过氧化氢预氧化复合高岭土去除水中颤藻的研究

研究了H2O2预氧化复合高岭土混凝工艺对水中颤藻的去除效果。结果表明,H2O2具有显著氧化抑制藻活性的功能,高岭土则具有良好的助凝作用,经H2O2预氧化复合高岭土混凝后形成的絮体大而密实,沉降速度更快。试验得出最佳复配条件为:原水pH值为7,预氧化时间为20 min,H2O2、高岭土和PAC的投加量分别为3,34和3.5 mg/L。在该最佳试验条件下,浊度和叶绿素a去除率分别达到95.6%和97.8%,残留铝含量为0.13 mg/L。     

CIO2预氧化与PDM复合药剂联用除藻技术研究

开展了CIO2预氧化与PDM复合药剂联用提高常规处理工艺除藻效果的试验研究.结果表明,对于藻类数为1.3 X 108个/L、浊度为10.32～15.50 NTU、温度为27～30℃的黄河下游引黄水库水,当CIO2投量为1.0 mg/L、PDM复合药剂投量为60 mg/L时,滤后水浊度能降至0.2NTU以下,对CODMn的去除率达到46.6%,对藻类的去除率高达99%以上.CIO2预氧化与PDM复合药剂联用技术是强化常规工艺处理高藻水库水的有效措施.     

壳聚糖-海泡石复合粘土去除铜绿微囊藻的试验研究

利用室内模拟试验,研究比较了海泡石、膨润土、凹凸棒、蒙脱土和高岭土对铜绿微囊藻的去除效果以及壳聚糖-海泡石复合粘土中各成分的适宜比例和用量。结果表明,单独投加粘土时,海泡石的除藻效果最为显著;壳聚糖-海泡石复合粘土的最佳投加比例为1∶8,此时藻液中的细胞数及叶绿素含量用常规方法已无法检出,浊度去除率也达到96.4%;KMnO_4预氧化对藻类的絮凝沉降具有促进作用,同时能够防止藻类上浮以及藻细胞破裂。该复合粘土除藻剂的pH适用范围广,用量少,效率高,经济适用,除藻效果明显。     

ClO_2预氧化与PDM复合药剂联用除藻技术研究

开展了ClO2预氧化与PDM复合药剂联用提高常规处理工艺除藻效果的试验研究。结果表明,对于藻类数为1.3×108个/L、浊度为10.32～15.50 NTU、温度为27～30℃的黄河下游引黄水库水,当ClO2投量为1.0 mg/L、PDM复合药剂投量为60 mg/L时,滤后水浊度能降至0.2NTU以下,对CODMn的去除率达到46.6%,对藻类的去除率高达99%以上。ClO2预氧化与PDM复合药剂联用技术是强化常规工艺处理高藻水库水的有效措施。     

高铁酸钾预氧化强化混凝除藻效能及机理研究

为了应对蓝藻水华,研究了高铁酸钾预氧化对混凝除藻效能的影响。结果表明,高铁酸钾预氧化能显著提高混凝工艺对藻细胞和溶解性有机物的去除效果。在4 mg/L的最佳高铁酸钾投量下,对藻细胞、浊度、总有机物、溶解性有机物的去除率分别为73. 0%、65. 6%、58. 5%、17. 4%,与单独混凝相比,分别提高了19. 0%、16. 9%、11. 4%、5. 6%。此外,高铁酸钾预氧化对含藻水中具有紫外特性和荧光特性的有机物均有一定的去除效果。机理研究表明,高铁酸钾预氧化使藻细胞失活,Zeta电位升高,且其分解产物纳米铁氧化物吸附在藻细胞表面,增加了藻细胞的密度,从而提高了混凝除藻效能。     

