Treatment of Dyeing Wastewater by Using Positive Pulsed Corona Discharge to Water Surface

This study investigated the treatment of textile-dyeing wastewater by using an electrical discharge technique （positive pulsed corona discharge）. The high-voltage electrode was placed above the surface Of the wastewater while the ground electrode was submerged in the wastewater. The electrical discharge starting at the tip of the high voltage electrode propagated toward the surface of the wastewater, producing various oxidative radicals and ozone. Oxygen was used as the working gas instead of air to prevent nitrogen oxides from forming. The simulated wastewater was made up with amaranth, which is a kind of azo dye. The results obtained showed that the chromaticity of the wastewater was almost completely removed within an hour. The ultraviolet/visible spectra of the wastewater treated by the electrical discharge revealed that the total hydrocarbon level also decreased significantly.

Degradation of Synthetic Dyeing Wastewater by Underwater Electrical Discharge Processes

Electrical discharge treatments of synthetic dyeing wastewater were carried out with two different systems： underwater pulsed electrical discharge （UPED） and underwater dielectric barrier discharge （UDBD）. Reactive Blue 4 （RB4） and Acid Red 4 （AR4） were used as model contaminants for the synthetic wastewater. The performance of the aforementioned systems was compared with respect to the chromaticity removal and the energy requirement. The results showed that the present electrical discharge systems were very effective for degradation of the dyes. The dependences of the dye degradation rate on treatment time, initial dye concentration, electrical energy, and the type of working gas including air, 02, and N2 were examined. The change in the initial dye concentration did not largely affect the degradation of either RB4 or AR4. The energy delivered to the UPED system was only partially utilized for generating reactive species capable of degrading the dyes, leading to higher energy requirement than the UDBD system. Among the working gases, the best performance was observed with O2. As the degradation proceeded, the concentration of total dissolved solids and the solution conductivity kept increasing while pH showed a decreasing trend, revealing that the dyes were effectively mineralized.

Treatment of Dye Wastewater by Using a Hybrid Gas/Liquid Pulsed Discharge Plasma Reactor

A hybrid gas/liquid pulsed discharge plasma reactor using a porous ceramic tube is proposed for dye wastewater treatment. High voltage pulsed discharge plasma was generated in the gas phase and simultaneously the plasma channel was permeated through the tiny holes of the ceramic tube into the water phase accompanied by gas bubbles. The porous ceramic tube not only separated the gas phase and liquid phase but also offered an effective plasma spreading channel. The effects of the peak pulse voltage, additive gas varieties, gas bubbling rate, solution conductivity and TiO2 addition were investigated. The results showed that this reactor was effective for dye wastewater treatment. The decoloration efficiency of Acid Orange II was enhanced with an increase in the power supplied. Under the studied conditions, 97% of Acid Orange II in aqueous solution was effectively decolored with additive oxygen gas, which was 51% higher than that with argon gas, and the increasing 02 bubbling rate also benefited the decoloration of dye wastewater. Water conductivity had a small effect on the level of decoloration. Catalysis of TiO2 could be induced by the pulsed discharge plasma and addition of TiO2 aided the decoloration of Acid Orange II.

Degradation of Dye Wastewater by Pulsed High-Voltage Discharge Combined with Spent Tea Leaves

Degradation of methylene blue （MB） was performed using the pulsed discharge process （PDP） combined with spent tea leaves （STLs）. The effects of STL dosage, concentration of initial solution, and pH were analyzed in the combined treatment. Results showed that the combined treatment was effective for dye wastewater degradation; when the dosage of STLs was 3.2 g/L, the degradation efficiency reached 90% after 15 rain treatment, and STLs showed a good repeatability. The degradation rate decreased with increasing initial MB concentration but not related to the solution pH in the combined treatment. Fourier-transform infrared spectra and N2 adsorption suggested that the number of acidic and basic groups in the STL surface increased after the treatment, but the surface area and pore volume remained unchanged.

Degradation of Acid Orange 7 Dye in Two Hybrid Plasma Discharge Reactors

To get an optimized pulsed electrical plasma discharge reactor and to increase the energy utilization efficiency in the removal of pollutants, two hybrid plasma discharge reactors were designed and optimized. The reactors were compared via the discharge characteristics, energy transfer efficiency, the yields of the active species and the energy utilization in dye wastewater degradation. The results showed that under the same AC input power, the characteristics of the discharge waveform of the point-to-plate reactor were better. Under the same AC input power, the two reactors both had almost the same peak voltage of 22 kV. The peak current of the point-to-plate reactor was 146 A, while that of the wire-to-cylinder reactor was only 48.8 A. The peak powers of the point-to-plate reactor and the wire-to-cylinder reactor were 1.38 MW and 1.01 MW, respectively. The energy per pulse of the point-to-plate reactor was 0.2221 J, which was about 29.4% higher than that of the wire-to-cylinder reactor （0.1716 J）. To remove 50% Acid Orange 7 （AO7）, the energy utilizations of the point-to-plate reactor and the wire- to-cylinder reactor were 1.02×10^-9 mol/L and 0.61×10^-9 mol/L, respectively. In the point-to- plate reactor, the concentration of hydrogen peroxide in pure water was 3.6 mmol/L after 40 min of discharge, which was higher than that of the wire-to-cylinder reactor （2.5 mmol/L）. The concentration of liquid phase ozone in the point-to-plate reactor （5.7×10^-2 mmol/L） was about 26.7% higher than that in the wire-to-cylinder reactor （4.5×10^-2 mmol/L）. The analysis results of the variance showed that the type of reactor and reaction time had significant impacts on the yields of the hydrogen peroxide and ozone. The main degradation intermediates of AO7 identified by gas chromatography and mass spectrometry （GCMS） were acetic acid, maleic anhydride, p- benzoquinone, phenol, benzoic acid, phthalic anhydride, coumarin and 2-naphthol. Proposed degradation pathways were elucidated in light of the analyzed degradation products.

