Double catholyte electrochemical approach for preparing ferratealuminum：a compound oxidant—coagulant for water purification

Ferrate is an excellent water treatment agent for its multi-functions in oxidation,disinfection,coagulation and adsorption,but its coagulation ability depends on its dosage and is after its oxidation.This paper focuses on preparing a new kind of ferrate combined with alum to enhance its coagulation function for water purification.An effective electrolysis reactor was designed and employed in the test.Some key parameters in the process of electrolysis concerning the prepar\ation efficiency,such as the current density,temperature and alkalinity were also investigated.The proper conditions for ferrate-alum preparation were determined.Under the condition of 5V given voltage,6h electrolyzing interval,below 2% alum concentration (in weight),a combined liquid ferrate-alum products was successfully prepared,which contained 0.0294 mol/L FeO4^2- and 0.0302 mol/L total soluble ferron with 2% Al2O3.There was no insoluble ferron produced by controlling an optimum electrochemical condition.     

多功能复合高铁水处理药剂的电解制备研究

通过膜电解方法合成具有氧化、絮凝、吸附等多功能的复合高铁水处理药剂，研究电流过程的电流、温度、碱度等重要参数与高铁制备效率的关系，实验证明，控制适宜的电解时间和条件，可以获得高铁浓度为０．０２３３ｍｏｌ／Ｌ、总铁２为０．０２８２ｍｏｌ／Ｌ的复合药液，其中不含铁的固体形态，适合作为以现场制备和投加为目的的高效多功能水处理药剂     

酸浸粉煤灰制备复合混凝剂及其处理生活污水的效果研究

研究了以粉煤灰和H_２ＳＯ₄为原料,常温常压下搅拌反应制备复合混凝剂的方法,考查了酸种类、酸浓度、酸灰比、搅拌时间等因素对Fe^３＋、Al^３＋溶出效果和生活污水混凝效果的影响.结果表明,酸灰比5 mL/g、浓度2 mol/Ｌ的H_２ＳＯ₄溶液与粉煤灰搅拌4 h并静置30 min后制得的混凝剂,其中Fe^３＋的浓度为0 .010 8 mol/Ｌ,溶出率为11 .4%;Al^３＋的浓度为0 .035 4 mol/Ｌ,溶出率为4 .3%;对生活污水的COD去除率70 .4%,SS去除率91 .9%,与市售聚合混凝剂效果相当,是一种有开发利用价值的水处理剂.     

高浓度制药废水预处理技术试验研究

以某制药厂排出的制药废水为处理对象,研究比较了混凝法、Fenton氧化法、臭氧氧化法、电解法和微电解法对废水的预处理效果。发现混凝法不能有效去除废水中的溶解性的有机物,微电解法和电解法对去除有机物有很好的效果,CODcr的去除率可达65％以上。Fenton氧化和微电解法对色度的去除效果较好,臭氧氧化和电解由于氧化还原反应可能生成一些新的物质,使得废水色度反而上升。除化学混凝法外,其他各种方法均能明显提高废水的B／C值,为后续的生化处理创造有利条件。     

品红染料工业废水治理工艺的试验研究

品红染料废水具有高ＣＯＤｃｒ、高色度、有机物成份复杂等特点。根据清污分流原则。对品红中和水及结晶水进行分别处理。经混凝、氧化、电解、还原等大量工艺试验，确定治理工艺方案为：中和水用混凝－电解氧化的方法，结晶水用直接电解的方法，取得了较满意的效果，各水质指标达到规定要求。     

pH值对氨氮电化学氧化产物与氧化途径的影响

摘要:研究了含氨氮废水在循环流动式电解槽中的电化学氧化,讨论了pH值对氨氮电化学氧化效果、产物及其途径的影响。结果表明,在弱碱性条件下,有利于电解过程中羟基自由基和游离氯的生成,氨氮的电化学氧化速率较大。在有氯离子存在的情况下,氨氮电化学氧化过程中有氯胺生成,氯胺的组成与体系的pH值有关,当pH>9时,一氯胺占优势;当pH=7时,一氯胺和二氯胺同时存在,并且近似相等;当pH<5时,主要是二氯胺;pH值大于5时,可以避免三氯化氮的生成。在电流密度为20mA/cm2时,电解产生的羟基自由基小于5×10-15mol/L,氨氮电化学氧化的2种途径中间接氧化起主要作用。     

