臭氧/生物活性炭深度处理密云水库水中试研究

采用臭氧／生物活性炭工艺（O3／BAC）对密云水库水进行深度处理中试研究，试验结果表明：臭氧／生物活性炭工艺的处理效果优于单独活性炭工艺（GAC），在最佳臭氧投加量（2．0mg／L）下，03／BAC对CODMn、UV254、BDOC的去除率分别比GAC工艺的高9．9％、30．5％、12．9％；同时，活性炭的结构特征对于生物降解作用有重要影响，破碎炭对BDOC的去除效果明显优于柱状炭的。     

臭氧生物活性炭深度处理黄浦江上游原水

对黄浦江上游原水进行臭氧生物活性炭中试研究表明：在臭氧有效投量为2．0mg／L、臭氧接触塔和活性炭柱停留时间均为11min的条件下，臭氧生物活性炭工艺对水中CODMn和UV254的平均去除率分别为29．95％和48．83％，出水CODMn和UV254值分别为2．96mg／L和0．053cm^-1；为保证炭柱出水氨氮浓度≤0．5mg／L，建议控制炭柱进水氨氮浓度≤1．5mg／L；水温、进水浓度、炭柱停留时间以及臭氧投量对污染物去除效果均有一定的影响。     

饮用水处理中臭氧-生物活性炭工艺机理

详细叙述了臭氧—生物活性炭工艺去除水中污染物的机理，并探讨了生物活性炭中生物降解与炭吸附的相互联系，提出了进一步的研究方向。     

上海市某水厂臭氧—生物活性炭技术的应用分析

臭氧—生物活性炭技术是目前国内外应对微污染水源水处理的最常用技术之一。上海某水厂采用预臭氧/常规处理/臭氧—生物活性炭组合工艺运行了4年,活性炭滤池的运行经历了吸附、生物活性炭和换炭3个阶段。运行结果表明,该工艺可以提高对高锰酸盐指数(CODMn)、氨氮、锰的去除率,改善出厂水的色度、嗅味和致突变性等多项水质指标,全面提高水质。但该技术也存在一定的局限性,如冬季对氨氮的去除率降低,原水的CODMn过高时出厂水CODMn仍会超过3 mg/L的标准;另外运行中要严格控制生物繁殖,防止微生物流出。此外,臭氧—生物活性炭技术会增加建设投资和运行成本,活性炭更换周期为3年半,以更换2/3的活性炭为宜。     

超滤/臭氧/生物炭组合工艺预处理源水

采用超滤、臭氧、生物活性炭及砂滤等工艺并进行组合，对源水中可溶性有机物和THM前驱物进行预处理。结果表明，超滤／臭氧／生物活性炭工艺组合对水中THM前驱物、DOC、E260及浊度都有明显的去除效果，尤其臭氧氧化对改善THM前驱物和难生物降解有机物的可生化性有十分显著的作用。生物活性炭与臭氧组合能有效地去除饮用水中的有害、有毒物质，提高饮用水的安全性。     

微污染北江源水的深度处理工艺优选

采用预氧化＋常规处理＋深度处理工艺对微污染北江源水进行了中试研究，考察了在预臭氧、预氯化和无预处理方式下，GAC和O3-BAC深度处理工艺的除污效果。结果表明：采用预臭氧氧化方式可大大改善常规处理工艺对CODMn、UV254的去除效果；在预臭氧氧化方式下，O3-BAC和GAC深度处理工艺均能在长时间内保持对有机物的高效去除，且前者的去除效果及其活性炭的使用周期均优于后者；活性炭吸附对氨氮无明显去除效果，而生物降解能较好地去除氨氮；预臭氧氧化能有效去除原水中的THMFP，但生成的CHCl3不能通过生物降解被去除，只能被活性炭所吸附，在活性炭吸附饱和后出水CHCl3浓度比进水的高；从长远角度考虑，对于北江源水，预臭氧＋常规处理＋O3-BAC是一种较优的组合工艺，它能够有效去除饮用水中的有毒、有害物质，并保障饮用水的安全性。     

