共查询到19条相似文献,搜索用时 390 毫秒
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聚铁硅型复合无机高分子絮凝剂的混凝性能 总被引:5,自引:0,他引:5
采用常规烧杯搅拌试验方法对聚铁硅型复合混凝剂的混凝性能进行了系统的研究 .结果表明 ,所研究聚合铁硅型复合混凝剂的混凝性能随氧化硅的种类与Si/Fe比的不同而有显明的差异 ,而碱化度的影响较为有限 .三类氧化硅中Silica(A)与Silica(B)的特性比较类似 ,显著地降低了混凝剂的电中和能力 ,仅仅在较高投药量时带来混凝效果一定的改善 .Silica(C)的引入对电中和能力的影响不大 ,但显著地提高了混凝效能 ,归因于其高效的架桥作用 相似文献
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采用[Al+Fe]-Ferron逐时络合比色法研究了典型聚磷氯化铝铁溶液的形态转化,结果表明,聚磷氯化铝铁的形态转化主要由P(/Al+Fe)、OH(/Al+Fe)和nAl/nFe等因素决定,聚磷氯化铝铁的形态转化特征是优势形态之间的转变。通过对模拟悬浊水样的絮凝实验,对其除浊性能进行了考察,通过测定zeta电位对其水解物的电动特性进行了研究,结果表明,聚磷氯化铝铁水解聚合产物的电动特性与P(/Al+Fe)、OH(/Al+Fe)和nAl/nFe的变化密切相关,聚磷氯化铝铁是通过电中和、吸附架桥和沉淀网捕作用起混凝作用的,三种作用的综合能力越强,其混凝效果就越好。 相似文献
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《环境科学与技术》2013,(12)
在以H2O2氧化Fe(Ⅱ)制得新生态铁的基础上,通过加入一定量的铝盐或聚合季铵盐进行复合改性,得到基于新生态铁的复合混凝剂。利用杯罐实验考察了不同复配比的新生态复配铁铝混凝剂和聚合季铵盐-新生态铁复合混凝剂对松花江水的浊度、色度以及TOC的去除效果,并在不同的混凝剂剂量下与单纯新生态铁或聚合氯化铝的混凝效果对比。实验结果表明:在不同的混凝剂剂量下新生态复配铁铝均可提高新生态铁对浊度、色度的去除效果,且在较低混凝剂剂量下,复配铝含量越高,对浊度和色度的去除效果越好;在剂量小于0.20 mmol/L时,新生态铁及新生态复配铁铝对浊度的去除效果均低于聚合氯化铝,但当剂量达到0.20 mmol/L及以上时,各混凝剂对浊度的去除效果相当;新生态铁对TOC的去除效果要优于新生态复配铁铝;在剂量低于0.10 mmol/L时,各新生态复配铁铝对TOC的去除效果次于聚合氯化铝,但当剂量在0.10 mmol/L以上时,随着剂量的增大,其去除效果逐渐赶超聚合氯化铝,且混凝沉后水残余铝含量低于聚合氯化铝。聚合季铵盐-复合新生态铁也可提高新生态铁对浊度、色度的去除效果,还可使混凝后残余铁含量大幅降低。聚合季铵盐-新生态铁在剂量6 mg/L时,沉后水浊度即可达到5 NTU以下,而单纯新生态铁在12 mg/L时,沉后水浊度才达到5 NTU以下。基于新生态铁的复合混凝剂与单纯新生态铁或聚合氯化铝相比,可以提高对浊度、色度或有机物的去除效果并降低沉后残余金属含量,因此是一种较有研究价值和开发前景的混凝剂。 相似文献
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聚合氯化铝铁净水剂的制备及净水对比试验 总被引:1,自引:0,他引:1
介绍了以河北某矿区伴生高岭土矿物为原料,制备聚合铝铁工艺和对影响聚合铝铁去浊效果的有关主要因素进行了试验研究,确定了聚合铝铁具有较佳混凝去浊效果的Fe/Al摩尔比等制备工艺参数以及净水投药量范围,研究了聚合铝铁对煤矿矿井水水质变化的适应性,并与常规净水剂进行了混凝去浊效果对比, 相似文献
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《环境科学与技术》2017,(12)
采用微量滴碱法制备聚合氯化钛铁混凝剂(PTFC),并对其混凝除砷性能进行了初步探究。对聚合氯化钛/铁混凝剂粉末SEM图进行分析,并考察不同Ti/Fe比例、曝气氧化、碱化度、碱化剂、混凝剂投加量、pH值、共存离子等对除砷率的影响。结果显示:pH值为7.5时,As(Ⅲ)去除率随PTFC投加量的增加而增大;PTFC在弱酸性条件下对As(Ⅲ)的去除效果最佳。曝气氧化对PTFC除As(Ⅲ)有显著促进作用,Ti/Fe物质的量比为5/5时制备的碱化度为0.6的PTFC混凝后经曝气20 min,对As(Ⅲ)的去除率从55.3%提高到93.1%。碱化剂对PTFC混凝除砷的影响不大。共存阴离子SiO_3~(2-)对As(Ⅲ)的去除有明显抑制作用,但PO_4~(3-)对PTFC混凝去除As(Ⅲ)的影响相比较于单一金属盐较小,共存阳离子Ca~(2+)对PTFC去除As(Ⅲ)有促进作用。 相似文献
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采用自行制备的具有不同SiO2 :Al:Fe(摩尔比值 )和碱化度的两类新型无机高分子混凝剂聚硅酸氯化铝铁 (PSAFC)和聚硅酸硫酸铝铁 (PSAFS)各 7种 ,直接对印染废水进行处理。从中选出 2种混凝剂 ,考察了pH值、混凝剂投量等对混凝效果的影响 ,并对混凝处理后 ,印染废水出水中残留混凝剂主要成分Al、Fe、SiO2 的含量进行分析。实验结果表明 ,氯化物型 (PSAFC)和硫酸盐型 (PSAFS)混凝剂对印染废水的色度、浊度、CODCr均有良好的去除效果 ;总体而言 ,PSAFS的混凝效果略优于PSAFC ;混凝处理后印染废水出水中残留铝、铁、硅的含量均比较低 ;pH值和碱化度对混凝剂在水体中残留铝含量有影响 相似文献
