Preparation of a composite coagulant: Polymeric aluminum ferric sulfate (PAFS) for wastewater treatment

A new composite coagulant polymeric aluminum ferric was synthesized and parameters affecting the coagulant performance such as reaction temperature and time, and OH/Fe, P/Fe and Al/Fe molar ratios in this study, were examined. In addition, to obtain the optimum synthetic conditions resulting in the maximum turbidity removal efficiency, response surface methodology (RSM) was used to assess their interactive effects on coagulation–flocculation performance. The results showed that reaction temperature (60–80 °C) and time (30–50 min), and OH/Fe (0.1–0.3), P/Fe (0.2–0.3) and Al/Fe (1:9–1:10) molar ratios were favorable to the preparation process. The optimum synthesis conditions were reaction temperature and time, and OH/Fe, P/Fe and Al/Fe molar ratios of 80 °C, 40 min, 0.1, 0.25 and 1:10, respectively. Evaluation of the coagulation–flocculation process showed that COD (chemical oxygen demand) and turbidity removal efficiency of 82.8% and 98.2%, respectively, were achieved at coagulant dosage of 45 mg/L, wastewater initial pH of 8.5, and rapid agitation speed of 250 rpm. In addition, charge neutralization and adsorption/bridging coagulation–flocculation mechanisms played an important role in reducing the surface charge of colloids.     

混凝对垃圾渗滤液中腐殖质的去除特性

通过分别投加混凝剂聚合氯化铝(PAC)、聚合硫酸铁(PFS)和聚合氯化铝铁(PAFC)对垃圾渗滤液进行混凝沉淀处理,考察了3种混凝剂对渗滤液中TOC、CODCr和UV254的去除效果,并且根据单因素试验确定出PAC为最佳混凝剂,最佳投药量为6g/L.对渗滤液腐殖质分离方法进行了简化,并对经3种混凝剂处理后水样内的腐殖酸...     

再生纸浆造纸废水的混凝处理

通过四种无机混凝剂（Al2（SO4）3、PAC、FeSO4、FeCl3）和两种有机助凝剂（PAM、海藻酸钠）对再生纸浆造纸废水进行了混凝处理研究。结果表明,混凝剂种类、投加量、投加方式及pH值对处理效果都起着重要作用,在pH为4左右,快速搅拌（150r／min）1min后加入200mg／LPAC,持续快速搅拌30s后加入1mg／L的PAM,慢速搅拌（60r／min）10min,其COD去除率可达44．14％,浊度去除率可达94．18％。     

不同混凝剂对马铃薯淀粉废水混凝效果的影响

用混凝剂Fe2(SO4)3、PAC、PFSS、PAFC处理马铃薯淀粉废水,研究了混凝剂的种类、投药量、废水pH值、助凝剂PAM的投加量以及沉降时间等对混凝效果的影响。结果表明,混凝沉淀法预处理马铃薯淀粉废水优选混凝条件为:pH为7,混凝剂PAFC为1 200 mg/L,助凝剂PAM为5 mg/L,沉降25 m in。在此条件下,废水的浊度、COD去除率分别达97.27%及40.55%。投药量明显减少,而沉积物产量较高,为后续生化处理提供了有利条件。     

赤泥制备混凝剂盐基度及混凝效果研究

根据盐基度测定以及混凝实验结果,对以赤泥为原料制备水处理混凝剂进行了研究.以碳酸镁为盐基度调整剂,通过正交实验确定混凝剂的最佳聚合条件如下:80℃下,pH=4,聚合时间为24 h,盐基度调整剂的投加量为60 g·L-1.对4种盐基度调整剂(碳酸镁、碳酸钙、氢氧化钙、碳酸钠)制备的混凝剂进行对比,结果发现,以碳酸钠为调整...     

