超滤与粉末活性炭组合工艺处理饮用水

采用超滤与粉末活性炭组合工艺,研究了粉末活性炭的投加对超滤膜运行性能的影响。结果表明:随粉末活性炭投量的增加,膜稳定运行时间延长,膜通量下降率降低。粉末活性炭的投加对膜过滤阻力影响不大。采用粉末活性炭和超滤组合工艺处理饮用水,在CODMn和TOC的质量浓度分别为5.5～9.5和1.8～3.5 mg/L,UV254为0.069～0.093 cm-1,浊度为1.29～1.98 NTU时,其平均去除率分别为68.5%、75%、55%和96%以上,粉末活性炭超滤膜组合工艺可用于制备优质饮用水。     

活性炭UF膜分离污水中COD的实验研究

试验考察了粉末活性炭的投加对超滤膜运行性能的影响,结果表明:随粉末活性炭投量的增加膜稳定运行时间延长,通量下降率降低。粉末活性炭的投加对膜过滤阻力影响不大。在此基础上又对PAC-UF组合系统去除有机物的效果进行了进一步研究,主要是对比研究了不同PAC投加量对5种不同配置水样中有机物的去除效果。得出如下结论:在相同PAC投加量下,CODMn值大的水样的CODMn平均去除率高,且出水CODMn值相近。说明了PAC-UF组合系统出水稳定,受水质差异的影响不大。     

不同超滤组合工艺净水及膜污染的中试研究

采用超滤中试系统处理深圳某水库原水,对比研究了粉末活性炭和混凝2种预处理工艺对超滤净水效果及对超滤膜污染的影响。结果表明,混凝/超滤工艺和粉末活性炭/超滤工艺对浊度、CODMn、UV254、DOC的平均去除率分别为99.6%、34.8%、31.3%、24.9%和99.4%、35.0%、32.4%、29.5%。粉末活性炭/超滤工艺对以CODMn、UV254、DOC表征的有机物的去除效果优于混凝/超滤工艺,而混凝/超滤工艺对有机物的去除效果受原水水质的影响较小,并且出水浊度效果稍好。在原水水质和运行条件相同的情况下,混凝/超滤工艺的跨膜压差的增长速度明显高于粉末活性炭/超滤工艺;但对超滤膜进行化学清洗后,粉末活性炭/超滤工艺膜表面仍有明显的污染物残留。     

粉末活性炭-超滤膜联用工艺去除水体藻毒素的特性研究

针对饮用水中藻毒素污染问题,本文对超滤膜(UF)、粉状活性炭(PAC)及其组合工艺去除藻毒素(MCs)的效果和特性进行了研究.结果表明,单独的超滤膜工艺对水体中溶解性藻毒素的去除率较低,一般低于5%.单独的粉末活性炭吸附技术在投加量高于20mg·L-1时对MCs的去除效率较高,可迭82.16%;粉末活性炭与超滤联用工艺在PAC投加量为20mg·L-1时,产水中未检测出微囊藻毒素.该组合工艺运行稳定,可有效减缓膜污染.     

超滤膜工艺技术在饮用水处理的应用研究进展

该文综述了饮用水常规处理工艺存在的弊端,介绍了超滤膜在饮用水净水工艺中的适用性和技术优势;重点阐述了"混凝-超滤"、"粉末活性炭-超滤"等超滤组合工艺在国内外的研究及应用状况;分析了膜污染的机理及防控措施;提出超滤膜技术存在的问题和发展方向。     

投加粉末活性炭对超滤膜去除海水中有机物的影响

超滤膜的有机污染问题是膜法海水预处理技术在海水淡化工程应用面临的重要挑战,粉末活性炭吸附是目前常用的膜前预处理手段之一。本文对比分析了直接超滤和投加粉末活性炭后对海水中有机物的截留能力,利用三维荧光光谱分析了投加粉末活性炭对超滤膜截留有机物的影响机制,并考察了海水超滤过程中通量变化及膜污染情况。研究结果表明,投加粉末活性炭能够强化超滤膜对海水浊度和有机物的去除,当粉末活性炭投量为200mg/L时,整个系统对海水中DOC去除率从直接超滤时的55.1%提高到77.6%。利用粉末活性炭的吸附作用及其在超滤膜表面形成的疏松滤饼层能够显著提高超滤系统对海水中腐植酸类有机物的去除能力。与直接超滤相比,粉末活性炭-超滤系统对改善膜通量的作用有限,但粉末活性炭形成的滤饼层能够避免超滤膜与有机物直接接触,可显著减缓超滤膜的不可逆污染。     

