Treatment of naphthalene derivatives with iron-carbon micro-electrolysis

The degradation of five naphthalene derivatives in the simulated wastewater was investigated using the iron-carbon micro-electrolysis method.The optimal initial pH of solution and adsorption of iron-carbon and removal efficiency of the total organic carbon(TOC)were investigated.The results show that the removal efficiency of the naphthalene derivatives can reach 48.9%?92.6% and the removal efficiency of TOC is 42.8%?78.0% for the simulated wastewater with 200 mg/L naphthalene derivatives at optimal pH of 2.0?2.5 after 120 min treatment.The degradation of five naphthalene derivatives with the micro-electrolysis shows the apparent first-order kinetics and the order of removal efficiency of the naphthalene derivatives is sodium 2-naphthalenesulfonate,2-naphthol,2,7-dihydroxynaphthalene,1-naphthamine,1-naphthol-8-sulfonic acid in turn.It is illustrated that the substituents of the naphthalene ring can affect the removal efficiency of naphthalene due to their electron-withdrawing or electron-donating ability.

Nitrogen removal efficiency of iron-carbon micro-electrolysis system treating high nitrate nitrogen organic pharmaceutical wastewater

The nitrate nitrogen removal efficiency of iron-carbon micro-electrolysis system was discussed in treating pharmaceutical wastewater with high nitrogen and refractory organic concentration. The results show that the granularity of fillings,pH,volume ratios of iron-carbon and gas-water,and HRT. have significant effects on the nitrogen removal efficiency of iron-carbon micro-electrolysis system. The iron-carbon micro-electrolysis system has a good removal efficiency of pharmaceutical wastewater with high nitrogen and refractory organic concentration when the influent TN,NH4+-N,NO3--N and BOD5/CODCr are 823 mg/L,30 mg/L,793 mg/L and 0.1,respectively,at the granularity of iron and carbon 0.425 mm,pH 3,iron-carbon ratio 3,gas-water ratio 5,HRT 1.5 h,and the removal rates of TN,NH4+-N and NO3--N achieve 51.5%,70% and 50.94%,respectively.

Experimental study on micro-electrolysis technology for pharmaceutical wastewater treatment

Experiments were conducted to study the role of micro-electrolysis in removng chromaticity and COD and improving the biodegradability of pharmaceutical wastewater.The results showed that the use of micro-electrolysis technology could remove more than 90% of chromaticity and more than 50% of COD and greatly improved the biodegradability of phamaceutical wastewater.Lower initial pH could be advantageous to the removal of chromaticity .A retention time of 30 minutes was recommended for the process design of micro-electrolysis.

Micro-electrolysis technology for industrial wastewater treatment

Experiments were conducted to study the role of micro-electrolysis in removing chromaticity and COD and improving the biodegradability of wastewater from pharmaceutical, dye-printing and papermaking plants. Results showed that the use of micro-electrolysis technology could remove more than 90% of chromaticity and more than 50% of COD and greatly improved the biodegradability of pharmaceutical wastewater. Lower initial pH could be advantageous to the removal of chromaticity. A retention time of 30 minutes was recommended for the process design of micro-electrolysis. For the use of micro-electrolysis in treatment of dye-printing wastewater, the removal rates of both chromaticity and COD were increased from neutral condition to acid condition for disperse blue wastewater; more than 90% of chromaticity and more than 50% of COD could be removed in neutral condition for vital red wastewater.

Treatment of chitin-producing wastewater by micro-electrolysis-contact oxidization

The technique of micro-electrolysis-contact oxidization was exploited to treat chitin-producing wastewater.Results showed that Fe-C micro-electrolysis can remove about 30% CODcr, raise pH from 0.7 to 5.5.The CODcr removal efficiency by biochemical process can be more than 80%. During a half year's operation,the whole system worked very stably and had good results, as proved by the fact that every quality indicator of effluent met the expected discharge standards; which means that chitin wastewater can be treated by the technique of micro-electrolysis, contact oxidization.

