活性炭负载金属改性对废水和废气处理的研究进展

活性炭表面化学改性方法包括氧化改性、还原改性和负载金属改性,本文主要介绍负载金属离子改性方法对活性炭性质的影响,以及综述了国内外学者对活性炭表面负载金属离子改性去除废水和废气中污染物质的研究进展.负载金属离子引起活性炭表面结构的变化.即比表面积,表面含氧量,孔结构,孔径分布,石墨碳网平面的变化而改变对污水中的有机物和重金属去除效果有显著的提高.     

珠江水源水厂臭氧-生物活性炭工艺对有机微污染物的去除效果

近年来,我国经济发展势头强劲的珠江流域的水质不断受到污染,珠海市给水厂的水源也受到污染.建议通过臭氧生物活性炭深度处理工艺进一步提高污染物的去除率.研究采用小试试验对臭氧生物活性炭深度处理工艺进行研究.重点考察了臭氧质量浓度为1.0 mg/L、活性炭柱空床时间为15 min和臭氧质量浓度为1.5 mg/L、活性炭空床时间为30 min这两个工况下,2-甲基异莰醇、土臭素、TOC、UV254、浑浊度的去除效果,以及对消毒副产物前体物的控制效果,并通过分子量分布和三维荧光对水中的溶解性有机物进行分析,发现臭氧-生物活性炭工艺可以很好地去除2-甲基异莰醇和土臭素.臭氧-生物活性炭工艺可以有效地去除水中的溶解性有机物,对三卤甲烷和含氮类消毒副产物的前体物也有一定的去除作用,但是对于HAAs卤乙酸类的DBPs消毒副产物前体物的去除效果不佳.同时,文中也给出了臭氧生物活性炭深度处理工艺运行工况的建议.     

改性活性炭去除饮用水中消毒副产物的实验分析

本文将普通活性炭清洗过滤后加入Fe2(SO4)3并经过高温焙烧得到改性活性炭,分析了改性活性炭在不同焙烧温度、焙烧时间以及不同Fe2(SO4)3浓度下对应的NDEA去除效果,研究了不同改性活性炭投加量、不同pH值下对应的NDEA(亚硝基二乙胺)去除效果,结果表明:(1)为达到最佳的NDEA去除效果,应控制焙烧温度为550℃,焙烧时间为1h,Fe2(SO4)3浓度为0.1mol·L~(-1);(2)改性活性炭对NDEA去除率比普通活性炭高20%左右;(3)为达到较好的NDEA去除率以及NDEA吸附量应控制活性炭投加量为5mg·L~(-1);(4)碱性环境下改性活性炭对水体中NDEA去除效果较好。研究结论可为进一步了解饮用水中消毒副产物的产生机理提供理论参考。     

活性炭去除氦气中CH4和N2杂质的性能研究

旨在有效去除氦气中存在的甲烷和氮气杂质组分,通过对活性炭77 K下N2吸附脱附等温线测试,比较不同活性炭的结构性能,选择性能较优的活性炭AC-1吸附材料,测试了吸附剂在不同温度下对甲烷和氮气的吸附性能.采用氢氧化钠溶液对活性炭AC-1进行了表面改性,研究了改性活性炭对甲烷和氮气的吸附性能.结果表明:不同温度时活性炭AC-1的吸附量有明显的差异;活性炭AC-1经改性后,其比表面积和孔容均有所增大,孔径分布得到优化,对甲烷与氮气的吸附量明显提高.     

巯基功能化活性炭对汞离子的吸附性能研究及机理初探

以活性炭为基体,利用γ-巯丙基三甲氧基硅烷(TMMPS)为改性剂对其进行巯基改性,获得了新型除汞材料巯基功能化活性炭(SFAC).采用SEM-EDS、FT-IR对材料进行表征,结果表明-SH成功被引入到活性炭表面.吸附等温线研究表明改性后活性炭(SFAC)的吸附容量高达472 mg/g,较原活性炭(AC)提高了近1倍.针对高酸性的PVC含汞废水环境,模拟考察了溶液酸度对材料吸附性能的影响,结果表明SFAC在高酸[w(HCl)=31％]下,材料仍能稳定存在,并保持一定的吸附能力,表明材料有很强的耐酸性.同时开展材料对汞离子的吸附动力学研究,初步探讨Hg2+在SFAC上的吸附机理.     