PACl-PAM复合絮凝剂处理高岭土-腐殖酸体系的混凝过程

为了解决PACl在某些水质条件下处理效果不佳的问题,研究了PACl-PAM复合絮凝剂处理高岭土-腐殖酸体系的混凝过程。结果表明:单独使用铝系混凝剂(PACl2.2)时,DOC与浊度的去除率随pH值的升高呈现先增大后减小的趋势,pH为7.0时两者的去除率最高。要达到80%以上浊度去除率、60%以上DOC去除率,3种混凝剂(PACl,PACl+0.25 g/L PAM-1,PACl+0.50 g/L PAM-1)中铝系混凝剂的投加量(以Al计)从0.10 mmol/L下降到0.06 mmol/L。当复配混凝剂中PAM浓度小于0.50g/L时,浊度与DOC的去除率随PAM浓度的增大而升高;PAM浓度大于0.50g/L后,浊度与DOC的去除率快速下降,且阳离子度为75%的PAM-3的混凝效果下降最为明显。当混凝剂中含有阳离子度为75%的PAM时,浊度下降较为明显且絮体的沉降性能更好。     

KMnO4强化混凝耦合超滤去除湖库水中共存铁锰藻

华南地区湿热环境下铁、锰和藻共存湖泊水具有明显的地域特征。对华南地区三个典型的高藻湖水进行了水质调研,针对性地研究了高锰酸钾预氧化强化混凝耦合超滤对高藻湖泊水中铁、锰、藻的去除效能及膜污染特征。结果表明,随着高锰酸钾投加量的增加,耦合工艺对铁、锰、藻、蛋白质和多糖的去除效果均增强,尤其当投加量为2.5 mg/L时,铁、锰、藻的去除率分别可达93.7%、91.5%、91.0%。进一步研究发现,高锰酸钾预氧化水中铁和锰的产物对高藻水具有助凝作用,使得藻细胞团聚并且形成了更大的颗粒,SEM-EDS和XPS分析显示高锰酸钾预氧化形成了铁与锰的氧化物。最后,对实际湖库水进行短周期和长周期实验,出水水质均保持稳定,且预氧化能有效缓解膜污染。     

强化混凝-沉淀-砂滤工艺去除海水中藻类的试验研究

通过考察强化混凝中混凝剂种类及投加量、氧化性助凝剂种类及投加量、氧化时间、pH以及水力条件等因素对海水中Chl-a、CODMn去除效果的影响,确定了试验参数,并后续加入砂滤工艺考察其除藻效果.结果表明:在调节海水pH值为5～6,选用3 mg/L高锰酸钾预氧化30min后,投加混凝剂聚合氯化铝铁(PAFC)对Chl-a和CODMn均有较佳的去除效果.强化混凝-沉淀-砂滤工艺对Chl-a平均去除率可以达到80%以上,对CODMn去除率在50%左右,对浊度的去除率大干97%.     

紫外/过硫酸盐预氧化强化混凝同步除藻和三氯酚

以铜绿微囊藻和三氯酚（TCP）为研究对象，探究了紫外/过硫酸盐（UV/PS）预氧化强化混凝技术同步除藻和TCP的效果。结果表明，经过UV/PS预氧化强化混凝沉淀以后，对OD680、Chl-a、浊度和TCP的去除率分别提高了66.2%、67.4%、51.7%和95.6%;UV/PS预氧化阶段最佳PS投加量为100 mg/L，最佳预氧化时间为10 min。机理分析发现，UV/PS预氧化可以破坏细胞的完整性，使藻细胞释放胞内有机物（IOM），并且能够进一步破坏核酸；同时，UV/PS预氧化还可以降低藻细胞表面的Zeta电位、改变细胞粒径，进而强化混凝除藻。     

预臭氧/混凝/气浮工艺去除水库原水中的藻类

采用预臭氧/混凝/气浮工艺处理水库高藻原水,研究该工艺的最优运行参数。结果表明,在原水藻含量为1.4×108个/L的条件下,当臭氧投加量为1 mg/L、聚合氯化铝铁(PAFC)投加量为20 mg/L、气浮回流比为10%时,除藻效果最好,去除率可达到90%以上;另外发现,适当的预臭氧氧化可提高气浮对藻类的去除效率,投加臭氧较不投加可将除藻率提高40%以上。     

Influence of cations on noncovalent interactions between 6-propionyl-2-dimethylaminonaphthalene (PRODAN) and dissolved fulvic and humic acids

