纳滤组合技术在垃圾渗滤液处理中的应用进展

垃圾渗滤液的处理技术成为目前研究的热点。简要介绍了垃圾渗滤液的化学成分和水质特点,对纳滤技术的特点和性能进行了概述,综述了近年来国内外纳滤组合技术用于处理垃圾渗滤液的研究进展,重点介绍了膜分离、化学混凝、化学氧化和吸附法与纳滤膜的组合技术在垃圾渗滤液处理上的研究和应用情况。最后提出了纳滤组合工艺技术可行、经济适用,其合理选择和优化是今后研究的方向,具有很好的应用前景。     

纳滤组合技术在垃圾渗滤液处理中的应用进展

垃圾渗滤液的处理技术成为目前研究的热点。简要介绍了垃圾渗滤液的化学成分和水质特点,对纳滤技术的特点和性能进行了概述,综述了近年来国内外纳滤组合技术用于处理垃圾渗滤液的研究进展,重点介绍了膜分离、化学混凝、化学氧化和吸附法与纳滤膜的组合技术在垃圾渗滤液处理上的研究和应用情况。最后提出了纳滤组合工艺技术可行、经济适用,其合理选择和优化是今后研究的方向,具有很好的应用前景。     

纳滤在垃圾渗滤液处理工程中的应用

纳滤较反渗透具有更低的操作压力且运行管理方便,使得其在垃圾渗滤液处理工程中得到广泛的应用.结合四川省垃圾渗滤液处理工程实例,介绍了纳滤在渗滤液处理中的两种应用:用作后处理和用于反渗透浓水的脱盐,通过对实例的分析总结了纳滤用于垃圾渗滤液处理工程改造应该考虑的4个方面问题,为纳滤在渗滤液处理工程的新建与改造中的应用提供借鉴.     

垃圾渗滤液处理工艺实例分析

介绍了垃圾渗滤液的特点及常用处理技术,对简阳垃圾填埋场的氨吹脱+生物处理(A+O)+混凝沉淀+砂滤+超滤+纳滤组合工艺、龙泉垃圾填埋场的AOAO+超滤+反渗透组合工艺以及广安垃圾填埋场的中温厌氧+膜生物反应器+纳滤组合工艺作了详细的介绍,3个垃圾填埋场的渗滤液处理之后均能达生活垃圾填埋污染控制标准(GB 16889-2008),并对3个组合工艺进行了技术及经济性的比较;最后对垃圾渗滤液处理的趋势进行展望.     

纳滤技术在垃圾渗滤液深度处理中的应用

采用纳滤技术对垃圾焚烧场渗滤液进行深度处理,探讨了该方法用于垃圾渗滤液深度处理的可行性.实验结果表明,COD去除率为80％～93％,氨氮去除率为45％～70％.实验过程中膜通量和脱盐率变化不大,膜性能稳定,可为垃圾渗滤液处理提供参考.     

物化法处理垃圾渗滤液的研究进展

简要介绍了垃圾渗滤液的特性及其物化处理技术,重点阐述了吸附法、吹脱法、混凝沉淀法、化学沉淀法、化学氧化法、电化学法、光催化氧化法、反渗透和纳滤法的原理、效果及存在的问题。对这些处理方法进行比较,并在此基础上对垃圾渗滤液处理技术的研究发展方向提出了一些建议。     

膜技术处理垃圾渗滤液特性分析

随着人们对环境污染问题的日益重视,垃圾渗滤液所产生问题得到越来越广泛的关注。在制定更严格的垃圾渗滤液排放标准的同时,我们对垃圾渗滤液的处理技术和工艺有更高的要求。本文简要概述了垃圾渗滤液的形成原因以及污染物的成分以及目前垃圾渗滤液的主要处理方式,膜技术分离垃圾渗滤液中无机盐分和重金属的优缺点,并分析比较了纳滤分离后浓缩液的国内外主要处理方法。膜技术在处理垃圾渗滤液中具有很好的处理效果和优势。     