Optimization of the N2 generation selectivity in aqueous nitrate reduction using internal circulation micro-electrolysis

The reduction of nitrate using internal circulation micro-electrolysis te chnology(ICE)was investigated.The effect of the reaction time,initial pH,Fe/C ratio,and aeration rate on the nitrate reduction was investigated using a single factor experiment.Based on the results of the single factor experiment,a response surface methodology(RSM)was applied to optimize the N2 generation selectivity.The effects and interactions of three independent variables were estimated using a Box-Behnken design.Using the RSM analysis,a quadratic polynomial model with optimal conditions at pH=8.8,Fe/C=1:1,and an aeration rate of 30 L·min-1 was developed by means of the regre ssion analysis of the experimental data.Using the RSM optimization,the optimal conditions yielded a N2 generation selectivity of 72.0%,which is in good agreement with experimental result(73.2%±0.5%)and falls within the 95%confidence interval(IC:66.8%-77.3%)of the model results.This indicates that the model obtained in this study effectively predicts the N2 generation selectivity for nitrate reduction by the ICE process,thus providing a theoretical basis for process design.

Study on Micro Electrolysis Treatment for Decolorizing Dyed Water

Method for decolrizing dyed wastewater was researched and the affecting factors dicussed. The result shows that the conditions for getting an optimum decolorization effect are: a reaction time of 60 min, a coke size of 5～10 mm, a solid/liquid ratio of 1∶10, an air blast volume of 4 m3/h, and proper Fe/coke ratio determined by the type of dye material. The system acidity influences dyed wastewater in different ways, i.e., acid condition is good for the decolorization of scarlet 3R and methyl orange simulated wastewater but bad for that of alkali violet 5BN simulated wastewater, while the decolorization of dispersed yellow E-RGFL simulated wastewater has nothing to do with pH.

Structural parameter optimization for novel internal-loop iron–carbon micro-electrolysis reactors using computational fluid dynamics

It is generally recognized that internal-loop reactors are well-developed mass and heat-transfer multiphase flow reactors. However, the internal flow field in the internal-loop reactor is influenced by the structure parameter of the reactor, which has a great effect on the reaction efficiency. In this study, the computational fluid dynamics simulation method was used to determine the influence of reactor structure on flow field, and a volume-offluid model was employed to simulate the gas–liquid, two-phase flow of the internal-loop micro-electrolysis reactor. Hydrodynamic factors were optimized when the height-to-diameter ratio was 4:1, diameter ratio was9:1, draft-tube axial height was 90 mm. Three-dimensional simulations for the water distributor were carried out, and the results suggested that the optimal conditions are as follows: the number of water distribution pipes was four, and an inhomogeneous water distribution was used. According to the results of the simulation,the suitable structure can be used to achieve good fluid mechanical properties, such as the good liquid circulation velocity and gas holdup, which provides a good theoretical foundation for the application of the reactor.

Degradation of Nitrobenzene Wastewater via Iron/Carbon Micro-electrolysis Enhanced by Ultrasound Coupled with Hydrogen Peroxide

The zero valent iron/granular active carbon(ZVI/GAC) micro-electrolysis enhanced by ultrasound(US) coupled with hydrogen peroxide(H_2O_2) was investigated for the deep degradation of nitrobenzene-containing wastewater. The results of scanning electron microscopy-energy dispersive X-rays analysis(SEM-EDS) demonstrated that continuously accelerated regeneration of ZVI and GAC in situ by US could improve the process for converting nitrobenzene(NB) to aniline(AN). H_2O_2 was decomposed catalytically by the byproduct Fe^(2+) ions generated in the micro-electrolysis process to hydroxyl radicals and the organic pollutants in the wastewater were finally mineralized to CO2 and H2O. Effects of the ZVI dosage, the ZVI/GAC mass ratio, the initial pH value and the H_2O_2 dosage on the efficiency for degradation of NB were studied in these experiments. The optimal operating conditions covered a ZVI dosage of 15 g/L, a ZVI/GAC mass ratio of 1:2,an initial pH value of 3 and a H_2O_2 dosage of 4 mL. In this case, the NB removal efficiency reached 97.72% and the total organic carbon(TOC) removal efficiency reached 73.42% at a NB concentration of 300 mg/L. The reduction of NB by USZVI/GAC followed the pseudo-first-order kinetics model, and the pseudo-first-order rate constants were given at different initial pH values. The reaction intermediates such as AN, benzoquinonimine, p-benzoquinone, p-nitrophenol and other organic acids were detected and a probable pathway for NB degradation has been proposed.

