在线混凝-超滤-反渗透组合工艺处理MBR出水的中试研究

建立了以混凝—超滤—反渗透组合工艺处理MBR出水的研究设备。研究表明,该组合工艺具有分离有机污染物和脱盐效果,对TOC、电导率、CODMn、UV254、浊度、总碱度、总硬度的去除率分别达到93.95%、98.94%、90.69%、99.83%、93.41%、89.21%、97.94%。产水电导率≤10μS/cm,可满足部分行业的纯水使用要求。同时,在线投加7mg/LFeCl3和0.35mg/L聚丙烯酰胺(PAM)时,超滤对浊度、UV254、CODMn的去除率分别为82%、20.5%、32.2%,跨膜压差增长趋势减缓,膜污染速率降低,节约了清洗膜的药剂,延长了超滤膜使用寿命,对反渗透膜也具有保护作用。     

短程反渗透海水淡化工艺在海岛中的应用

根据海岛海水淡化的应用环境,分析了海岛对集约型海水淡化工艺的需求,提出了短程反渗透海水淡化工艺,从工艺原理、技术特点及在海岛中的应用优势进行了阐述,并通过300m3/d的工程案例从反渗透产水水质、压差能量回收装置性能和系统能耗等方面考察了短程反渗透海水淡化工艺的运行效果,处理效果验证了该工艺的可行性和技术优势。     

机械搅拌澄清池调试总结

介绍机械搅拌澄清池在再生水回用系统应用,经调试改变加药方式、运行工况,结果表明,澄清池出水pH平均值10.2,出水浊度平均值5.3NTU,对浊度平均脱除率达79.2%,产水清澈,悬浮物减少,水质有明显好转,2P-M碱度达到控制指标。出水满足后续处理设施进水要求。有力保障后处理系统安全稳定运行,再生水反渗透清洗次数较A阶段月减少2次,清洗药剂用量减少,生产成本降低。     

集成膜技术工业废水深度处理回用试验研究

试验采用超滤+反渗透集成膜分离技术,目的是研究其集成工艺处理有色冶金工业废水的合理性和可行性。超滤试验主要测试了在不同水质情况下超滤膜的相关运行参数,主要测定指标有超滤系统的进水、产水和反冲洗水的水量,运行压力,出水浊度,SDI值等;反渗透试验主要测定指标有电导率,反渗透系统的进、出水量,运行压力等。试验研究表明:以预处理+超滤+反渗透组成的集成膜处理工艺,能够满足有色冶金工业废水处理回用的要求。     

微污染水库水超滤膜处理工艺的试验研究

利用PVC合金超滤膜中试装置与不同预处理组合成"混凝-超滤"、"混凝-沉淀-超滤"和"混凝-气浮-超滤"3种工艺处理微污染水库水,研究其净水效果及跨膜压差变化规律。结果表明:3种组合工艺的浊度去除率均在99%以上;镜检出水细菌、藻类含量基本接近零;对CODMn、UV254的去除效果顺序为:"混凝-气浮-超滤""混凝-沉淀-超滤""混凝-超滤";红外光谱分析结果显示,亲水性有机物是引起膜污染的主要物质;低温低浊期,跨膜压差随着产水时间变化趋势线的斜率为0.016 4、跨膜压差平均值为23.57 k Pa;高温高藻期斜率为0.043 2、跨膜压差平均值为21.28k Pa。     

海水淡化预处理系统选择

介绍了海水淡化预处理的目的,分析了外部条件对海水淡化预处理的影响,详细论述了反渗透淡化原水预处理和蒸馏法淡化原水预处理的工艺流程.结合国内外海水淡化技术的发展现状,提出了采用原水混凝沉降除浊技术方案,对海水淡化工程的预处理系统选择提出了建议.     

净水厂通过无泵虹吸膜工艺改造实现节能增效

环湖水厂原有膜池设计产水量2万m3/d,实际产水量仅为1.2万～1.5万m3/d,冬季产水量低于1万m3/d,无法满足要求,运行跨膜压差达20～40 kPa.改造后更换性能更好的热法PVDF超滤膜,原有膜池原位改造成产水量3万m3/d膜池,运行跨膜压差为5～12 kPa,产水浊度大部分情况下维持在0.05 NTU以下,...     

