城市供水管网中铝形态特征分析

城市供水管网的水力及水质变化均会对管网水中铝的形态产生一定的影响,为了明确管网中铝的形态特征及变化规律,采用挖取的实际管段设置了不同的管段通水环境,考察管段进水和管段浸泡后出水中溶解铝、颗粒铝、总铝浓度的变化情况。结果显示,管网内水力条件较好时析出颗粒铝的概率较小;pH值升高会促进颗粒铝的溶解;新生成的颗粒铝易于被水流带出;水流停滞、pH值降低是促进颗粒铝发生析出和沉积的重要因素;非均相体系中的颗粒铝被水流带出,是导致少数龙头水总铝过高的原因。     

印刷电路厂废水处理

印刷电路版生产过程中有化学镀铜、电解镀铜、焊接等工艺,排出废水中含有大量金属。用氢氧化物沉淀去除金属,不能达到要求严格的排放标准。废水中的螯合剂使金属处于溶解状态而不沉淀。废水中溶中多种金属,无法选用对各种金属沉淀都是最优的pH值,某种金属仍以高浓度留在水中。高pH值条件下有些重金属会再溶解,因此要避免过量投加碱。氢氧化物沉淀缓慢,脱水困难。用硫化物沉淀法处理印刷电路厂废水时,虽然硫化物溶解度低,处理后     

原水突发六价铬污染的应急处理技术

本文以南方某水源水库水为研究对象,探讨了采用硫酸亚铁还原、碱性条件下沉淀去除原水中高含量六价铬的可行性。研究结果表明,只要原水的酸碱性适宜、硫酸亚铁的投加量足够,混凝沉淀的pH值控制得当,对总铬的去除率可以达到接近100％,且出厂水中总铁和铝的浓度都能达到生活饮用水水质标准的要求。偏酸性的原水（pH3～5）有利于六价铬的去除,但对于试验的中性原水,不调节pH值出厂水中的总铬也能降低至0．05mg／L以下;硫酸亚铁的投加剂量以3倍最低化学反应剂量为宜,即硫酸亚铁剂量与六价铬浓度比为26;沉淀反应的pH值控制在8．5左右。     

处理低温低浊水的混凝剂优选

通过混凝沉淀烧杯试验和水厂生产性试验,对硫酸铝（AS）和几种聚氯化铝（PAC）进行了优选,最终确定由深圳中润水工业技术发展有限公司提供技术、太仓新星轻工助剂厂生产的ZR-3型聚氯化铝的混凝沉淀效果最佳.在水温较低（＜10℃）时,与硫酸铝相比其投加量（以氧化铝计）可降低50%左右,药剂费可降低15%左右,出厂水pH值可提高0.2～0.3,余铝含量可下降约50%,并可大幅减少污泥产量,同时混凝剂投加量与沉淀池出水的pH值和铝含量具有较高的相关性.工程投产后取得了显著的社会效益和经济效益.     

混凝法去除水中TiO_2纳米颗粒

为了探讨混凝法去除水中纳米颗粒的可行性及最佳条件,研究了无机混凝剂(PAC、PFS、PAFC)和有机絮凝剂(CPAM、APAM、NPAM)对TiO_2纳米颗粒的去除效果,并考察了投加量、pH、沉淀时间、水力条件及有机无机复配对TiO_2纳米颗粒去除效率的影响。单独投加PAC、PFS和PAFC时,三者对应的最高去除率分别为92.51%、84.43%、95.66%。单独投加CPAM、APAM、NPAM时三者对应的去除率仅为61.72%、29.06%、55.37%。复配最佳混凝条件为:投加40mg/LPAC和3mg/LCPAM,pH值为9,G值143.5/s,沉淀时间15min,此时,TiO_2纳米颗粒去除率为99.6%。     