针对低温期有机物去除率低的生物活性炭更换探究

江苏某水厂生物活性炭投运至今已达6年,出水水质指标能够稳定达到《生活饮用水卫生标准》（GB 5749—2006）的要求。但对照新实施的《江苏省城市自来水厂关键水质指标控制标准》（DB 32/T 3701—2019）要求,在其投产第三年的低温期即出现了CODMn不能稳定达标的问题,即生物活性炭寿命不足3年。研究显示主要是低温期炭上微生物活性较差且活性炭运行年限较长吸附能力不足所致。为保证出水水质,亟需进行活性炭更换。对活性炭更换方式的研究表明：新炭填充比例越高,对有机物的去除效果越好。但更换成本较高,且浪费了原有活性炭的吸附能力。中试研究表明,更换20%新炭的换炭方式能保证低温期出厂水CODMn值达到DB 32/T 3701—2019湖库水源不高于2.2 mg/L的要求,因此建议水厂于每年低温期到来之前（10月中旬）更换活性炭,更换比例为20%。与一次性全部更换相比,能够减少20%～40%的更换成本。     

臭氧/生物活性炭工艺对阿特拉津的去除效能研究

模拟太湖水中阿特拉津浓度突增的情况,研究了臭氧氧化、生物活性炭吸附降解及臭氧/生物活性炭联用工艺对其去除效果,并初步分析了各工艺参数的影响.结果表明,单独臭氧氧化对阿特拉津的去除率约为31%,而生物活性炭工艺的去除率则可达到73%;臭氧氧化可强化生物活性炭对阿特拉津的去除效果,两者联用对阿特拉津的去除率高达95%;破碎炭上的生物量明显高于柱状炭,针对水中阿特拉津的去除,破碎炭更为适用;臭氧/生物活性炭工艺的炭层厚度建议采用150 cm,此值可在保证阿特拉津去除效果的同时,保障出水水质安全性.     

"三氮"在深度处理中的去除与转化

就氨氮、硝酸盐氮、亚硝酸盐氮(简称“三氮”)在臭氧-生物活性炭(O3／BAC)给水深度处理系统中的去除与转化规律进行了研究。结果表明，炭滤池对NH3-N的单元去除率接近30％，但是整个系统对NH3-N的总去除率仅约10％；系统对NO2^-—N有着优异的去除能力，主臭氧接触塔和炭滤池出水中均未检测出NO2^-—N；炭滤池中的生物硝化作用明显；系统进、出水的“三氮”总浓度基本没有变化。     

去除痕量邻苯二甲酸酯的活性炭选型与试验研究

为了提高饮水厂对微污染水体中邻苯二甲酸酯(PAEs)的去除效果,以活性炭为吸附剂,进行活性炭选型和炭柱吸附PAEs试验。结果表明,木质炭、煤质炭、果壳炭的吸附行为均符合Freundlich经验模型。当果壳炭投加量为8 g/L时,对邻苯二甲酸二丁酯(DBP)、邻苯二甲酸二(2-乙基己基)酯(DEHP)的去除率均达到100%,对邻苯二甲酸二甲酯(DMP)、邻苯二甲酸二乙酯(DEP)的吸附容量分别为14.712和5.143μg/g,高于煤质炭和木质炭的相应值。动态吸附试验中,果壳炭对4种PAEs的去除率均在85%以上,平衡浓度低于0.5μg/L。在PAEs进水浓度为5~20μg/L条件下进行果壳活性炭柱吸附试验,发现该深度处理工艺对PAEs的去除效果均满足《生活饮用水卫生标准》(GB 5749—2006)的要求,且在去除率和吸附稳定性上优于常规水处理工艺。     

Discriminating and assessing adsorption and biodegradation removal mechanisms during granular activated carbon filtration of microcystin toxins

Microcystins are cyanobacterial toxins that are problematic for water authorities due to their resistance to conventional water treatment. Granular activated carbon (GAC) filtration has been shown to be effective in removing microcystin from water using both adsorption and biodegradation removal mechanisms; however, little is known regarding which removal mechanism predominates and to what extent. In this study, microcystin removal due to adsorption and biodegradation in GAC filtration were discriminated and assessed by commissioning three parallel laboratory columns, including a sterile GAC column, a conventional GAC column and a sand column. The results demonstrate that biodegradation is an efficient removal mechanism once it commences and that the rate of biodegradation was dependent upon temperature and initial bacterial concentration. Adsorption of microcystins was prevalent during the initial stages of the GAC columns and was modelled using the homogeneous surface diffusion model (HSDM). The HSDM provided evidence that an active biofilm present on the surface of the conventional GAC hindered adsorption of microcystin compared with the sterile GAC with no active biofilm. Up to 70% removal of microcystin-LR was still observed after 6 months of operation of the sterile GAC column, indicating that adsorption still played a vital role in the removal of this toxin.     