常用超滤膜组合工艺在饮用水处理中的进展及应用

介绍了三种常用超滤膜组合工艺——混凝／超滤、常规处理／超滤、活性炭／超滤的特点和处理效果,并分类整理了近几年超滤膜组合工艺在饮用水处理中的研究进展以及相应的成功建设实例。     

浸没式超滤膜组合工艺处理饮用水的中试研究

通过中试实验研究了混凝沉淀-超滤、混凝沉淀-砂滤-超滤和混凝沉淀-升流式曝气生物活性炭-超滤三种工艺处理饮用水的净水效果及对膜污染影响情况。结果表明,3种工艺的浊度和颗粒数去除率均能达到99%以上且不受原水水质影响,都能去除水中大多数的微生物和浮游动物,说明超滤膜组合工艺能有效的保证出水的生物安全性。超滤膜本身对水中溶解性有机物和氨氮的去除效果较差,相对于混凝沉淀-超滤工艺,选用混凝沉淀-砂滤-超滤工艺和混凝沉淀-升流式曝气生物活性炭-超滤工艺对COD_(Mn)、UV_(254)及氨氮的去除率分别提高了21.2%、18.2%、28.6%和40.8%、63.7%、59.2%,且这两种工艺的过滤阻力也远小于混凝沉淀-超滤工艺的过滤阻力。     

粉末活性炭-超滤膜组合工艺去除水体中藻类及微囊藻毒素

研究粉末活性炭(PAC)、超滤膜(UF)及二者组合工艺对微囊藻毒素(MC-RR)及藻细胞的去除效果,发现粉末活性炭对MC-RR吸附容量为0.23μg/g,其吸附等温线可以用Langmuir吸附等温线模拟,吸附效果随PAC投加量增大而增大。单独超滤膜运行初期对MC-RR去除效果仅为8.5%,且随着藻细胞在超滤膜上聚集,去除率有所下降。BPAC-UF组合工艺运行初期MC-RR去除率达到85%,运行20 d后去除率稳定在70%。对组合工艺中微生物进行高通量测序显示在门水平上变形菌门和拟杆菌门分别占比为80.8%和11.6%,在种水平上最主要的三类为粘细菌、屈挠杆菌和甲基营养菌,其占比分别为34.3%、8.4%和12.7%。     

超滤在饮用水处理中的应用和研究进展

介绍了超滤在饮用水处理中的应用和研究进展;研讨微絮凝+超滤组合工艺、粉末活性炭(PAC)+超滤组合工艺,以及膜污染及其防治技术;从处理效果、经济性能上对超滤工艺与常规过滤工艺进行对比。认为超滤工艺必将成为未来饮用水最重要最有效的处理技术之一;而混凝+超滤工艺比较适合我国国情,具有很好的发展前景。     

PAC-UF组合系统在饮用水处理中的试验研究

试验考察了粉末活性炭(PAC)的投加对超滤膜(UF)运行性能的影响,结果表明：PAC投加到蒸馏水中使膜通量产生微小下降。单独用UF膜系统处理自来水时,膜的通量急剧下降,而PAC作为UF膜的预处理方式处理相同水量时,可以明显延长膜的运行周期;随PAC投量的增加膜稳定运行时间延长,通量下降率降低。物理清洗方式对PAC-UF组合系统中膜通量的恢复效果较好,而化学清洗方式对单独UF膜系统中膜通量的恢复效果较好。     

PAC/AC与超滤组合去除水中有机物效果的研究

分别以粉末活性炭(PAC)和活性焦(AC)作为超滤(UF)前处理材料,考察了PAC-UF和AC-UF两种组合工艺对水中不同分子质量大小有机物的去除能力,并对两种吸附材料对膜污染的影响进行了评价。实验结果表明:PAC和AC均可有效吸附水中分子质量为1~10 k Da的有机物,并能有效缓解膜污染;AC表现出了良好的吸附性能,可在再生水的深度处理中作为替代PAC的吸附材料。     

用活性炭吸附强化超滤过程脱除废水中染料的研究(英文)

In this study, orange G dye was efficiently removed from aqueous solution by ultrafiltration (UF) mem-brane separation enhanced with activated carbon adsorption. The powdered activated carbon (PAC) was deposited onto the UF membrane surface, forming an intact filter cake. The enhanced UF process simultaneously exploited the high water permeation flux of porous membrane and the high adsorption ability of PAC toward dye molecules. The influencing factors on the dye removal were investigated. The results indicated that with sufficient PAC incor-poration, the formation of intact PAC filtration cake led to nearly complete rejection for dye solution under opti-mized dye concentration and operation pressure, without large sacrificing the permeation flux of the filtration process. Typically, the dye rejection ratio increased from 43.6% for single UF without adsorption to nearly 100% for the en-hanced UF process, achieving long time continuous treatment with water permeation flux of 47 L·m 2·h 1. The pre-sent study demonstrated that adsorption enhanced UF may be a feasible method for the dye wastewater treatment.     

