PAC与FeCl_3复配处理饮用水中痕量磷的试验研究

通过混凝试验去除饮用水中的磷,对单独投加混凝剂和混凝剂复配除磷效果进行了研究,确定了混凝剂复配时的最佳投加方式,投加比例和投加时间。单独投加混凝剂时FeCl_3投量为15 mg/L时,能够满足饮用水的生物稳定的限制范围要求,但存在出水色度的问题,采用FeCl_3与PAC复配可以减少出水色度同时减少混凝剂用量。复配总的投加量为10 mg/L,PAC紧随FeCl_3投加,FeCl_3与PAC投加比例为3:1,先投加FeCl_3再投加PAC时除磷效果最佳,出水满足饮用水的生物稳定的限制范围要求。FeCl_3与PAC复配除磷效果较好,可减少单一投加FeCl_3的用量,同时减少出水色度,适合饮用水除磷。     

PAC与PFS深度处理垃圾渗滤液出水的对比研究

针对垃圾渗滤液经生化处理后出水CODCr和色度偏高,可生化性差(BOD5/CODCr≤0.1)的特点,为进一步去除CODCr,降低色度,采用PAC和PFS两种混凝剂对出水进行处理,并对两者的混凝效果进行比较。试验表明,PFS最佳投加量为0.7 mL.L-1,CODCr去除率达到74.3%,色度去除率88.6%;PAC最佳投加量为1 g.L-1,去除率达到51.9%,色度去除率达到77.8%。无论从CODCr或色度的去除率来看,PFS的混凝效果均优于PAC。     

混凝工艺对给水厂滤池反冲洗废水的净化效果

通过实验室杯罐试验,对水厂滤池反冲洗废水的混凝沉淀处理进行了研究.分别采用硫酸铝、聚合氯化铝和三氯化铁为混凝剂,在不同混凝剂投量下的对色度、浊度、CODMn、及UV254的去除效果进行了考察.试验结果表明,对浊度和色度的去除,最佳混凝剂为聚合氯化铝PAC,而对其有机物的去除三氯化铁则最佳.按除浊要求得到的最佳混凝剂投量但不能满足对有机物的去除,所以选择哪种混凝剂及投加量应根据对反冲洗废水的处理要求等综合慎重考虑.     

UV-Fenton催化氧化处理印染废水的实验研究

对采用UV-Fenton催化氧化反应处理印染废水的主要影响因素及其处理效果的影响进行了实验研究.主要考察了FeSO4·7H2O的投加量和H2O2的投加量、pH、反应时间、投加方式等对色度和COD去除率的影响.正交实验结果显示,UV-Fenton催化氧化反应对色度和COD都有较好的去除效果.在0.1 mol/L FeSO4·7H2O的投加量为1.5 mL,30%H2O2的投加量为2 mL,pH为3,反应时间为3 h,H2O2分三次投加的情况下,色度去除率达到90.4%,COD去除率达到86.2%.同时与Fenton反应和UV-H2O2反应处理方法进行了比较实验,结果表明,UV-Fenton处理效果最佳.     

高锰酸盐复合药剂强化混凝工艺研究

以某受污染地表水为研究对象,考察了高锰酸盐复合药剂(PPC)强化混凝工艺的除污染效能.静态试验结果表明,高锰酸盐最优投加方式应在混凝荆前投加,预氧化时间为20～40min,投量为1.2～2.4mg/L.生产性试验结果表明,采用高锰酸盐预氧化技术可以提高常规给水工艺去除有机污染物效能,使出厂水水质优于国家饮用水水质标准.     

芬顿氧化法深度处理亚麻生产废水

亚麻生产要进行煮炼脱胶处理,过程中产生的大量胶质,常规的生物处理不能有效去除.往往需要后续氧化处理.试验采用芬顿氧化法处理生物处理后的亚麻废水.该废水COD的质量浓度为1747 mg/L,色度为200倍,通过正交试验和单因素影响试验获得最佳控制条件为pH值为4.5.FeSO4投加量1 500mg/L,H2O2投加量1500mg/L,反应时间为1 h,在最佳条件下,COD去除率为57%,色度去除率达到90%以上.     

臭氧催化氧化法处理煤化工废水研究

为解决臭氧氧化处理煤化工废水现阶段所存在的臭氧利用率不高,并进一步处理煤化工废水中的难降解有机物.论文采用臭氧催化氧化法对煤化工调节池废水进行深度处理,研究了温度、pH、臭氧投加量、反应时间、催化剂投加量等因素对COD和色度去除效率的影响.通过单因素实验分析,得到其最佳工况条件为臭氧投加量为4g/h,废水pH=9,水温...     

