管式电凝聚法处理印染废水COD的特性研究

研究了电解质成分、pH值、电流密度及电解时间对管式电凝聚法去除不同浓度聚乙烯醇(PVA)废水COD以及对废水可生化性的影响。分析了管式电凝聚法去除PVA废水COD及改善其可生化性的主要机理。     

印染废水铁盐絮凝脱色的研究

本文以三种无机铁盐,对六种不同类型的染料水和印染废水进行絮凝脱色的研究表明:铁盐的脱色效果与其投加量和 pH 值关系极大。六种染料水脱色的结果是:三种疏水性染料的脱色率平均达90%以上,远远超过三种亲水性染料。三种铁盐的脱色次序是:PFS(聚铁)>FeCl_3相似文献   

锰砂与粉末活性炭对印染废水脱色的研究

利用除铁用锰矿砂(PGM)为处理剂进行罗丹明B与甲基橙模拟废水的静态脱色试验,并与粉末活性炭(PAC)进行对比。结果表明:PAC与染料的作用机理是物理吸附,脱色率受pH影响较小,对甲基橙和罗丹明B分别符合Langmuir和Freundlich方程。PGM在酸性条件下对染料的脱色是氧化与吸附的综合作用,较低的pH、较高的投量和恰当的反应时间可提高PGM的脱色效能,pH是影响PGM脱色能力的关键因素,pH=1.2时,符合Langmuir方程。酸性条件下较大的吸附容量和较短的平衡时间使PGM有可能应用于染料废水深度处理。     

卤水用于印染废水脱色处理的研究

将卤水作为一种成本较低的水处理药剂用于印染废水脱色处理。考察pH、卤水投加量、沉降时间等对单一组分有色废水脱色效果的影响,并对实际废水进行了脱色处理试验。结果表明,卤水对试验单一有色废水具有良好的脱色效果,在Mg2+浓度为150mg/L,pH为10.5~11时,脱色率可以达到92.4%;实际废水的脱色率平均为90.6%,CODCr去除率平均为58.6%。     

光催化-好氧生物降解处理染料废水试验研究

考察了pH值、催化剂用量、酸性大红(GR)染料初始浓度、曝气量对染料去除率的影响,确定了GR染料去除的较佳反应条件:pH值为3,催化剂投加量为0.6 mg/L,GR染料进水浓度为20mg/L,曝气量为60mL/min.在较佳反应条件下,对光催化工艺、好氧生物降解工艺和光催化-好氧生物降解组合工艺处理单一染料废水效果进行了比较,并考察了组合工艺处理混合染料废水的效果,结果表明:反应5 h时,组合工艺对单一染料废水中活性墨绿(B-4BLN)和GR染料的去除率分别为85.66%和76.93%,去除效果明显高于单一工艺;组合工艺对混合染料废水中B-4BLN和GR染料的去除率分别为83.76%和71.84%.     

催化铁内电解法处理染料废水试验研究

利用催化铁内电解法对染料废水进行了探索性实验，结果表明：染料初始浓度400m班，铁铜质量比为6：1，pH值为7，铁水比75g/L，反应时间1h，搅拌速度100rpm，染料废水的脱色率达到90％以上，其可生化性有所改善，有利于后期的生化处理。     

电氧化产活性氯、活性氧处理废水研究进展

随着废水排放增加,环境污染问题日益严重,电氧化技术不仅可以通过产生活性氯和活性氧等强氧化性物质有效处理废水,而且其本身作为一种绿色氧化技术,对未来构建“碳中和”模式水处理技术及实现“碳达峰”目标具有重要意义。论述了电氧化处理工业废水、农业废水、生活废水及垃圾渗滤液的研究现状,着重分析了在电极类型、电解质种类及浓度不同的条件下电氧化生成活性氯和活性氧处理废水的性能,总结归纳电氧化生成活性氯和活性氧高效处理不同领域废水的适用条件,并对电氧化处理不同领域废水的发展方向进行展望。     