用高压脉冲放电等离子体处理印染废水的研究

提出了用高压毫微秒脉冲产生的非平衡等离子体处理印染废水的方法。用该法对直接蓝２Ｂ染料水溶液进行处理试验的结果表明：在溶液初始ｐＨ值于小９．０４，染料水溶液处理３０秒时，水样上清液ＣＯＤ降低４２．６％。随着处理时间的加长，水样上清液的ＣＯＤ不再降低，反而不断升高，在处理一定时间后，ＣＯＤ高于未处理水样的ＣＯＤ。包括沉淀水样的ＣＯＤ，随处理时间的加长，不断升高．用色质联用法检测处理后染料溶液中的产物，发现有有机酸生成，说明该处理方法能有效破坏染料分子中的苯环或苯环结构。

非均相湿式过氧化氢氧化H-酸废水的研究

为研究催化剂对湿式过氧化氢氧化印染废水效果的影响,采用共沉淀法制备了TiO2-CeO2催化剂,并用浸渍法制备了不同铁负载量的Fe/TiO2-CeO2系列催化剂。以过氧化氢湿式催化氧化法处理COD=10 125 mg/L的H-酸模拟印染废水,结果表明：以TiO2-CeO2催化剂处理水样,当催化剂质量浓度为4 g/L,n（Ti）∶n（Ce）=9∶1,水样初始pH=5,反应温度80℃,反应时间2 h,COD去除率达44.3%;以Fe/TiO2-CeO2处理水样,当催化剂质量浓度为4 g/L,n（Ti）∶n（Ce）=9∶1,w（Fe）=2.0%,在水样初始pH=5,反应温度100℃,反应时间1.5 h的条件下,COD去除率可达86.9%。

脉冲电晕放电对印染废水脱色效果的实验研究

用高压毫微秒脉冲产生直接与废水接触的非平衡等离子体，能使印染废水在处理数１０秒内脱除颜色。对模拟印染废水的实验研究表明：当脉冲峰值电压达３８ｋＶ时，脱色率不受试样ｐＨ值影响，在处理４０ｓ后，脱色率达９５％以上；当脉冲峰值电压较低时，脱色率与试样ｐＨ值有关，中性试样的脱色率较低，处理４０ｓ后脱色率在４０％－５０％，而当ｐＨ＜４或ｐＨ＞７时，处理４０ｓ后脱色率最高也可达８０％以上。试样中加入ＮａＣｌ和Ｎａ２ＳＯ４的实验结果表明：Ｃｌ－使脱色率降低，而ＳＯ使脱色率提高．

等离子体催化降解有机废水研究

研究了多种因素对高压脉冲介质阻挡放电低温等离子体法处理印染废水效果的影响。通过实验得出结论:随着有效处理时间和峰值外施电压的增加,废水中的有机物的去除率增加;随着水样浓度的增加,废水中有机物的去除率降低;随着催化剂(TiO)2量的增加,废水中有机物的去除率先升高后降低,最佳催化剂的加入量为0.5 g/L TiO2悬浮液0.5 mL。

脉冲电流处理印染废水的研究

研究了高压脉冲电流对几类典型染料废水的处理效果。试验结果表明 :高压脉冲电流可以有效地破坏试品中染料分子的发色基团 ,脱色效果明显 ;处理后的试品 ,包含沉淀废水的化学需氧量 (COD)值明显升高 ,所以需要利用金属氢氧化物的絮凝作用来最终降低试品的COD值 ;

高压脉冲放电等离子体处理含偶氮染料活性红195废水

采用高压脉冲放电等离子体处理含偶氮染料活性红195废水,实验结果表明:当电极间距为10 mm、空气流量为0.10 m3/h、溶液初始pH为3.05,放电反应时间为21 min时,活性红195去除率为98.72%;废水中加入Cu2+时,随Cu2+加入量的增加,活性红195的去除率先减小后增大;加入自由基抑制剂可使活性红195去除率减小。

