超滤膜在自来水厂的应用试验研究

超滤技术能够有效消除饮用水中的颗粒、浊度、病毒以及病原微生物等,降低自来水COD,并减少水中的消毒副产物。超滤膜具有良好的除浊功能和良好的灭菌作用,试验采用浸没式超滤膜,设计不同膜通量、曝气风量等运行工况,试验比较膜产水率、膜运行压力、运行能耗、出水水质等,为后续自来水厂升级改造提供技术参数。自来水厂升级改造工程中选用浸没式超滤膜技术,膜系统能耗较低、产水浊度0.1 NTU,产水水质稳定,符合生活饮用水卫生标准要求。     

浸没式超滤膜在市政污水深度处理中的应用研究

浸没式超滤膜应用于北京市北控沙河再生水厂工程,在长期连续运行过程中考察其对市政污水深度处理效果以及系统的运行稳定性。结果表明:浸没式超滤膜在市政污水深度处理中稳定运行,产水水质稳定。长期运行数据显示,跨膜压差稳定在20~50KPa之间,针对性CIP清洗可确保CIP清洗周期长达6个月及以上;浸没式超滤膜对浊度具有良好的去除效果,出水浊度达到0.1NTU以下,而且出水SDI低于2.5;浸没式超滤膜系统运行成本相对较低,吨水药耗成本约0.01~0.015元,吨水耗电成本约0.02~0.03元。     

水厂超滤膜工艺自控系统的实现

给水工程中的超滤膜处理工艺控制过程比较复杂,自控系统的编程、调试和网络架构等直接影响到超滤膜处理效果和运行成本。廊坊市地表水厂一期工程规模为15×104m~3/d,采用超滤膜工艺,其控制流程包括膜池过滤控制流程、维护性清洗控制流程、恢复性化学清洗控制流程、膜完整性检测控制流程。2016年底投入运行以来,超滤膜池自动运行稳定,既保证了产水水质,又提高了运行效率,可为同行业相关设计提供借鉴和参考。     

超滤膜在沿淮某水厂与各生产工艺联用试验研究

将超滤膜技术分别与给水厂斜板沉淀池、平流气浮池和上向流生物滤池联用,考察各组合工艺的运行情况,并与水厂快滤池进行对比。结果表明,沉淀、气浮与压力式超滤膜联用,对致浊颗粒物与微生物有很好的去除效果,但对CODMn、氨氮等指标的去除效果有限。浮后水溶解氧浓度升高,存在促进压力式超滤膜柱内截留微生物滋生的可能。将生物滤池分别与压力式、浸没式超滤膜工艺组合,在常规化学安全性指标达标的基础上,超滤膜可以有效地截留微生物,降低生物滤池生物泄漏风险,保障出水的生物安全性。在抗生物污染方面,浸没式超滤膜比压力式超滤膜更具优势。快滤池对非溶解性指标的控制虽不及超滤膜,但仍然可以有效地保障出厂水的安全性。     

超滤膜技术在西山水厂工程设计中的应用

厦门西山水厂一期工程处理规模为10万m3/d,本工程采用超滤膜技术作为大型水厂的深度处理工艺。在工程设计中,将V型滤池处理后的出水进入超滤膜系统进行深度处理;运营后不仅工艺设备运行稳定,去除效果良好,还可以达到节能降耗的效果;最终本厂出水浊度为0.042NTU,达到了国内领先水平。     

超滤膜组合工艺在大型净水厂扩建工程中的应用

为及时发挥千岛湖配水工程效益,R水厂启动扩建工程,新建40×10~4m~3/d预处理、20×10~4m~3/d常规处理和40×10~4m~3/d超滤膜深度处理构筑物。介绍了R水厂扩建工程工艺流程和浸没式超滤膜系统的设计。一期工程预处理由生物接触氧化调整为预臭氧工艺,末端增加浸没式超滤膜系统;扩建工程设计采用"预臭氧+平流沉淀、炭砂滤池+浸没式超滤膜"组合净水工艺。设计出水水质目标优于《生活饮用水卫生标准》(GB 5749—2006)。     

佛山新城浸没式超滤膜水厂设计经验及运行调试实践

作为自来水的第三代水处理工艺,以超滤膜为核心的水处理工艺近年来得到迅速的推广应用。结合运行八年的佛山市新城区浸没式超滤膜水厂生产运营经验以及第二次改扩建超滤膜水处理工程建设情况,总结了水厂重点生产工艺(如颗粒活性炭过滤系统、超滤膜过滤系统、电气及自动化系统等)的设计经验及运行调试方面的优化实践,可供相关水厂参考。     

超滤技术在无锡中桥水厂深度处理工程中的应用

近年来,膜处理技术在水处理领域的应用已趋成熟。随着对供水安全的日益关注,超滤技术在饮用水处理领域中得到越来越广泛的应用。无锡市自来水总公司中桥水厂于2009年采用西门子外压式超滤膜处理技术,率先建成15×104m3/d采用超滤膜饮用净水处理系统,出水水质全面达到且部分优于《生活饮用水卫生标准》(GB 5749—2006)。根据无锡中桥水厂升级改造工程的经验以及两年多的实际运行情况,分析了超滤系统运行操作的特点。超滤技术在无锡中桥水厂的应用可以为国内其他水厂的工艺升级改造,特别是大型水厂的膜法水处理工程项目的决策和建设提供参考。     

