北方某水厂原水和处理过程中邻苯二甲酸酯类的监测

采用SPE-GC-MS方法对北方某水厂原水和传统工艺各处理单元水样中的邻苯二甲酸酯类(PAE)浓度进行监测。结果表明,水样中的主要物质是DBP和DEHP,其原水中最高浓度分别为0.91μg/L,0.47μg/L,管网水中的浓度为0.57μg/L,0.44μg/L;邻苯二甲酸丁苄酯(BBP)检出率为20%,其最高浓度出现在4月前氯采样点,为0.03μg/L;邻苯二甲酸二乙酯(DEP)仅在4月检出,最高浓度出现在4月前氯采样点,为0.11μg/L;邻苯二甲酸二甲酯(DMP)低于检出限。由于传统工艺并不能将PAE去除,所以其出厂水浓度与进水浓度相似,甚至略高。将管网水的浓度与《生活饮用水卫生规范》比较,发现该水样中PAE的浓度符合规范要求,但与最终目标值仍有差距。     

家用间歇慢滤池去除饮用水中DEHP的效能

探究了家用间歇慢滤池运行过程中停留时间、滤层高度、进水浓度、暂停时间等因素对于去除饮用水中的邻苯二甲酸二(2-乙基己基)酯(DEHP)效能的影响,并优化工艺条件。实验结果表明,暂停时间对于DEHP的去除效果无明显影响,当DEHP进水浓度为80μg/L左右时,在三种暂停时间(6.3h、10.3h、22.3h)工况下,平均出水浓度为3.2~5.4μg/L,平均去除率在93.4%~95.6%之间,但暂停时间过短会影响过滤周期。DEHP的去除率不随停留时间有明显变化,运行15min后水质即能达标,15min后去除率均在86%以上。滤层高度的增加可以提高DEHP的去除率,75%以上的DEHP在20cm高度的滤料中被去除,总填料高度为60cm以上时水质可以达标。DEHP出水浓度没有随进水浓度的增加有明显变化,进水浓度从40μg/L上升到120μg/L过程中平均去除率从87.3%升至94.4%。DEHP的去除率与温度有关。实验表明,家用新型慢滤池通过物理截留过滤和生物降解共同作用达到了DEHP良好的去除效果。     

污水再生利用过程中邻苯二甲酸酯的分布特征

邻苯二甲酸酯(PAEs)是一类重要的环境激素化合物,污水再生过程中难于全部去除PAEs。当含PAEs的再生水用于河道补给时,对于PAEs将发生哪些变化、沉积物对PAEs影响如何等问题的研究较少。因此,选择北京市2座主体工艺为MBR的典型污水再生处理厂,分析其进、出水中6种PAEs组分含量的变化,探讨处理工艺对PAEs去除的机理,研究河道沉积物对PAEs的迁移阻滞作用以及受水前后地下水中PAEs含量变化。结果表明:污水再生处理厂进、出水中检出DMP、DEP、DnOP和DEHP,但DnBP和BBP均低于检出限,进、出水中所检出的组分中DEHP浓度均为最大,分别达到1-10μg/L和0-1μg/L。由于再生水补给河道中的沉积物粒径小、有机质含量在1.0%以上,具有较强的吸附能力,解吸试验显示,沉积物吸附组分包括DMP、DnBP和DEHP,并以DEHP的吸附量最大,达到5.04 mg/kg,其他组分的吸附量在0.01 mg/kg数量级。离河道约100 m的地下水水质检测结果显示,地下水水质已受到再生水中PAEs的影响,检出组分包括DMP和DEHP,浓度分别为42.7 ng/L和1 450 ng/L。     

某市饮用水生物稳定性研究

以西南某城市第L水厂出水和管网水为研究对象 ,研究了常规水处理工艺对AOC的去除特性以及AOC在管网中的变化规律 ,明确了该市管网水质生物稳定性情况。研究结果表明 :该市管网水中AOC冬、春季在 89～ 16 3μg/L ,属于饮用水生物稳定性的临界区间 ;夏、秋季在 16 2～ 2 75μg/L ,属于略不稳定的饮用水 ,但问题并不严重。从出厂到管网末梢 ,沿程各点AOC变化不大。因此 ,可以用出厂水中AOC的浓度作为整个管网生物稳定性的评价指标。常规处理工艺对AOC的去除效果在 4 0 7%～ 75 4 %之间。水厂出水加氯消毒后 ,AOC浓度均有增加 ,因此即使处理工艺对AOC有较好的去除效果 ,仍然不能保证出水生物稳定性。     