STUDY ON TREATING ALKALI EXTRACTION-STAGE EFFLUENT FOR COLOR REMOVAL BY MICRO-ELECTROLYSIS METHOD

The micro-electrolysis technology was applied in the decolorizing treatment of bleaching E-stage effluent and the influencing factors were discussed in this paper. The initial pH and the retention time were main factors influencing the color removal rate, in addition, adding air and enough pH for neutralization were necessary for the treatment. The test showed that the decolorizing result was efficient by micro-electrolysis treatment when adding air, initial pH was 3, 20 minutes of reaction time, the final pH 10 for neutralization. The color removal rate was up to 90%. The chance of ultraviolet absorption spectrum also demonstrated the mechanism of color removal in the wastewater treatment.

高浓度有机废水处理及回用工程实践研究

本文以某化工企业为例,采用“微电解-高级芬顿氧化-生物处理-砂滤-炭滤-反渗透-三效蒸发”的组合工艺,对其排放的高浓度有机废水进行处理。工程实践表明,系统维持相对稳定时,出水指标均可满足企业内部生产用水的水质要求,实现废水零排放。

Ce掺杂海绵Fe/Cu-C复合微电解填料制备及己内酰胺废水降解研究

己内酰胺废水COD高,可生化性较差。为了提高微电解降解己内酰胺的效率,制备掺杂铈的复合微电解填料,并对其使用条件、降解效果和作用机理进行研究。复合微电解填料的制备方法为利用化学置换法向海绵铁(s-Fe)表面负载铜,形成的双金属还原颗粒与活性炭、碳酸锰、氧化铈等组分混合,随后高温焙烧。使用BET,SEM及XRD等方法,分析不同组分配比填料的物理化学性质,探究各组分所发挥的作用及其机理。研究结果表明,铈掺杂的复合微电解填料对己内酰胺的降解效果显著提升。在双金属颗粒(s-Fe/Cu)、碳酸锰、活性炭按照m(s-Fe)∶m(Cu)∶m(Mn)∶m(C)为15∶5∶1∶6.3、铈含量为9%、膨润土含量为30%的最佳制备条件下,复合微电解填料对己内酰胺废水的降解率达到74.68%,COD的去除率达到90.43%。与市售填料相比,自制填料对己内酰胺废水的去除率比市售填料高55.65%,B/C由原水的0.25提高到0.81,高于市售填料0.43,可生化性显著提高。XPS分析和淬灭实验表明,该填料通过微电解反应过程产生·OH,·O-2和1O2三种自由基团,促进了有机物的降解。

Fenton耦合铁碳微电解技术处理电镀废水的工艺优化

以福建某电镀厂镀镍废水为研究对象,采用Fenton耦合铁碳微电解技术对其进行处理,考察了铁投加量、铁碳质量比、初始pH值及H_(2)O_(2)投加量对COD_(Cr)去除率的影响,通过响应面法优化工艺条件,建立二次多项式预测模型,分析各因素间的交互作用,并检验模型的准确性。结果表明,各因素对COD_(Cr)去除率的影响显著性排序为:初始pH值>H_(2)O_(2)投加量>铁碳质量比>铁投加量;当铁投加量为40 g·L^(-1)、铁碳质量比为0.8、初始pH值为4.0、H_(2)O_(2)投加量为30 mmol·L^(-1)时,COD_(Cr)去除率为78.2%,与预测值(78.9%)基本吻合,说明采用响应面法优化得到的工艺条件准确可靠。

氯化钠对铁碳微电解工艺处理硝基苯废水的影响研究

为了探究铁碳微电解工艺在含盐环境下对水中污染物的去除效率和稳定性,以硝基苯作为处理对象,以氯化钠为盐分来源,构建模拟废水的连续处理装置,通过单因素试验获得反应最佳条件。研究结果表明,铁碳微电解处理硝基苯废水的最佳条件为:废水初始pH值为3,水力停留时间为2 h,曝气量为1 L/min;此条件下氯化钠对铁碳微电解降解硝基苯具有明显的强化作用,在氯化钠质量分数为0.5%~1.5%时,硝基苯去除率可提高20%~30%。