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聚硅酸铁水解规律及混凝机理的探讨 总被引:12,自引:0,他引:12
以水玻璃、硫酸亚铁及氯酸钠为原料,用共聚法制备聚硅酸铁混凝剂(PSF),同时研究PSF的水解过程以及PSF与聚合硫酸铁(PFS)、复合铝铁(PFA)的微观品质(微观结构、形态尺寸及Zeta电位)及混凝性能,并结合水解形态分布及微观品质对PSF的混凝机理进行初步探讨.结果表明,PSF是由许多链节样物种连接而成的分维数很大的敞开式枝状结构,其平均粒径比PFS、PFA分别大近5、11倍,而PFS、PFA是由一些低分维数及尺寸很小的棒状或球状形态组成,PSF、PFS的Zeta电位相近,远远低于PFA(为PFA的1/20左右),PSF的形态尺寸及Zeta电位分布不均.在较宽的pH范围内(浊度为5.5~12 NTU,UV254为5.5~10 cm-1),PSF的混凝效果明显优于PFS、PFA.PSF在纯水中的水解可以代表在地表水中的水解过程.PSF具有的特征微观品质使其在不同pH值范围内具有不同的水解形态分布,导致混凝机理差异很大.在宽泛的pH范围内(53、Fe(OH)2+及Fe3+稳定存在于水体中,是PSF在较宽pH范围内具有优异混凝性能的根本原因,也是PSF同时具有增强电中和/脱稳及架桥混凝机理的内在原因.微观品质、水解形态分布及混凝效果的对比合理解释了电中和/脱稳是混凝的前提条件,架桥是必要条件,二者要紧密配合才能取得高效的混凝效果. 相似文献
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Polyferric silicate sulfate (PFSS) with high concentration was prepared using the composite-poly method. The coagulation properties and mechanisms of this new complex were probed using TEM, Fe-Ferron timed complex-colorimetric method, and infrared spectrum method. The results showed that the flocculating effect of polyferric silicate sulfate had an advantage over polyferric sulfate (PFS), as the optimum coagulation effect could be obtained when the Si/Fe mole ratio was 0.75 in accordance with its macrostructure of PFSS. According to the Fe-Ferron timed complex-colorimetric method, the Si species was mainly Sic, whereas, the Fe species were Fea and Fec in the copolymerization system. The infrared spectra indicated that the structure of these new flocculants was formed by polymers, mainly by olation, which was different from polyferric sulfate, and the vibration of M-OH-M of around 1100 cm^-1, also proved that there existed Fe-OH-Fe and its polymers in some forms. 相似文献
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The denitrification for the coking wastewater was conducted by means of original battery principle with Fe-C micro-electrolysis. Fe-C serves as positive and negative electrodes, by which N02?-N and TN were reduced to nitrogen, and then the purpose of denitrifieation for coking wastewater was realized. The influences of pH value, carbon particle size, Fe/C ratio (mass ratio), reaction time and coagulation pH value on removal rate of N02?-N and TN were investigated. Coking wastewater originated from Jiamusi Coal Chemistry Engineering Company. The optimum conditions of treatment were as follows: the initial pH was 3.0, the dosage of Fe 73.5 g/L, reaction time 70 min, mass ratio of Fe/C ratio 1.0:1.3, coagulation pH 9.0 and sedimentation time 40 min. Under those conditions, nitrogen removal efficiencies of N02?-N and TN were beyond 50% and 45%, respectively. 相似文献