A bio-electrochemical reactor coupled with adsorber for the removal of nitrate and inhibitory pesticide

In this study, the treatment characteristics of nitrate and toxic pesticide by a combined bioelectrochemical reactor (BER)/adsorption process was investigated. Experimental results showed that the disappearance of NO3- in BER was in accordance with the applied current. NO2- was not detected in the effluent, but the production of N2O was increased with increasing IPT loading. In the presence of IPT, up to 30% of the nitrate nitrogen consumed was converted to N2O, while more than 95% converted to N2 in the absence of IPT. In adsorption column, IPT was efficiently removed onto either granular activated carbon or silicone resin so as to meet the guideline value (40 microg/I) and to reduce the N2O accumulation. A simplified kinetic model that considers the sequential reduction of nitrate and inhibition of the N2O reduction step by pesticide as well as Langmuir adsorption isotherm was developed and used to evaluate the process performance. Theoretically predicted effluent concentrations were in good agreement with the observed results for nitrate, nitrite, N2O, N2 and IPT. It was considered that high removal performance of nitrate and pesticide by the combined process is attributable to high affinity of adsorbates for IPT in comparison with relatively large inhibition constant (Ki).     

生物强化滤池在低温低浊水处理中的应用

在低温低浊条件下,通过对生物强化炭砂滤池(BCSFR)与普通炭砂滤池(CSFR)进行对比实验,研究有机物及消毒副产物的去除效果及机制。结果表明,在原水温度4~10°C,浊度为2~6NTU条件下,BCSFR对高锰酸盐指数(PI)、TOC和UV254的平均去除率分别达到48.28%、31.80%和29.32%。此外,可生物同化有机碳(AOC)和可生物降解有机碳(BDOC)的去除率分别为50.83%和51.16%。由于微生物降解与活性炭吸附的协同作用,BCSFR能够比普通CSFR更有效去除有机物,因此有可能成为一种适合处理寒冷地区低温低浊水的安全饮用水保障技术。     

Removal of the surfactant sodium dodecylbenzenesulphonate from water by simultaneous use of ozone and powdered activated carbon: comparison with systems based on O3 and O3/H2O2

A study was conducted on the efficacy of the system based on the simultaneous use of ozone and powdered activated carbon (PAC) in removing sodium dodecylbenzenesulphonate (SDBS) from drinking waters and on the influence of operational parameters (PAC dose, ozone dose and presence of radical scavengers [HCO3-]) on this process. Results obtained showed that low doses of PAC during SDBS ozonation markedly increased the rate of SDBS removal from the medium. These results are due to the combined effect of two processes: (i) SDBS adsorption on the activated carbon surface and (ii) transformation of the dissolved ozone into .OH radicals. At higher ozone and PAC doses, there was a higher rate of SDBS removal from the medium. The presence of HCO3- in the medium reduced the SDBS removal rate of the O3/PAC system. This finding confirms that the presence of PAC during SDBS ozonation favours ozone transformation into .OH radicals. Comparison of the O3/PAC system with systems based on the use of O3 or O3/H2O2 showed that the efficacy of the O3/PAC system to remove SDBS is much greater than that of the traditional oxidation methods. Thus, in the first 5 min of treatment (usual hydraulic retention time), the percentage of SDBS removed was 18% and 30% for the O3 and O3/H2O2 systems, respectively, compared with 70% for the O3/PAC system. SDBS ozonation in surface waters intended for human consumption demonstrated that the O3/PAC approach is the most efficacious of the studied systems, considerably increasing the SDBS removal rate and also reducing the concentration of dissolved organic carbon. Therefore, the results of this study show that the system based on O3/PAC is a highly attractive option for the treatment of drinking water.     