Improvement in the coagulation performance by combining Al and Fe coagulants in water purification

This study evaluated the beneficial effects on the coagulation process of combining coagulants with Fe and Al in the removal of turbidity and DOC (dissolved organic carbon), and proposed conditions for proper operation of a coagulation process. In addition, the floc characteristics and sludge dewater ability were evaluated. Blended coagulants were more effective than single coagulants at lower concentrations in water purification. The optimal blended ratio for the removal of DOC was 1.45 mM as Al/mM as Fe. Also, blended coagulants were less affected than single coagulants by pH, temperature, and rapid mixing intensity. Based on the results of the change in the apparent molecular weight distribution (AMWD) of DOC in raw and treated water by coagulation, low molecular weight organic matters were removed by 40.7% for the blended coagulant (1.45 mM as Al/mM as Fe). Blended coagulants formed larger flocs than single coagulants did. At pH 6.0, floc strength and sludge dewaterablity were both improved.     

混凝法强化城市污水一级处理试验

以济南市水质净化一厂初沉池进水为试验水样,在设定的反应条件下,以三氯化铁、聚合氯化铝、聚合氯化铁铝为试验混凝剂,以浊度、COD、TP、TN等为测定指标,进行了大量的烧杯搅拌试验。并在此基础上进行了无机混凝剂与有机混凝剂复配的正交试验。试验结果显示：最佳混凝剂为聚合氯化铁铝,其最佳投药量为25mg／L左右;去除率浊度在90％以上．、COD70％-90％、TP70％-95％、TN、NH3-N分别在30％和15％左右;正交试验最佳复配模式为：先投加无机混凝剂聚合氯化铁铝20mg／L,再投加有机混凝剂阴离子聚丙烯酰胺1．0m2／L。     

中国无机铝铁盐水处理剂行业60年发展历程及未来发展趋势

介绍了中国无机铝铁盐行业在混凝剂应用方面60 a来的发展历程,包括一些重点混凝剂（聚硫酸铁、聚氯化铁、聚氯化铝和硫酸铝）的制备方法和工艺流程如铝灰法、铝酸钙法、氢氧化铝酸溶法、空气/氧气氧化法等;以及国内各大水厂/企业使用混凝剂的发展历史和现状。最后对铝铁盐行业的未来发展趋势进行了展望：混凝理论有待进一步发展、开发新型复合混凝剂投入实际生产应用并倡导用户避免走进“药剂纯度越高,效果越好”这一误区。     

ZW130混凝剂处理造纸废水

本文针对废纸造纸厂产生的废水，试用了不同混凝药剂的处理效果，并合成了一种处理造纸废水的专用混凝剂ZW130，该混凝剂与有机高分子絮凝剂配合使用，能达到比目前市场上常见的Al2(SO4)3、聚合氯化铝（ＰＡＣ）、聚合硫酸铁（ＰＦＳ）等混凝剂的处理效果好，药剂费用低。本文试验了该混凝剂的使用条件，并和其它几组混凝药剂处理效果做了对比实验。     

染料废水脱色混凝剂PSDC-Ⅵ的开发及工程应用

采用从杭州钢铁厂采集来的钢渣(水渣),经过粉碎、碱浸、酸溶、聚合(加入不同量的Fe3+和Al3+)和过滤等方法制得脱色混凝剂PSDC-Ⅵ系列3种。研究了它们对染料废水的脱色效果,考察了影响PSDC-Ⅵ系列混凝剂混凝及脱色效果的因素,并与PAC进行比较。试验表明,PSDC-Ⅵ系列混凝剂在pH≤7和pH≥10时,对试验的染料废水脱色效果较差,在pH=8时,达到最佳脱色效果点。同时在杭州市某印染厂染料废水工程中应用,改进了原有染料废水处理工艺流程,取得了良好的处理效果。PSDC-Ⅵ系列混凝剂处理该厂染料废水的混凝和脱色效果比用PAC时的效果好。     

PDM复合混凝剂用于低温低浊水源水处理的研究——低浊度宁波姚江水处理

该文报道了用特征黏度系列化的有机阳离子高分子聚二甲基二烯丙基氯化铵(PDM)与无机混凝剂复合物对宁波低浊度姚江水的脱浊处理研究过程。通过混凝烧杯实验,考察了无机混凝剂的种类及其与PDM的复合配比对低浊度姚江水脱浊效果的影响。结果表明,对低浊度姚江水,要达到1.0~1.2 NTU的沉淀出水余浊,硫酸铝(AS)需5 mg/L左右的投加量,聚合硫酸铁(PFS)需8 mg/L左右的投加量,而聚合氯化铝(PAC)的投加量在10 mg/L左右;PDM对无机混凝剂强化混凝脱浊效果明显,无机混凝剂与PDM的复合配比越低,复合混凝剂混凝脱浊效果越好,在达到水厂沉淀出水浊度标准的前提下,AS/PDM复合药剂能比单独使用AS减少20%AS投加量;PFS/PDM复合药剂能比单独使用PFS减少30%~40%PFS投加量;PAC/PDM复合药剂能比单独使用PAC减少30%~50%PAC投加量。     