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采用溶胶-凝胶法制备Fe-TiO2(Fe掺杂纳米二氧化钛)催化剂,通过XRD(X射线衍射仪)、SEM(扫描电镜)、EDX(能量色散X射线光谱仪)和UV-Vis谱对其形态、结构、组成和性质进行表征. 采用Fe-TiO2催化剂脱除气态Hg0(元素汞),研究了该催化剂在紫外光和可见光下的脱汞效果,并考察了Fe3+的最佳掺杂比. 结果表明:在Fe-TiO2光催化剂中,TiO2以锐钛矿相形态存在,当Fe3+掺杂浓度〔以n(Fe)/n(Ti)计〕达到0.010时,所制备的Fe-TiO2在紫外光和可见光下的脱汞率均达到最大,分别为54.76%和18.92%. 提出了Fe-TiO2光催化脱汞的可能机制:Fe3+掺入TiO2结构中,使TiO2的导带与Fe3+的d轨道发生重叠,导致TiO2能带变窄,从而扩展了可见光的响应范围;Fe3+在TiO2中作为一个浅俘获阱,当其俘获光生电子以后,光生空穴能够继续扩散到TiO2表面发生表面化学反应,生成具有强氧化性的超氧自由基O2-和·OH,对Hg0进行氧化;当Fe3+掺杂浓度大于0.010时,由于过多的Fe3+成为了光生电子和光生空穴的俘获位,从而使俘获的电子-空穴对通过量子隧道效应复合的概率增加,同时,活性氧化物种O2-和·OH相互消耗,抑制了光催化效率. 相似文献
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Fenton法处理类长填龄渗滤液的氧化和絮凝作用 总被引:13,自引:6,他引:7
采用Fenton法对难降解的类长填龄渗滤液进行处理,考察其氧化和絮凝作用对有机物去除的贡献. 结果表明:以CODCr去除率最大为目标,试验在最优条件下,c(H2O2)/c(Fe2+)为7.0,Fe2+投加量(c(Fe2+))为60 mmol/L,pH为3.0,此时CODCr总去除率为60%;其中氧化作用去除率为44%,氧化和絮凝作用的效率比为2.7. c(H2O2)/c(Fe2+),c(Fe2+)和pH的变化对氧化和絮凝作用有明显影响,氧化作用对CODCr去除率随H2O2投加量增大而增大.絮凝作用对CODCr的去除率不仅受Fe2+投加量直接影响,随其增加而增大;还间接受氧化作用去除率影响,氧化作用去除率越大,剩余有机物大分子所占比例降低,絮凝作用对有机物的去除率越低. 相似文献
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实验以三氯化铁和三氯化铝作为混凝剂,对比研究了混凝去除EDTA土壤淋洗废液中砷、锑的效果,重点探讨了反应终点pH、EDTA浓度、Fe/Al投加量以及共存重金属离子对砷、锑去除效果的影响。结果表明:1)对于EDTA土壤淋洗废液中As(Ⅴ)、Sb(Ⅴ)的去除,铝盐比铁盐效果更优;2)EDTA的存在不仅降低了铁盐/铝盐混凝对As(Ⅴ)、Sb(Ⅴ)的吸附去除效果,同时抑制了砷酸铁、锑酸铁等物质的生成,削弱了铁盐对As(Ⅴ)、Sb(Ⅴ)的沉淀去除。EDTA导致铁盐混凝过程中生成粒径较大、表面活性较低的稳定结晶态絮体;3)当c(EDTA)=0.05 mol/L时,在pH=5、ρ(Al)=2000 mg/L的条件下,铝盐对EDTA土壤淋洗废液中As(Ⅴ)、Sb(Ⅴ)的去除率分别高达98.00%和93.09%;4)共存重金属离子通过与EDTA络合,增加了絮体Al(OH)3的生成量,促进了As(Ⅴ)、Sb(Ⅴ)去除。由此表明,铝盐能够有效实现EDTA土壤淋洗废液中As(Ⅴ)、Sb(Ⅴ)的去除,对于推动基于EDTA的土壤淋洗技术的广泛应用具有重要意义。 相似文献
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The aim of the present work was to produce a polyaluminium ferric silicate chloride (PAFSiC) coagulant from acidic and alkaline
wastewater of purifying graphite by roasting, and subsequently to evaluate coagulation efficiency of the reagent by treating surface
water from the Yellow River as well as municipal wastewater in comparison with the conventional coagulant polyaluminium chloride