自来水厂反冲洗废水生物稳定性及回用研究

自来水厂中砂滤及活性炭工艺的反冲洗废水量大,具有循环利用的价值。然而,反冲洗废水中浊度、氨氮、COD_(Mn)、DOC、可生物降解溶解性有机碳(BDOC)、可同化有机碳(AOC)等对水质安全造成隐患。以南方某水厂(采用常规处理-臭氧-生物活性炭深度处理工艺)的砂滤池与炭池反冲洗废水为研究对象,通过探讨反冲洗废水水质的化学与生物特性,评价其回用价值。结果表明,回用水浊度明显高于原水,氨氮、COD_(Mn)、DOC含量无明显变化,BDOC浓度(砂滤池平均值0.638mg/L,炭池平均值0.447mg/L)高于原水中浓度(平均值0.331 mg/L);AOC浓度(砂滤池93.18μg/L,炭池97.78μg/L)低于原水中浓度(平均值106.36μg/L)。水温与回用水的生物稳定性具有较好的相关特性。研究建议可充分回收利用反冲洗废水,减少水厂的自用水量,为水厂水资源的可持续利用提供理论与技术支撑。     

常规处理工艺对可同化有机碳去除特性的研究

对镇江市金西水厂常规处理工艺去除饮用水中可同化有机碳的特性进行了研究。试验结果表明原水与出厂水中AOC浓度波动较大,分别为41~178μg/L和47~198μg/L,均属于饮用水生物稳定性临界区间;因氯氧化、混凝沉淀和砂滤等共同作用,常规处理工艺对总AOC、AOC-P17、AOC-NOX的去除率分别为-13%、17.1%与-83.3%,且受水温影响明显;常规处理工艺改变了水中AOC的组成比例,出厂水中AOC-NOX所占比例由30%升至49%。     

净水工艺模式与净化效果探讨

上海某自来水公司下属3家水厂供水区域广泛,供水总规模达217万m3/d。主要介绍A、B、C 3家水厂分别采用常规处理工艺、深度处理工艺以及深度处理并联膜处理工艺的净水效果。数据分析发现3家水厂处理工艺各有特色,其中A水厂去除浊度效果最佳,达到99.4%以上;C水厂的耗氧量去除效果最好,在59%以上;而B水厂的浊度与耗氧量去除效果是3家水厂中最为稳定的。     

锰砂/石英砂滤池与纳滤膜组合工艺去除水中砷的研究

采用锰砂/石英砂滤池与纳滤膜组合工艺处理含砷水,考察锰砂/石英砂、纳滤膜(NF90、HL)、锰砂/石英砂滤池与纳滤膜组合工艺对水中砷的去除效果.结果表明,三价砷(As(Ⅲ))和五价砷(As(Ⅴ))经锰砂/石英砂过滤后能得到很好的去除,原水砷浓度250 μg/L,出水砷浓度小于50μg/L;纳滤膜对五价砷(As(Ⅴ))的去除能力很高,能达到90%以上,但是对三价砷(As(Ⅲ))的去除率不理想,为40%～60%;锰砂/石英砂复合滤池与纳滤膜组合工艺对水中砷有很好的去除效果,出水砷浓度均小于10μg/L,是理想的饮用水除砷方法.     