聚铁混凝-Fenton法-SBR工艺对成熟垃圾场渗滤液深度处理的研究

联合运用聚铁混凝、Fenton方法以及SBR牛物法3种工艺对老龄垃圾场的渗滤液进行深度处理.在综合考虑出水符合垃圾渗滤液国家一级排放标准以及运行成本经济性的前提下,在进水主要污染物COD为640 mg·L-1、色度为500的条件下,推荐了聚铁混凝反应及Fenton反应的最优条件:聚铁加药量为0.45 mL·L-1,[Fe2 ]投加量为0.006 mol,[H2O2]投加量为0.006 mol.L-1,反应时间4 h,Na2CO3投加量约为0.7 g·L～,0.1%PAM投加量为2 mL·L-1,出水COD为68 mg·L-1,BOD为20mg.L-1.同时研究证明,在Fenton方法之前使用聚铁混凝法具有大幅度降低成本、省却pH调节步骤的优点.聚铁混凝反应及Fenton反应总药剂成本低于3.2元/t,实用价值高.Fenton反应后使用SBR生物法处理,其出水水质:COD≤80 mg·L-1.BOD≤8mg.L-1,,NH 4-N≤3 mg.L-1.色度≤5倍,SS≤10 mg·L-1.符合垃圾渗滤液国家一级排放标准.     

pH值对氨氮电化学氧化产物与氧化途径的影响

研究了含氨氮废水在循环流动式电解槽中的电化学氧化.讨论了pH值对氨氮电化学氧化效果、产物及其途径的影响.结果表明,在弱碱性条件下.有利于电解过程中羟基自由基和游离氯的生成.氨氮的电化学氧化速率较大.在有氯离子存在的情况下,氨氮电化学氧化过程中有氯胺生成,氯胺的组成与体系的pH值有关.当pH>9时,一氯胺占优势;当pH=7时.一氯胺和二氯胺同时存在,并且近似相等;当pH<5时,主要是二氯胺;pH值>5时,可以避免三氯化氮的生成.在电流密度为20mA/cm2时.电解产生的羟基自由基<5×10-15mol/L,氨氮电化学氧化的2种途径中间接氧化起主要作用.     

非膜技术处理生物稳定渗滤液的效果及成本

以经厌氧-好氧处理的生物稳定渗滤液为研究对象,分别比较了其经活性炭吸附、混凝、芬顿和电解处理后的溶解性有机碳(DOC)、COD、溶解性氮(DN)和比紫外吸光度(SUV254)的变化,及去除单位COD的成本变化.研究发现,活性炭吸附、芬顿和混凝对生物稳定渗滤液的COD、DOC和DN的去除效率均随药剂投加量的增加而提高;包...     

Optimum conditions for the formation of Al13 polymer and active chlorine in electrolysis process with Ti/RuO2-TiO2 anodes

A polyaluminum containing a high concentration of Al₁₃ polymer and active chlorine (PACC) was successfully synthesized by a new electrochemical reactor using Ti/RuO₂-TiO₂ anodes. PACC can potentially be used as a dual-function chemical reagent for water treatment. The obtained results indicated that the formation of Al₁₃ polymer and active chlorine, were the most active components in PACC responsible for coagulation and disinfection respectively. These components were significantly influenced by electrolyte temperature, current density, and stirring rate. It was observed that high electrolyte temperature favored the formation of Al₁₃. Increasing current density and stirring rate resulted in high current efficiency of chlorine evolution, thus favoring the generation of Al₁₃ and active chlorine in PACC. When the PACC (Al_T = 0.5 mol/L, basicity = 2.3) was prepared at the optimum conditions by electrolysis process, the Al₁₃ polymer and active chlorine in product reached above 70% of Al_T and 4000 mg/L, respectively. In the pilot scale experiment with raw polyaluminum chloride used as an electrolyte, PACC was successfully prepared and produced a high content of Al₁₃ and active chlorine products. The pilot scale experiment demonstrated a potential industrial approach of PACC preparation.     

Fenton法处理类长填龄渗滤液的氧化和絮凝作用

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COD_Cr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COD_Cr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COD_Cr去除率随H₂O₂投加量增大而增大.絮凝作用对COD_Cr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.      