高浓度贲亭酸甲酯生产废水的处理研究

研究了Fe/C微电解耦合Fenton工艺对高浓度贲亭酸甲酯生产废水的预处理,在优化反应条件下,氧化出水经中和絮凝沉淀后,COD平均去除率达54%,B/C由0.11提升到0.34。氧化预处理后的废水进入生物倍增系统,经驯化培养完成后,生物倍增系统兼氧区和好氧区的污泥质量浓度分别达10.4、11.5 g·L^(-1)以上,较传统污泥增长1.7倍以上。通过逐步提升进水盐分质量浓度对系统进行耐盐驯化,当盐分达到10 000 mg·L^(-1)时,出水中COD、NH3-N、TN质量浓度平均在400 mg·L^(-1)、15 mg·L^(-1)、35 mg·L^(-1)以下。对于高浓度的生产废水,全流程运行时,最终出水COD、NH3-N、TN质量浓度分别在400 mg·L^(-1)、5 mg·L^(-1)、20 mg·L^(-1)以下,平均去除率分别达到94.5%、97%、90%。

微电解催化氧化在垃圾渗滤液处理中的应用

目前国内垃圾渗滤液处理主要采用膜过滤,但膜处理产生的浓缩液较难处理,而且处理成本高。某工程采用“微电解催化氧化预处理工艺+A/O+MBR”处理工艺,处理规模为50m^(3)/d,出水水质达到《生活垃圾填埋场污染控制标准》(GB 16889—2008)中表2的排放要求。工程应用结果表明,微电解催化氧化工艺不产生浓缩液、工艺运行较稳定、运行控制较简单,在垃圾渗滤液处理中具有推广价值。

“微电解+芬顿氧化法”在红曲色素废水处理中的应用与研究

采用“微电解+芬顿氧化法”对红曲色素废水中的高浓度压滤废水进行预处理,通过两组试验找出最佳投药量及验证对废水可生化性提高的效果。第一组试验(最佳投药量试验)过程及结果:取200 mL压滤废水水样,经0.5 h曝气微电解反应后,投加芬顿试剂,在投药量30%双氧水5 mL,亚铁盐1.2 g,氧化时间1 h时,COD从24520 mg/L降至18231 mg/L,去除率为25.6%;色度从7500(倍)降至3680(倍),去除率为50.9%。第二组试验(可生化性提高效果试验)过程及结果:原废水B/C比(可生化性)为24%,经0.5 h曝气微电解后提升至36%,再经芬顿氧化后(芬顿试剂投药量:30%双氧水5 mL,亚铁盐1.2 g,氧化时间1 h),B/C比可提升至58%,试验证明B/C比提升效果非常显著,废水中的有机污染物具备了易于生化降解的特性。以上试验及其结果,可为红曲色素废水处理达标排放工程设计时,在工艺流程选择、工艺参数设计及运行费用分析上,提供非常重要的参考依据。

铁炭微电解催化氧化处理高浓度有机废水处理试验研究

采用铁炭微电解催化氧化预处理工艺处理高浓度有机废水能显著提高废水的可生化性,为后续废水生化处理提供有利条件。某一化工废水经该工艺处理,出水能稳定达到排放标准。

微电解技术及其在工业废水中的应用研究

微电解技术作为一种先进的环保废水处理技术,表现出低成本、高效处理、可减少二次污染的优越特性。在富氧和酸性环境下,其原电池效应显著增强,从而提升了处理效果。相对于其他废水处理技术,微电解技术不仅具备强大的处理稳定性,而且适用范围广泛,处理成本相对较低,实现了以废治废的理念。研究表明,在水环境科研领域,微电解技术及其优化已成为热点,深入了解该技术有助于推动该领域的不断发展。该技术的不同之处在于其在富氧条件下的独特表现,使其在处理废水时具有更高效的性能。因此,随着对微电解技术的不断深入研究,该技术在工业废水处理领域的应用前景将更加广阔,可以为环境保护事业贡献更大的力量。

微电流电解灭菌抑藻箱在丘陵果园的应用研究

微电流电解灭菌抑藻技术及装置可通过电解时电极上产生的一系列活性物质有效杀灭菌藻,最大限度地避免丘陵果园滴灌系统菌藻堵塞现象。为了寻求一种高效、环保的果园灭菌抑藻方法,文章对微电流电解灭菌抑藻箱进行优化,并通过试验验证其杀灭菌藻的效果。试验结果显示,该装置菌藻杀灭率达91%,持续2 d,且对其他水质指标影响小。多次现场应用检测结果显示,微电流电解灭菌抑藻箱在江西省上犹县和德安县得以推广试用后,对当地典型集蓄雨水的处理能力约为1.5 m^(3)/h,菌藻灭活率达90%以上,降低了丘陵果园滴灌系统菌藻堵塞风险,为山区特色果业发展提供了技术支持。