无机盐对复合混凝剂黏度行为和混凝性能的影响

本文探究了无机盐对聚合氯化铝(PAC) / 聚二甲基二烯丙基氯化铵（PDM）复合混凝剂黏度行为和混凝性的影响,进一步考察了这两种影响相互间的关联性。用乌氏黏度计测定了无机盐对PAC/PDM比浓黏度的影响,同时采用混凝烧杯考察了无机盐对PAC/PDM混凝脱浊效果的影响。结果表明,不同无机盐对复合混凝剂黏度行为有不同影响,这种影响强度排序依次为AlCl3>MgCl2>NaCl,Na2SO4和Na3PO4使复合混凝剂产生白色沉淀;由混凝实验可得：对于复合混凝剂的混凝脱浊效果,AlCl3能使其明显提高,MgCl2和NaCl对其无明显影响,Na2SO4使其效果明显变差,Na3PO4使其效果想变差后变好。由此可见,在实验范围内,无机盐对复合混凝剂黏度行为的影响与其对复合混凝剂混凝性能影响无显著关联。     

无机盐对PAC/PDM黏度行为和混凝性能的影响

该文考察了无机盐对聚合氯化铝(PAC)/聚二甲基二烯丙基氯化铵(PDM)复合混凝剂黏度行为和混凝性的影响,进一步考察了两种影响的关联性。用乌氏黏度计测定了无机盐对PAC/PDM比浓黏度的影响,同时采用混凝烧杯考察了无机盐对PAC/PDM混凝脱浊效果的影响。结果表明,不同无机盐对复合混凝剂黏度行为有不同影响,影响强度顺序依次为AlCl3>MgCl2>NaCl,Na2SO4和Na3PO4使复合混凝剂产生白色沉淀;由混凝实验可知:对于复合混凝剂的混凝脱浊效果,AlCl3能使其明显提高,MgCl2和NaCl对其无明显影响,Na2SO4使其效果明显变差,Na3PO4使其效果先变差后变好。由此可见,在实验范围内,无机盐对复合混凝剂黏度行为的影响与其对复合混凝剂混凝性能的影响无显著关联性。     

城镇污水处理厂尾水深度化学除磷试验研究

以位于太湖流域的某城市污水处理厂A/O处理工艺的尾水为对象,进行了化学混凝除磷试验.结果表明,无机高分子混凝剂PFS和PAC较其他无机低分子混凝剂具有更好的除磷效果,且铁系混凝剂比铝系混凝剂除磷效果要好,PFS的除磷效果最好,PAC次之;混凝剂投加量为15 mg·L-1时,可使处理后出水TP的质量浓度＜0.5 mg·L-1,混凝剂PFS当n(Fe3+)/n(P)为1.25时除磷效果最好,是一种高效的混凝剂,投加量少、成本低;混凝剂和助凝剂联用时,非离子型PAM对PAC和三氯化铁的助凝效果较明显.降低城镇污水处理厂尾水中磷含量,化学除磷方法是一种有效、可行的选择.     

利用工业废弃物制备聚合硫酸铁铝硅混凝剂

以粉煤灰、废铁屑、废硫酸等工业废弃物为原料,在浸取阶段（碱溶和酸溶）温度90～95℃、液固比（体积比）3.0、时间3h和制备阶段硅酸聚合pH2.0、硫酸总量与硫酸亚铁摩尔比0.37、Si/（Fe＋Al）摩尔比0.10的条件下,制备出了新型无机高分子混凝剂-聚合硫酸铁铝硅（PFASS）,并对其混凝性能、晶形貌像和形态分布进行了研究。实验结果表明：所制PFASS聚合度高、分子链长、最优形态Fe_b和Al_b含量大,对工业废水浊度去除率达99％以上、COD去除率达93％以上,明显优于市售聚合硫酸铁（PFS）、聚合氯化铝（PAC）和聚铝铁（PFAC）混凝剂的处理效果。     

