聚合硫酸铁的制备及改性研究

【作者】 唐剑；

【导师】 邱运仁；

【作者基本信息】 中南大学 ， 化学工程， 2010， 硕士

【摘要】 聚合硫酸铁以其优良的絮凝性能为人们所关注,制备工艺简单、成本低廉的PFS产品具有重要意义。本文以七水硫酸亚铁、硫酸为原料,以氯酸钠为氧化剂制备了液体PFS、固体PFS和Mn2+改性固体PFS,并研究了其对工业废水的处理特性。采用空气-氧化剂联合氧化法制备了液体PFS,研究了投料比、溶液pH和反应温度对液体PFS产品质量的影响。确定了制备液体PFS的最优工艺,在投料比(FeSO4·7H2O:H2SO4) 1:0.35～0.40,溶液pH0.5-1,反应温度60℃下,空气氧化7h后投加氯酸钠,可减少氧化剂用量80%。在印染废水处理实验中,液体PFS投加量为146 mg·L-1时,COD去除率为65.2%,浊度去除率为91.4%。考察了原料配比、反应温度、反应时间、时效处理和固化温度对固体PFS性质的影响,得到了制备固体PFS的优化条件：原料配比(FeSO4·7H2O:H2SO4)1:0.23,反应温度54℃,反应时间90 min,固化温度54-59℃。相比液体PFS蒸发法,该工艺可节约能量2331kJ·kg-1。在涂料废水处理实验中,固体PFS投加量为100 mmg·L-1时,COD去除率为82.1%,浊度去除率达98.3%。将Mn2+引入PFS,制备了改性PFS,研究了原料配比、和反应温度对其絮凝性能的影响,得到了优化工艺条件：绿矾27.8g,硫酸锰8.45g,硫酸1.5ml,反应温度50℃。在处理印染废水、涂料废水和造纸废水的实验中,比较了改性固体PFS与未改性固体PFS的絮凝性能,絮凝剂在上述三种废水中投加量分别为150mg·L-1、100mg·L-1和150mg·L-1时,改性固体PFS的COD去除率分别为71.3%、87.6%和73.7%,浊度去除率分别为96.5%、99.7%和91.3%；未改性固体PFS处理印染废水和水性涂料废水时,COD去除率分别为65.8%和82.1%,浊度去除率分别为93.1%和98.3%。结果表明,改性固体PFS絮凝性能优于固体PFS,对印染废水、水性涂料废水和造纸废水都有较好的絮凝效果。更多还原

【Abstract】 Polyferric sulfate(PFS) attracts people’s attention for its excellent coagulant performance. It is very important to synthesis PFS with simple process and low cost. Liquid PFS, solid PFS and solid modified PFS were prepared from ferrous sulfate, sulfuric acid and sodium chlorate, and the application to the industrial wastewater treatment were also studied.Liquid PFS was prepared by air-oxidant method. The effects of the material composition, reaction temperature, pH value on liquid PFS quality were studied, and the optimum preparation condition was obtained. The molar ratio of FeSO4·7H2O to H2SO4 is 1:0.35-0.40, pH value is 0.5-1, reaction temperature is 60℃, NaClO3 is added by 7h oxidization with air. This method can reduce 80% consumption of oxidant. The removal rate of COD and turbidity are 65.2% and 91.4% respectively with the addition of 146 mg·L-1 in the treatment of dye wastewater.Effects of the molar ratio of raw materials, reaction temperature, reaction time, aging time and drying temperature on the quality of solid PFS were investigated. The optimality preparation conditions are as follows:the molar ratio of FeSO4·7H2O to H2SO4 is 1:0.23, reaction temperature is 54℃, reaction time is 90 min, drying temperature is 54～59℃. The new technology can reduce energy cost of 2331 kJ·kg-1 compared with the direct evaporation from liquid PFS. The removal rates of COD and turbidity are 82.1% and 98.3% respectively with the addition of 100 mg·L-1 in the treatment of dope wastewater.A kind of modified PFS is prepared by intruducing Mn2+ into PFS. Effects of the molar ratio of Fe to Mn, reaction temperature, and the dosage of H2SO4 on the flocculation performance of solid modified PFS were investigated. The optimality preparation conditions are as follows: the amount of FeSO4·7H2O is 27.8g, MnSO4 is 8.45g, H2SO4 is 1.5ml, reaction temperature is 54℃. The flocculation performances of solid modified PFS and solid unmodified PFS were compared in the treatment of dye wastewater, dope wastewater and papermaking wastewater, with the flocculant dosage of 150 mg·L-1,100 mg·L-1 and 150 mg·L-1, respectively in the above three kind of wastewater, for solid modified PFS, the removal rate of COD is 71.3%,87.6% and 73.7%, respectively, the removal rate of turbidity is 96.5% ,99.7% and 91.3%, respectively. In the treatment of dyestuff wastewater, dope wastewater with solid PFS, the removal rate of COD is 65.8% and 82.1%, respectively, the removal rate of turbidity is 93.1% and 98.3%, respectively. The results indicate that the flocculation performance of modified solid PFS is better than that of unmodified solid PFS in the treatment of dye wastewater, dope wastewater and papermaking wastewater.更多还原