聚硅氯化铝混凝剂除油效果的试验

制备不同碱化度和不同Ａｌ／Ｓｉ摩尔比的系列聚硅氯化铝作为混凝剂，实验考察了Ｂ，Ａｌ／Ｓｉ摩尔比及ＰＨ值对除油效果的影响，并考察了ＰＡＳＣ去除ＣＯＤ的效果。结果表明，Ｂ对ＰＡＳＣ混凝除油效果影响较大，随Ｂ值增大，除油效果提高；Ａｌ／Ｓｉ摩尔比对ＰＡＳＣ混凝除油效果影响较小；     

Separating method and dynamic processes of Nano-Al13

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. Translated from Acta Scientiae Circumstantiae, 2005, 25(6): 767–772 [译自: 环境科学学报]     

Effect of viscosity, basicity and organic content of composite flocculant on the decolorization performance and mechanism for reactive dyeing wastewater

A coagulation/flocculation process using the composite flocculant polyaluminum chloride-epichlorohydrin dimethylamine (PAC-EPI-DMA) was employed for the treatment of an anionic azo dye (Reactive Brilliant Red K-2BP dye). The effect of viscosity (ηup), basicity (B = [OH]/[Al]) and organic content (W_P) on the flocculation performance as well as the mechanism of PAC-EPI-DMA flocculant were investigated. The ηup was the key factor affecting the dye removal efficiency of PAC-EPI-DMA. PAC-EPI-DMA with an intermediate ηup (2400 mPa.sec) gave higher decolorization efficiency by adsorption bridging and charge neutralization due to the co-effect of PAC and EPI-DMA polymers. The W_P of the composite flocculant was a minor important factor for the flocculation. The adsorption bridging of PAC-EPI-DMA with ηup of 300 or 4300 mPa.sec played an important role with the increase of W_P, whereas the charge neutralization of them was weaker with the increase of W_P. There was interaction between W_P and B on the removal of reactive dye. The composite flocculant with intermediate viscosity and organic content was effective for the treatment of reactive dyeing wastewater, which could achieve high reactive dye removal efficiency with low organic dosage.     

Performance of bimetallic nanoscale zero-valent iron particles for removal of oxytetracycline

In this study, bimetallic nanoscale zero-valent iron particles(nZVI), including copper/nanoscale zero-valent iron particles(Cu/nZVI) and nickel/nanoscale zero-valent iron particles(Ni/nZVI), were synthesized by one-step liquid-phase reduction and applied for oxytetracycline(OTC) removal. The effects of contact time and initial p H on the removal efficiency were studied. The as-prepared nanoscale particles were characterized by scanning electron microscopy(SEM), energy dispersive spectroscopy(EDS) and X-ray diffraction(XRD). Finally, the degradation mechanisms of OTC utilizing the as-prepared nanoparticles were investigated by using X-ray photoelectron spectroscopy(XPS) and mass spectrometry(MS). Cu/n ZVI presented remarkable ability for OTC degradation and removed71.44% of OTC(100 mg/L) in 4 hr, while only 62.34% and 31.05% of OTC was degraded by Ni/nZVI and nZVI respectively. XPS and MS analysis suggested that OTC was broken down to form small molecules by ·OH radicals generated from the corrosion of Fe0. Cu/nZVI and Ni/n ZVI have been proved to have potential as materials for application in OTC removal because of their significant degradation ability toward OTC.     

Synchronous removal of CuO nanoparticles and Cu2+ by polyaluminum chloride-Enteromorpha polysaccharides: Effect of Al species and pH

Copper oxide nanomaterials have been extensively applied and can have serious impacts when discharged into the aquatic environment, especially when complexed with humic acid(HA) to form composite contaminants.As an innovative recycled coagulant aid,Enteromorpha polysaccharides(Ep) were associated with polyaluminum chloride(PACl)(denoted as PACl-Ep) to simultaneously remove CuO nanoparticles, Cu²⁺and HA in this study.The influence of different Al species coagulants(AlCl₃, PA...     

