MMT decreases from 71.9% to 69.6%, indicating a very slow release rate of ammonium salts of O-MMT in water. These findings suggest that the O-MMT is a potential algaecide with high effectiveness and environment safety.