pH对聚合铝形态分布与混凝效果的影响

为了解聚合铝的混凝作用机理,以不同碱化度的聚合铝为混凝剂,考察了p H对聚合铝的形态分布、混凝效果及总溶解性残余铝的影响。结果表明,p H对聚合铝形态分布的影响十分明显,碱化度越低影响越显著;预制Alb和Alc在混凝过程中相对比较稳定,而低聚合度的Ala受p H影响显著;Ala在混凝过程中表现出阳离子的性质,电中和能力弱;与高Alb含量的聚合铝相比,高Alc含量的聚合铝出水浊度降低,但不能提高出水中的溶解性有机物去除率;总溶解性残余铝含量与混凝过程中Ala的含量有直接关联。     

CPAM的制备及其对环境激素DMP的去除

引言混凝沉降法作为提高水质处理效率的一种经济、简便的方法备受关注,而混凝处理过程中,混凝剂的种类、性质是混凝处理效果好坏的关键因素。其中有机高分子混凝剂更是成为近年来的研究热点[1-4]。聚丙烯酰胺作为一种高效的有机高分子混凝剂,具有正电荷密度高、相对分子质     

化学混凝法处理造纸废水的研究

研究了洛阳市龙翔造纸厂的生产废水进行混凝处理时所需要的最佳混凝剂。实验结果表明：PAC作为混凝剂,PAM作为助凝剂联合处理该废水时,能够取得较好的去浊率和CODCr去除率,并且相对其他几种混凝剂经济费用更少;PAC＋PAM作为最佳混凝剂时,PAC和PAM的投加量分别为133、16.6mg/L,充分混凝沉淀20min后,去浊率可达99.7%,CODCr去除率可达46.0%,取得了较好的去除效果。     

复合混凝剂PAC/PDM存储稳定性研究

该文研究了由聚合氯化铝(PAC)和聚二甲基二烯丙基氯化铵(PDM)制成的复合混凝剂PAC/PDM的存储稳定性。采用Al-Ferron逐时络合比色法,考察了常温存储和水浴高温80℃存储前后复合混凝剂铝形态分布的变化,并用混凝烧杯实验考察了存储前后复合混凝剂的混凝脱浊性能和对CODMn去除率的变化。结果表明,经常温存储180 d和高温80℃水浴存储10 d后,未观察到Ala、Alb、Alc(摩尔分数)有明显变化;针对所用模拟水,不同温度下存储不同时间后复合混凝剂的混凝脱浊曲线几乎重合,CODMn去除率也基本不变。由此可知,复合混凝剂PAC/PDM具有良好的存储稳定性。     

Effect of coagulant types on textile wastewater reclamation in a combined coagulation/ultrafiltration system

A combination of coagulation and ultrafiltration (UF) processes for textile wastewater reclamation was investigated using various types of coagulating chemicals such as polyamine, alum, polyaluminum chloride (PACl), and ferric salts. The potential of the combined system was evaluated to replace the existing treatment processes which are composed of a flotation tank (primary step) and a series of filtration beds including sands, granular carbons, and diatomaceous powders. Regardless of the type and dosage of the coagulants, the UF system achieved substantial colloidal particle removal (>97% of turbidity was removed), but membrane fouling was mitigated in a different manner. The degree of fouling reduction was highly dependent upon the type of coagulants used, even though the turbidity and organics removal efficiencies were nearly the same. The polymeric coagulant aggravated membrane fouling, whereas the inorganic coagulants always helped reduce fouling. A residue of the coagulating polymer, which was added in the primary step and its concentration in the effluent was at an immeasurable level, was found to cause serious membrane fouling. The use of polymeric coagulants should be prevented or minimized if UF is considered for textile wastewater reclamation. Polymerized aluminum was found to be the most effective among the coagulants tested, although ferric salt was better than alum in controlling fouling. In particular, it seemed that the characteristics of coagulation chemistry and the coagulated particles had a great impact upon membrane fouling.