膜法组合工艺在处理垃圾渗滤液的应用

介绍垃圾渗滤液的来源、特性及危害。阐述了垃圾渗滤液的现有处理方法,以及膜分离技术在垃圾渗滤液处理中研究和应用。主要有超滤、纳滤、反渗透膜和膜组合工艺,并分析几种膜分离技术的特点和在垃圾渗滤液处理中的应用,提出膜法组合工艺分离技术在垃圾渗滤液处理中有很好的发展前景。     

垃圾渗滤液纳滤膜浓缩液减量中试处理研究

采用二级物料分离膜工艺对垃圾渗滤液处理过程中产生的纳滤浓缩液进行处理,研究了温度、压力、膜通量、截留率等的影响,确定工艺的可靠性及稳定性。结果表明,在试验条件下垃圾渗滤液纳滤浓缩液可减量73.1%以上,产水清液满足《生活垃圾填埋场污染控制标准》(GB 16889—2008)中生活垃圾填埋场水污染物排放标准。     

南京已投运的大型化垃圾渗滤液处理工程介绍(二)——南京市轿子山垃圾渗滤液处理改扩建工程

文章系统的介绍了南京轿子山垃圾渗滤液处理工程的基本情况,天井洼垃圾渗滤液处理工程采用的是"MBR+纳滤/反渗透处理"组合工艺,同时对该渗滤液处理工程的工艺流程、主要设计技术参数以及浓水和污泥的处理、投运以及运营管理的意义进行了阐述和说明。     

Landfill leachate treatment using hybrid coagulation-nanofiltration processes

In this study, treatment of landfill leachate using a novel electrocoagulation - nanofiltration (EC-NF) hybrid system was investigated. Leachate sample was collected from Whytes Gully landfill in Wollongong, Australia. The performance of electrocoagulation (EC) using aluminium electrodes as a pretreatment step for the nanofiltration process was compared against a conventional chemical coagulation (CC) process. Results reported here indicate that electrocoagulation is superior over the conventional coagulation process with respect to total organic carbon (TOC) and turbidity removal. At the optimum reaction time, TOC and turbidity removals by the electrocoagulation process were 67% and 80%, respectively. In comparison, at the optimum dosage of Al₂(SO₄)₃ obtained by a standard jar testing procedure, TOC and turbidity removals by the chemical coagulation process were only 10% and 65%, respectively. It is noteworthy that the amount of aluminium released by the electrocoagulation process to the solution was significantly higher than the optimum dosage of the chemical coagulation process. Therefore, better performance of the electrocoagulation process can possibly be explained by the higher coagulation concentration and the formation of polymeric aluminium which is known to be more effective for small organic compounds which are prevalent in landfill leachate. A remarkable difference between electrocoagulation and chemical coagulation pretreatment was also observed with respect to fouling mitigation in a subsequent nanofiltration process. For the two different nanofiltration membranes (NF 270 and SR2) used in this study, severe membrane fouling was evident when filtering raw landfill leachate or chemical coagulation pretreated landfill leachate. In contrast, fouling was not observed with an electrocoagulation pretreated feed solution. However, the use of electrocoagulation pretreatment did not result in any improvement in treated effluent quality by the hybrid system. Over all, there was no discernible variation between the EC - NF and CC - NF hybrid systems in their TOC and turbidity removals, which were approximately 92% and 99%, respectively. The reported results demonstrate that an EC - NF hybrid system can be a promising candidate for landfill leachate treatment, particularly for small and decentralised landfills where simplicity and robustness are required.     