The influence of cations (Na(+), Ca(2+) and Mg(2+)) on noncovalent interactions between 6-propionyl-2-dimethylaminonaphthalene (PRODAN) and dissolved fulvic acids (FAs) (Norman landfill leachate fulvic acid (NLFA) and Suwannee River fulvic acid (SRFA)) and dissolved humic acids (HAs) (Suwannee River humic acid (SRHA) and Leonardite humic acid (LHA)) was examined using steady-state fluorescence spectroscopy at pH 4, 7 and 10 as a function of cation concentration (up to 25-100mM). Regardless of pH and cation concentration, PRODAN quenching by FA was unaffected by cations. However, interactions between PRODAN and HA decreased in the presence of cations at pH 7 and 10. Cation concentrations below the HA charge density resulted in the greatest decrease of PRODAN quenching, while very little additional decrease in PRODAN quenching occurred at cation concentrations above the HA charge density. This suggests that as the HA carboxylic acid functional groups form inner sphere complexes with divalent cations, intramolecular interactions result in a contraction of the HA molecular structure, thereby preventing PRODAN from associating with the condensed aromatic, electron accepting moieties inherent within HA molecules and responsible for PRODAN quenching. However, once the HA carboxylic acid functional groups are fully titrated with divalent cations, PRODAN quenching is no longer significantly influenced by the further addition of cations, even though these additional cations facilitate intermolecular interactions between the HA molecules to form supramolecular HA aggregates that can continue to increase in size. Regardless of FA and HA type, pH, cation type and concentration, the lack of blue-shifted fluorescence emission spectra indicated that micelle-like hydrophobic regions, amenable to PRODAN partitioning, were not formed by intra- and intermolecular interactions of FA and HA.     

超细粉体凹凸棒石助凝去除富营养化河水中的藻类

考察了投加超细粉体(200目)凹凸棒石对聚合氯化铝(PAC)混凝沉淀去除富营养化河水中藻类的影响.结果表明,添加凹凸棒石能大大提高PAC对浊度和叶绿素a的去除效果.且可以明显增加絮体的密度,改善絮体的沉降性能,抑制絮体中藻类的上浮.当PAC投量为40ms/L、凹凸棒石投量为0.08%时,PAC与凹凸棒石联用对浊度和叶绿素a的去除率较单用PAC时分别提高了14.5%和14.0%,形成的絮体沉降体积仅为单用PAC时的1/2,降低了后续处理难度.     

聚硅铁混凝去除腐殖酸的研究

考察了聚硅铁(PSF)对腐殖酸(HA)的去除效果及影响因素,并与聚合硫酸铁(PFS)、硫酸铁[Fe_2(SO_4)_3]进行了比较.结果表明,当5相似文献   

混凝剂中的铝形态对藻类混凝过程的影响

为了考察混凝剂中的铝形态对藻类混凝过程的影响,使用3种具有不同铝形态分布的混凝剂对含藻水进行了混凝试验。结果表明,硫酸铝由于具有较低含量的Alb,电中和能力较差,故需要较大的投量才能去除藻类,形成絮体;含藻水体系中的有机物主要是腐殖酸及富里酸类物质,微生物代谢产物(SMP)在硫酸铝作混凝剂时得到较好的去除,而腐殖酸及富里酸的去除率较低可能是造成硫酸铝混凝效果较差的原因; Alc(Al(30))在混凝中的作用机理主要是吸附架桥作用,可有效去除水体中的有机物,Al₁₃的主要作用机理是电中和作用,可以有效去除水体中的颗粒物;Al₁₃与Al₃₀由于具有形态的稳定性,其混凝过程受pH值的影响较小。絮体强度因子随着pH值的升高先增大后减小,Al₁₃作混凝剂时絮体恢复因子随pH值的升高先增大后减小,而其他两种混凝剂所形成絮体的恢复因子随pH值的升高而增大。     

Steady-state humic-acid-containing blanket in upflow suspended bed

We investigated the effects of turbidity and concentration of humic acid on the steady-state behavior of the blanket, which was coagulated using polyaluminum chloride (PACl) as coagulant. The three-dimensional solid-flux plot was constructed. Based on fixed PACl dosage, the iso-humic-acid solid-flux surfaces stacked that enveloped the feasible regime for the blanket bed. The steady-state point moved toward low solid flux and low solid fraction regime with decreasing initial raw water turbidity and/or increasing humic-acid concentration. Low water turbidity and high humic-acid concentration yielded a bulky blanket, with the former producing clean, and the latter turbid effluent. The presence of humic acid was thereby harmful to blanket strength, except for the case of low raw water turbidity. An optimal range of humic acid for blanket strength and clarification efficiency existed at 1 mg l(-1). Low level of humic acid is beneficial to blanket development with low-turbidity raw water.     