供水厂浸没式超滤膜系统的运行调试和清洗维护

对某市采用超滤膜为核心工艺的优质水厂进行第二次改扩建,根据调试及生产运行维护实际情况,分析总结了浸没式超滤膜过滤系统的运行调试、物理反冲洗及化学清洗维护过程,为实际工作提供参考。     

浸没式超滤膜净化西江水中试研究

分析了浸没式超滤膜处理西江水的净水效能及运行稳定性,探讨了超滤膜化学清洗的效果。结果表明,原水分别经过混凝沉淀—超滤和混凝沉淀—砂滤—超滤两种工艺处理后,出水水质均有很大提升,出水平均浊度分别为0.07、0.06 NTU;中试运行过程中,对COD_(Mn)的平均去除率为20%,略优于常规处理工艺;出水中均未检测到剑水蚤、红虫等微型动物。对超滤膜进行化学清洗后跨膜压差恢复显著,清洗后TMP_(20℃)由33 k Pa降至16 k Pa。两种工艺的TMP_(20℃)平均增长速率分别为0.33、0.10 k Pa/d,超滤膜系统的跨膜压差增长缓慢,运行相对稳定。     

大型超滤水厂PVC和PVDF膜运行特性差异与优化

超滤技术已广泛应用于城镇给水处理厂,使得饮用水水质得到显著改善。不同材质超滤膜的运行周期、膜通量、跨膜压差(TMP)等的变化规律会有显著的差异,需要根据各自的特点对超滤系统进行运行参数调控与优化,以保证超滤系统的长期稳定运行。分析了山东某大型超滤水厂超滤系统长期运行的特点,对比了PVC膜和PVDF膜孔结构特征、膜通量、跨膜压差变化趋势及膜过滤阻力特性,调控和优化超滤系统运行参数,并进行了长时间的运行验证。结果表明,膜孔径和膜孔结构不同造成的膜污染是PVC膜与PVDF膜过滤特性差异的主要因素,恒定过滤周期运行模式下PVC膜通量加速衰减时段为82~220 min,造成PVC膜通量衰减了9. 14%,并形成了约5%的永久衰减膜通量,而PVDF膜的通量衰减并不明显,使得水厂超滤系统在恒定过滤周期(180min)运行模式下,出现了PVC膜的污染速率明显高于PVDF膜、系统的运行工况出现显著差异的现象。按照恒定过滤阻力模式运行时,PVC膜和PVDF膜的最佳过滤周期范围分别为82~108 min和96~155 min。水厂超滤系统在恒定过滤阻力运行模式下将PVC膜与PVDF膜在高温期和低温期的过滤周期分别调整为110、90 min和150、120 min,TMP的增长速率和化学维护清洗周期均基本一致,超滤系统实现了长期稳定运行。研究成果为我国超滤水厂中不同材质超滤膜的运行参数优化及协同稳定运行提供了参考。     

超滤膜处理净水厂沉淀池出水的中试研究

采用中试规模的内压式超滤膜系统处理水厂沉淀池出水,考察超滤膜系统长期运行的出水水质情况。结果表明,超滤膜系统在处理不同水质期沉淀池出水时具有较高的除浊率,平均除浊率达到93.4%,且99.4%的出水浊度<0.1 NTU,去除效果明显优于同期传统的滤池工艺。超滤膜系统对沉淀池出水中有机物的去除效果有限,对CODMn和UV254的平均去除率分别为17.2%和8.2%,出水CODMn≤2.0 mg/L的保证率在98%以上,膜出水CODMn浓度受进水水质和运行条件的影响不大。膜进水中以小分子质量有机物为主,在MW<1 ku区间内的DOC和UV254占到整体有机物含量的57.3%和53.5%。超滤膜系统对微生物的去除效果良好,膜出水水质大部分时间无需经过消毒就能保证卫生要求,可降低后续消毒的加氯量,从而减少消毒副产物的生成量。     

Studies on the effect of humic acids and phenol on adsorption-ultrafiltration process performance