膜分离技术在垃圾渗滤液处理中的应用

垃圾渗滤液是一种重污染的有毒有机废水,对生态环境造成了严重的威胁。本文综述了垃圾渗滤液现有的膜处理技术,与传统处理工艺相比,膜技术具有低能高效等优点,是未来渗滤液处理技术的重要发展方向。由于垃圾渗滤液组成的复杂性,根据不同处理目的,微滤膜(MF)、超滤膜(UF)、纳滤膜(NF)和反渗透膜(RO)4种膜在垃圾渗滤液处理中都得到了一定的应用。总结发现,其中MF和UF对渗滤液的处理效果较差,一般作为渗滤液的预处理技术;NF和RO对渗滤液的处理效果较好,主要作为其深度处理技术。然而,膜污染阻碍了膜技术在渗滤液处理方面的发展与应用,为此可通过研究开发新型膜材料、有效的预处理技术和膜分离工艺优化等方面来防止膜污染的发生,以便膜技术在渗滤液及其他水处理方面得到更加广泛的应用。     

微细通道内CO2沸腾换热与干涸特性

CO₂作为一种天然制冷剂在微通道内应用具有很大的换热优势,然而由于微尺度效应及其物性,在低干度区容易发生干涸,严重影响换热效果。为研究微细通道内CO₂流动沸腾换热与干涸特性,搭建了相应实验装置,对内径分别为1mm、2mm、3mm以及内表面粗糙度为16μm的不锈钢管,在CO₂制冷剂热流密度2~34kW/m²、质量流率50~1350kg/(m²·s)、饱和温度-10~15℃下进行换热性能与干涸实验对比研究。结果表明:常规管径换热特性在微细通道内不再适用;热流密度的增加对于强化核态沸腾换热具有显著影响,高于临界热流密度(critical heat flux,CHF)则发生干涸;质量流率对于核态沸腾区换热系数的影响则较小;不同饱和温度时换热特性有所不同,高饱和温度下换热系数随其升高而提高,低饱和温度下则相反;干涸过程对总换热系数的影响占34%。研究结论为CO₂微通道换热器的研究开发提供理论依据。     

Applicability of nanofiltration for the advanced treatment of landfill leachate

Landfill leachates are generated from municipal solid waste landfills under the action of water percolating through the landfilled waste. A treatment system using a combined membrane engineering process was developed to effectively treat the landfill leachate in the Dahanzhuang sanitary landfill (Tianjin, China). The process combines a membrane bioreactor (MBR) and nanofiltration (NF) technology to treat the leachate. The results indicate that the NF system, including the hollow‐fiber NF membrane, is an appropriate advanced treatment alternative for landfill leachates. This system provided good removal of chemical oxygen demand and color. The membrane flux renewal reached over 96% after washing with 0.01 mol/L HCl. As a result, the effluent water quality met effluent discharge standards (GB16889‐2008). © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

纳滤膜特性及对水中微污染物的控制

随着膜技术的发展与应用,20世纪80年代出现的纳滤膜充分弥补了反渗透与超滤之间的空白。介绍了纳滤膜的特性及其独特分离特点,阐述了纳滤膜在处理饮用水中有机污染物的必要性和合理性。最后指出了它的应用前景。     

Removal of metal ions from an acidic leachate solution by nanofiltration membranes

This paper presents the feasibility of the application of two commercial nanofiltration (NF) membranes (Desal5 DK and NF-270) in the removal of metal ions from an acidic leachate solution generated from a contaminated soil using H₂SO₄ as a soil washing agent. The experimental results of soil washing indicated that H₂SO₄ is highly effective in removing metal ions from contaminated soil. Following this process, the treatment of this acidic solution by nanofiltration membranes showed good metal ion rejection (between 62% to 100%) where divalent ions were better rejected than monovalent ions. For characterization purposes, the membrane experiments were conducted using K₂SO₄ solutions at different pHs. Membrane performance criteria were evaluated according to membrane permeability and ionic retention in the tank and permeate, taking into account different operating conditions such as pressures, flow rate and pH. These results demonstrated the effectiveness and feasibility of the application of nanofiltration treatments in the cleaning-up of contaminated water residues generated during soil washing processes.     

