Regeneration of activated carbon adsorbed EDTA by electrochemical method

Activated carbon after saturated adsorption of EDTA was used as particle electrode in a three-dimensional electrode reactor to treat EDTA-containing wastewater.Electrochemical method was used to regenerate activated carbon after many times of electrolysis.Based on the analysis of infrared spectra of activated carbon after adsorption and repeated electrolysis,EDTA was degraded into glycine,and then non-catalytic activated associated complex was formed with N—H bond on the activated carbon.The catalytic ability of the activated carbon vanished and the EDTA degradation efficiency was dropped.Activated carbon could be effectively regenerated by electrochemical method in the three-dimensional reactor.Effects of electric current,conductivity and pH on activated carbon regeneration were investigated,and the optimum conditions were concluded as follows：100-300 mA of current intensity,1.39 mS/cm of electric conductivity,60 min of electrolysis time and pH 6.0-8.0.Under the optimized conditions,the activity of the activated carbon can be recovered and the residual total organic carbon（TOC） was below 10 mg/L（the initial TOC was 200 mg/L） in the three-dimensional electrode reactor.

Degradation of phenol using a combination of granular activated carbon adsorption and bipolar pulse dielectric barrier discharge plasma regeneration

A combined method of granular activated carbon（GAC） adsorption and bipolar pulse dielectric barrier discharge（DBD） plasma regeneration was employed to degrade phenol in water.After being saturated with phenol,the GAC was filled into the DBD reactor driven by bipolar pulse power for regeneration under various operating parameters.The results showed that different peak voltages,air flow rates,and GAC content can affect phenol decomposition and its major degradation intermediates,such as catechol,hydroquinone,and benzoquinone.The higher voltage and air support were conducive to the removal of phenol,and the proper water moisture of the GAC was 20%.The amount of H2 O2 on the GAC was quantitatively determined,and its laws of production were similar to phenol elimination.Under the optimized conditions,the elimination of phenol on the GAC was confirmed by Fourier transform infrared spectroscopy,and the total removal of organic carbons achieved 50.4%.Also,a possible degradation mechanism was proposed based on the HPLC analysis.Meanwhile,the regeneration efficiency of the GAC was improved with the discharge treatment time,which attained 88.5% after 100 min of DBD processing.

Iron Species-Impregnated Granular Activated Carbon as Modified Particle Electrodes Applied in Benzothiazole Adsorption and Electrocatalytic Degradation

The object of this study is to prepare iron species-impregnated granular activated carbon as particle electrodes in order to improve their adsorption and electrocatalytic degradation capacity in Benzothiazole removal.The incorporation of Fe-containing catalysts was performed by Fe(NO_3)_3 impregnation.The obtained samples were characterized by BET,Fourier transform infrared spectroscopy,SEM-EDS,powder X-ray diffraction,X-ray photoelectron spectra and TG.Compared with pure activated carbon,this modified particle electrodes show higher static adsorption capacities and TOC removal,which have respectively increased by25.9% and 54.4%.Both physisorption and chemisorption exist in the process of benzothiazole adsorption,where the latter plays a major role.In this way,the Fe-containing catalysts on modified particle electrodes are demonstrated to make a greater contribution to the improvement of electrocatalytic degradation by decreasing the activated energy by 32%.

Superfast and solvent-free core-shell assembly of sulfur/carbon active particles by hail-inspired nanostorm technology for high-energy-density Li-S batteries

The demand on low-carbon emission fabrication technologies for energy storage materials is increasing dramatically with the global interest on carbon neutrality.As a promising active material for metal-sulfur batteries,sulfur is of great interest due to its high-energy-density and abundance.However,there is a lack of industry-friendly and low-carbon fabrication strategies for high-performance sulfur-based active particles,which,however,is in critical need by their practical success.Herein,based on a hail-inspired sulfur nano-storm(HSN)technology developed in our lab,we report an energy-saving,solvent-free strategy for producing core-shell sulfur/carbon electrode particles(CNT@AC-S)in minutes.The fabrication of the CNT@AC-S electrode particles only involves low-cost sulfur blocks,commercial carbon nanotubes(CNT)and activated carbon(AC)micro-particles with high specific surface area.Based on the above core-shell CNT@AC-S particles,sulfur cathode with a high sulfur-loading of 9.2 mg cm^(-2) delivers a stable area capacity of 6.6 mAh cm^(-2) over 100 cycles.Furthermore,even for sulfur cathode with a super-high sulfur content(72 wt%over the whole electrode),it still delivers a high area capacity of 9 mAh cm^(-2) over50 cycles in a quasi-lean electrolyte condition.In a nutshell,this study brings a green and industryfriendly fabrication strategy for cost-effective production of rationally designed S-rich electrode particles.

