板间距对电絮凝处理微污染水的影响

电絮凝作为一种具有广泛应用前景的低廉高效污水处理技术,已经被证明在工业废水、生活污水等污染严重的水体处理上具有显著效果,但是目前对于电絮凝净化微污染水的相关研究较少。通过对电絮凝分批处理河水的实验研究,分析电絮凝方法处理微污染水的可行性,讨论极板间距的改变对电絮凝处理效果的影响。结果表明,电絮凝处理技术可以用于微污染水净化中,在电流密度为17.75 A/m2、极板间距为1.5 cm的条件下,反应30 min时,色度去除率为73.76%,浊度去除率为76.00%,悬浮固体去除率为85.71%,化学需氧量去除率为42.86%,总磷去除率为61.36%。在电絮凝反应中,极板间距对于微污染水的色度、浊度、悬浮固体和总磷去除效果具有明显的影响。     

电絮凝处理黄土塬地区村镇集蓄雨水的实验研究

采用电凝聚对黄土塬地区村镇集蓄雨水进行处理。通过改变极板间距、极板电压、电解时间,进行了对集雨水中COD,浊度,NH3-N,UV254的去除率研究。结果表明：电解时间15 min,极板间距为10 mm,极板电压为15 V的条件下,电絮凝对集蓄雨水中浊度、氨氮、UV254、COD有较好的去除效果,去除率分别为95%、63%、48%、80%,高于化学絮凝的处理效果。     

高铁酸盐在线制备及其预氧化强化絮凝除藻的中试研究

从电极组合方式、碱液浓度、极间距、电流强度和电解质浓度等因素,探索了电化学法在线制备高铁酸盐的最佳条件。采用高铁酸盐预氧化,结合常规水处理工艺,研究对厦门某水厂原水中浊度、UV_(254)、氨氮和叶绿素a的去除效果;对比了单独絮凝和高铁酸盐强化絮凝对微污染物的去除。结果表明:在最优电解条件下,电化学在线制备高铁酸盐的最大浓度可达2mmol/L;高铁酸盐作为预氧化剂能够强化絮凝沉淀过程,不但产生的絮体沉降性能好,而且可以显著减少絮凝剂的投加量,并且对原水浊度、UV_(254)、叶绿素a、氨氮都有较好的去除效果。     

电絮凝法去除饮用水中氟的技术研究

以自来水加氟标准液为试验水样,采用铝电极电絮凝法去除饮用水中的氟,进行了pH、电极间距、原水氟含量、出水流量等因素对氟去除率影响的试验。结果表明,电絮凝法去除饮用水中氟无需添加任何化学成分和改变pH,对于氟>1.0mg/L的地下水,在电流密度为20～60A/m2、电极板间距离5～15mm、四级过滤条件下,氟去除率为70%以上,原水中铁、悬浮物等也有明显降低,处理出水氟含量符合国家饮用水卫生标准。     

铁阳极电凝聚法除磷条件初探

采用铁板作阳极,白钛网板作阴极的电凝聚方法处理含磷废水。结果表明,极板间距为3cm时,电流效率为88.1%;当原水磷浓度为5mg/L时,最优电流密度为2mA/cm~2;连续通电比只通电45min和25min对磷的去除率分别高10%和40%左右;将电凝聚用于活性污泥混合液中磷的去除,污泥絮体和有机物对电凝聚除磷效果无明显影响,去除率仍达95%以上。电解后污泥沉降性有所改善,SV值从83%降至40%,污泥浓度仅由2.41g/L增至2.47g/L,增幅2.4%。     

低温低浊水絮凝工艺的数值模拟与响应面优化试验研究

为探究微涡流絮凝工艺处理低温低浊水时,絮凝区流场流态的变化以及水中浊度、CODMn、UV254的最优去除效果,采用CFD数值模拟探究不同流量(絮凝时间)下絮凝区流场流态,确定最佳絮凝时间;应用响应面中Box-Behnken的中心组合设计方法,研究了流量、混凝剂投加量与涡流反应器投配比及其交互作用对微涡流絮凝工艺去除浊度...     