Effectiveness in the Removal of Organic Compounds from Municipal Landfill Leachate in Integrated Membrane Systems: Coagulation – NF/RO

The article presents the results of studies concerning the hydraulic permeability of integrated membrane systems during the treatment of municipal landfill leachate. The laboratory-scale experiments were conducted to determine the effectiveness of coagulation as a pretreatment option for treating stabilized landfill leachate and effectiveness of nanofiltration (NF) and reverse osmosis (RO) processes. The municipal landfill leachates were analyzed for the concentration of the following: polycyclic aromatic hydrocarbons (PAHs), nitrate nitrogen, ammonium nitrogen, chemical oxygen demand (COD), total organic carbon (TOC), total carbon (TC), suspended soils (SS), turbidity, pH. The commercially available coagulant – aluminum sulfate Al₂(SO₄)₃·18H₂O (alum) was used as a coagulant. The NF process was carried out at the transmembrane pressure of 1.5 MPa. The membrane separation process was based on a thin film membrane (DK). The transmembrane pressure of the RO stood at 2 MPa and for this process one polyamide membrane (AG) was used. The level of leachate treatment was defined for raw and cleaned wastewater indicators. Both NF and RO membranes allowed obtaining the high level of pollutants removal. In the coagulation–NF system, the removal efficiency was equal to 77% for PAHs, 88% for COD, 72% for ammonium nitrogen, 80% for nitrate nitrogen, 67% for TOC, 80% for TC, 96% for SS and during the RO – 86% for PAHs, 98% for COD, 93% for ammonium nitrogen, 87% for nitrate nitrogen, 89% for TOC, 100% for TC, 98% for SS. The calculations based on the assumptions of the mathematical filtration model (relaxation) made it possible to predict the efficiency of commercial filtration membranes used for leachate treatment.     

芳香聚酰胺纳滤膜的制备及性能研究

以芳香聚酰胺为原料,采用相转化法制备了芳香聚酰胺纳滤膜,通过正交试验确定了最佳制膜工艺.详细讨论了纳滤膜的分离特性,并对纳滤膜的耐溶剂及抗污染性能进行了初步研究.实验结果表明,所制芳香聚酰胺纳滤膜对无机盐及小分子有机物具有较好的选择分离性能.操作压力为0.4MPa时,该膜对蔗糖的截留率为63.74%,对葡萄糖的截留率为54.36%.膜具有很好的耐溶剂性和抗污染性.     

纳滤/反渗透/石灰混凝法深度处理垃圾渗滤液

采用纳滤-反渗透法深度处理垃圾渗滤液T-MBR生化出水,考察了纳滤膜和反渗透膜对COD、总氮、硬度、重金属的去除效果,以及压力和运行时间对通量的影响。对纳滤的浓缩水进行石灰混凝处理,考察石灰投加量对COD、硬度的去除效果。结果表明,纳滤和反渗透可以有效去除COD、总氮、硬度、重金属等,出水各指标稳定达到垃圾渗滤液排放限值,通量在较长时间内能够保持稳定。回收率为80%的纳滤浓缩水经过石灰混凝后,当石灰投加量为3 g.L-1时,COD去除率为31%,硬度去除率达到89%。混凝后的上清液回到纳滤系统继续处理,系统的水总回收率为86%。     

海藻酸钠/聚砜复合纳滤膜的制备与性能研究

以海藻酸钠(SA)水溶液为活性层铸膜液,分别以聚砜( PSF)、聚丙烯腈(PAN)为基膜,采用涂敷、热处理、交联剂交联的方法制备了荷负电复合纳滤膜,考察了海藻酸钠浓度、基膜、交联剂浓度等对膜性能的影响,制膜条件优化结果为,以聚砜超滤膜为基膜,海藻酸钠铸膜液质量分数为3％,交联剂为质量分数0.5％的硫酸和质量分数1％的戊...