FeSO_4对A—O工艺处理印染废水效果的影响

采用在水解酸化池投加FeSO4的方法来对"水解酸化—好氧氧化"(A—O)工艺进行改进。对比了水解酸化池有无投加FeSO4时,A—O工艺系统的运行结果,同时研究了FeSO4投加量对A—O工艺处理效果的影响。结果表明,投加了FeSO4的COD和色度的去除效果均好于未投加FeSO4的,当进水水质为COD 653mg/L、色度480倍、pH=9.2、水解酸化池的反应时间为7h、FeSO4投加量为30mg/L时,去除效果最佳,再经好氧反应器处理7h后,出水水质为COD 88mg/L、色度52倍。     

Fenton氧化-絮凝组合工艺处理墨盒清洗废水

墨盒清洗废水水质具有色度高、COD高、可生化性差等特点。对墨盒清洗废水采用Fenton氧化-絮凝组合工艺进行处理。Fenton氧化阶段试验研究最佳条件为:H2O2投加量为2 000 mg.L-1,Fe2+/H2O2的质量比为0.05,pH为3,反应时间为120 min。对Fenton氧化后出水进行絮凝试验,絮凝最佳条件为:聚合氯化铝(PAC)投加量为150mg.L-1,pH为8。实际废水经过Fenton-絮凝组合工艺处理后,出水TOC质量浓度为28 mg.L-1,色度为10度,相应的TOC去除率为92%,色度去除率为98.7%,出水符合排放标准。     

仲丁灵生产废水混凝预处理研究

以仲丁灵生产废水为研究对象,COD(化学需氧量)与色度为指标,研究了几种混凝剂与新型混凝脱色剂DH复合使用的混凝处理特性。通过不同的投配选择,得出了最佳的复合投加方式以及最佳药剂投加量。结果表明,采用硫酸亚铁与混凝脱色剂这种投加方式对该生产废水的预处理效果最佳,其色度去除率为70%,COD去除率为58%,有利于后续的生化处理;确定了最佳的药剂投加量为硫酸亚铁200mg/L,混凝脱色剂DH为250mg/L。     

几种高效混凝剂去除水中痕量磷的效果

本文通过混凝试验,比较了聚铝、聚铁、聚铝铁三种混凝剂对水中痕量磷的去除效果,考察了pH值对聚铁、聚铝、聚铝铁除磷的影响,同时研究了聚丙烯酰胺(PAM)、高锰酸钾复合药剂(PPC)的助凝除磷效果。结果表明:聚铁混凝除磷效果明显好于聚铝和聚铝铁;三种混凝剂除磷最佳pH值分别为:聚铁7.5,聚铝6.5,聚铝铁6.0;pH值对聚铝、聚铝铁除磷的影响显著,对聚铁的影响较小;PAM和PPC具有较好的助凝除磷效果;将PAM和PPC联用能进一步提高助凝效果。     

An MINLP model for biofouling control in seawater-cooled facilities

The use of seawater as a cooling agent in industrial plants is becoming a common practice in regions with water scarcity. One of the main problems of this approach is the heat transfer reduction due to biofouling in the heat exchangers. Biocide agents and scheduled maintenances are commonly used to control the biofilm growth. Dechlorination agents are also used to reduce the biocide concentration in the water discharge. In this work, a mathematical programming approach to develop optimal policies of biocide continuous dosing, dechlorination agents continuous dosing and maintenance scheduling for a seawater-cooled power desalination plant is presented. The resulting mixed integer nonlinear programming model can be used to test different dosing policies to detect a superior one. For the case study presented, results show that daily dosing policies offer an optimum economic policy, although biweekly and monthly dosing policies might provide a suitable compromise between economic and operating issues.     

化学混凝沉淀法处理高炉煤气洗涤水的研究

用化学混凝共沉淀的方法处理高炉煤气洗涤水,实验确定了最佳的药剂为聚合氯化铝钙,工艺的最佳操作条件是聚合氯化铝钙加入量为33mg/L,PAM加入量为0.5mg/L,搅拌时间为60s,搅拌强度为90r/min。按本法确定的工艺处理此类废水工艺简单,操作方便,处理费用低,易于推广。某铁厂采用此法处理该类废水取得良好的效果,达到国家的排放标准和循环使用的标准。     

Epoxy resins toughened by poly(propylene carbonate)

Poly(propylene carbonate) (PPC) was used as a toughening agent for improving the brittleness of cured epoxy resins (EP). Methyl tetrahydrophthatic anhydride (MTHPA) was used as a curing agent. The activation energies for the reactions of PPC/MTHPA and EP/MTHPA measured by FTIR were 115.8 and 66.5 kJ/mol, respectively, while for the composite system of PPC/EP/MTHPA, the activation energy obtained from DSC was 52.9 kJ/mol. Gel contents, DMA, and DSC displayed that the cured resins of PPC/EP/MTHPA were phase-separation crosslinking systems and most of PPC could react with MTHPA or the epoxy group. The toughness of cured resins was reinforced by the addition of PPC. The optimum mechanical properties and toughness for cured resins of PPC/EP/MTHPA corresponded to the system containing 20 phr PPC, which achieved a 33% increase in tensile strength and a 45% increase in the fracture toughness at no expense of the elongation of cured resins. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 2457–2465, 1997     

