排序方式: 共有37条查询结果,搜索用时 78 毫秒
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针对石化废水中不同特征污染物,采用人工分离筛选去除COD和油工程菌6株、硝化工程菌10株(亚硝化细菌5株、硝化细菌5株)构建高效混合菌群,通过臭氧固定化生物活性炭滤池除污染效能中试研究表明,该系统深度处理石化难降解有机废水是可行的,能同时实现去除COD、油类、NH3 N等污染物的功效,对COD、油类、NH3 N和色度的平均去除率分别为73 0%、90 5%、81 2%和90%,相应的出水分别为33 2mg/L、0 4mg/L、4 5mg/L和10倍,各项指标均达到了国家循环冷却水的用水要求,它的推广应用必将带来显著的环境效益、社会效益和经济效益。 相似文献
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腐殖酸在水合二氧化锰表面的吸附行为 总被引:20,自引:4,他引:16
研究了腐殖酸在水合MnO2 (S) (δMnO2 )表面的吸附行为 .考察了不同分子量分布范围腐殖酸的吸附性能 ,探讨了阳离子对吸附行为的影响及其可能作用机理 ,并利用FTIR光谱对吸附行为进行了光谱学研究 .结果发现 ,具有较高分子量的腐殖酸HAa 的吸附去除率比具有较低分子量的腐殖酸HAb 高 3 0 % ,表明腐殖酸分子量越大越倾向于吸附在δMnO2 表面 .Ca2 + 较Mg2 + 更能促进腐殖酸在δMnO2 表面的吸附 ;紫外 -可见吸收光谱分析表明Ca2 + 较Mg2 + 具有更强的与腐殖酸络合的能力 ;此外 ,ζ电位测定发现 ,1 0mmol·L- 1 Mg2 + 使δMnO2 的 ζ电位由 -3 7mV(pH =7 9)升高至 -9mV(pH =6 5 ) ,而 1 0mmol·L- 1 Ca2 + 则使ζ电位升高至 + 7mV(pH =7 2 ) .FTIR光谱的结果证实了腐殖酸在δMnO2 表面的吸附 ,并表明腐殖酸的羧基及δMnO2 的表面羟基 (Mn OH)在吸附过程中起着重要作用 .上述结果表明 ,腐殖酸性质、背景阳离子等因素对腐殖酸的吸附行为有重要影响 相似文献
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Calcium-enhanced ferric hydroxide co-precipitation of arsenic in the presence of silicate. 总被引:1,自引:0,他引:1
Ruiping Liu Xing Li Shengji Xia Yanling Yang Rongcheng Wu Guibai Li 《Water environment research》2007,79(11):2260-2264
This study focuses on the effectiveness of calcium (Ca2+) improving ferric (hydro)oxides precipitation and its subsequent effects on arsenic co-precipitation with ferric (hydro)oxides. The effects of Ca2+ on surface charge characteristics and precipitating behavior, which are respectively represented as zeta (zeta) potential and R(PDA), are investigated for ferric (hydro)oxides precipitates. The presence of Ca2+ increases the potential of ferric (hydro)oxides, and a more significant effect is observed at higher pH conditions. Calcium apparently facilitates ferric (hydro)oxide floc aggregation, increasing the maximum R(PDA) from 3.19 to 5.27% (in the presence of 3.5 mg/L silicate as silicon). These positive effects contribute to reduce the adverse effects resulting from the presence of silicate and enhance arsenic removal via ferric (hydro)oxides co-precipitation under different conditions. Furthermore, the effect of Ca2+ facilitating ferric precipitation (and therefore providing more precipitated solids for arsenic) is predominant in favoring arsenic removal compared with that of increasing surface charge. Calcium plays an important role in arsenic co-precipitation with ferric (hydro)oxides in the presence of silicate. 相似文献
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氯胺消毒对三卤甲烷类消毒副产物的控制研究 总被引:5,自引:0,他引:5
在氯消毒研究的基础上,研究氯胺对消毒副产物的控制,将氯与氨氮的比值降至5,能够使单独氯消毒所生成消毒副产物减少89%,二溴一氯甲烷也不再检出;消毒副产物的生成量与氯胺的投加量呈很好的线性关系;接触时间对消毒副产物的生成量影响很小,24 h增加缓慢;pH升高至8消毒副产物的总量比pH为7时减少82.3%,一溴二氯甲烷不再检出;氯胺代替氯消毒能够很好地控制溴代消毒副产物种类和总量. 相似文献
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As a routine measurement to alleviate membrane fouling, hydraulic cleaning is of great significance for the steady operation of ultrafiltration (UF) systems in water treatment processes. In this work, a comparative study was performed to investigate the effects of the composition of backwash water on the hydraulic cleaning performance of UF membranes fouled by humic acid (HA). Various types of backwash water, including UF permeate, Milli-Q water, NaCl solution, CaCl2 solution and HA solution, were compared in terms of hydraulically irreversible fouling index, total surface tension and residual HA. The results indicated that Milli-Q water backwash was superior to UF permeate backwash in cleaning HA-fouled membranes, and the backwash water containing Na+ or HA outperformed Milli-Q water in alleviating HA fouling. On the contrary, the presence of Ca2 + in backwash water significantly decreased the backwash efficiency. Moreover, Ca2 + played an important role in foulant removal, and the residual HA content closely related to the residual Ca2 + content. Mechanism analysis suggested that the backwash process may involve fouling layer swelling, ion exchange, electric double layer release and competitive complexation. Ion exchange and competitive complexation played significant roles in the efficient hydraulic cleaning associated with Na+ and HA, respectively. 相似文献
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在对天然有机物分类的基础上进行了水体中有机物的特性研究,并采用氯胺对不同特性有机物的氯化消毒副产物进行了控制研究。结果表明,疏水酸占有机物总量的24%,疏水中性物质占41%,疏水性有机物占67%;对于三卤甲烷类消毒副产物生成势,疏水酸所产生的最多,疏水碱次之,亲水酸最少;对于卤乙酸类消毒副产物生成势,疏水碱产生的三卤乙酸最多,其次为疏水酸,亲水酸最少。氯胺对不同类有机物氯化消毒副产物控制程度不同,氯胺对疏水中性物质控制三卤甲烷类消毒副产物最好,其次是疏水碱和亲水碱;对疏水酸的三卤甲烷生成量控制较弱,对亲水酸的控制效果最差;氯胺对亲水碱氯化产生卤乙酸的控制效果最好,其次是疏水碱,控制效果最差的为疏水中性物质。 相似文献
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Polyaluminum chloride (PAC) was used as coagulant and suspended particles in kaolin water. Online instruments including turbidimeter and particle counter were used to monitor the flocculation process. An evaluation model for demonstrating the impact on the flocculation effect was established based on the multiple linear regression analysis method. The parameter of the index weight of channels quantitatively described how the variation of floc particle population in different size ranges cause the decrement of turbidity. The study showed that the floc particles in different size ranges contributed differently to the decrease of turbidity and that the index weight of channel could excellently indicate the impact degree of floc particles dynamic distribution on flocculation effect. Therefore, the parameter may significantly benefit the development of coagulation and sedimentation techniques as well as the optimal coagulant selection. 相似文献