高浊水处理投药方式的选择

在常规处理条件下,对西南岷江地区突发性非多砂高浊水进行了原水特性的分析及絮凝优化试验。结果表明,采用单级絮凝、分级沉淀工艺,先投加PAC,60~120s后投加PAM,对高浊度原水有良好的去除效果。原水浊度为15000NTU时,投加200mg/LPAC、0.4~0.5mg/LPAM,静沉30min后,出水浊度为1.73~2.48NTU。     

锌铝电极电絮凝法对含氟水除氟效果研究

饮用水中氟的含量对人体健康有重要影响,相较于常用的水处理除氟方法存在除氟效率低和成本高等问题,电絮凝法除氟具有工艺简单、易于操作等优点。使用自制的电絮凝反应槽,在双铝极板电絮凝基础上引入锌铝电极,进行电絮凝的动态试验,研究电絮凝法处理高氟饮用水时不同进水流量、不同F^-含量、不同pH值对除氟效果的影响及其变化规律,并对锌铝电极与双铝电极的除氟效果进行了比较,结果表明:不同进水流量,在电解槽内的水力停留时间不同,对除氟效果有一定影响,进水流速过快时,不能将水中氟离子含量处理到符合生活饮用水标准要求;在动态运行条件下,氟离子含量低的水样,电絮凝法可以将水样中的氟离子处理达标,氟离子含量较高时,则需要调节pH值才能使电絮凝法得到更好的处理效果;与双铝电极相比较,锌铝电极不仅能有效去除水中的氟离子,而且还能有效降低水的COD含量和浊度。同时指出,水中氟离子的电解去除过程与极板材料的损耗过程同步,在电絮凝过程中,可以采用倒换电极的正负极、减小极板厚度、设置pH值调节池等措施对阳极钝化过程进行控制。     

高浊水处理投药方式的选择

摘要：在常规处理条件下,对西南岷江地区突发性非多砂高浊水进行了原水特性的分析及絮凝优化试验。结果表明,采用单级絮凝、分级沉淀工艺,先投加PAc,60～120s后投加PAM,对高浊度原水有良好的去除效果。原水浊度为15000NTU时,投加200m∥LPAC、0．4-0．5mg／LPAM,静沉30min后,出水浊度为1．73-2．48NTU。     

流量对电絮凝连续处理微污染水的影响

对雨水等微污染水进行净化利用是解决水资源短缺问题的一条有效途径。电絮凝作为一种具有广泛前景的低廉高效污水处理技术,已经被证明在工业废水、生活污水等污染严重的水体处理上具有显著效果,但是目前对于电絮凝净化微污染水的相关研究较少。与分批处理相比,连续电化学处理更简单快捷,处理量大,且无需人为值守。通过河水处理试验,讨论流量的改变对电絮凝处理效果的影响,结果表明流量对电絮凝连续处理微污染水的效果具有明显的影响,存在一个较佳流量,但规律并不显著。试验中在电流密度为14.79 A/m~2、极板间距1.5 cm条件下,该流量约为2.0 mL/s,此时反应3 h后,色度去除率为48.88%,浊度去除率为73.17%,悬浮固体去除率为58.06%,化学需氧量去除率为35.00%,总磷去除率51.22%;处理后溶液pH值稍有提高,电导率有所下降。可见运用电絮凝处理技术连续净化微污染水具有一定的可行性。     

A case study of dissolved air flotation for seasonal high turbidity water in Korea.

A DAF (Dissolved-Air-Flotation) process has been designed considering raw water quality characteristics in Korea. Although direct filtration is usually operated, DAF is operated when freshwater algae blooms occur or raw water turbidity becomes high. Pre-sedimentation is operated in case when the raw water turbidity is very high due to rainstorms. A main feature of this plant is that the operation mode can be changed (controlled) based on the characteristics of the raw water to optimize the effluent quality and the operation costs. Treatment capacity (surface loading rate) and efficiency of DAF was found to be better than the conventional sedimentation process. Moreover, low-density particles (algae and alum flocs) are easily separated while the removal of them by sedimentation is more difficult. One of the main concerns for DAF operation is a high raw water turbidity. DAF is not adequate for raw water, which is more turbid than 100 NTU. In order to avoid this problem, pre-sedimentation basins are installed in the DAF plant to decrease the turbidity of the DAF inflow. For simulation of the actual operation, bench and full-scale tests were performed for highly turbid water conditions. Consequently, it is suggested that pre-sedimentation with optimum coagulation prior to DAF is the appropriate treatment scheme.     

聚合氯化铝铁强化混凝去除藻类试验研究

采用聚合氯化铝铁,对微污染黄河水库水进行了强化混凝除藻试验.试验结果表明:针对原水水质,PAFC的最佳投加量为15mg/L,此时浊度和叶绿素a的去除率分别为94.67%和80.15%;PAFC的最佳pH范围是5.0～9.0,试验过程中无需对原水进行调节pH值;投加高分子助凝剂(JY)对原水的浊度、高锰酸盐指数和叶绿素a有一定的去除效果,助凝剂与混凝剂的复配可改善PAFC的混凝去除效果,助凝剂JY的投加量为0.3mg/L时,叶绿素a的去除率可提高12.9%.     