活性炭多维电极法去除水中溶解态腐殖酸研究

本文以活性炭多维电极法，去除水中氯消毒副产物的前驱物－溶解态腐殖酸。文章比较了活性炭多维电极法与活性炭单纯吸附的去除效果，讨论了水样pH值、Ca^2 浓度、外电压、活性炭粒径和加入量对去除效果的影响。     

活性炭对水中有机物去除的研究进展

目前我国大部分城市水源受到不同程度污染,在常规处理工艺不能有效工作的情况下,活性炭可作为饮用水处理深度处理、预处理的有效手段。通过对活性炭的基本特性、活性炭的吸附机理、活性炭去除水中有机物的影响因素以及活性炭表面化学性质改性方法进行综述,总结归纳出可联合不同的改性方法对活性炭表面进行改性,以达到更好的改性效果,从而提高活性炭对饮用水中有毒有害有机物的去除率。     

碳载催化剂在脱氯化氢反应中的应用研究进展

介绍了以活性炭、改性活性炭、负载活性炭为催化剂或催化剂载体,应用于气相催化卤代烷烃脱除氯化氢生成卤代烯烃的反应。讨论了反应中影响催化剂活性的因素及活性炭基催化剂的失活机理。     

活性炭的改性及应用进展

综述了活性炭改性的研究进展,介绍了活性炭材料在各个方面的应用,指出活性炭材料的发展前景.     

炉渣及活性炭对不同废液中重金属的去除作用研究

以河南省危险废物处置中心的焚烧炉渣和有机气体吸收设施(VOC)所使用煤质活性炭为吸附材料,对废水中重金属进行吸附,进而探究炉渣相较于常规活性炭吸附材料对废水中重金属的去除效果.另探究VOC设备新旧活性炭对废水中重金属的去除作用是否存在差异,以期讨论以废治废的可行性.实验结果表明,炉渣对于酸性及碱性废液中的重金属均有很好的去除作用,酸性废液中各重金属元素去除率均达到90％以上,碱性废液中Cu的去除率达到75％以上,VOC设备新旧活性炭对废水中重金属的去除效果基本一致,两者对于酸性废液中重金属去除效果呈现一定的规律性,对碱性废液中Cu没有明显的去除作用.     

Pilot study of the removal of THMs, HAAs and DOC from drinking water by GAC adsorption

The objective of this pilot study was to evaluate the performance of a GAC postfilter-adsorber for the removal from the drinking water of Athens, Greece, of the two main groups of chlorination by-products, trihalomethanes (THMs) and haloacetic acids (HAAs), as well as of dissolved organic carbon (DOC). The analyses performed during the whole operation period (638 days) showed that the GAC breakthrough capacity for DOC was much higher than the capacity for total HAAs, which was higher than that for total THMs. The removal of THMs and the most part of the removal of HAAs and DOC should be attributed to adsorption by GAC, while that of a smaller part of HAAs and DOC may be attributed to biodegradation in the adsorber bed, where dechlorination, caused catalytically by the carbon surface, favoured microbial growth. Additionally, the GAC postfilter-adsorber showed a much higher adsorption efficiency than a GAC filter-adsorber, due to the smaller size of the carbon and the lower hydraulic loading rate. Also, observed desorption incidents of THMs (mainly) and HAAs, especially during the postfilteradsorber operation, were favoured by the same factors. Formation of THMs within the GAC bed was also indicated by the mass balance of total THMs during the whole cycle.     

Effect of Ozone and GAC Process for the Treatment of Micropollutants and DBPs Control in Drinking Water: Pilot Scale Evaluation

To improve the quality of water supplied to the City of Seoul in Korea, a pilot-scale evaluation of how the conventional treatment process could be upgraded was conducted. Three candidate processes were evaluated and compared: a conventional process (consisting of coagulation, sedimentation, and rapid sand filtration) plus GAC (Train A); a conventional process plus ozone and GAC (Train B); and a process consisting of coagulation, sedimentation, intermediate ozone, sand filtration, and GAC (Train C). Treatment efficiency of the unit process and overall treatment trains were evaluated using several parameters such as turbidity, dissolved organic carbon (DOC), UV absorbance at 254 nm (UV₂₅₄), specific ultraviolet absorbance (SUVA), micropollutants (pesticides, benzenes, and phenols), disinfection by-products (trihalomethanes (THMs), haloacetic acids (HAAs) and aldehydes), and total organic halogen (TOX). Results showed that ozone and/or GAC was effective for removing micropollutants and controlling chlorinated by-products such as THMs and HAAs. However, any synergistic effect of ozonation (adsorption and biodegradation) on GAC was observed due to the low concentration of aldehydes in raw and process water.     

