聚合氯化铝去除污泥水中磷的工艺优化

在对比聚合氯化铝(PAC)对浓缩脱水污泥水及其上清液除磷效果的基础上,通过响应曲面法(RSM)分析了污泥水上清液PAC除磷过程中Al/P摩尔比、pH和搅拌转速(MS)对除磷效果的单独效应和联合效应,并探讨了PAC除磷动力学.结果表明,PAC直接对污泥水混凝除磷会恶化其沉降性能,且除磷效率不高.RSM优化得到的上清液除磷最优工艺条件为:Al/P摩尔比为2.49,pH为8.3,MS为398 r·min-1,除磷效率为97.8%,实验验证结果表明该优化操作模式行之有效.动力学分析结果表明,PAC对污泥水的除磷过程分为化学沉淀与絮凝体快速吸附除磷和二级动力学沉淀除磷两阶段.     

Removal of nanoparticles by coagulation

<正>Nanoparticles(NPs)from anthropogenic sources have applications in several commercial products,including cosmetics,pharmaceuticals,and materials.There is evidence that during their usage and disposal,engineered nanoparticles can and will be released into wastewater(Gottschalk et al.,2013;Pasricha et al.,2012;Westerhoff et al.,2013;Zheng et al.,2015).If water and wastewater treatment plants are inefficient or incapable of removing NPs from water,NPs will be released with the treated effluent,entering drinking water sources and natural aquatic environments,increasing exposure for plants,microorganisms,     

垃圾焚烧烟气中氯化氢产生机理及其脱除技术研究进展

焚烧处理已经成为我国许多城市的主要垃圾处理方式之一。垃圾中PVC塑料和餐厨垃圾等含氯组分在焚烧过程释放出氯化氢气体。介绍了垃圾焚烧过程氯化氢气体产生机理,分析了氯化氢气体对有机氯代污染物生成及重金属气化的影响以及氯化氢气体对焚烧设备造成的严重危害,综合论述了国内外氯化氢气体脱除技术研究进展。最后指出高温烟气中HCl控制技术在我国具有很好的应用前景。     

万宁地区近地面氯离子沉积速率的影响因素研究

目的 研究热带海洋大气环境中不同地貌下氯离子沉积速率的分布规律及主要影响因素。方法 通过挂片法采集万宁地区的氯离子沉积速率,并分析离海距离、地形地貌对氯离子沉积速率的影响,以及其与海水因素、自然环境因素间的相关性。结果 近海开阔区域氯离子沉积速率受离海距离和地貌的影响显著,在300 m处降低至90 m处的1/3左右,地貌的变化导致同一距离点处的氯离子沉积速率相差30倍。另外,高的海水有效波高、风速和东风占比使春季氯离子沉积速率高于夏季。结论 不同地貌下的氯离子沉积速率均与海水有效波高、风速间呈较强的正相关性。     

The role of metal oxides on oxidant decay and disinfection byproduct formation in drinking waters: Relevance to distribution systems

Maintaining a residual disinfectant/oxidant (e.g., chlorine and chlorine dioxide), is a generally used strategy to control microbial contaminants and bacterial regrowth in distribution systems. Secondarily oxidant, such as hypobromous acid (HOBr), can be formed during chlorination of bromide-containing waters. The decay of oxidants and formation of disinfection byproducts (DBPs) due to the interaction between oxidants and selected metal oxides were studied. Selected metal oxides generally enhanced the decay of these halogen-containing oxidants via three pathways: (1) catalytic disproportionation to yield an oxidized form of halogen (i.e., halate) and reduced form (halide for chlorine and bromine or chlorite for chlorine dioxide), (2) oxygen formation, and (3) oxidation of a metal in a reduced form (e.g., cuprous oxide) to a higher oxidation state. Cupric oxide (CuO) and nickel oxide (NiO) showed significantly strong abilities for the first pathway, and oxygen formation was a side reaction. Cuprous oxide can react with oxidants via the third pathway, while goethite was not involved in these reactions. The ability of CuO on catalytic disproportionation of HOBr remained stable up to four cycles. In chlorination process, bromate formation tends to be important (exceeding 10 µg/L) when initial bromide concentration is above 400 µg/L in the presence of dissolved organic matter. Increasing initial bromide concentrations increased the formation of DBPs and calculated cytotoxicity, and the maximum was observed at pH 8.6 during chlorination process. Therefore, the possible disinfectant loss and DBP formation should be carefully considered in drinking water distribution systems.     