利用溶气气浮工艺强化处理低浊高色富含有机物地表水

低浊高色富含有机物地表水难于混凝,试验采用“混凝-溶气气浮”(“混凝-DAF”)工艺处理此类水,并与常规“混凝-沉淀”工艺进行了比较。结果表明,“混凝-DAF”工艺在较低投药量时能取得更好的处理效果;对于“混凝-DAF”工艺,增大混凝剂投量后出水浊度基本不变,但出水色度及CODMn可进一步降低;“混凝-DAF”工艺去除水中有机物的能力优于“混凝-沉淀”工艺。最后,对“混凝-DAF”工艺去除水中有机污染物的机理进行了探讨。     

Lab scale study on electrocoagulation defluoridation process optimization along with aluminium leaching in the process and comparison with full scale plant operation

An excess or lack of fluoride in drinking water is harmful to human health. Desirable and permissible standards of fluoride in drinking water are 1.0 and 1.5 mg/L, respectively, as per Indian drinking water quality standards i.e., BIS 10500, 1991. In this paper, the performance of an electro-coagulation defluoridation batch process with aluminium electrodes was investigated. Different operational conditions such as fluoride concentration in water, pH and current density were varied and performance of the process was examined. Influence of operational conditions on (i) electrode polarization phenomena, (ii) pH evolution during electrolysis and (iii) the amount of aluminium released (coagulant) was investigated. Removal by electrodes is primarily responsible for the high defluoridation efficiency and the adsorption by hydroxide aluminium floc provides secondary effect. Experimental data obtained at optimum conditions that favored simultaneous mixing and flotation confirmed that concentrations lower than 1 mg/L could be achieved when initial concentrations were between 2 and 20 mg/L. pH value was found to be an important parameter that affected fluoride removal significantly. The optimal initial pH range is between 6 and 7 at which effective defluoridation and removal efficiencies over 98% were achieved. Furthermore, experimental results prominently displayed that an increase in current density substantially reduces the treatment duration, but with increased residual aluminium level. The paper focuses on pilot scale defluoridation process optimization along with aluminium leaching and experimental results were compared with a full-scale plant having capacity of 600 liter per batch.     

载粉末活性炭过滤处理微污染原水的试验研究

载粉末活性炭(PAC)过滤集PAC吸附与过滤于一体,能够应用于微污染原水处理。配水试验结果表明:粒径为1.25-2.5mm,厚度为1000mm的聚苯乙烯滤料层能够用于载PAC过滤。影响过滤效果的主要因素为PAC载量和混凝剂投加量,当混凝剂T3010和聚氯化铝的投加量分别为0.09mg/L和2.5mg/L,PAC载量为2-3g/L滤料时,载PAC过滤处理浊度为20-40NTU的微污染原水的效果达到最佳,对CODMn和浊度都具有很好的去除效果。Z河水作为原水的试验结果表明:载PAC过滤对河水浊度、UV254、CODMn的去除率分别为97%-97.9%、50.9%-63.4%、68.5%-71.4%。     

强化混凝技术处理南淝河污染水的效果

选用聚合氯化铁(PFC)、聚合硫酸铁(PFS)、聚合氯化铝(PAC)和聚合氯化铝铁(PAFC)作为混凝剂;选用阳离子型聚丙烯酰胺(CPAM)、阴离子型聚丙烯酰胺(APAM)和非离子型聚丙烯酰胺(NPAM)作为助凝剂,通过室内试验对比研究强化混凝技术中多种混凝剂单用及其和助凝剂联用对南淝河污染水的除浊和去污效果,并用于南淝河现场构建的混凝沉淀系统。结果表明,4种混凝剂单用时,PAFC对浊度、TP去除效果最优,对CODMn有良好的去除效果,且不影响原水的p H值,而PFC和PFS单用时可明显降低原水p H值,4种混凝剂单用时对TN均没有明显去除效果;PAFC与CPAM联用时对浊度的去除效果最佳,明显优于PAFC与APAM和NPAM联用和PAFC单用的效果;混凝剂与CPAM联用提高了其除浊和去除TP的能力,但不能明显改善其去除CODMn的效果,对原水p H和TN的影响与单用时相同。选取"PAFC+CPAM"作为南淝河示范工程的混凝剂和助凝剂,现场混凝沉淀出水水质稳定,浊度和TP的去除效果较好,去除率分别达到90%和80%,对CODMn的去除率约为52%,而对TN的去除效果有限,去除率约为22.4%。