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1.
聚合氯化铝与有机高分子复合絮凝剂的电荷特性及其絮凝作用 总被引:29,自引:2,他引:27
用流动电流技术研究了聚合氯化铝(PAC)与不同类型有机高分子复合絮凝剂的电荷特性,并用ζ电位分析仪结合混凝烧杯实验研究了不同碱化度(B)的PAC与阳离子型有机高分子C109P复合絮凝剂的电中和水体颗粒物的能力与絮凝效能的关系,对无机-有机复合型絮凝剂中有机高分子在凝聚絮凝过程中所起的作用进行了讨论. 相似文献
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"类龟式"Al13盐酸盐的制备及絮凝性能 总被引:4,自引:0,他引:4
采用氯化铝溶液电解法、氯化铝溶液溶铝法、稀盐酸溶铝法、氯化铝溶液碱性阴离子树脂交换法、氯化铝溶液补水蒸馏法、氯化铝溶液压溶氢氧化铝或氧化铝法等促使氯化铝水解-聚合的方法,通过控制起始溶液的浓度、水解-聚合的程度和体系的温度,制成"类龟式"Al13含量超过96.5%的聚合氯化铝结晶,其中电解法制备的产物纯度达99.9%,盐基度61.48%,总铝(Al2O3)33.75%,水不溶物0.01%,Alb达97%.化学分析、X-射线粉末衍射和X-射线单晶结构解析结果表明,产物是一种由十三个铝氧八面体连接组成的Al13(OH)24Cl15·37H2O化合物.高岭土模拟水样和黄河水样絮凝试验表明,絮凝效果优于市售固体聚合氯化铝、氯化铝和硫酸铝,经絮凝处理的黄河水主要水质质量指标达到国家生活饮用水标准GB5749-85的要求. 相似文献
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采用聚丙烯酰胺凝胶层析法分离纯化聚合氯化铝(PAC)中的Al13形态,并采用Al-Ferron逐时络合比色法和27Al-NMR对Al13形态进行分析和表征;结果表明,在层析法分离中,随着洗脱时间的延长各种铝形态按分子的大小依次被洗脱下来,因此,截取中间组分即可得到最高含量为99%以上的纳米Al13形态;通过对水解过程的研究可以推断,各种铝形态最终水解产物的粒径多集中在20μm和100μm附近,不同的铝形态到达最终水解产物的速度各不相同,具有最高Alb含量的纳米Al13形态具有较高的水解稳定性. 相似文献
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李理成 《湖南环境生物职业技术学院学报》2008,14(4):15-19
基于铝水解聚合形态产生再稳现象的反应机制,对Al13的再稳现象的成因、影响铝水解形态吸附再稳发生的因素进行了分析,同时从理论上对胶粒表面浓度与凝聚剂剂量、体系随pH变化对混凝效果的影响、颗粒物的扩散传质速率进行了研究.结果表明:再稳现象的产生与凝聚剂剂量与胶体颗粒物表面浓度的相对比值、混凝体系的pH和流体的扩散输送状况有关.尤其是低颗粒物表面浓度下的混凝最易出现再稳.图3,参12. 相似文献
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Al(Ⅲ)与Fe(Ⅲ)溶液共聚合研究 总被引:7,自引:0,他引:7
以AlCl_3·6H_2O和FeCl_3·6H_2O混合溶液通过滴加NaOH溶液的方法制备了不同Al/Fe(摩尔比,下同)和不同[OH]_b/[Al+Fe]值的共聚物.测定了聚合过程和熟化过程中的pH值变化,并对不同碱化度和熟化时间下的聚合物进行了混凝效能实验.结果表明,在共聚过程中,Fe(Ⅲ)与 OH~-的络合速度比Ai(Ⅲ)快,即 Fe(Ⅲ)具有较强的共聚合活性.Al/Fe,[OH」_b/[Al+Fe]值对铝铁共聚物形态分布有明显影响.不同条件下共聚物混凝对比实验表明,在Al/Fe为5:5,[OH]_b/[Al+Fe]为 1.6,熟化时间为24h时,显示出了较优异的混凝效能. 相似文献
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工业聚合氯化铝的形态分布及混凝效果 总被引:5,自引:1,他引:5
对铝浓度为2.50mol·l-1的聚合氯化铝.采用Al-Ferron络合比色法和烧杯混凝实验对样品的形态分布和混凝性能进行了研究.结果表明:三个工业系列样品中Al的形态分布规律基本一致,Ala随盐基度的升高而逐渐降低;Alc随盐基度的升高而升高;Alb则先随盐基度的升高而升高,达到最大值后,再随盐基度的升高而降低.同一系列样品在相同加药条件下,盐基度愈高,混凝效果愈好,Alb含量愈高,混凝效果并不一定愈好.因此,提高Alb不一定能提高混凝效果,工业产品的质量控制以及追求目标应当是尽量提高盐基度,而不是Alb的含量. 相似文献
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聚合氯化铝与有机机高分子复合絮凝剂的电荷特性及其絮凝作用 总被引:7,自引:0,他引:7
用流动电流技术研究了聚合氯化铝与不同类型有机高分子复合絮凝剂的电荷特性。并用ζ电位分析仪结合混凝烧杯实验研究了不同碱化度(B)的PAC与阳离子型有机高分子C109P复合絮凝剂的电中和水体颗粒物的能力与絮凝效能的关系。 相似文献
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采用密度泛函DFT量子化学计算,初步探讨了"平面型"十三聚合铝(F-Al13)的水交换反应.在B3LYP/6-31G水平下模拟了气相体系中全水合F-Al1153+与脱质子形态(F-Al913+和F-Al313+)中η-OH2(1)键合水位点的水交换反应;比较了F-Al13和K-Al13两种不同十三聚合铝形态的水交换反应特点;讨论了不同铝形态(二聚铝Al2、三聚铝Al3、Al6六元环以及Al7Anderson内核等)水交换反应研究对于阐明F-Al13形成机制的重要意义. 相似文献
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以聚合氯化铝(PACl)和壳聚糖(CTS)为主要原料合成了聚合氯化铝-壳聚糖(PACl-CTS)复合絮凝剂,考察了PACl与CTS的质量比、反应温度、反应液pH和反应时间等因素对PACl-CTS絮凝性能的影响,优化出PACl-CTS合成最佳工艺条件为:温度控制在70℃,m(PACl)∶m(CTS)=4∶1,反应时间1 h,pH值为4.通过红外图谱(IR)和扫描电镜(SEM)对PACl-CTS的微观结构进行了表征,表明PACl以一定的晶体结构镶嵌在CTS中,PACl和CTS之间存在一定的相互作用,而不是简单的复配.将合成的PACl-CTS应用于蓝藻沼液废水处理,结果表明,PACl-CTS对浊度、COD、TP具有良好的絮凝性能,当投加量为21.0 mg.L-1时,浊度、COD、TP的去除率分别达到了98.15%、67.78%和84.05%,可作为新型高效絮凝剂应用于蓝藻沼液废水预处理. 相似文献