UF膜过滤天然原水阻力特性的研究

黄浦江原水中的溶解性有机物是造成膜过滤阻力的重要因素。投加混凝剂会大大降低膜过滤阻力。使膜过滤阻力最小的最佳混凝剂投加量与去除水中溶解性有机物效果最佳的投加量一致。粉末活性炭的投加对膜过滤阻力影响不大。     

模糊专家控制在南洲水厂投矾控制的应用

介绍南洲水厂的工艺流程、投矾工艺及其控制系统的设计,通过研究国内外投矾自动控制的模式,提出采用自学习的模糊专家控制系统进行投矾自动控制,利用周边水厂和广州自来水公司的经验数据和实际运行的一些数据,初步建立一个模糊专家数据库,利用该数据库在线控制投矾泵的运行,并在实际运行中在线自学习修改模糊专家数据库,逐渐达到最优控制的目的.通过南洲水厂在线运行调试,证明此控制有较强的适应性、鲁棒性和自学习性,为水处理的加药控制提供了一种新的自动控制方式.     

高锰酸盐复合药剂预氧化处理微污染水

通过生产性试验考察了高锰酸盐复合药剂预氧化处理微污染水的除污染效能.结果表明,高锰酸盐复合药剂预氧化强化了对浊度、有机物及铁、锰等污染物质的去除,并且与常规工艺相比能较好地控制出厂水三卤甲烷的生成量.     

High Strength and Barrier Properties of Biodegradable PPC/PBSA Blends Prepared by Reaction Compatibilization for Promising Application in Packaging

Poly(propylene carbonate) (PPC)/poly(butylene succinate-co-butylene adipate) (PBSA) blends are prepared via melt mixing using a twin-screw extruder. A one-step method based on the reaction compatibilization mechanism is used to prepare PPC/PBSA/AX8900(ethylene-methyl acrylate-glycidyl methacrylate random terpolymer) blends. The films of blends are prepared by an extrusion blown film machine. Fourier transform infrared spectroscopy results show that there is a strong hydrogen bonding between PPC and PBSA. The epoxy group of AX8900 can react with molecular chains of PPC and PBSA. It is shown from the rheological behavior that AX8900 can extend the molecular chains and increase the compatibility of PPC and PBSA. The films of PPC/PBSA blends exhibit more orientation structure than pure PPC film. The tensile strength of machine direction and transverse direction for 70PPC/30PBSA/1AX8900 film is higher than that for pure PPC film. The PPC/PBSA/AX8900 films have similar excellent barrier properties, compared with PPC film. The modified Maxwell theoretical model is used to predict and analyze changes in film barrier properties.     

Preparation and properties of poly(propylene carbonate) and nanosized ZnO composite films for packaging applications

A series of polypropylene carbonate (PPC)/ZnO nanocomposite films with different ZnO contents were prepared via a solution blending method. The morphological structures, thermal properties, oxygen permeability, water sorption, and antibacterial properties of the films were investigated as a function of ZnO concentration. While all of the composite films with less than 5 wt % ZnO exhibited good dispersion of ZnO in the PPC matrix, FTIR and SEM results revealed that solution blending did not lead to a strong interaction between PPC and unmodified ZnO. As such, poor dispersion was induced in the composite films with a high ZnO content. By incorporating inorganic ZnO filler nanoparticles, the diffusion coefficient, water uptake in equilibrium, and oxygen permeability decreased as the content of ZnO increased. The PPC/ZnO nanocomposite films also displayed a good inhibitory effect on the growth of bacteria in the antimicrobial analysis. The enhancement in the physical properties achieved by incorporating ZnO is advantageous in packaging applications, where antimicrobial and environmental‐friendly properties, as well as good water and oxygen barrier characteristics are required. Furthermore, UV light below ～ 350 nm can be efficiently absorbed by incorporating ZnO nanoparticles into a PPC matrix. ZnO nanoparticles can also improve the weatherability of a PPC film. In future research, the compatibility and dispersion of the PPC matrix polymer and the inorganic ZnO filler nanoparticles should be increased. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.     

Studies on the blends of CO2 copolymer. IV. Natural rubber/poly(propylene carbonate) systems

The blends of a carbon dioxide copolymer, poly(propylene carbonate)(PPC) with natural rubber (NR), were prepared and their mechanical properties and morphology were studied. The optimum formulation blend was obtained by orthogonal experiments. The tensile strength of the blend containing 30 phr PPC was 18.9 MPa, with an elongation at break of 755%. The factors such as PPC and dicumyl peroxide content, PPC molecular weight, sulfur content, curing time, and curing temperature responsible for controlling the mechanical properties were discussed. Transverse electron micrographs showed a two‐phase structure for this blend. Gel content data revealed that PPC was crosslinked. The phase stability of PPC in the blend improved because of the interpenetrating new work structure. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2140–2144, 2002