The Effect of Bromide Ion on the Formation of Organohalogen Disinfection By-products During Ozonation

Ozonation of water containing bromide ion (Br^?) leads to the formation of brominated disinfection byproducts (DBPs). The purpose of this study was to examine the influence of bromide ion upon the distribution and variation of organohalogen DBPs. Bromide ion concentration had a negative effect on chloroform formation as opposed to increased formation of brominated trihalomethanes (THMs). The results of factor analysis lead clearly to the interpretation that the bromide ion was strongly correlated with brominated THMs and less strongly with brominated HANs (haloacetonitriles). Compared to THMs and HANs, brominated HAAs (haloacetic acids) demonstrated a relatively weak correlation to bromide ion concentration. The addition of alkalinity enhanced the formation of chloroform when ozonation time was 10 to 30 minutes, while concentrations of other bromide ion-containing THMs decreased with increasing alkalinity.     

Chlorination by-products in surface water treatment process

Chlorine disinfection is carried out for the purpose of sterilization of microbes existing in drinking water. Chlorination may cause the formation of disinfection by-products (DBPs) by the reaction of free chlorine with humic substance in the water. In particular, the DBPs including trihalomethanes (THMs), haloacetic acids (HAAs), haloacetonitriles (HANs), and haloketones exist in tap water. The US Environmental Protection Agency (US EPA) suggests 80 μg/L THMs and 60 μg/L HAAs as maximum contamination levels for drinking water. This study was performed to detect the level of DBPs in drinking water and to measure disinfection by-product formation potential (DBPFP) of raw water with four different properties. After 24 h of chlorination, the measured level of trihalomethane formation potential (THMFP), haloacetic acid formation potential, and haloacetonitrile formation potential ranged from 55.0 to 102.6 μg/L, from 9.1 to 23.6 μg/L, and from 10.3 to 33.6 μg/L, respectively. DBPFP was the highest at pH 7.0 and increased with the reaction time. Among the DBPFP, THMFP was detected more frequently than the others. In the treated water, DBPs were measured with a mean value of 47.0 μg/L. Chloroform, dichloroacetic acid, trichloroacetic acid, and dichloronitrile all known as hazardous compounds, were measured as major parts of DBPs.     

饮用水处理中氯化消毒副产物三卤甲烷和卤代乙酸研究进展

三卤甲烷和卤代乙酸是饮用水氯化消毒的典型副产物。该文结合国内外学者对三卤甲烷和卤代乙酸的研究成果对这两类物质的形成的影响因素、主要检测方法及控制方法进行了总结。     

微污染水库原水的消毒副产物控制

上海市南汇自来水厂从青草沙水库取水,原水加氯后在输送途中反应生成的消毒副产物(DBPs)使得原有处理技术和工艺难以达到上海市的新版地方标准DB31/T 1091—2018,为此,需要进行研究改进DBPs的控制方法和工艺。试验以水厂原水为研究对象,分析活性炭的吸附、多点加氯等工艺对消毒副产物生成的影响,同时研究了温度与消毒副产物产生的关系。研究发现,投加粉末活性炭15~20 mg/L后,三卤甲烷(THMs)的控制效果明显,即使加氯量达到3 mg/L,THMs也不超过0.15mg/L。多点加氯可以有效降低前期加氯造成的消毒副产物生成量,水温升高使得余氯量明显降低,从而影响消毒副产物的生成量。消毒后的水样中三氯甲烷浓度约为其他组分的一倍,控制三氯甲烷的生成是控制THMs的关键。本研究推荐采用添加粉末活性炭、控制水温夏天方法来削减南汇自来水厂出水中THMs的总量,研究也为自来水厂消毒副产物的控制提供了实操性的建议和技术依据。     

活性炭表面含氧官能团对水中卤乙酸吸附去除的影响

为了改善极性、亲水性卤乙酸(HAAs)分子在非极性、疏水性活性炭上的吸附性能,利用N₂等温吸附实验、X射线光电子能谱实验（XPS）、HAAs等温吸附实验等方法,对几种不同产地的活性炭孔隙结构、表面元素形态结构组成,以及HAAs吸附性能进行了研究,考察了活性炭孔结构及含氧官能团对HAAs吸附性能的影响.活性炭表面含氧官能团对HAAs的吸附性能影响显著,当活性炭表面含氧官能团组成较小时,其HAAs吸附能力较强.     