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Effects of humic acid on residual Al control in drinking water treatment plants with orthophosphate addition 总被引:2,自引:0,他引:2
Wendong WANG Hua LI Zhenzhen DING Xiaochang WANG Rui LIU 《Frontiers of Environmental Science & Engineering》2012,6(4):470-476
This study aimed to investigate the effects of humic acid (HA) on residual Al control in drinking water facilities that used orthophosphate addition. The results showed that adding orthophosphate was an effective method for residual Al control for the raw water without HA. When orthophosphate was added at 1.0 min before the addition of poly aluminum chloride (PACl), the concentrations of soluble aluminum (Sol-Al) and total aluminum (Tot-Al) residue were 0.08 and 0.086 mg·L-1, respectively; both were reduced by 46% compared with the control experiment. The presence of HA would notably increase the residual Al concentration. For the raw water with 5 mg·L-1 of HA, the concentrations of Sol-Al and Tot-Al increased from 0.136 and 0.174 mg·L-1 to 0.172 and 0.272 mg·L-1, respectively. For water with a HA concentration above 5 mg·L-1, orthophosphate was ineffective in the control of residual Al, though there were still parts of orthophosphate were removed in coagulation. The amounts of Al removal were positively correlated with the solids freshly formed in coagulation. Similar to the raw water without HA, the best Al control was obtained with orthophosphate salt added at 1.0 min before PACl. HA concentrations in the raw water, solution pH, and the orthophosphate dosage suitable for residual Al control by orthophosphate precipitation were also investigated. 相似文献
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聚合铝的形态稳定性及其动电特性的研究 总被引:10,自引:2,他引:10
本文采用改进的Al-Ferron快速测定法研究了混凝过程中铝盐与聚合铝水解形态的转化规律及稳定性,并对混凝反应过程中铝与聚合铝溶解-沉淀形态分布与理论溶解度进行了对比,同时采用流动电流技术直接测定了铝盐与聚合铝絮凝剂的荷电状况,最后对发生在混凝过程中铝与聚合铝最佳凝聚形态进行了讨论。 相似文献
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本文对Al-Ferron逐时络合比色法和~(27)AI-NMR法对PASC和PAC中铝的形态分布的测定结果进行了对比分析和讨论.结果表明,在PAC中,Al_(13)和AI_b之间具有良好的对应关系,Al_(13)/Al_b比值为1.0左右 但对PASC而言,情况有所不同,在低碱化度(B)和低Al/Si摩尔比情况下,Al_(13)和Al_b之间不存在对应关系,Al_(13)和Al_b比值远远小于1.0,随着B值和Al/Si摩尔比的升高,Al_(13)/Al_b比值逐渐趋近于1.0.这意味着在低B值和低Al/Si摩尔比情况下,由于聚硅酸与铝水解聚合产物间的相互作用,形成了铝硅复合新产物,该新产物对PASC中铝的形态分布产生了影响. 相似文献
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Baoyu Gao Yongbao Chu Qinyan Yue Chunyan Kong Xiaona Wang 《Frontiers of Environmental Science & Engineering》2007,1(3):368-373
In order to investigate the characteristics of pure Nano-Al13, Nano-Al13 was separated and purified from a series of poly-aluminum chloride (PAC) solutions which had the same Al13 percentage but different total Al concentrations, by using column chromatography, ethanol-acetone resolving and SO2? 4/Ba2+ displacement. The Al13 species yield was characterized by Al-ferron timed complexation spectrophotometry and 27Al-NMR (nuclear magnetic resonance). The coagulation efficiency of Nano-Al13, PAC and AlCl3 in synthetic water was also investigated by Jar tests. The dynamic process and aggregation state of kaolin suspensions coagulating with Nano-Al13, PAC and AlCl3 were similarly investigated using a photometric dispersion analyzer 2000 (PDA2000). The experimental results indicated that the ethanol-acetone resolving method was simple and could separate the PAC solution at different concentrations, while column chromatography could separate PAC solutions at low concentrations. The SO4 2?