白腐真菌脱色降解染料废水的试验研究

探讨了白腐真菌对染料废水的脱色和降解。试验结果表明,白腐真菌不但对活性艳红X3B染料有较好的脱色作用,而且对难处理的成分复杂的实际染料废水也有较好的降解作用,能有效去除印染废水的COD和BOD5。但是降解过程中COD有波动现象,经过5d后出水的COD仍然较高。虽然白腐真菌未能彻底生化降解染料废水,但给后续的深度处理带来极大方便。     

H2O2／强化日光协同光解脱色直接湖蓝染料研究

在H2O2存在条件下,对直接湖蓝染料进行强化日光辐照处理。研究染料初始浓度、H2O2浓度、pH值、不同阴离子等因素对直接湖蓝染料的脱色效果影响。结果表明:在pH酸性媒介中直接湖蓝能有效地光解脱色。与SO42-、NO2-、Cl-相比,Br-和NO3-对脱色作用抑制最显著,而且两者能形成协同作用抑制光解脱色。染料光解脱色速率随H2O2浓度的增加而增加,但在高H2O2浓度时,降解速率增加不明显。处理前后的UV-Vis谱图分析表明直接湖蓝在H2O2/强化日光光解处理中脱色是因为染料发生光解作用。     

混凝脱溶法处理印染废水试验研究

根据弱酸性染料、还原性染料和分散染料、直接染料、活性染料、中性染料的分子结构特点 ,针对含有亲水性基团染料的印染废水 ,分析不同的pH值及脱色剂的投加量对脱色效果的影响 ,利用含Mg2 + 和Ca2 + 等离子的脱溶剂与亲水基团反应生成难溶性的磺酸盐类或羧酸盐类 ,使其脱溶。试验表明 ,在pH值为 1 2左右时 ,该方法对含有高色度水溶性染料的印染废水具有较好的处理效果     

Decolorization of anthraquinone dye Reactive Blue 19 by the combination of persulfate and zero-valent iron

Decolorization of anthraquinone dye Reactive Blue 19 (RB19) with sulfate radicals generated in situ from persulfate and zero-valent iron (ZVI) was investigated. The effects of initial solution pH, initial concentration of RB19, ZVI and persulfate, reaction temperature and common dissolved anions were studied. 100% color removal efficiency and 54% TOC removal efficiency were achieved in 45 min with an initial RB19 concentration of 0.1 mM under typical conditions (pH 7.0, 0.8 g L(-1) ZVI, 10 mM persulfate and 30 C). The decolorization efficiency of RB19 increased with higher iron dosage, higher initial persulfate concentration, and higher reaction temperature. It is also an acid driven process. The decolorization process followed pseudo-first order kinetics and the activation energy was 98.1 kJ mol-1. RB19 decolorization was inhibited by common dissolved anions such as CL-, NO3-, H2PO4- and HCO3- since they reacted with sulfate radicals that retarded the oxidation process. The experiment demonstrated that the combination of persulfate and ZVI was a promising technology for the decolorization of dye wastewater.     

Obtention of plant peroxidase and its potential for the decolorization of the reactive dye Remazol Turquoise G 133%

Peroxidases can be used in the decolorization process. There is a growing interest for new sources of this enzyme and for obtaining economically viable processes. In this work, a low-cost vegetable peroxidase extraction process is proposed; the resulting enzyme is characterized to determine its optimum pH, temperature, and stability conditions, and it is then applied in the decolorization of reactive dye Remazol Turquoise G 133%. The turnip peroxidase (TP) was utilized as an enzymatic source. This enzyme exhibited maximum activity at pH 7.0, and it was active in the temperature range of 30 to 50 °C, which favors its use in industrial processes. Acetone was the most efficient solvent to induce precipitation. The removal of Remazol Turquoise G 133% was 56.0% complete after 50 min, while 41.0% of the same dye was removed with the commercial horseradish peroxidase enzyme in 50 min. TP presents potential as a viable alternative in the decolorization of textile wastewaters.     