混凝-Fenton氧化预处理抗生素废水的研究

实验采用混凝-Fenton氧化预处理抗生素废水,筛选出最佳的混凝条件及氧化条件,同时对经混凝-Fenton试剂预处理后的废水与未经处理的废水按同样反应条件开展好氧生化试验。实验发现,采用聚合氯化铝(PAC)和聚丙烯酰胺(PAM)复合混凝处理该废水,在pH为8,PAC与PAM的用量分别为400mg/L和12mg/L时混凝效果较好。混凝后的废水再用芬顿体系氧化,当pH为3,FeSO·47H2O投加量为0.01mol/L,H2O2/Fe2+摩尔比4:1下,反应30min时,取得了满意的结果。实验表明,采用混凝-芬顿氧化法预处理抗生素废水后,明显改善了其可生化性,为后续生化处理打下了良好的基础。     

高锰酸盐复合剂强化混凝对水中天然有机物的去除机制研究

利用流动电流、絮凝脉动颗粒检测技术、分子量分布及XAD树脂分类技术对高锰酸盐复合剂强化混凝去除水中天然有机物的机制进行了研究.结果表明,高锰酸盐复合剂提高了硫酸铝的混凝效果,投加0.75 mg/L高锰酸盐复合剂后,较单独投加硫酸铝对天然有机物的去除率可提高13个百分点.流动电流(SC)检测结果表明,高锰酸盐复合剂使有机物表面所带的负电性减弱,稳定性降低.如单独投加60 mg/L硫酸铝时SC值为55.2,而投加0.50、 0.75和1.0 mg/L的高锰酸盐复合剂预氧化处理后,SC值分别升高至61.4、 69.6和87.0.投加高锰酸盐复合剂后,絮凝指数增加,表明高锰酸盐复合剂及反应过程中生成的新生态水合二氧化锰对混凝起到了强化作用.分子质量分布及XAD树脂分类结果表明,高锰酸盐复合剂提高了混凝过程对小分子质量和亲水性有机物的去除能力,如硫酸铝混凝后亲水性有机物的含量为1.90 mg/L,而投加高锰酸盐复合剂后,可使其含量降至1.32 mg/L.     

Fe2+-H2O2法处理DSD酸生产氧化母液的研究

为改善DSD酸氧化母液的可生化降解性,将废液先用有机絮凝剂TS-1(一种季胺盐)处理,TS-1的投加量为3g/L,其后用Fe²⁺-H₂O₂法氧化,Fe²⁺和H₂O₂的量分别为150mg/L,7g/L,废液COD和色度的去除率分别可达64%和62%。经处理后的废水,其BOD₅/COD≈0.3,可以认为已达到生化处理的要求。当H₂O₂的投量为2g/L,经Fe²⁺-H₂O₂氧化处理后的废液,再用FeCl₃进行两级混凝处理(FeCl₃的投加量分别为5g/L和2g/L),则COD和色度的去除率可达90%和95%。     

Dyes wastewater treatment by reduction-oxidation process in an electrochemical reactor packed with natural manganese mineral

A novel technology which combined electrochemical process catalyzed by manganese mineral with electro-assisted coagulation process was proposed in this study. The mineralization of organic pollutant from simulated dye wastewater containing an azo dye Acid Red B（ARB） was experimentally investigated using this method. It was found that the manganese mineral could catalyze the electrochemical process dramatically. The TOC removal percentage of electrochemical treatment catalyzed by manganese mineral was 43.6% while the TOC removal percentage of the process using the manganese mineral alone and using the electrolysis alone were 9.3% and 20.8%, respectively. Moreover, it was found that combined electroxidation with electro-assisted coagulation process could more effectively eliminate ARB. After a period of 180 min electrooxidation and 300 min electroreduction, almost 66.9% of TOC was removed, and the dissolved Mn^2＋. could be effectivly removed. The effects of the order of oxidation and reduction, the proper ratio electrooxidation/reduction time, and current density on the removal efficiency were investigated in detail. In addition, a proposed mechanism of manganese-mineral-catalyzed electrooxidation-reduction process was discussed in this paper.     

Influential factors of formation kinetics of flocs produced by water treatment coagulants

The growth rate and size of floc formation is of great importance in water treatment especially in coagulation process.The floc formation kinetics and the coagulation efficiency of synthetic water were investigated by using an on-line continuous optical photometric dispersion analyze and the analysis of water quality.Experimental conditions such as alum dosage,pH value for coagulation,stirring intensity and initial turbidity were extensively examined.The photometric dispersion analyze results showed that coagulation of kaolin suspensions with two coagulants(alum and polyaluminium chloride) could be taken as a two-phase process:slow and rapid growth periods.Operating conditions with higher coagulant doses,appropriate pH and average shear rate might be particularly advantageous.The rate of overall floc growth was mainly determined by a combination of hydraulic and water quality conditions such as pH and turbidity.The measurement of zeta potential indicates that polyaluminium chloride exhibited higher charge-neutralizing ability than alum and achieved lower turbidities than alum for equivalent Al dosages.Under the same operating conditions,the alum showed a higher grow rate,but with smaller floc size.     