生物粉末活性炭/超滤组合工艺处理微污染原水

针对微污染原水中存在的有机物和氨氮等污染物,采用生物粉末活性炭/超滤(BPAC/UF)组合工艺进行处理。结果表明,当进水氨氮浓度较低时,硝化细菌活性较差,无法充分发挥生物降解作用,氨氮去除率较低,同时有机物去除率也较低;当进水氨氮浓度在0. 6 mg/L左右时,可以形成稳定的生物活性炭,组合工艺对氨氮的去除率较高,且对有机物的去除率较为稳定。进水中主要以分子质量<5 ku的有机物为主,组合工艺对这部分有机物的去除率也最高。组合工艺对疏水性物质的去除,主要依靠生物粉末活性炭的吸附降解和膜面滤饼层的截留作用。NaClO强化反冲洗可以很好地降低跨膜压差的增长速度,当NaClO浓度为400 mg/L、反冲洗时间为10min时可达到最佳清洗效果。     

Natural waste materials containing chitin as adsorbents for textile dyestuffs: batch and continuous studies

In this work three natural waste materials containing chitin were used as adsorbents for textile dyestuffs, namely the Anodonta (Anodonta cygnea) shell, the Sepia (Sepia officinalis) and the Squid (Loligo vulgaris) pens. The selected dyestuffs were the Cibacron green T3G-E (CI reactive green 12), and the Solophenyl green BLE 155% (CI direct green 26), both from CIBA, commonly used in cellulosic fibres dyeing, the most used fibres in the textile industry. Batch equilibrium studies showed that the materials' adsorption capacities increase after a simple and inexpensive chemical treatment, which increases their porosity and chitin relative content. Kinetic studies suggested the existence of a high internal resistance in both systems. Fixed bed column experiments performed showed an improvement in adsorbents' behaviour after chemical treatment. However, in the column experiments, the biodegradation was the main mechanism of dyestuff removal, allowing the materials' bioregeneration. The adsorption was strongly reduced by the pore clogging effect of the biomass. The deproteinised Squid pen (grain size 0.500-1.41 mm) is the adsorbent with highest adsorption capacity (0.27 and 0.037 g/g, respectively, for the reactive and direct dyestuffs, at 20 degrees C), followed by the demineralised Sepia pen and Anodonta shell, behaving like pure chitin in all experiments, but showing inferior performances than the granular activated carbon tested in the column experiments.     

Enhanced mitigation of para-chlorophenol using stratified activated carbon adsorption columns

The adsorptive removal of toxic para-chlorophenol using activated carbon adsorption columns is a proven effective engineering process. This paper examined the possibility to stratify an adsorbent bed into layers, in order to enhance the adsorption process performance in terms of increased column service time and adsorbent bed saturation. Four different types of fixed-bed adsorption columns are used and compared under the same operating conditions, but with the variation of column geometry and activated carbon particle size stratification. The Type 3 column - a cylindrical column with particle stratification packing, is found to be the most efficient choice, as the extent of column service time and adsorbent bed saturation are the largest. This could eventually decrease the frequency of adsorbent replacement/regeneration and hence reduce the operating cost of the fixed-bed adsorption process. The Homogeneous Surface Diffusion Model (HSDM) was applied successfully to describe the dynamic adsorption of para-chlorophenol onto Filtrasorb 400 (F400) activated carbon in different types of columns. The Redlich-Peterson isotherm model equation, an experimentally derived external mass transfer correlation and a constant surface diffusivity are used in the HSDM. The optimised surface diffusivity of para-chlorophenol is found to be 1.20E-8 cm²/s, which is in good agreement with other phenolics/F400 carbon diffusing systems in literature.     

从分子质量的变化分析臭氧活性炭工艺

为了解臭氧活性炭工艺的机理并优化运行条件,采用臭氧活性炭处理黄浦江原水,分析了原水及经不同工艺单元处理后溶解性有机物 (DOM)分子质量 (MW)的变化。结果表明:黄浦江原水中的DOM主要为小分子有机物;臭氧对大分子有机物的氧化分解作用明显强于对小分子有机物的氧化作用;MW<1ku的有机物经臭氧氧化后则表现出不同程度的增加;混凝、沉淀、过滤对MW>3ku的大分子有机物去除效果较好,而对MW<3ku的小分子有机物去除效果较差;生物活性炭单元能有效去除MW为 3~1ku和MW<1ku的小分子有机物;臭氧氧化与活性炭吸附在去除不同MW有机物的过程中有很好的互补性,从而使该工艺能有效去除原水中的DOM。