Biosorption of chromium(VI), nickel(II) and Remazol blue by Rhodotorula muciloginosa biomass

The passive removal of commonly used reactive dye and two heavy metals, from aqueous solutions by inexpensive biomaterial, yeast Rhodotorula muciloginosa biomass, termed biosorption, was studied with respect to pH, initial dye concentration and initial metal ion concentration. The biomass exhibited maximum dye and chromium(VI) uptake at pH 5 and pH 6 for nickel(II) in media containing 50 mg/L heavy metal and 50 mg/L remazol blue. It was found that the highest chromium(VI) removal yields measured were 31.3% for 49.0 mg/l initial chromium(VI) concentrations. The nickel(II) removal yield was 32.5% for 22.3 mg/L. Higher R. Blue removal yields were obtained, such as 77.1% for 117.5 mg/L. The maximum dye biosorption yield was investigated in medium with a constant dye (approximately 50 mg/L) and increasing heavy metal concentration. In the medium with 48.8, 103.8 and 151.8 mg/L chromium(VI) and constant dye concentration, the maximum chromium(VI) biosorption was 7.4, 9.3 and 17.1%, whereas the maximum dye biosorption was 61.6, 56.6 and 55.9%. The maximum nickel(II) biosorptions in the medium with dye were 38.1, 22.1 and 8.8% at 23.7, 37.7 and 60.1 mg/L nickel(II) concentrations. In these media, dye biosorptions were 93.9, 86.4 and 93.3%, respectively.     

Photodegradation of hydrophobic disperse dyes and dye-bath effluents by silicadodecatungstate (SiW12O40(4-/5-)) nanoparticles.

Polyoxometalate (POM) silicadodecatungstic acid has been applied as a photochemical catalyst for the degradation of SETAPERS Black WNSP, a disperse dyestuff preparation widely used to dye polyester and polyamide fabrics. It could be demonstrated that the disperse dyestuff was photo-reduced by SiW12O40(5-), the one-electron reduced form of POM, as evidenced by Heteropolyblue (HPB) formation. For completion of the photochemical redox cycle, isopropanol (IsOH) was required. Acetone (Ac) served solely as an effective solute and photosensitizer; however this effect was suppressed in the presence of POM. Threshold (0.087 mM) and optimum (0.375 mM) POM concentrations existed and decolorization kinetics were inhibited upon the addition of dye auxiliary chemicals. Increasing the dyestuff concentration from 50 mg/L to 150 mg/L did not affect initial decolorization kinetics revealing that not the formation of the excited [POM-Substrate]* complex, but its reduction to HPB was the rate limiting step. POM-mediated, IsOH-assisted UV-photodegradation of disperse dyes and dye-baths is by far more effective than applying other, more well known chemical oxidation methods (O3, H202/UV, Power Ultrasound). Key to the action of POM redox catalysts is the feature that particularly heteropoly tungstates undergo facile re-oxidation to their original state, thus allowing regeneration of the photocatalyst, a feature that may become critical for real-scale application.     

A bifunctionalized dye-sensitized TiO(2) film for efficient degradation of methyl orange under visible light irradiation

A new bifunctionalized TiO(2) film containing a dye-sensitized region and a degradation region was described. A similar structure of dye-sensitized solar cell (DSSC) was fabricated in the dye-sensitized region to accomplish separation of electrons from positive charges, and separation of dye from pollutants to avoid dye decomposition. The bifunctionalized TiO(2) film electrode and anode electrode can degrade methyl orange (MO) in reactors A and B, respectively. The degradation efficiency was enhanced remarkably by an external electrical potential. The decolorization of MO reaches as high as 95% after 2 h visible light irradiation at an external potential of 0.5 V along with a loss of 41% total organic carbon (TOC). The possible reason for the improvement of degradation by external DC potential was discussed. Effects of pH and inorganic salts on the decolorization are present.     

