活性炭的电化学再生技术研究

本文在测定了苯酚于椰壳活性炭上的吸附平衡和添加2％NaCl对吸附平衡的影响基础上,对用苯酚吸附饱和后的活性炭在一个搅拌槽电化学反应器中进行了再行试验研究。在室温条件下,通过改变再生电流的大小,在不同的时间间隔内,测定了反应器中溶液的残余酚深度与活性炭的再生效率随再生时间和再生电流大小的变化关系。     

Regeneration of exhausted activated carbon by electrochemical method

The regeneration of coconut shell activated carbon contaminated with phenol was systematically investigated by electrochemical method under different operating conditions. The effects of several operating parameters on the electrochemical regeneration efficiency were measured at room temperature. The experimental results show that the electrochemical method can be used to regenerate the activated carbon exhausted with phenol. The electrochemical regeneration efficiency depends on several operating variables such as electrolyte concentration, regeneration current intensity and regeneration time. The residual phenol concentration in solution was much lower and the regeneration efficiency can reach 85.2% in a stirred electrochemical reactor after regeneration for 5 h.     

Electrochemical Regeneration of Activated Carbon Saturated with Toluene

The electrochemical regeneration of an activated carbon, previously saturated with toluene by gas phase adsorption, was studied. Cathodic and anodic regeneration methods were analyzed using a small batch electrochemical cell. In both cases, a stripping efficiency close to 100% was obtained under appropriate conditions of potential, current, and time of electrolysis. Successive loading and regeneration cycles of the activated carbon were performed under cathodic conditions without loss of the adsorption properties of the activated carbon, thus achieving a high regeneration efficiency (close to 99%). This electrochemical method is very effective for regeneration of activated carbon compared to conventional thermal regeneration as it does not modify the porous texture of the material.     

电化学再生活性炭的工艺参数研究

对所选定的活性炭，吸附苯酚饱和后者电化学再生。在室温条件下，选择４因素、２水平的正交试验方法进行了相关试验。结果表明，再生位置是活性炭再生工艺中最重要的影响因素，电解质ＮａＣｌ浓度是较重要的影响因素，再生电流和再生时间对活性炭的电化学再生有一定的影响。     

超声辅助熔融草酸法高效绿色再生饱和活性炭

饱和活性炭的高效绿色再生对活性炭在污染物吸附过程中的循环利用是非常重要的。本文利用超声波辅助熔融草酸的方法对饱和活性炭进行高效绿色再生，讨论了温度、时间、超声振幅和固液比对饱和活性炭再生效率的影响。结果表明，在超声辅助作用下，熔融草酸可在20min内使饱和活性炭得到快速再生，再生效率高达94.72%。通过5次吸附-脱附循环后，再生效率仍可达到78.02%，与此同时有机酸的回收率极高，平均达到98.35%，再生过程十分绿色环保。在超声的辅助作用下，强氢键缔合能力的熔融草酸更充分地与焦糖反应，形成草酸-焦糖强氢键缔合体系，降低焦糖与活性炭表面的亲和力，将焦糖解吸，实现活性炭的再生。该法可为绿色高效的活性炭再生方法的研究开发提供新思路。     

活性炭填充床脱除水中苯酚及填充床的再生

实验研究了活性炭填充床脱除水中苯酚的吸附性能,探讨其饱和吸附填充床的再生方法,结果表明当平衡浓度范围为0－0．8kg/m^3时,活性炭对水中苯酚的吸附能力达230kg/kg（吸附剂）,吸附等温线符合Langmuir型,填充床的穿透曲线和穿透时间强烈依赖于实验条件,较高的进料浓度,较大的进料速度,以及较短的床层长度都将使填充床穿透较快;用热的NaOH稀溶液可再生被苯酚饱和的活性炭纤维填充床,再生效率达90％以上。     

Rapid regeneration of chelated iron desulfurization solution using electrochemical reactor with rotating cylindrical electrodes简

A new electrochemical reactor with rotating cylindrical electrodes was designed and used to increase the regeneration efficiency of chelated iron desulfurization solution. The influence of operating parameters, such as the rotation speed of electrode, voltage, and inlet air and liquid flow rates, on the regeneration rate was investigated. Compared with the traditional tank-type reactor, the regeneration rate with the new electrochemical reactor was in- creased significantly. Under the optimum conditions, the regeneration rate was increased from 45.3% to 84.8%. Experimental results of continuous operation indicated that the new electrochemical regeneration method had some merits including higher regeneration efficiency, smaller equipment size and good stability in operation.     