小型反渗透海水淡化简易预处理方案设计与应用

海水淡化是解决海岛供水的重要途径,海水预处理是海水淡化技术的关键环节,完善的预处理方案可以保证反渗透海水淡化系统的正常运行,延长反渗透膜的使用寿命,降低海水淡化成本。本文针对小型海水淡化系统的预处理技术的应用,比较分析不同取水方式条件下的预处理方案,并结合福建东门屿独立新能源海水淡化项目的具体应用,对海岛小型海水淡化系统预处理技术的应用展开研究,在试运行过程中积累了一定的经验,可为类似工程提供借鉴和指导。     

某核工程海水淡化工艺比选

通过分析目前主流海水淡化工艺的优缺点和某核工程自身的特点,并参考已建和在建核电工程海水淡化系统的相关经验,确定某核工程采用反渗透海水淡化工艺。根据该核工程厂址所在地附近海域海水水质情况,选用絮凝反应沉淀池+V型滤池+超滤的预处理工艺,以保证反渗透海水淡化工艺的稳定运行。     

UF膜与混凝联用处理淮河水的中试研究

采用超滤处理工艺对淮河水进行了中试。为了提高有机物的去除效果和膜通量 ,采用微絮凝和砂过滤作为预处理。结果表明 ,膜出水浊度低于 0 5NTU ,CODMn低于 3mg/L ,色度为 5度 ,氨氮低于 0 5mg/L ,均低于同期常规处理出水指标。超滤膜运行一个多月 ,膜压差增长缓慢     

Correlations between silt density index,turbidity and oxidation-reduction potential parameters in seawater reverse osmosis desalination

The reverse osmosis method is one of the most widely used methods of seawater desalination at present.Hydrophilic and desalting membranes in reverse osmosis systems are highly susceptible to the input pollutants.Various contaminants,including suspended organic and inorganic matter,result in membrane fouling and membrane degradation.Fundamental parameters such as the turbidity,the amount of chlorine injection,and silt density index(SDI)are the most predominant parameters of fouling control in the membranes.In this study,the operation system included a water intake unit,a pretreatment system,and an RO system.The pretreatment system encompassed a clarifier,a gravity sand filter,pressurized sand filters,and a cartridge filter.The correlation between the amount of chlorine injection in terms of the oxidation-reduction potential(ORP)and the SDI value of the input water was investigated at a specified site next to the Persian Gulf.The results showed that,at certain intervals of inlet turbidity,injection of a certain amount of chlorine into the raw water has a distinct effect on the decrease of SDI.     

Particle count and size alteration for membrane fouling reduction in non-conventional water filtration.

If coagulation is not completely successful and produces aggregates which are too small, fouling may increase. In some cases, a deep-bed filter could perhaps provide a solution. The paper examines these effects using experimental results for different waters. Activated sludge effluents, stormy seawater containing microalgae and spent filter backwash water (SFBW) were coagulated by alum or ferric chloride. Sand filtration tests were carried out. Tests were performed in a membrane filtration stirred cell, filtration pilot plant equipped with SDI analyzer (seawater) and pilot UF plant (SFBW). For activated sludge effluent, alum residual ratio curves of turbidity and total particle count (TPC) followed one another. With ferric chloride, low coagulant dosage showed negative turbidity removal. Contact granular filtration reduced membrane fouling intensity. Increasing the dose resulted in higher improvement in membrane flux. For seawater, a filter run period under storm conditions reached 35 hours with satisfactory filtrate quality. An iron chloride dose of 0.3 mg/l during normal conditions and 0.5 mg/l for stormy condition should be injected, mixed well before the filters, while maintaining 10 m/hr filtration rate and pH 6.8 value. For SFBW, alum flocculation pretreatment of SFBW was effective in reducing turbidity, TPC, viruses and protozoa. SFBW settling prior to flocculation did not enhance turbidity and TPC removal. The largest remaining particle fraction after alum flocculation was 3-10 microm in size, both Cryptosporidium and Giardia are found in this size range. Coagulation enhanced the removal of small size particles, a positive impact on reducing membrane fouling potential.     

The Role of Aquifer Media in Improving the Quality of Seawater Feed to Desalination Plants

This study focuses on the role of the aquifer media as a tool to improve the characteristics of seawater used to supply desalination plants, quantifying this improvement from a considerable number of physicochemical parameters. The evolution of both physicochemical and microbiological characteristics through the aquifer media has been determined by comparing the composition of seawater samples taken via direct intake with those taken over the aquifer. The principal improvements are due to the process of filtration. It includes up to a 95 % reduction in turbidity and up to a 50 % reduction in SDI. Other parameters are also notably reduced (TOC is cut on average by 60 %, and DO by 80 %), due to bacterial activity in the aquifer. It is also important to highlight that only a short distance of water flow through the aquifer is needed to achieve this improvement. If it used the seabed as the filter material, it would be necessary a minimum thickness of a few meters due to biological activity involves a significant increase in the TOC. An understanding of the filtration processes occurring within the aquifer provides a natural analogue on which future improvements in artificial pre-treatment can be based.     

Assessing the health implications of turbidity and suspended particles in protected catchments.