受污染原水处理的聚四氟乙烯中空膜组合工艺

该文以排洪期东江水为原水,开展了聚四氟乙烯（PTFE）中空纤维膜组合工艺处理受污染原水的小试和中试研究。工艺将臭氧、混凝与膜过滤集成,后置生物活性炭过滤。试验的PTFE膜孔径为0.12μm,外径×内径为2.3 mm×1 mm。小试试验测得临界膜通量为60 L/m^2·h,臭氧能够促进组合工艺对有机物的去除,并能提高氨氮的去除。中试试验规模为120 t/d,膜通量为41.67 L/m^2·h。结果表明,投加臭氧时组合工艺对氨氮的处理负荷能提高至3.19~4.31 mg/L,COD去除率为70%~94%,UV254去除率达到73%~87%,工艺出水浊度〈0.2 NTU,大于2μm颗粒数〈50 CNT/mL。工艺出水中THMs、HAAs、甲醛、溴酸盐均符合新的饮用水卫生标准;膜出水未检出细菌总数和总大肠菌群数。投加臭氧（O3/TOC=0.6~0.8）可显著减轻膜污染,达到同样的污染程度所需的运行时间较未投加臭氧时延长1倍;投加7~9 mg/L臭氧可逐渐消除膜污染,达到原位修复膜污染,减少化学清洗频次的目的。     

Effect of Ozonation on Trihalomethane and Haloacetic Acid Formation and Speciation in a Full-Scale Distribution System

Disinfection by-product (DBP) formation was evaluated before and after ozone implementation at two full-scale drinking water facilities in Las Vegas, NV USA. The two treatment plants used preozonation for primary disinfection followed by direct filtration with subsequent chlorination for secondary disinfection. DBP data was evaluated from the finished water of the two treatment plants along with six locations in the distribution system. Results showed that preozonation reduced the formation of total trihalomethanes (TTHM) by up to 10 μg/L and the sum of five haloacetic acids (HAA5) by up to 5 g/L. These reductions were primarily due to decreases in the di- and trichlorinated DBPs such as chloroform, bromodichloromethane, and trichloroacetic acid. Ozonation appeared to shift the speciation of TTHMs and HAA5 to favor increased formation of the di- and tribrominated species such as bromoform, chlorodibromomethane, and dibromoacteic acid. A bromide mass balance showed that <30% of the raw water bromide was accounted for by the formation of TTHMs (8–21%), HAAs (2–3%) and bromate (5%). Reducing the concentration of THMs and HAAs is often not the primary purpose of ozonation, but it can assist utilities in meeting regulatory requirements during drinking water treatment.     

Continuous and efficient removal of THMs from river water using MF membrane combined with high dose of PAC

A combination of microfiltration (MF) membrane with a high concentration (40 g/L of the reactor) of powdered activated carbon (PAC) efficiently and continuously removed trihalomethanes (THMs) and total organic carbon (TOC) from river water for a period of two months. Without PAC, the membrane reactor was able to remove less than 18% of THMs and less than 5% of TOC; with PAC, 65 to 95% of THMs and TOC were removed. Even though the THMs concentration in the influent was steadily increasing (reaching 50 μg/L), THMs concentration in the effluents from the reactors with PAC were consistently below 15 μg/L. While the MF membranes alone could not remove organics, PAC and microbial activity in the biofilm deposited on the PAC particles assured long term and continuous removal of THMs. No additional PAC was added into or removed from the reactors during the filtration period. Operational parameters such as the backwashing of the membrane, interval of the filtration cycle and biological pretreatment of the river water had a small effect on the extent of THMs removal, but they increased the filtration time prior to membrane cleaning and improved the overall performance of the reactors.