饮用水钙硬度去除中C/Ca值对CaCO3结晶的影响

饮用水中钙硬度去除效能主要受CaCO3结晶过程影响。通过改变C/Ca值模拟饮用水钙硬度去除,考察不同C/Ca值条件下,溶液体系pH值和Ca^2+浓度变化、上清液浊度变化以及结晶产物颗粒粒径分布、晶型和形态,以阐明钙硬度去除过程中CaCO3结晶行为。结果表明:试验条件下结晶产物均为方解石;溶液体系中加入的CO3^2-首先发生质子化,提高体系pH值,然后与Ca^2+结晶反应降低体系pH值;C/Ca值的增大提高了pH值,有助于Ca^2+的去除,但同时也会提高结晶产物颗粒数量、密度和减小结晶产物颗粒粒径,导致上清液浊度增大。饮用水钙硬度去除中要综合考虑残余Ca^2+浓度、出水pH值和浊度以及混凝剂用量等来优化确定C/Ca值。     

镉污染源水的应急处理技术研究

分析了发生突发性镉污染时镉在水体中的存在形式,考察了常规混凝、化学沉淀以及两者联用对镉污染源水的处理效果.结果表明:发生突发性镉污染时,镉在水体中主要以溶解态形式存在,所占比例＞60%;常规混凝沉淀可有效去除吸附态镉,但对溶解态镉的去除效果有限;化学沉淀法对镉有良好的去除效果,但会增加滤后水的浊度;化学沉淀与混凝联用技术可大大提高对镉的去除效果,在预调pH值至10、PAC的投加量为20 mg/L时,对镉的去除率＞97.7%,最大可处理浓度提高至0.220～0.264 mg/L.     

锌铝电极电絮凝法处理高氟饮用水的研究

在双铝极板电絮凝法的基础上引入锌电极,考察锌铝电极电絮凝法对高氟饮用水的除氟效果.静态试验结果表明,采用锌铝电极可以有效降低水中的氟离子浓度,对CODMn和浊度的去除效果优于双铝电极;当原水的氟离子浓度为6 mg/L时,最佳处理条件:锌、铝极板比为1:3、电解电压为18 V、反应pH值为6、反应时间为25～30 min.动态试验结果表明,当进水流量和氟离子浓度分别高达42 mL/min、8 ms/L时,调节进水pH值为6可使其出水中的氟离子浓度达标.     

机械搅拌造粒法处理含锶废水

针对沉淀/微滤除锶工艺中产生的污泥浓缩难及膜污染问题,采用机械搅拌造粒法,以Na2CO3为沉淀剂,CaCO3作为晶种,在去除水中锶元素的同时,形成密实的晶体颗粒,改善沉淀的性能,降低出水浊度,以减轻后续微滤工艺的负荷.试验结果表明,在采用造粒法处理含锶废水后,反应器出水pH值为10.48±0.02,浊度在0.45～2.00 NTU之间,对锶的平均去除率为97％.出水通过0.22 μm的膜过滤之后,除锶效果得到进一步提高.造粒700次后,所得沉淀颗粒的最小粒径为45.71 μm,相应的沉降速度为2.5 mm/s,总处理水量为504 L,沉淀颗粒的体积只有49 mL,污泥浓缩倍数大于10 000,具有实际应用的潜力.     

溶气气浮法与沉淀法的处理效果比较

对松花江原水采用气浮法和常规沉淀法进行处理发现，气浮法的除浊效果优于常规沉淀法，在低温、低浊时二者的处理效果差距更大，故从颗粒尺寸、颗粒密度、水温、颗粒沉降速率和反应时间等角度阐述了气浮和沉淀工艺在除浊效果方面的差异。此外，两种工艺对CODMn、UV254和TOC的去除效果表明有机物质的去除只与混凝步骤有关而与沉淀或气浮步骤无关。     

Comparison of polyaluminum silicate chloride and electrocoagulation process,in natural organic matter removal from surface water in Ghochan,Iran

Removal of natural organic matter (NOM) is one of the most important objectives of water treatment plants but reducing these pollutants either present in water as dissolved or suspended form is not as efficient as is required in conventional treatment plants. The purpose of this study was comparison performance of composite polyaluminum silicate chloride (PASiC) and electrocoagulation (EC) process by aluminum electrodes in NOM removal from raw surface water. In this study, the effects of turbidity, total organic compounds (carbons) (TOC), adsorption at a wavelength of 254 nm (UV254), chemical oxygen demand (COD), alkalinity, residual aluminum in finished water by application of EC process and PASiC were investigated. The results demonstrate that PASiC coagulant at optimum concentration of 1–5 ml/L was capable of removing TOC, COD, U.V., and turbidity from raw water by 93.77, 93.5, 63 and 95 %, respectively. In contrast, EC process, removed TOC, COD, UV and turbidity from raw water by 89, 99.75, 37 and 50%, respectively. The pilot-scale results demonstrated the significant advantage of PASiC compared to EC process in removal of NOM and turbidity form raw water. Residual aluminum in finished water was below the recommended WHO guidelines 0.2 mg/L for both processes. Finally it can be concluded that PASiC and EC process are reliable, efficient and cost-effective methods for removal of NOM from surface water.     