The supply of unfiltered disinfected drinking water from Melbourne's fully protected catchments means that the water-quality managers must ensure that the source water poses no public health risk. High turbidity is currently used as a surrogate of pathogens, and harvesting of water is based on its measurement. The work presented here summarises suspended particle and associated pathogen, microbial indicator and faecal biomarker concentrations collected to (a) quantify turbidity in an Australian water supply system and (b) assess the possibility of increasing water harvesting from selected tributaries. Pathogens and microbial indicators were present in low numbers in these source waters; increased turbidity during storm events was not associated with an increase in pathogen concentration. The results confirmed that protected catchments, along with good management, were effective barriers to pathogen contamination. Aesthetic issues still need to be addressed, but no measurable increase in microbiological risk was associated with storm-generated particles.     

九龙江流域水厂生产废水回用条件的初步研究

以九龙江原水为研究对象,从改善低浊水混凝条件优化净水工艺角度,对生产废水的回用条件和作用规律进行了研究。研究认为:回用具有适当含固率的生产废水可以改善水处理过程的混凝条件,节省投药量,节药率一般为10%～40%;存在改善混凝条件、节省投药量的最佳含固率和最佳混合水浊度范围,最佳含固率为0.1%～0.7%,最佳混合水浊度为60～400NTU;原水浊度是显著影响最佳含固率的因素。当原水浊度小于60NTU时,最佳含固率随原水浊度的升高而增加,当原水浊度大于60NTU时.最佳含固率随原水浊度的升高而降低,最佳混合水浊度表现出相同的规律;在生产过程中,建议以最佳混合水浊度控制生产废水的回用。     

Evaluation of flow regime of turbidity currents entering Dez Reservoir using extended shallow water model

In this study, the performance of the extended shallow water model （ESWM） in evaluation of the flow regime of turbidity currents entering the Dez Reservoir was investigated. The continuity equations for fluid and particles and the Navier-Stokes equations govern the entire flow of turbidity currents. The shallow water equations governing the flow of the depositing phase of turbidity currents are derived from these equations. A case study was conducted on the flow regime of turbidity currents entering the Dez Reservoir in Iran from January 2002 to July 2003. Facing a serious sedimentation problem, the dead storage of the Dez Reservoir will be full in the coming 10 years, and the inflowing water in the hydropower conduit system is now becoming turbid. Based on the values of the dimensionless friction number （ Nf ≤1 ） and dimensionless entrainment number （ NE≤ 1 ） of turbidity currents, and the coefficient of determination between the observed and predicted deposit depths （R2 = 0.86） for the flow regime of negligible friction and negligible entrainment （NFNE）, the flow regime of turbidity currents coming into the Dez Reservoir is considered to be NFNE. The results suggest that the ESWM is an appropriate approach for evaluation of the flow regime of turbidity currents in dam reservoirs where the characteristics of turbidity currents, such as the deposit depth, must be evaluated.     

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%。     

黄河口水下三角洲冬季床面变化初步观测研究

黄河携带大量泥沙入海,底床沉积物在波、潮、流等水动力条件作用下会不断地发生再悬浮与输运,形成黄河三角洲海底面的动态变化过程。利用自主研发的电阻率探杆三脚架,观测了水动力作用下海床面的侵蚀与淤积过程。研究结果显示,研究区涨落潮过程中海水浊度的变化主要受波高的影响,近底床位置海水浊度的变化趋势是涨潮过程中海水浊度上升,落潮过程中海水浊度降低。侵蚀或淤积是海床面泥沙的再悬浮与悬沙沉降共同作用的结果。研究区冬季的海床面变化以侵蚀为主,当沉降作用强于侵蚀淤积作用时,即使海床所受切应力大于沉积物临界切应力,海床仍发生淤积。     

Measurement and mathematical modelling of nutrient level and water quality parameters

Physico-chemical water quality parameters and nutrient levels such as water temperature, turbidity, saturated oxygen, dissolved oxygen, pH, chlorophyll-a, salinity, conductivity, total nitrogen and total phosphorus, were measured from April to September 2011 in the Karaj dam area, Iran. Total nitrogen in water was modelled using an artificial neural network system. In the proposed system, water temperature, depth, saturated oxygen, dissolved oxygen, pH, chlorophyll-a, salinity, turbidity and conductivity were considered as input data, and the total nitrogen in water was considered as output. The weights and biases for various systems were obtained by the quick propagation, batch back propagation, incremental back propagation, genetic and Levenberg-Marquardt algorithms. The proposed system uses 144 experimental data points; 70% of the experimental data are randomly selected for training the network and 30% of the data are used for testing. The best network topology was obtained as (9-5-1) using the quick propagation method with tangent transform function. The average absolute deviation percentages (AAD%) are 2.329 and 2.301 for training and testing processes, respectively. It is emphasized that the results of the artificial neural network (ANN) model are compatible with the experimental data.