活性炭吸附法脱除废水中的苯酚及吸附剂再生的研究

对活性炭对废水中苯酚的吸附平衡以及活性炭的再生进行了试验性研究和理论性探讨。结果发现,温度对活性炭的吸附能力有显著的影响,低温地吸附有利,吸附平衡可用Ｌａｒｇｍｕｉｒ方程描述;ＰＨ值对活性炭对苯酚捐附也有较强的影响,酸性的水溶液对吸附有利,强碱性水溶液对再生有利。分别采用乙醇、丙酮、ＮａＯＨ溶液、ＮａＯＨ溶液＋乙醇的混合液对吸附剂活性炭进行再生,再生率均能达到８５％以上,基本满足工业要求。     

不同化学方法再生活性炭的对比研究

本文研究了苯酚水溶液在活性炭上的吸附平衡关系,溶液ＰＨ值对活性炭吸附性能的影响。     

光催化再生型活性炭的研制

光催化再生型活性炭的研制是实现吸附饱和活性炭原位再生的重要环节。本文采用溶胶凝胶——再活化法在商品活性炭表面合成TiO2光催化剂，制得新型炭吸附材料一光催化再生型活性炭。以苯酚为模型化合物，考察了该材料的吸附性能和紫外光照射条件下的光催化再生性能。以扫描电子显微镜、低温液氮吸附研究光催化再生型活性炭的表面结构、孔径结构和TiO2的分布状况。结果表明，光催化再生型活性炭保留了原料活性炭的吸附性能，在紫外光照射下即可逐渐恢复其吸附性能。其吸附性能随担载量的增加而降低，再生率随担载量的增加而升高，催化剂担载量为2．0wt％活性炭具有适宜的吸附性能和光催化再生性能。其再生率随再生次数增加而下降。光催化再生型活性炭具有原料炭相似的表面结构和孔径结构。TiO2在活性炭基材料表面呈不均匀分布，主要集中在活性炭的大孔和表面凹陷处。     

水处理活性炭的电化学再生技术研究

选择椰壳水处理活性炭作为吸附剂吸附处理低浓度苯酚废水,在室温条件下,在静止的电化学电极上对吸附苯酚后的活性炭进行电化学再生,探讨了各个操作参数对活性炭的电化学再生效率的影响。实验结果表明,电化学再生活性炭的效率较好,基本没有二次污染。再生效率随着电解质（氯化钠）溶液浓度的增加而增加,但达到１％以后基本没有变化。同时,再生效率随着再生电流的增加而提高,随着再生时间的增加,再生效率亦随之提高,但到５ｈ以后,再生效率基本不随时间的变化而变化。     

Activated carbon as catalyst in wet oxidation of phenol: Effect of the oxidation reaction on the catalyst properties and stability

Catalytic wet oxidation (CWO) of phenol has been carried out in a continuous three-phase reactor by using a commercial activated carbon (AC) as catalyst, feeding oxygen as gas phase and an aqueous solution 1000 ppm in phenol to the reactor. A stable catalyst under operation conditions is one of the main difficulties to pass up in the catalytic wet oxidation process, so the stability of the activated carbon with the time on stream (TOS) was investigated. To do this the phenol conversion change was analyzed with TOS and results were contrasted to the change of the physicochemical properties of the AC with the TOS. Gas adsorption/desorption, TPD, XPS and SEM measurements were applied to the AC taken from the reactor after several TOS values. A significant reduction of the micro-pore volume and BET surface area of the catalyst was observed with TOS. However, as reaction proceeded the external surface area and the total amount of oxygen surface group increased. Moreover, regeneration of the initial catalyst properties was done by washing with water saturated in oxygen, at the reaction conditions or by heating in N₂ atmosphere at 450, 700 and 900 °C. The total micro-pore volume and internal surface area of the catalyst were not recovered by the regeneration process, probably due to blockage of the narrow micropores by pyrolytic carbon produced during the first step of the wet oxidation process.     

Electrochemical regeneration and porosity recovery of phenol-saturated granular activated carbon in an alkaline medium

The electrochemical regeneration of phenol-saturated activated carbon has been carried out in a filter-press electrochemical cell. The feasibility of the electrochemical regeneration has been assessed by monitoring the regeneration efficiency and the textural properties of a phenol-saturated granular activated carbon (GAC) electrolysed in NaOH medium. The influence of the following factors: (i) the electrolysis treatment (either anodic or cathodic); (ii) the separation of compartments; (iii) applied current and (iv) electrolysis time has been studied. Basing on the obtained results, an overall phenomenological mechanism for the electrochemical regeneration has been proposed. The general worse performance of anodic regenerations can be attributed to an important surface blockage of the GAC by reaction products such as quinones, phenolic oligomers and polymers coming from phenol electrooxidation. The cathodic regeneration in NaOH medium, where phenolate desorption is favoured, and in an undivided configuration, where surface blockage is minimized, produces a significant recovery of the porosity of the original GAC, in agreement with the highest RE values (close to 80%).     