Performance of activated carbon coated graphite bipolar electrodes on capacitive deionization method for salinity reduction

This research investigates a capacitive deionization method for salinity reduction in a batch reactor as a new approach for desalination.Reductions of cost and energy compared with conventional desalination methods are the significant advantages of this approach.In this research,experiments were performed with a pair of graphite bipolar electrodes that were coated with a one-gram activated carbon solution.After completing preliminary tests,the impacts of four parameters on electrical conductivity reduction,including(1)the initial concentration of feed solution,(2)the duration of the tests,(3)the applied voltage,and(4)the pH of the solution,were examined.The results show that the maximum efficiency of electrical conductivity reduction in this laboratory-scale reactor is about 55%.Furthermore,the effects of the initial concentration of feed solution are more significant than the other parameters.Thus,using the capacitive deionization method for water desalination with low and moderate salt concentrations(i.e.,brackish water)is proposed as an affordable method.Compared with conventional desalination methods,capacitive deionization is not only more efficient but also potentially more environmentally friendly.

富含表面羟基的活性炭制备及其在电催化氧化垃圾渗滤液中的应用

为探究表面羟基对铁碳三维粒子电极电催化氧化性能的影响,采用5 g活性炭中KMnO_(4)用量15 g、用20 mL质量分数10%的H_(2) SO_(4)酸化、反应温度35℃、反应时间1 h的方法对市售活性炭进行氧化改性,并进行结构表征,发现改性活性炭相较于原始活性炭表面羟基量大大增加。然后将改性前后的活性炭制备成铁碳三维粒子电极,用于电催化氧化垃圾渗滤液。结果表明,在100 mL垃圾渗滤液中加入3 g电极、电催化氧化的反应温度50℃、电解电压8 V、O_(3)流量0.2 L/min、电磁搅拌转速600 r/min的条件下,反应30 min,改性活性炭制备的铁碳三维粒子电极比未改性活性炭制备的电极对垃圾渗滤液的总有机碳、氨氮降解率分别提升了26、20百分点。

造纸产业废水应用复合活性炭三维粒子电极绿色处理研究

深入探讨了复合活性炭三维粒子电极在造纸废水处理中的应用,通过系统实验研究了其处理效果、影响因素、优化措施及实际应用前景。结果显示,该技术在去除造纸废水中的COD、色度和重金属等污染物方面表现出显著效果。通过选择复合多孔活性炭作为粒子电极基底材料,负载多金属化合物催化剂和二氧化硅(SiO_(2))稳定剂,并通过高温烧结处理制备出高效的粒子电极。研究表明,复合活性炭三维粒子电极技术在绿色环保和高效节能方面具有一定优势,为造纸产业废水处理提供了一种新颖而有效的方法。

负载型活性炭粒子三维电极法处理亚甲基蓝模拟废水

为了改善三维电极体系中粒子电极对亚甲基蓝(MB)模拟废水的电催化氧化处理效果,采用等体积浸渍法和烧结法成功合成了金属氧化物与颗粒活性炭相结合的粒子电极(M/AC),并对其进行表征。考察了金属组分种类和金属组分负载量对粒子电极催化性能的影响,并对所合成粒子电极的反应机理进行了探讨。结果表明:M/AC粒子电极为多通道多孔网状结构,可以提供大量的表面活性位点;M/AC粒子电极在三维电极体系中对高浓度MB模拟废水表现出良好的电催化降解能力;Mn/AC粒子电极的最佳负载量为5%(质量分数),其电催化氧化性能优于Fe/AC和Ni/AC粒子电极;Mn(5)/AC在三维电极体系中运行8 h后对MB模拟废水的电催化降解率为90%,200 h后仍可达到80%以上;在电催化氧化过程中,Mn/AC粒子电极表面的Mn^(2+)、Mn^(3+)和Mn^(4+)可以实现催化循环,产生活性物质,即羟基自由基和超氧自由基。Mn/AC粒子电极具有长期稳定电催化降解水中有机污染物的潜力。

活性炭电极对溶液中NaCl的电吸附行为

用活性炭、酚醛树脂和乌洛托品制备了活性炭电极。利用扫描电子显微镜(SEM)、傅立叶变换红外光谱仪(FTIR)分析了电极的表面性质,发现电极表面的黏结剂可完全碳化,且活性炭上带有大量含氧官能团;利用电化学工作站采用循环伏安法对电极进行了测试,表明电吸附是一稳定而又可逆的过程,电极电流的最大值由碳化前的0.019 8A升至碳化后的0.042 7A,双电层电容提高到碳化前的2.16倍;对NaCl的电吸附实验表明碳化后电极的电吸附率是碳化前的1.59倍,活性炭的吸附容量也由1.14mg/g提高到3.29mg/g,且活性炭电极具有良好的重复利用性。