Hydrolyzed Al(Ⅲ) clusters: Speciation stability of nano-Al13

Pure nano-Al13 and aggregates at various concentrations were prepared to examine the particle size effect of coagulation with inorganic polymer fiocculant. The property and stability of various species formed were characterized using Infrared, 27Al-NMR,photo correlation spectroscopy (PCS), and Ferron assay. Results showed that concentration and temperature exhibited different roles on the stability of Al13. The quantity of Alb species analyzed by ferron assay in the initial aging period corresponded well with that of Al13, which has been confirmed in a dimension range of 1-2 nm by PCS. Al13 solutions at high concentrations (0.5-2.11 mol/L)were observed to undergo further aggregation with aging. The aggregates with a wide particle size distribution would contribute to the disappeared/decreased Al13 basis on the 27Al-NMR spectrum, whereas a part of Al13 would still remain as Alb. At low concentrations,Al13 solution was quite stable at normal temperature, but lost its stability quickly when heating to 90°C.     

Hydrolyzed AI（Ⅲ） clusters： Speciation stability of nano-All3

Pure nano-Al13 and aggregates at various concentrations were prepared to examine the particle size e ect of coagulation with inorganic polymer flocculant. The property and stability of various species formed were characterized using Infrared, 27Al-NMR, photo correlation spectroscopy (PCS), and Ferron assay. Results showed that concentration and temperature exhibited di erent roles on the stability of Al13. The quantity of Alb species analyzed by ferron assay in the initial aging period corresponded well with that of Al13, which has been confirmed in a dimension range of 1–2 nm by PCS. Al13 solutions at high concentrations (0.5–2.11 mol/L) were observed to undergo further aggregation with aging. The aggregates with a wide particle size distribution would contribute to the disappeared/decreased Al13 basis on the 27Al-NMR spectrum, whereas a part of Al13 would still remain as Alb. At low concentrations, Al13 solution was quite stable at normal temperature, but lost its stability quickly when heating to 90°C.     

高锰酸钾氧化水中乙硫醇的动力学研究

研究了高锰酸钾氧化水中乙硫醇的动力学规律,并考察了高锰酸钾在原水混凝条件下对原水中乙硫醇的去除效果.结果表明,高锰酸钾对乙硫醇的氧化去除效果非常明显,去除率可达到90%以上;高锰酸钾对乙硫醇的氧化过程符合二级反应动力学模型;在高锰酸钾过量的情况下,氧化反应的伪一级动力学常数k'=0.025·[KMnO4]-0.008,再根据所用初始高锰酸钾浓度,得到了二级反应的动力学常数k=0.025 L(min·mg).高锰酸钾在原水混凝条件下对乙硫醇的去除效果劣于纯水条件下的去除效果,在水中其它有机物与高锰酸钾反应条件下高锰酸钾浓度变化的拟合结果与实际情况存在偏差,是产生差异的主要原因.     

Effects of Ca(OH)2 assisted aluminum sulfate coagulation on the removal of humic acid and the formation potentials of tri-halomethanes and haloacetic acids in chlorination

The effects of addition of calcium hydroxide on aluminum sulphate(or alum) coagulation for removal of natural organic matter(NOM) and its subsequent effect on the formation potentials of two major types of regulated disinfection byproducts(DBPs),haloacetic acids(HAAs) and trihalomethanes(THMs),have been examined.The results revealed several noteworthy phenomena.At the optimal coagulation pH(i.e.6),the coagulation behavior of NOM water solutions versus alum dose,showed large variation and a consequent great change in the formation potentials of the DBPs at certain coagulant doses.However,with addition of a relatively small amount of Ca(OH) 2,although the zeta potential of coagulated flocs remained almost the same,NOM removal became more consistent with alum dose.Importantly,also the detrimental effect of charge reversal on NOM removal at the low coagulant dose disappeared.This resulted in a steady decrease in the formation potentials of DBPs as a function of the coagulant dose.Moreover,the addition of Ca(OH) 2 broadened the pH range of alum coagulation and promoted further reduction of the formation potentials of the DBPs.The enhancement effects of Ca(OH) 2 assisted alum coagulation are especially pronounced at pH 7 and 8.Finally,synchronous fluorescence spectra showed that the reduction in DBPs formation potential by Ca(OH) 2-assisted alum coagulation was connected to an enhanced removal of small hydrophobic and hydrophilic HA molecules.Ca(OH) 2-assistance of alum coagulation appeared to increase substantially the removal of the hydrophilic HA fraction responsible for HAAs formation,prompting further reduction of HAA formation potentials.