新生态铁锰氧化物的混凝及强化混凝效能分析

采用FeSO4与KMnO4反应制备成新生态铁锰氧化物,并对松花江水进行处理。试验结果表明：新生态铁锰氧化物较新生态二氧化锰的除污效果好,但新生态铁锰氧化物的除污能力会随着放置时间的延长而逐渐下降;在不同温度和浊度的松花江水的混凝试验中,浊度低时新生态铁锰氧化物对水中有机物的去除效果较好,温度对其混凝效果影响较小;利用新生态铁锰氧化物强化硫酸铝的混凝过程,能够明显提高对低温、低浊水中有机物的去除效果,对UV254的去除率较单独投加硫酸铝时几乎提高了1倍,对TOC的强化去除作用在混凝剂投量低时更为明显。     

聚硅氯化铝的混凝效果及在处理水中的残留铝研究

采用共聚与复合两种工艺,制备出了具有不同碱化度（Ｂ）和Ａｌ／Ｓｉ磨尔比的聚硅氯化铝（ＰＡＳＣ）混凝剂。试验结果表明,ＰＡＳＣ较ＰＡＣ具有更好的混凝除浊效果和较低的残留铝含量;共聚法制备的ＰＡＳＣ又较复合法制备的ＰＡＳＣ具有更好的混凝效果和低的残留铝含量。Ｂ值的升高和Ａｌ／Ｓｉ摩尔经的降低均有利于降低混凝剂在水体中的残留铝含量;ｐＨ值对ＰＡＳＣ混凝土剂在水体中的残留铝量有一定的影响,在中性条件下,Ｐ     

纳米SiO2的分散表征及其强化混凝低温低浊水研究

采用原子力显微镜、激光粒度仪对超声分散纳米SiO2的粒径分布、微观形状等进行了表征，并使用该纳米分散液对低温、低浊水进行了强化混凝研究。结果表明：纳米SiO2可均匀、稳定地分散在水溶液中，平均粒径为30nm，形状呈球形，在pH值为3～12时其表面带负电；将其用于强化混凝处理低温、低浊水时可以显著降低出水浊度，提高所形成矾花的密实程度，同时改善矾花的沉降性能。     

臭氧/高锰酸盐预氧化助凝及影响因素

提出了高锰酸盐强化臭氧氧化助凝技术,并分析了复合氧化助凝效果的各种影响因素。试验结果表明,复合氧化比单独臭氧氧化更有利于对浊度的去除。复合氧化的投加顺序是先投加高锰酸盐后投加臭氧,较佳的剂量配比是高锰酸盐0.4mg/L与臭氧1.0mg/L。复合氧化除浊的效果受诸多因素影响,复合氧化可适应更大的G值变化范围;助凝效果受原水水质的影响,原水硬度为160mgCaCO3/L时助凝效果最佳,原水TOC浓度为3mg/L时对混凝的影响最小;低温有助于复合氧化助凝;复合氧化受pH值影响较小,可以适应较大范围的pH值变化。与臭氧氧化相比,复合氧化更能适应水力和水质条件的变化。     

Impact of recycling filter backwash water on organic removal in coagulation-sedimentation processes

The overall purpose of this research was to examine the impacts of filter backwash water (FBWW) and membrane backwash water (MBWW) recycles on water quality in coagulation-sedimentation processes. Specifically, the impact of recycling 5 or 10% by volume of FBWW and MBWW with surface water on the removal of natural organic matter (NOM) was evaluated at bench-scale using a standard jar-test apparatus and measurement of specific water quality parameters including total organic carbon (TOC), dissolved organic carbon (DOC), UV254, turbidity, total aluminum and zeta potential. The results of jar test conducted on a source water with a specific UV absorbance (SUVA) value within the range of 2-4 mg/L m showed a significantly higher removal of DOC from the raw water that was blended with 5 and 10% by volume of FBWW as compared to control trials where backwash water was not added. Increasing rates of MBWW that did not contain destabilized hydroxide precipitates did not significantly change DOC concentrations in the settled water samples as compared to the control trials. For source waters that are characterized as having low turbidity with medium SUVA values, these results could hold particular significance for plants that have reached treatment ceilings in terms of dissolved NOM removal using conventional coagulation designs.     