Fe^(3+)-TiO_(2)/AC三维电极处理氨氮模拟废水研究

采用泥浆法制备Fe^(3+)-TiO_(2)/AC复合材料,通过XRD和SEM对复合材料进行表征,以复合材料为粒子电极,石墨板为阴阳极,构建三维电极系统处理氨氮模拟废水,探究电解电压、电解质NaCl浓度、初始pH值及粒子电极投入量对氨氮去除的影响,并应用响应曲面法对处理废水的条件进行优化。结果表明:在电解电压为18 V,电解质NaCl浓度为6.7 g·L^(-1),溶液初始pH值为9.00,粒子电极投入量为10.0 g·L^(-1)时,电解40 min后,氨氮去除率为96.86%。采用响应曲面法优化后,在电解电压为18 V,粒子电极投入量为9.9 g·L^(-1),初始pH值为9.10条件下,电解40 min后,氨氮去除率最佳为97.61%。以上研究结论可为氨氮废水的工业处理提供一定的参考。

负载型三维粒子电极技术处理农药生产废水研究

以活性炭为载体制备了负载Cu、Zn、Ni、Mn氧化物为活性成分的粒子电极,并应用于农药生产混合废水的预处理。通过对比实验发现负载Mn氧化物活性炭粒子电极对农药生产混合废水中有机物的降解催化效果最好,反应2 h后COD去除率最高达到49.5%。探讨了Mn氧化物负载活性炭粒子电极预处理农药生产混合废水的最佳工艺条件。实验显示在p H为3,槽电压为18 V和辅助电解质Na2SO4浓度为0.09 mol/L的条件下反应2 h后COD去除率最高达到59.5%。采用一级反应动力学方程对Mn氧化物负载活性炭粒子电极预处理农药生产混合废水的反应过程进行拟合,结果表明降解过程较好地符合一级反应动力学方程。

复极性三维电极处理硝基苯废水中各影响因子分析

以不锈钢片为阳极,石墨为阴极,经吸附饱和的活性炭粒子为填充材料,研究了复极性三维电极法的处理硝基苯废水的时各影响因子的相互作用。通过正交实验确定了复极性三维电极处理硝基苯废水的最佳操作条件为:电解电压10 V,活性炭投加量25 g,反应时间50 min,初始pH值为5。此条件下废水COD的去除率普遍大于75%。

Ti-rGO/GAC粒子电极降解苯酚废水的影响因素试验研究

难降解苯酚废水的高效处理是污水处理领域中亟需解决的难题。以椰壳活性炭为基底材料,在其表面负载石墨烯和钛,制备出新型复合负载型催化粒子电极(Ti-rGO/GAC)填充于三维电极反应器中用于处理苯酚废水,采用单因素试验和正交试验考察了Ti-rGO/GAC三维电极降解体系处理苯酚废水的影响因素和最佳反应条件。试验结果表明:当反应液体积为200 mL、模拟废水中苯酚的初始浓度为310 mg/L、极板间距为4.5 cm、电解质(Na 2SO 4)投加量为10 g/L、溶液的pH值为3、粒子电极投加量为100 g/L、施加电压为13 V时,为Ti-rGO/GAC三维电极降解体系处理苯酚废水的最佳反应条件;在该最佳反应条件下,电解反应100 min后,模拟废水中苯酚和COD的平均去除率分别为93.51%、81.25%;pH值对废水中苯酚和COD去除率的影响最大,电压、极板间距和电解质浓度对其的影响效果依次减弱。Ti-rGO/GAC三维电极降解技术对处理苯酚这类生物难降解污染物具有一定的借鉴意义。

活性炭三维电极-电吸附降解炼油废水

研究了活性炭三维电极-电吸附降解炼油废水中有机物的影响因素及对废水COD、NH_4^+-N以及重金属的处理效果,并与直接电解、调节pH值、添加活性炭、添加活性炭并曝气、调节pH添加活性炭并曝气等几种实验条件对COD和NH_4^+-N的去除效果进行了对比.考察了电解电压、电解时间、初始pH值、活性炭加入量、曝气等实验条件对炼油废水处理效果的影响.结果表明:在电解电压15V、初始pH值3.0、电解时间60min、活性炭颗粒投加量3g/200mL炼油废水、以NaSO_4为电解质的条件下曝气电解对炼油废水的处理效果最佳,COD及NH_4^+-N的去除率分别为80.7%和82.1%.文中采用碘量法与比色法验证了电吸附降解过程中产生的H_2O_2与OH·,探讨了炼油废水的降解机理.