Application of pressure-driven membrane processes, such as ultrafiltration (UF) and microfiltration (MF) for surface water treatment have become very popular during last decades. Membrane fouling by humic substances (HS) is one of the major limiting factors in these processes. In order to alleviate the unfavorable effects of the presence of HS in the feed on the process performance UF and MF are often combined with adsorption on powdered activated carbon (PAC). The main goal of the present study was to evaluate the effect of humic acid (HA) on membrane fouling during UF. Moreover, the effect of PAC addition to the feed on UF process, especially on flux decline was determined. The applicability of the adsorption-ultrafiltration (PAC/UF) system to purification of water containing low (phenol) and high molecular (HA) was also investigated. Three different polymer UF membranes, prepared from polysulfone (PSF), cellulose acetate (CA) or polyacrylonitrile (PAN) were applied. It was found that the membranes prepared from PSF and CA are very susceptible to fouling caused by HA. The permeate flux decreased for ca. 50% during UF of HA solution through the PSF membrane and for ca. 45%-through the CA membrane. In the case of the PAN membrane, a negligible effect of HA on the flux was observed. On the basis of the FTIR spectra it was found that the drop in the permeate flux through these membranes may result from interactions between the negatively charged functional groups present on the membrane surface, such as carboxyl groups (CA) and sulfone groups (PSF) with HA, which results in coating of the membrane surface with HA. When PAC was added to the feed containing HA, the permeate flux through the CA and PAN membranes was maintained on a practically unchanged level. However, in case of the PSF membrane, a 50% drop in the permeate flux in comparison with the flux value, when process was conducted without PAC addition was observed. That was supposed to be due to attractive forces among hydrophobic PAC particles, HA molecules and PSF membrane surface. The performed studies showed that the application of PAC/UF system was very effective in the removal of organic substances having both, low and high molecular weights. The role of PAC suspended in a feed in the PAC/UF system is the adsorption of low molecular organic compounds, which cannot be removed by UF alone.     

Fate of antibiotics in activated sludge followed by ultrafiltration (CAS-UF) and in a membrane bioreactor (MBR)

The fates of several macrolide, sulphonamide, and trimethoprim antibiotics contained in the raw sewage of the Tel-Aviv wastewater treatment plant (WWTP) were investigated after the sewage was treated using either a full-scale conventional activated sludge (CAS) system coupled with a subsequent ultrafiltration (UF) step or a pilot membrane bioreactor (MBR) system. Antibiotics removal in the MBR system, once it achieved stable operation, was 15-42% higher than that of the CAS system. This advantage was reduced to a maximum of 20% when a UF was added to the CAS. It was hypothesized that the contribution of membrane separation (in both systems) to antibiotics removal was due either to sorption to biomass (rather than improvement in biodegradation) or to enmeshment in the membrane biofilm (since UF membrane pores are significantly larger than the contaminant molecules). Batch experiments with MBR biomass showed a markedly high potential for sorption of the tested antibiotics onto the biomass. Moreover, methanol extraction of MBR biomass released significant amounts of sorbed antibiotics. This finding implies that more attention must be devoted to the management of excess sludge.     

超滤工艺处理引黄水库高藻原水的中试研究

采用混凝沉淀-超滤工艺处理山东某引黄水库的夏季高藻原水,研究了PVC合金超滤工艺的除污染物效果,并与同期水厂出水进行了比较,分析了超滤膜的运行稳定性和技术经济性。试验结果表明,超滤工艺可以显著去除藻类、致病微生物,出水浊度低于0．1NTU,组合工艺对有机物总去除率在35％左右。预处理能够有效延缓膜污染,提高系统的运行稳定性。     

中桥水厂超滤膜深度处理工艺中试研究

分别以滤后水和沉后水作为进水,考察了超滤膜深度处理工艺的净水效能、膜通量、渗透性及清洗方式.结果表明,超滤膜深度处理工艺对浊度、总铁及色度具有较好的去除效果;以滤后水和沉后水作为超滤膜进水时,适宜的膜通量范围分别为(70 ～80)和(50～60) L/(m2·h);超滤膜-粉末活性炭组合工艺对浊度的去除效果很好,当PAC投加量为15 mg/L时,浊度去除率大于80.7％,TOC、CODMn 、UV254及氨氮去除率基本小于30％.     

中空纤维超滤膜处理滦河水中试研究

采用混凝-超滤工艺对滦河原水进行了中试研究,重点考察了PVC中空纤维超滤膜对不同水质期的滦河水中污染物的去除情况。结果表明：水温降低使膜性能下降。膜污染较严重;在高藻期进行预氯化有助于减缓膜污染;针对不同的水质期要采用不同的预处理方法。在低温期适当增加铁盐投量,高藻期进行预氯化都有助于系统稳定运行;膜出水在3个水质期（低温、常温、高藻期）均很稳定,与常规工艺相比,膜工艺具有一定的优越性,在去除浊度和颗粒物方面尤为突出。     

Purification of oily wastewater by hybrid UF/MD

Investigations on the treatment of oily wastewater by a combination of ultrafiltration (UF) and membrane distillation (MD) as a final purification method have been performed. A tubular UF module equipped with polyvinylidene fluoride (PVDF) membranes and a capillary MD module with polypropylene membranes were tested using a typical bilge water collected from a harbour without pretreatment. The permeate obtained from the UF process generally contains less than 5 ppm of oil. A further purification of the UF permeate by membrane distillation results in a complete removal of oil from wastewater and a very high reduction of the total organic carbon (99.5%) and total dissolved solids (99.9%).     

微/超滤膜组合饮用水处理技术及工程应用

为达到合格的出水水质,需要将微/超滤膜与其他饮用水处理技术进行有效组合,在实际工程中选取何种工艺流程视原水水质、出水要求、现场条件和经济技术分析最终确定。分类整理了国外相关膜技术组合工艺及其成功建设实例,以供参考。