Removal of arsenic from water: Effects of competing anions on As(III) removal in KMnO4–Fe(II) process

Effects of sulfate, phosphate, silicate and humic acid (HA) on the removal of As(III) in the KMnO₄–Fe(II) process were investigated in the pH range of 4–9 with permanganate and ferrous sulfate applied at selected dosage. Sulfate decreased the removal of arsenic by 6.5–36.0% at pH 6–9 and the decrease in adsorption did not increase with increasing concentration of sulfate from 50 to 100 mg/L. In the presence of 1 mg/L phosphate, arsenic removal decreased gradually as pH increased from 4 to 6, and a sharp drop occurred at pH 7–9. The presence of 10 mg/L silicate had negligible effect on arsenic removal at pH 4–5 whereas decreased the arsenic removal at pH 6–9 and the decrease was more significant at higher pH. The presence of HA dramatically decreased the arsenic removal over the pH range of 6–9 and HA of higher concentration resulted in greater drop in arsenic removal. The effects of the competing anions on arsenic removal in the KMnO₄–Fe(II) process were highly dependent on pH and the degree of these four anions influencing As(III) removal decreased in the following order, phosphate > humic acid > silicate > sulfate. Sulfate differed from the other three anions because sulfate decreased the removal of arsenic mainly by competitive adsorption while phosphate, silicate and HA decreased the removal of As(III) by competitive adsorption and sequestering the formation of ferric hydroxide derived from Fe(II).     

不同混凝剂强化除藻、除浊的研究

采用聚合氯化铝(PAC)、聚合氯化铝铁(PAFC)、聚合硫酸铁(PFS)、聚合硫酸铝(PAS)和硫酸铝(AS)五种混凝剂对某含藻湖水进行强化混凝除藻、除浊试验研究,考察了混凝剂种类及投量、原水pH、沉降时间等因素对强化混凝效果的影响。结果表明,五种混凝剂的综合除藻、除浊性能排序为:PACPAFCPFSPASAS;在原水pH值为5~9的范围内,含铁混凝剂PFS和PAFC对pH的适应性较强,且在pH值为5~7的弱酸性条件下,PFS的除藻、除浊性能最优,当其投量为4 mg/L时,除藻率近80%,除浊率可达80%以上;而在pH值为7~9的弱碱性条件下,PAC则表现出更好的除藻、除浊效果,当其投量为4 mg/L时,除藻率和除浊率可分别达到83%和90%;AS对pH的适应性最差,其除藻、除浊效果最差;另外,五种混凝剂的除藻率、除浊率均随沉降时间的延长而增大,最佳沉降时间为20 min。     

Isolation of humic acid from the terrestrial plant Brugmansia sanguinea

A brown residue has been isolated from the dried terrestrial plant Brugmansia sanguinea with a standard solvent extraction procedure augmented with removal of alginic acid. The residue is identified as humic acid (HA) by comparison of its analytical, spectroscopic and morphological properties with an International Humic Substance Society standard soil-derived HA and with those of HA isolated from the live marine alga Pilayella littoralis and municipal compost with the same combined procedure.     

Removal of humic acid from aqueous solution using MgO nanoparticles

The main purpose of this work was to investigate the removal of humic acid (HA) from aqueous solutions using MgO nanoparticles as a novel adsorbent. The effect of contact time, competing anions in the aqueous solutions, for the removal of HA in batch system was studied. The nanoparticle was characterized by scanning election microscope method. Experimental results show that MgO nanoparticles can remove more than 90% of HA under optimum conditions. The results showed that the examined interfering anions influenced the HA removal. The adsorption kinetics and isotherm were also studied. The adsorption kinetics was well described by the pseudo-second-order equation, and the adsorption isotherms were better fitted by the Langmuir model.     

强化混凝技术去除腐殖酸的研究进展

综述了腐殖酸对水处理过程的影响及其与饮水水质的关系，并对采用强化混凝技术去除腐殖酸的研究进展进行了系统介绍，指出今后可从物化形态学出发去优化反应器的设计和运行。