Dye-tolerant marine Acinetobacter baumannii-mediated biodegradation of reactive red

The objective of this study was to isolate a potent dye-degrading microbe that can be used to reduce the pollution caused by industrial dyes.Reactive red 198 is an extensively used textile dye and is a major environmental pollutant in water bodies. In this study, a bacterial strain was isolated from sea sediments and identified as Acinetobacter baumannii with 16S rRNA sequencing. The isolated bacteria were immobilized in calcium alginate and decolorization studies were carried out to determine the optimum pH, temperature, dye concentration, inoculum volume,and static/agitated condition using the one factor at a time(OFAT) approach. The Box-Behnken design, a type of response surface methodology,was adopted to improve the degradation efficiency. At 37℃ using an inoculum volume of six beads, 96.20% decolorization was observed in 500 mg/L of reactive red 198 after 72 h. Dye degradation was confirmed with UV-visible spectroscopy and Fourier-transform infrared(FTIR)spectroscopy studies of the dye and degraded metabolites. Microbial toxicity studies using Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa and phytotoxicity studies using Vigna radiata proved that the toxicity of the dye was significantly reduced after degradation. We can conclude that the isolated A. baumannii strain is an efficient dye-degrading microbe that can be used to reduce the pollution caused by industrial dyes.     

A novel technology for on-site cupric oxide recovery from cupric chloride etchant waste

For on-site copper recovery in print circuit board factories, we propose a novel technology to obtain cupric oxide with a low content ratio of chloride from high chloride concentration waste, such as cupric chloride etchant waste. Our technology is designed to avoid formation of double salt and accumulation of cupric hydroxide. In the proposed method, etchant waste mixed with hydrogen peroxide solution is added to sodium hydroxide solution by stepwise addition. We performed lab-scale experiments on the influence of reaction pH conditions on the content ratio of chloride in recovering cupric oxide. The results show that recycled cupric oxide tends to contain a lower content ratio of chloride under higher starting temperatures and higher final pH conditions of the reaction. We also confirmed the optimized conditions; the starting temperature of the sodium hydroxide solution is higher than 70 degrees C, and the final pH of the reaction is 11.5 to 12. Based on the optimized temperature and pH conditions, we also performed a pilot trial to recover cupric oxide from real etchant waste. Then, we successfully obtained cupric oxide with a content ratio of chloride in 80 mg-Cl/kg-CuO.     

Effects and mechanism of ozonation for degradation of sodium acetate in aqueous solution

The degradation efficiencies and mechanism of ozonation for the degradation of sodium acetate in aqueous solution were investigated under atmospheric pressure at room temperature (293 K). The effects of the initial pH value, reaction time, and concentrations of HCO3-, CO32-, CaCl2, and Ca(OH)2 on the removal rate of chemical oxygen demand (COD) were studied. The results indicated that ozonation obviously improved the degradation rate of sodium acetate when the pH value of the solution was not less than 8.5. A suitable long reaction time may be helpful in increasing the COD removal rate, and a removal rate of 36.36% can be obtained after a 30-minute treatment. The COD removal rate increased firstly and decreased subsequently with the increase of the HCO3- concentration (from 0 to 200 mg/L), and under the same experimental condition it reached the optimum 34.66% at the HCO3- concentration of 100 mg/L. The COD removal rate was 5.26% lower when the concentration of was 200 mg/L than when there was no HCO3-. The COD removal rate decreased by 15.68% when the CO32- concentration increased from 0 to CO32- 200 mg/L. has a more obvious scavenging effect in inhibiting the formation of hydroxyl radicals than HCO3-. CaCl2 and Ca(OH)2 could increase the degradation efficiency of sodium acetate greatly, and the COD removal rates reached 65.73% and 83.46%, respectively, after a 30-minute treatment, 29.37% and 47.10% higher, respectively, than with single ozone oxidation. It was proved that the degradation of sodium acetate in the ozonation process followed the mechanism of oxidization with hydroxyl free radicals (·OH).     

木质纤维素对水溶液中亚甲基蓝的吸附性能

以木质纤维素为吸附剂,分析吸附时间、初始浓度、pH值、温度等因素对木质纤维素吸附亚甲基蓝阳离子染料的影响.结果表明:木质纤维素对亚甲基蓝吸附300min后达到平衡,初始浓度超过180mg/L后吸附量不再增加,pH值由2增加到8时,吸附量由23.0mg/g增加到40.1 mg/g,温度对吸附量呈现先增大后减小的趋势.讨论...