聚硅酸铝镁锌混凝剂的制备及去除抗生索性能和机理初探

为提高混凝剂对含有抗生素废水的处理效果,首次以氯化铝、氯化镁、硫酸锌、硅酸钠为原料,制备了新型混凝剂聚硅酸铝镁锌(PSAMZ),分别以碳酸氢钠、硝酸钠、高岭土调节碱度(以p(CaCO3)计)、离子强度、浊度,进行混凝模拟试验.研究了混凝剂投加量、碱度、浊度对PSAMZ去除四环素(TC)及土霉素(OTC)的影响.结果表明,混凝剂投加量为0.02 mol/L,碱度为25 mg/L,浊度为10 NTU,OTC最高去除率可达到91.95％;混凝剂投加量为0.03 mmol/L,碱度为25 mg/L,浊度为10 NTU,TC最高去除率可达到90.03％.用光学显微镜和能谱分析等仪器对混凝剂进行表征,并分析混凝剂去除抗生素TC和OTC的作用机理,得出吸附架桥和电中和可能是该混凝剂去除抗生素的主要作用机理.

Preparation of inorganic polymer coagulant-PSAMZ and the mechanism for its antibiotics removing performance

In order to improve the performance of coagulation in treating antibiotic sewage,the present paper has developed a new coagulant (PSAMZ coagulant) consisting of aluminum chloride,magnesium chloride,zinc sulfate and sodium silicate produced by the copolymerization method with the help of an optical microscope and EDAX technique.The newly developed coagulant (PSAMZ coagulant) is produced to be used for identifying the structure and element constituents of the sampling materials in the research work.In proceeding with our study,we have applied the target antibiotics OTC and TC at a content concentration rate of 100 μg/L by putting it into a beaker with the sodium bicarbonate and kaolin for adjusting the alkalinity and turbidity of the sampling materials,respectively.And,then,the six-in-one sized electromotive stirrer can be put into the beaker to finish the coagulation-mixing experiment pre-and-post the coagulation broughtin.Afterwards,the pH value and the turbidity of coagulation can be measured by means of a pH meter and a turbidity meter,whereas the antibiotics' content can be measured through a high-performance liquid chromatographer (HPLC).Furthermore,it is also necessary to analyze the effects of the dosage of the coagulant,the alkalinity and the coagulant turbidity on the turbidity removal so as to find and determine the best conditions for the experiment.And,finally,it is also necessary to analyze and discuss the mechanism of the coagulant in removing the antibiotics in a certain environment.All in all,the PSAMZ coagulant samples gained in our research can display various kinds of branch shapes and long-chain structures under the optical microscope,whose turbidity removing capability has increased so high as to 99.82％ with the coagulant concentration being 0.04 mmol/L.However,since alkalinity may cause the pH value to change in the solution,thus,affecting the hydrolyzation and polymerization of the coagulant,there would be found different species of coagulants in the water solution.Therefore,further studies of the mechanism that accounts for the removal of OTC and TC by the coagulant remain still of great necessity so as to find the charge neutralization and adsorption bridging factors based on the results of the given work.