Removal of Phenolic Substances from Water by Adsorption and Adsorption-Ultrafiltration

In this work a magnetic adsorbent, magnetic activated carbon (MAC) was prepared and characterized by powdered X-Ray diffraction (XRD). A comparison was made between powdered activated carbon (PAC) and MAC for foul control in ultrafiltration (UF) membrane processes. First, the adsorptive parameters for PAC and MAC were determined for phenol, chlorophenol, nitrophenol, and hydroquinone. Equilibrium data fitted well to the Langmuir model in the studied concentration range of the adsorbates. Adsorption kinetics followed a pseudo second-order kinetic model rather than pseudo first-order kinetic model. These adsorbents were then used in combination with UF membrane. The parameters like percent rejection and flow rate for the hybrid UF/PAC and UF/MAC were determined. The influences of both adsorbents on flow rates and percent rejections were almost equal. The problems associated with PAC in the UF processes like cake formation and blackening of the pipes were not observed for MAC. MAC was removed from the slurry after use through a magnetic process.     

Integration of immersed membrane ultrafiltration with coagulation and activated carbon adsorption for advanced treatment of municipal wastewater

A pilot-scale hollow-fiber ultrafiltration unit was installed in the wastewater treatment plant of Rethymno, Crete, Greece. The system was fed with treated unchlorinated effluent. Three sets of experiments were conducted. At first, the UF pilot unit was operated as a direct filtration unit. During the second phase, ultrafiltration was combined with the addition of a coagulant (alum). The last phase of the experiments involved the addition of activated carbon (either powdered or granular) into the system. During direct filtration, the average COD removal was 19%, while the average DOC was removed to a similar extent (25%). Effluent turbidity was practically independent of the influent turbidity with an overall average removal of 90%. Faecal and total coliform were also removed efficiently reaching average removals of 99.94% and 99.96%, respectively. Removal of heavy metals in particulate form also took place. When ultrafiltration was combined with in-line coagulation, the results were similar to those exhibited without coagulation. Combining ultrafiltration with powdered activated carbon resulted in DOC removal as high as 60%. However, after the addition of the PAC, the transmembrane pressure increased rapidly due to the formation of PAC cake on the membrane surface. Application of granular activated carbon resulted in 36% reduction of DOC without causing an increase to the trans-membrane pressure. Heavy metals present in the secondary effluent were also removed very efficiently by the GAC in the UF tank.     

Application of ultrafiltration hybrid membrane processes for reuse of secondary effluent

This study evaluates the factors affecting pretreatment conditions for hybrid UF membrane processes for reuse of secondary effluent from the sewage treatment plant. The experimental results obtained from the ultrafiltration (UF) membrane process showed that the particles of the size range between 0.2 and 1.2 μm caused a significant impact on membrane fouling in all cases even with or without the coagulation process. As pretreatment of UF membrane process, the coagulation significantly improved the permeate flux. Optimal flux improvement was seen at an alum dose of 50 mg/L. In addition, it was found that the permeate flux was least declined under the coagulation condition of charge neutralization (pH 5.0). Also, the powdered activated carbon (PAC) adsorption enhanced the permeate flux. Application of the direct filtration as a pretreatment of UF membrane process was also very effective in reducing the UF membrane fouling.     

Application of an ozonation–adsorption–ultrafiltration system for surface water treatment

Investigations are presented on the effect of the preliminary ozonation on ultrafiltration (UF) and powdered activated carbon (PAC) /UF process performance, especially on permeate flux decline and the effectiveness of model organics removal. Flat membranes from regenerated cellulose were used. A model solution was prepared as a mixture of humic acids and phenol. PAC dosage was equal to 100 mg/l⁻¹. The ozone dosages were in the range of 1–3 mg O₃ l⁻¹ (0.2–0.6 mg O₃/mg TOC). It was found that the most advantageous configuration was preliminary ozonation with an ozone dosage of 0.4 mgO₃/mg TOC–UF. The permeate flux reached a value equal to the pure water flux value. Moreover, a very high effectiveness of model organics removal was obtained: TOC was reduced by about 96% and UV₂₅₄ absorbance was removed completely. When PAC was added to the feed containing humic acids without ozonation, a drop in a permeate flux was observed compared to UF. Similarly, the addition of PAC to feed treated with ozone resulted in a significant drop in the permeate flux in comparison with pure water flux, regardless of ozone dosage applied.