摘要
为了确定粉煤灰和赤泥经HCl改性制得的复合絮凝剂PAFC处理含磷废水的合适工艺技术条件,对浓度为50.0μg/mL的模拟含磷废水进行了适宜除磷pH值和PAFC用量试验,并对反应过程中的水力条件进行了研究。结果表明:在pH=8、PAFC投加量为180 mg/L、快速搅拌速度为200 r/min、快速搅拌时间为60 s、慢速搅拌速度为50r/min、慢速搅拌时间为15 min情况下,取得了97.55%的磷去除率。除磷机理分析表明:1PAFC结构杂乱无章、参差不齐,表面积极大,孔隙度极高,这十分有利于对磷的吸附。2PAFC通过自身携带的Fe—OH、Al—OH、H—OH羟基基团,以及Al3+和Fe3+水解形成的氢氧化铝(铁)等羟基络合物吸附磷;PAFC中的Al3+和Fe3+除了与水中溶解的正磷酸盐反应生成不溶性磷酸盐沉淀,还通过电性中和作用,降低或消除污水中胶体的ζ电位,从而令水中胶体消除静电斥力,使悬浮物快速脱稳并沉降到水底,表现出良好的絮凝除磷效果。粉煤灰和赤泥可制备优质除磷絮凝剂PAFC,实现了这些工业固体废弃物的资源化利用,且达到了以废治废效果。
In order to determine the suitable technological conditions for phosphorus wastewater treatment by adopting composite flocculant PAFC which was prepared from fly ash and red mud by hydrochloric acid modification, tests are carried out to find out suitable pH value for phosphorus removal and PAFC dosage to treat simulated phosphorus wastewater with the concentration of 50.0 μg/mL, and the optimum hydraulic condition was investigated. The results showed that under conditions of pH value 8 and the dosage of PAFC 180 mg/L,rapid stirring for 60 s at 200 r/min,slow stirring for 15 min at 50 r/min, phosphorus removal rate reached 97.55%. The phosphorus removal mechanism analysis showed：① The PAFC has features of disorder and uneven structure,large surface area, high porosity, which are favor for adsorption of phosphorus. ② Based on the self-owned hydroxyl groups such as Fe--OH, A1--OH and H--OH, as well as hydroxy complex of aluminum hydroxide （iron） formed by hydrolysis of A13 ~ and Fe3 ~ , PAFC can adsorb phosphorus ; In addition to reacting with the water dissolved ortho- phosphate to generate insoluble phosphate precipitation, A13 ＋ and Fe3 ＋ among PAFC also can reduce or eliminate the zeta po- tential in colloid of wastewater by electrical neutralization, so as to eliminate electrostatic repulsion in colloid of water, and quickly keep the suspended matter stable and settle down to the bottom. PAFC shows good flocculation and phosphorus remov- al performance. The fly ash and red mud can be used to prepare the high-quality phosphorus removal flocculant PAFC. By this process, the industrial solid wastes can be recycled as resources, to gain the goal of treating wastes by one another.
出处
《金属矿山》
CAS
北大核心
2014年第7期168-171,共4页
Metal Mine
基金
国家水体污染控制与治理科技重大专项(编号:2012ZX07104-002)
关键词
粉煤灰
赤泥
含磷模拟废水
复合絮凝剂PAFC
Fly ash, Red mud, Simulated phosphorus wastewater, Compound flocculants PAFC