含油废水吸附饱和活性炭纤维的电化学再生

为了对有机物吸附饱和的活性炭纤维(ACF)进行电化学再生研究,以含油废水为模拟有机物,通过测量再生前后ACF对含油废水的吸附效果,考察了电流密度、再生时间、pH值、电解质的电化学再生的影响因素,并研究了电化学再生过程对ACF结构的影响以及ACF电化学再生的机理。结果表明,在电流密度为30 mA·cm^-2,pH值为4,15 g·L^-1 NaCl的溶液中再生120 min,再生率可达到90%,5次电化学再生循环后,ACF保持较高的吸附容量。再生后ACF的表面没有明显损伤,比表面积也没有明显减小,微孔孔径分布于0.5～1.0 nm。由紫外光谱分析可知,ACF的电化学再生机理主要包括电脱附及电化学氧化过程。     

苯酚在活性炭上的吸附与脱附研究

本文研究了苯酚水溶液在活性碳上的吸附平衡关系,溶液ｐＨ值对活性炭吸附性能的影响,苯酚在固定床上的吸附动力学和脱附动力学。同时采用间歇法和固定床连续法研究吸附苯酚后的活性炭碱再生工艺过程,多次再生对活性炭再生效率的影响,探讨了碱法再生活性炭的初步规律。     

NaOH Regeneration of Pb and Phenol-Laden Activated Carbon. I. Batch Study Results

Abstract

Granular activated carbon (GAC) has been used to remove organics and metals simultaneously from wastewaters (4). For a regeneration procedure to be effective on GAC containing both metals and organics, it must remove both the metals and organic compounds. In this study, GAC saturated with Pb and phenol was regenerated using an NaOH rinse in batch mode. Four variables were investigated: 1) regenerant concentration (0, 0.1, and 1.0 N), 2) regenerant to carbon mass ratio (5:1 and 10:1), 3) regenerant temperature (22 and 80°C), and 4) regeneration time (0.33, 1, 3, 7, and 21 days). Maximum regenerations of 47% for Pb and 48% for phenol were observed. The 1.0 N NaOH regenerated a higher percentage of both Pb and phenol when compared to the other regenerants. The 10:1 regenerant to carbon ratio resulted in increased regeneration over the 5:1 regenerations. Pb regeneration was slightly higher at 80°C than at 22°C whereas phenol regeneration was slightly lower at 80°C than at 22°C. Maximum regenerations for both Pb and phenol were observed within the first day of regeneration, in most cases within the first 8 hours.     

Novel technique to regenerate activated alumina bed saturated by fluoride ions

A novel technique to regenerate adsorbent column is presented. The process used is based on the utilization of an electrochemical cell which regenerates several saturated adsorbent bed. This paper presents the regeneration of the activated alumina (AA) bed saturated by fluoride ions. The results obtained in this study demonstrated that desorption of fluoride from activated alumina is a rapid process. Most of the fluoride content desorbed within 6–15 min. The utilization of the electrochemical cell allows a complete desorption of the fluoride under optimum conditions. The reduction of about 90% of the sodium hydroxide amount was attained by the electrochemical process. A study of adsorption–regeneration cycles showed that the electrochemical technique was more efficient than current techniques. A 95%, recovery of the adsorption capacity was realized with the electroregeneration system. In addition, the volume of water used to regenerate the saturated bed was lower than for current regeneration techniques. The washing did not exceed 6% of the treated water volume. The electrodesorption operation was successfully applied for fluoride desorption from saturated activated alumina column by natural water with strong mineralisation.     

Fenton试剂再生活性炭的试验研究

采用Fenton试剂再生被苯酚吸附饱和的活性炭,研究H2O2和Fe2+的投加量、pH值、温度、振荡速率、反应时间等因素对再生效果的影响,并确定最佳再生条件.试验结果表明,当H2O2投加量为7.5mL、FE2+投加量为400mg/L、反应pH值为3、温度为25℃、振荡速率300r/min、反应时间60min时,再生活性炭...     

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。     

Kinetic parameter determination in monoculture and monosubstrate biological reactors

The kinetic parameters of a biological reactor, operating under monoculture and monosubstrate conditions, have been determined. Pure cultures of Nocardia corallina and Pseudomonas fluorescens species have been used with phenol as the only organic carbon source. The experimental runs have been carried out both in a batch and in a continuous stirred reactor. The batch results have been interpreted by zero order kinetics in phenol and first order kinetics in biomass. The kinetic-constants have also been calculated. The activation energy has been determined only for the Nocardia species. Using this strain, the continuous reactor, working without biomass recycle, has confirmed the first order kinetics with respect to biomass.