高压脉冲放电等离子体处理活性红X-3B染料废水

采用高压脉冲放电等离子体技术对活性红X-3B染料废水进行处理,考察了废水电导率、脉冲电压、脉冲频率、针板间距以及曝气量对处理效果的影响。实验结果表明,当废水电导率为200μS/cm、脉冲电压为34kV、脉冲频率为60Hz、针板间距为15mm、曝气量为12L/h、处理时间为60m in时,活性红X-3B染料废水脱色率能达到98.6%。

高压脉冲放电处理KN-B染料废水的试验

为研究高压脉冲放电水处理技术工艺参数对废水处理效果的影响,以偶氮染料活性黑5(KN-B)废水为处理对象,选择脉冲电压U、电极距离L、气流量Q、初始质量浓度ρ、初始pH值为试验参数,采用部分析因试验法,分析各因素及其一级交互作用的影响显著程度,筛选出3个显著因素,脉冲电压、初始pH值和气流量,通过正交试验法设计三因素三水平进行试验,对显著因素进行优化.试验结果表明,最优条件为U=1 200 V,Q=300 mL/min,pH=3.1,其预测脱色率为89.68%,经检测相对误差为1.10%;另外由紫外光谱和GC/MS分析可知,染料分子中由苯环、偶氮、萘环所形成的大共轭体系以及苯环、萘环均被打开,同时产生新的中间产物.

高压脉冲处理活性蓝染料KN-R废水的研究

采用高压脉冲技术处理活性蓝染料KN-R废水,通过测量废水脱色率来分析实验效果。探讨了溶液的电导率、初始废水的浓度、脉冲峰值电压、脉冲频率、针板间距及辅助气体对处理效果的影响。试验结果表明溶液的电导率越高,处理效果越低;处理最佳条件为废水初始浓度100 mg/L,脉冲电压32 kV,脉冲频率60 Hz,针板间距15 mm,曝气量12 L/h,处理时间50 min;活性蓝染料KN-R废水脱色率能达到99.3%,鼓入氧气处理效果最佳。

等离子体技术在印染废水处理中的应用

在总结国内外文献的基础上,对等离子体技术及其在废水处理中的应用进行了介绍和综述。主要介绍了高压脉冲放电法、辉光放电法、滑动弧放电法及介质阻挡放电法的基本特性以及该技术处理废水的研究和应用进展,并探讨了该技术现存的主要问题,指出了今后发展的前景。

不同改性膨胀珍珠岩处理印染废水的试验研究

采用硫酸(H2SO4)和(或)十六烷基三甲基溴化铵(CTMAB)对膨胀珍珠岩进行改性,制备了不同改性膨胀珍珠岩(H2SO4-EP、CTMAB-EP、H2SO4+CTMAB-EP),并研究了不同改性膨胀珍岩对实际印染废水色度和COD的去除效果。试验结果表明:4mol/L H2SO4+5%CTMAB复合改性膨胀珍珠岩对实际印染废水的处理效果最好,且当该复合改性膨胀珍珠岩的投加量为27g/L、pH值为8、反应时间为4h时,COD去除率达到95.5%,色度去除率达到80%。

在线水质分析仪表在印染废水处理中的应用

介绍了pH计、COD分析仪、溶解氧分析仪、悬浮物分析仪等不同在线水质分析仪的特点及其在印染废水设计应用中的必要性。精密的在线水质分析仪的使用不但能实时监测水质情况,而且能针对异常状况及时报警联动控制或进行人工工艺参数调整,确保废水的高效处理并达标排放。其次,在线水质仪的设置在污水处理、节能降耗方面亦有重大作用。

染料废水等离子体处理技术的研究进展

综述了产生等离子体的方法,除高压脉冲放电法以及辉光放电法以外,还有电弧放电法,客观认为介质阻挡放电更具潜力。阐明了等离子体的本质,以及降解染料废水的原理和优缺点,简单介绍了各类方法的发展现状以及应用前景,同时在查阅国内外资料的基础上列举了相关实验实例。

介质阻挡放电等离子体降解工业印染废水研究

以工业印染废水为降解目标,采用介质阻挡放电等离子体技术,研究了不同电极结构、放电电压、放电功率以及放电气氛对降解印染废水的影响。结果表明,不同电极结构会影响印染废水的降解效果,铜网越密集,放电效果越好,降解效果越好;且铜片电极降解效果最佳。放电电压越高、放电功率越大,降解效果越好,综合考虑等离子体功率转化效率,当放电100V时,等离子体反应器效率最高,降解效果也较好。当放电间距为3 mm时,降解效果为佳。空气放电好于氮气和氩气气氛放电,因为空气放电不仅可以产生大量活性粒子,还可以产生臭氧,形成协同效应,从而提高降解效果。

有机染料废水处理技术研究进展

有机染料废水的特点及染料废水处理技术,如物理化学方法、生物处理技术等方面的最新研究进展以及高级氧化技术及非平衡等离子体技术,并比较了这些处理方法的优缺点。非平衡等离子体水处理技术是一种高效、无二次污染的绿色环保技术。