UF膜与混凝粉末活性炭联用处理冬季黄河水

针对低温低浊水处理的难题,采用混凝和粉末活性炭预处理超滤系统对冬季黄河水进行了净化研究,通过投加混凝剂Al(2SO)4·318H2O以及粉末活性炭,比较了其对于原水的处理效果和对膜过滤性能的影响。试验结果表明,混凝超滤系统用于处理冬季黄河水在技术上是可行的,混凝剂与粉末活性炭对水中污染物质的去除和膜过滤性能有很大的影响;调整合适的操作参数,其对低温黄河水中的高锰酸盐指数、UV254、NH3-N、铁和浊度的平均去除率分别达到70%、60%、30%、80%和96%以上,出水水质达到《生活饮用水源水质标准》(CJ3020-93)的标准。对于已污染的膜,水反冲洗、水/酸洗、水/碱洗可使膜通量恢复至新膜的38%,82%,89%。     

Optimized Coagulation of High Alkalinity, Low Temperature and Particle Water: pH Adjustment and Polyelectrolytes as Coagulant Aids

The Yellow River in winter as source water is characterized as high alkalinity, low temperature and low particle concentrations, which have brought many difficulties to water treatment plants. This study fully examines the optimized coagulation process of the Yellow River by conventional and pre-polymerized metal coagulants, pH adjustment and polyelectrolytes as the primary coagulants or coagulant aids. For all the metal coagulants, polyaluminum chlorides are superior to traditional metal coagulants due to their stable polymeric species and low consumption of alkalinity. The removal of natural organic matter by monomeric metal coagulants can be improved through pH adjustment, which is in accordance with the higher concentration of polymeric species formed at corresponding pH value. With the addition of polyelectrolytes as coagulant aids, the coagulation performance is significantly improved. The effective removal of dissolved organic matter is consistent with high charge density, while molecular weight is relatively important for removing particles, which is consistent with polyelectrolytes as primary coagulants. These results suggest that the coagulation mechanisms in the removal of dissolved organic matter and particles are different, which may be exploited for optimized coagulation for the typical source water in practice.     

铝、铁、钛3种金属盐基混凝剂调理污泥的性能比较

以铝盐、铁盐和钛盐混凝剂为研究对象,重点比较了3种混凝剂的污泥调理性能.通过测定调理前后污泥比阻、胞外聚合物中蛋白质和多糖的含量变化,结合三维荧光光谱与分子量变化分析及调理前后污泥尺寸大小与颗粒表面形貌变化,系统比较了它们对污泥的调理性能,并揭示了调理机制.3种无机混凝剂的污泥调理能力依次为:聚合氯化铝(PAC)、钛凝胶混凝剂(TXC)、聚合硫酸铁(PFS);调理后,污泥胞外聚合物中蛋白质和多糖含量明显降低;PFS和TXC对有机物的结合能力要强于PAC,疏松结合的胞外聚合物中多糖含量是影响污泥脱水性能的关键因素;调理过程中3种混凝剂所形成污泥颗粒的大小顺序为:TXCPFSPAC,所形成污泥颗粒的大小并非影响污泥脱水性能的关键因素,无机混凝剂电中和能力和与有机物的络合能力共同影响无机混凝剂的污泥调理性能.本研究为污泥调理混凝剂的选取提供了实验和理论依据.     

煤泥水沉降实验研究

针对某选煤厂煤泥水难以自然沉降的问题,从煤泥水本身的矿物组成出发,探讨了絮凝的机理,通过理论分析和实验研究,选用了3种凝聚剂和3种絮凝剂对煤泥水进行絮凝沉降实验,研究出最佳的凝聚剂和絮凝剂以及最佳药剂配比,加速了煤泥水的沉降,实现了洗水闭路循环。     

A new method of inhibiting pollutant release from source water reservoir sediment by adding chemical stabilization agents combined with water-lifting aerator

A new method of adding chemical stabilization agents combined with water-lifting aerator can inhibit pollutant release from source water reservoir sediment effectively.     

Application of a green coagulant with PACl in efficient purification of turbid water and its mechanism study

The applications of natural polymeric flocculants due to their green feature has been recently received much more attention. In this work, the combined usages of a cationic starch-based coagulant and polyaluminum chloride (PACl) were extensively evaluated for various addition sequences in the coagulation of both raw (surface water from the Jiuxiang River) and synthetic turbid water (two kaolin suspensions with different initial turbidities). Two typical cationic starch-based coagulants with different structures (St-G and St-E) were tried. In comparison to St-G, St-E and PACl used individually as well as St-G and St-E dosed after PACl, the combination of the starch-based coagulants fed before PACl showed higher turbidity removal efficiency, which featured not only less optimal doses of both inorganic and organic coagulants but also lower residual turbidity. On the basis of a detailed analysis of the particle size and its distribution in solution supernatants before and after coagulation by two starch-based coagulants and PACl, polymeric coagulants preferentially coagulate the small-sized colloids due to their distinct long-chain structures, but PACl preferentially coagulates the medium-sized ones. Thus, the medium-sized particles that were previously formed by the starch-based coagulants would be collectively and effectively removed by the subsequent addition of PACl. The addition sequence of the inorganic and organic coagulants in their combined usage is an important factor for improvement of the turbidity removal efficiency in practice.