Degradation Mechanism of CF/EP Composites in Supercritical <Emphasis Type="Italic">n</Emphasis>-Butanol with Alkali Additives

CF/EP (carbon fibre/epoxy resin) composites were degraded by supercritical n-butanol with alkali additive KOH in a batch reactor. The catalytic degradation mechanism of the composites was investigated based on the analysis of liquid phase products by GC–MS and solid phase products by FTIR. The results indicate that alkali additive (KOH) can promote Guerbet reaction and increase hydrogen donor capability of supercritical n-butanol. The H^· can combine promptly with the free radical formed by the scission of linear and crosslinked chains in epoxy resin to generate the liquid products, including phenol, 4-isopropylphenol, 4-(2-methylallyl)phenol and other derivatives of benzene and phenol. The combination of supercritical n-butanol with alkali additive is an effective way to degrade and recycle CF/EP composites.     

纳米Al13的分离方法及混凝效果动态过程的研究

以相同Al13含量、不同浓度的PAC为原料,利用乙醇-丙酮混合溶剂法、SO4^2-／Ba^2 沉淀置换法以及柱层析法分离提纯纳米Al13形态,同时利用Al-Ferron逐时络合比色法、^27Al-NMR等多种现代分析手段进行分析鉴定,比较其分离效果,并采用烧杯实验法和透光率脉动检测技术对Al13形态以及PAC、AlCl3的絮凝效果及絮凝过程中絮集物形成和增长的变化差异作了对比性研究．实验结果表明,乙醇．丙酮混合溶剂法对Al13分离纯化效果最好,分离所得Al13平均粒径大,聚合程度高．柱层析法受柱体积的影响只对低浓度的PAC有较好的分离效果;SO4^2-／Ba^2 沉淀置换法虽具有较好的分离效果,但分离过程有其他杂质离子的加入,影响到产品品质．混凝效果和动态实验结果表明,Al13形态是在絮凝过程中起电中和作用的主要形态,具有较强的除浊及脱色能力,在混凝过程中当絮体受到剪切力的破坏时Al13形态比PAC和AlCl3具有更强重新絮凝的能力．     

不同电荷的聚丙烯酰胺对焦化废水的絮凝性能研究

以聚合氯化铝铁(PAFC)为混凝剂,以阴离子型、阳离子型和非离子型聚丙烯酰胺(PAM)分别为助凝剂,研究了三种PAM对焦化废水的絮凝性能。从对废水初始浊度变化的适应性、絮凝剂用量、处理效果和处理费用等几个方面比较了三种PAM絮凝性能的差异,并对絮凝机理进行了分析。对于焦化废水的絮凝处理,发现三种PAM中非离子PAM具有最好的应用性。最后对非离子PAM的最佳用量及影响因素进行了考察。最佳条件下,浊度去除率可达85%以上,但是COD去除率较低为6%左右,这与悬浮颗粒对COD的贡献较小有关。     

Application of Fe0/C/Clay ceramics for decoloration of synthetic Acid Red 73 and Reactive Blue 4 wastewater by micro-electrolysis

Dyes are common pollutants in textile wastewaters, and the treatment of the wastewater has now attracted much attention due to its wide application and low biodegradability. In this study, Fe⁰/C/Clay ceramics, a kind of novel micro-electrolysis filler, were sintered and employed in a dynamic micro-electrolysis reactor for synthetic Acid Red 73 (AR73) and Reactive Blue 4 (RB4) wastewater treatment. The effects of influent pH, hydraulic retention time (HRT), and aeration on the decoloration efficiencies of AR73 and RB4 were studied. The optimum conditions for wastewater treatment were: AR73, influent pH of 4, HRT of 2 h and aeration; RB4, influent pH of 5, HRT of 6 h and aeration. Under the optimum conditions, decoloration efficiency of AR73 and RB4 wastewater was 96% and 83%, respectively. Results of UV-vis spectrum scanning demonstrated that the chromophores were broken. Continuous running tests showed that improvement of micro-electrolysis system with Fe⁰/C/Clay ceramics for AR73 and RB4 synthetic wastewater treatment could avoid failure of micro-electrolysis reactor, which indicated great potential for the practical application of the ceramics in the field of actual industrial wastewater treatment.     

以河砂为填料的接触氧化法处理高铁锰地下水研究

分别选用河砂、锰砂、改性页岩3种滤料作为滤柱填料,采用接触氧化法去除地下水中的铁锰,通过对比实验选取最佳填料,并对最佳填料去除铁锰的影响因素进行了研究.实验结果表明,3种滤料成熟期基本相同且对铁锰均有较好的去除效果,由于河砂具有广泛易得、成本低廉等优点,因此更适用于小城镇地区使用.对以河砂为填料的接触氧化法除铁除锰的深...