涂铁砂的直接过滤效果及其再生方法研究

以某低温、低浊江水为研究对象，用表面涂渍氧化铁的石英砂（简称涂铁砂）进行直接过滤试验，考察了涂铁砂对浊度和有机物的去除效果，并与天然石英砂的直接过滤效果进行了对比。试验结果表明，涂铁砂在去除浊度和有机物方面明显优于天然石英砂，但经反冲洗后的涂铁砂对有机物去除经很低。另外，对被穿透的滤柱进行了再生处理，发现用硫酸铝溶液可使涂铁帮的除污能力得到恢复，对浊度和有机物均有显著的去除效果。     

复合混凝剂PTA-CPAM的形貌结构与净水性能

以聚合氯化铝(PAC)、四氯化钛(TiCl_4)、阳离子聚丙烯酰胺(CPAM)为原料成功制备无机-有机复合混凝剂聚钛氯化铝-阳离子聚丙烯酰胺(PTA-CPAM),采用红外光谱(IR)、扫描电镜(SEM)、能谱分析(EDS)与差热热重(TG-DTA)对产物的结构、组成及热稳定性进行分析。此外,对PTA-CPAM的混凝性能进行研究。结果表明:当m(CPAM)/m(PTA)=0.4、PTA-CPAM投加量为9.0mg/L、pH为9.0的条件下,混凝剂的净水效果最优,且PTA-CPAM对不同初始浊度的水样都有较优的除浊能力;协同增效作用使PTA-CPAM具备更强的吸附电中和与吸附架桥网捕能力,表现出优异的除浊性能。     

Assessment of the nutrient removal performance in integrated constructed wetlands with the self-organizing map

The self-organizing map (SOM) model was applied to predict outflow nutrient concentrations for integrated constructed wetlands (ICWs) treating farmyard runoff. The SOM showed that the outflow ammonia-nitrogen concentrations were strongly correlated with water temperature and salt concentrations, indicating that ammonia-nitrogen removal is effective at low salt concentrations and comparatively high temperatures in ICWs. Soluble reactive phosphorus removal was predominantly affected by salt and dissolved oxygen concentrations. In addition, pH and temperature were weakly correlated with soluble reactive phosphorus removal, suggesting that soluble reactive phosphorus was easily removed within ICWs, if salt concentrations were low, and dissolved oxygen, temperature and pH values were high. The SOM model performed very well in predicting the nutrient concentrations with water quality variables such as temperature, conductivity and dissolved oxygen, which can be measured cost-effectively. The results indicate that the SOM model was an appropriate approach to monitor wastewater treatment processes in ICWs.     

Modeling copper partitioning in surface waters

Suspended particulate matter from the surface waters of the Susquehanna, Christina and Brandywine Rivers was collected by tangential flow filtration to study copper partitioning. Copper adsorption increased with an increase of suspended particles and decreased with low pH values or with an increase of dissolved organic matter. Effects of particulate organic matter on copper distribution between suspended particulate and solution phases were studied using modified aluminum oxide. An increase of particulate organic matter enhanced copper adsorption. Copper adsorption per mass of particulate organic carbon was similar for the different sources of suspended particles. A model, based on copper adsorption on particles and complexation with dissolved organic matter, was developed to assess copper partition coefficient as a function of the easily measurable water quality parameters: pH, alkalinity, dissolved organic carbon and particulate organic matter. The partitioning model was calibrated on pH edge data using suspended particles collected from the three rivers. The model was verified using partitioning data as a function of dissolved organic matter. The model adequately describes the system containing natural suspended solids collected from the surface waters.