高效能活性炭基底石墨烯粒子电极制备及表征

目的制备和筛选出一种高效、稳定的新型石墨烯复合负载型粒子电极.方法采用溶胶凝胶法制备了一系列不同基底的石墨烯负载型粒子电极,以苯酚为目标污染物考察粒子电极的催化活性,确定最优粒子电极,通过正交试验优化其制备条件.最后采用SEM、EDS、BET、XRD、LSV、CV手段对粒子电极的结构、表面形貌及电化学性能等进行表征.结果筛选出Ti-r GO/GAC-S(椰壳活性炭)为最优粒子电极,对苯酚去除率为85. 26%;正交试验优化其制备条件为钛酸丁酯投加量75 mL、r GO投加量0. 2 g、煅烧温度400℃、煅烧时间1 h;负载Ti和r GO后表面积、析氧电位增大,对苯酚直接氧化能力提高.结论筛选出的Ti-r GO/GAC-S粒子电极电催化活性最高,表面积大,活性点位多,对苯酚的直接氧化能力高.

三维光电催化氧化对硝基苯酚的研究

对硝基苯酚(p-NPh)类废水具有很强的"三致"性,可生物降解性差,在环境中长期滞留、富集会严重危害人类的健康。将自制的TiZnSn/AC粒子电极应用于光电体系下p-NPh模拟废水的降解研究,探究了粒子加量、p-NPh浓度、pH和电流密度对其处理效果的影响。据对硝基苯酚降解过程中COD值和紫外-可见吸收光谱的变化可知,在自由基等活性基团作用下,p-NPh经开环逐渐被氧化为小分子物质直至被全部降解。证明该粒子构成的三维光电催化体系对p-NPh有很好的降解能力。

复极性粒子群电极用于印染废水的处理

本文研究了用复极性粒子群电极法处理印染废水,并对其工作原理进行了探讨。实验说明本法具有高效率、低能耗、使用寿命长等优点。

MOx颗粒活性炭镀层粒子电极对苯酚的电催化降解特性

为研究半导体金属氧化物颗粒活性炭镀层粒子电极苯酚电催化性能，采用溶胶-凝胶、氧化还原与热分解方法，将TiO2、MnO，与SnO2-Sb和SnO2-Sb—Mn纳米金属氧化物镀层于AC（颗粒活性炭）表面，制备了催化型粒子电极，使用X-射线衍射（XRD）、扫描电镜（SEM）及循环伏安曲线（Cv）对其物相组成、微观形貌及电催化活性进行表征与分析．结果表明，这4类金属氧化物可以不同赋存状态存在于AC表面，粒子电极表面活性组分晶格尺寸分别为10．64、11．34、14．68及13．50am；催化型粒子电极电催化活性明显高于未负载AC，各粒子电极电催化活性顺序为SnO2-Sb-Mn／AC〉TiO2／AC〉SnO2-Sb／AC〉MnO2／AC．半导体金属氧化物镀层可提高填充床电极反应器苯酚废水的催化降解性能，废水苯酚及CODCr去除率显著提升，TiO2／AC、MnO2／AC、SnO2-Sb／AC及SnO2-Sb—Mn／AC粒子电极在电流密度为8．0mA／cm^2的条件下连续电解2．72h，出水苯酚及CODCr去除率分别为87．1％、92．8％、90．4％、100．0％和92．5％、89．3％、88．7％、97．2％，高于AC粒子电极的84．2％和79．1％，并且可消除苯酚电催化反应中醌类物质积累．

活性炭再生新方法的研究

本文对被阳离子艳蓝染料溶液吸附饱和的活性炭进行了再生试验研究。根据复极性粒子群电极理论,提出了新的活性炭再生方法。此法再生效率高,能耗低,炭损和再生成衣低,操作简单,再生后的活性炭可反复使用。此法特别适用于吸附质是易吸附又易氧化还原的活性炭的再生。

活性炭负载铁钴电催化氧化焦化废水生化尾水的研究

采用浸渍-焙烧法制备了负载铁钴复合催化元素的活性炭(Fe-Co/GAC)粒子电极。X射线衍射、场发射扫描电子显微镜及能谱仪、N_2吸附脱附曲线等分析表明:负载的催化组分是Fe_3O_4和钴铁氧体(CoFe_2O_4)的混合晶型;Fe和Co元素在颗粒活性炭(GAC)表面元素的质量分数分别为7.4%和3.2%;GAC负载前后吸附行为没发生明显变化。以Fe-Co/GAC作为粒子电极,使用两级串联电催化反应装置处理焦化废水生化尾水,结果表明,在两级反应装置水力停留时间都为20min、电流都为0.2A时,第一、二级反应装置出水COD分别在75.8~79.1、42.6~44.8mg/L,平均去除率分别达到54.4%和74.2%,处理效果相对于GAC提高了10.5百分点。同时,不同电流组合条件表明,两级反应装置的电流条件存在最佳匹配关系,适当降低第一级反应装置电流至0.2A,并适当增加第二级反应装置电流至0.6A,可获得较佳的COD去除效果,以及较低的能耗。