(PAC). The PAFSiC coagulant was prepared by co-polymerization. The effects of (Al+Fe)/Si molar ratio, OH/(Al+Fe) molar ratio (i.e.,
value), coagulant dosage and pH value of test suspension on the coagulation behavior of FAFSiC and the stability of the PAFSiC were
also examined. Results showed that PAFSiC performed more efficiently than PAC in removing turbidity, chemical oxygen demand
(COD), and total phosphate (TP). The PAFSiC with a
value of 2.0 and (Al+Fe)/Si ratio of 5 (PAFSiC 2.0/5) showed excellent
coagulation effect for both turbidity and COD, while PAFSiC 1.0/5 was the best for TP. The optimum coagulation pH range of PAFSiC
2.0/5 was 5.0–9.0, slightly wider than that of PAC (6.0–8.0). The process can be easily incorporated into high-purity graphite production
plants, thereby reducing wastewater pollution and producing a valuable coagulant. 相似文献
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Ni/Fe-Fe_3O_4 nanocomposites were synthesized for dechlorination of 2,4-dichlorophenol(2,4-DCP). The effects of the Ni content in Ni/Fe-Fe_3O_4 nanocomposites, solution pH, and common dissolved ions on the dechlorination efficiency were investigated, in addition to the reusability of the nanocomposites. The results showed that increasing content of Ni in Ni/Fe–Fe_3O_4 nanocomposites, from 1 to 5 wt.%, greatly increased the dechlorination efficiency; the Ni/Fe–Fe_3O_4 nanocomposites had much higher dechlorination efficiency than bare Ni/Fe nanoparticles. Ni content of 5 wt.% and initial p H below 6.0 was found to be the optimal conditions for the catalytic dechlorination of 2,4-DCP. Both 2,4-DCP and the intermediate product 2-chlorophenol(2-CP) were completely removed, and the concentration of the final product phenol was close to the theoretical phenol production from complete dechlorination of 20 mg/L of 2,4-DCP, after 3 hr reaction at initial p H value of 6.0,3 g/L Ni/Fe-Fe_3O_4 , 5 wt.% Ni content in the composite, and temperature of 22℃. 2,4-DCP dechlorination was enhanced by Cl-and inhibited by NO3-and SO_4~(2-). The nanocomposites were easily separated from the solution by an applied magnetic field. When the catalyst was reused, the removal efficiency of 2,4-DCP was almost 100% for the first seven uses, and gradually decreased to 75% in cycles 8–10. Therefore, the Ni/Fe–Fe_3O_4 nanocomposites can be considered as a potentially effective tool for remediation of pollution by 2,4-DCP. 相似文献