/Ba2+ displacement method could separate PAC solutions at high concentrations. However, extra inorganic cation and anion could be added in the solution during separation. The coagulation efficiency and dynamic experimental results showed that Nano-Al13 with high positive-charged species was effective in removing turbidity and color. The dynamic process results showed that Nano-Al13 also had the best recovery capability after shearing compared with PAC and AlCl3 because the Nano-Al13 conformation is more effective in charge neutralization. 相似文献
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Diatom aggregate formation was analyzed using coagulation theory. Population dynamics models show that coagulation has an important impact on species succession during diatom blooms. When different species collide and form mixed aggregates this process causes interspecific interference competition within the diatom community. The outcome can be predicted by a set of simple differential equations. For a twospecies system the equations reduce to the Lotka-Volterra two-species competition model. The outcome of this interference competition depends on species-specific growth rates, cell sizes, stickiness and on the species composition of the seeding populations of a bloom. Due to mutual flocculation some species may disappear from the environment. Small and fast growing diatoms are favoured by high stickiness coefficients. The impact of stickiness on species succession was found to be most pronounced in eutrophic and hydrographically isolated environments. The sticking properties of the diatom Skeletonema costatum are discussed in an evolutionary context; we suggest that mutual coagulation increases the abundance of S. costatum relative to other diatom species in coastal areas. The model was tested on field data, and the predicted dynamics of a spring bloom was very similar to that observed. 相似文献
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研究了由FeSO4制备聚合硫酸铁过程中,钛对聚铁聚合态分布和稳定性的影响,并进一步考察了含钛聚合硫酸铁的絮凝性能.应用络合比色法对聚铁中不同水解形态聚铁的含量进行了分析测定,并通过沉淀实验考察了不同钛含量对聚铁稳定性的影响;随后,通过出水浊度、TOC、金属离子残余量和出水pH等指标测试,研究了钛对聚合硫酸铁混凝性能的影响.结果表明,较低的钛含量(<0.025)在一定程度上有利于中聚态聚铁的形成,提高了聚铁絮凝剂的混凝效率;反之,钛含量超过0.025时不仅聚铁的稳定性显著下降,而且处理后出水的钛残留增加,pH降低. 相似文献
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Yanxia Zhao Huiqing Lian Chang Tian Haibo Li Weiying Xu Sherub Phuntsho Kaimin Shih 《Frontiers of Environmental Science & Engineering》2021,15(4):58
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浅论铝盐的水解和吸附电中和过程中被凝聚物浓度的影响 总被引:10,自引:0,他引:10
通过对凝聚机理和铝盐在水中水解过程的分析,提出了铝盐水解物吸附起胶本电和中和数学模式,论述了被凝聚物浓度对铝盐水解过程的影响,在实际的凝集过程中,铝盐的水解和向胶体表面的吸附是同时进行的,部分铝盐在完成水解之前就以中间产物的形态吸附于胶体表面,胶体溶液的浓度愈高,这种倾向就愈强,由于较低水解度的物种具有较高的单位电位浓度,它们能显示较强的电中和能力,因此,随着胶体溶液浓度增高,达到最佳凝聚ζ电位所 相似文献