活性染料印染废水混凝脱色研究

对以活性染料为主的印染废水，用硫酸亚铁、碱式氯化铝（ＰＡＣ）加内烯酰（ＰＡＭ）进行混凝土脱色实验，并分析了脱色机理实验表明，混凝剂投加量，ＰＨ值大小均对脱色效果有影响，通过比较，该文给出了取得最佳效果的控制条件。     

废二氯甲烷回收工艺的研究

文章为使废二氯甲烷回收再利用,研究了直接精馏和洗料精馏两种回收工艺,确定采用洗料-精馏回收方法可以使废二氯甲烷的收率达95%以上,且回收后的二氯甲烷的各项指标均达到再利用的标准.     

羟基聚合氯化铝铁溶液的形态转化规律

采用改进的 Al-Fe-Ferron逐时络合比色法和酸滴定实验研究了典型羟基聚合铝铁(n_Al/n_Fe=9∶1,5∶5)溶液的形态转化 .结果表明 ,羟基聚合铝铁的形态转化主要由 n_Al/n_Fe值、碱化度和熟化等因素决定 ;羟基聚合铝铁的形态转化特征是优势形态之间的转变 ;当n_Al/n_Fe>5∶5,随碱化度的升高 ,[Al+Fe]_a和 [Al+Fe]_b 2类形态逐渐占优势 ;随n_Al/n_Fe值的减小 ,[Al+Fe]_a和 [Al+Fe]_c增加 ,而 [Al+Fe]_b 减少 .讨论了羟基聚合铝铁的形态转化规律 .     

厦门海岸气溶胶中氯亏损研究

对厦门海岸两个采样点大气气溶胶进行观测分析,研究发现在1号采样点由于人为排放的影响,使粗、细粒径气溶胶中Cl^－/Na⁺比值大于1.16,研究还表明,在人为污染较轻的２号采样点,当粗粒径气溶胶中Na⁺/Ca²⁺比值大于1.0,细粒径气溶胶中Na⁺/Ca²⁺比值大于2.0时,气溶胶中Cl^-/Na⁺比值小于1.16,存在氯亏损现象,反之,气溶胶中存在氯富集。前者是由于二次反应产生;后者由于人为一次排放源的贡献所致。     

Estimating source strengths of HCl and SO2 emissions in the flue gas from waste incineration

HCl and SO_2 emission is one of the major concerns related to municipal solid waste incinerator(MSWI). In this study, a material flow analysis model was developed to estimate the HCl and SO_2 concentrations in the MSWI flue gases(FGs), and their concentrations in the full-scale MSWI were monitored. The calculated concentrations of HCl and SO_2 in the FG were 770–1300 mg/Nm~3 and 150–640 mg/Nm~3, respectively, in close agreement with the monitored values. More than 99% of Cl and 92% of S from the FG were captured into solid residues by the air pollution control(APC) systems. Moreover, since only 48.4%–67.5% of Cl and 21.3%–53.4% of S were transferred to the FG from the municipal solid waste(MSW), it was more reliable to estimate the source strengths and release amounts of HCl and SO_2 in the FG based on the amounts of Cl and S in the APC residues(AR) and exhaust gas rather than in the MSW. This simple method is easily applicable and the estimated results could provide scientific basis for the appropriate design and operation of the APC systems as well as corrosion control of heat recovery systems.