O_3-BAC深度处理工艺对有机物及三氯乙醛生成潜能的去除

以我国南方某O_3-BAC深度处理工艺水厂为研究对象,对工艺过程中有机物及三氯乙醛生成潜能(CHFP)进行每月一次为期1年的监测,同时对温度较高的夏季水样予以极性分离,以明晰O_3-BAC深度处理工艺对有机物及CHFP的去除能力与工艺过程中有机物的极性变化等。结果表明,O_3-BAC深度处理工艺原水TOC、UV_(254)、CHFP均呈现一定的季节性变化趋势,高温季节(4~9月)相对较高,范围分别为1.03~2.13mg/L、0.024 1~0.053 5cm~(-1)、17.49~41.40μg/L;O_3-BAC深度处理工艺对TOC、UV_(254)、CHFP去除率范围分别为31.54%~58.83%、46.59%~79.53%、46.20%~75.24%,混凝沉淀和BAC单元在去除有机物和CHFP中起主要作用。此外,臭氧化作用增加了亲水性有机物含量使CHFP升高,同时亦强化了BAC单元对CHFP的去除作用。     

粉末活性炭去除饮用水中2-MIB应用研究

随着我国《生活饮用水卫生标准》(GB 5749-2022)的实施,城市供水水质进一步提高的同时给部分仅使用常规处理工艺水厂的带来了挑战。为确保2-甲基异莰醇(2-MIB)稳定达标,常规处理工艺自来水厂将使用投加粉末活性炭的方法达到去除的目的。通过系统性研究实际生产中粉末活性炭的投加量、吸附时间、投加点对2-MIB去除的影响,结合出厂水水质、运行管理效率和经济性评价,确定应用粉末活性炭去除饮用水中2-MIB是可行的技术。结果表明,当原水2-MIB浓度为(61.2±3.70) ng/L时,在0～330 min吸附时间内,随着吸附时间延长,投加5～40 mg/L的粉末活性炭2-MIB的去除率增加;当吸附时间为300 min时,投加40 mg/L的粉末活性炭能将2-MIB浓度为(61.05±2.24) ng/L的原水降至低于10 ng/L;多级投加粉末活性炭对2-MIB去除效果明显优于原水单级投加,原水2-MIB浓度为(63.85±22.13) ng/L时,多级投加50 mg/L粉末活性炭2-MIB去除率(85.1±2.63)%。投加30 mg/L的粉末活性炭能将原水中高锰酸盐指数平均去除率从...     

常规水处理工艺多环芳烃和邻苯二甲酸酯变化分布

以多环芳烃(PAHs)(包括萘、蒽、荧蒽三种物质)和邻苯二甲酸酯(PAEs)(包括邻苯二甲酸二甲酯(DMP)、邻苯二甲酸二乙酯(DEP)、邻苯二甲酸二异丁酯(DIBP)、邻苯二甲酸二(2-乙基己基)酯(DEHP)4种物质)作为研究对象,采用GC-MS方法测定了以长江为原水的某大型城市给水厂各工艺段水样中的上述物质.结果表明,7种物质均有检出,但含量均在纳克级,两种常规的水处理工艺对PAHs的控制有一定的效果,对PAEs的控制作用则相当有限.滤后水经加氯消毒、二次加压等工序后,水中的PAHs和PAEs略有增加.     

紫外光照射处理水中邻苯二甲酸二异辛酯的研究

对水体中邻苯二甲酸二异辛酯(DEHP)在紫外光照射下降解情况进行了分析。结果表明, DEHP遵循一级动力学方程进行紫外光解。其紫外光解半衰期在9．63-15．23 min。在不同pH溶液中DEHP紫外光解都生成了邻苯二甲酸单异辛酯和邻苯二甲酸,推测反应机制为:紫外光激发诱导DEHP酯基团断裂,并与H+或OH-进行结合反应。溶液酸、碱性越强,越利于DEHP的水解电离,从而促进此物质紫外光解。此结论可为紫外光照射处理DEHP污染水体提供一定的参考依据。     

杭嘉湖地区饮用水源半挥发性有机物污染现状

采用固相萃取-GC-MS法对杭嘉湖地区16个集中式饮用水源水体中的氯代苯、多环芳烃、硝基苯、多氯联苯、邻苯二甲酸酯等43种半挥发性有机物（SVOCs）进行了分析检测。结果表明,16个集中式饮用水源水共检出10余种有机污染物,浓度范围为0.01~4.26μg/L,检出率为5%~100%;邻苯二甲酸二甲酯、邻苯二甲酸二乙酯、邻苯二甲酸二丁酯、邻苯二甲酸双（2-二乙基己酯）、2,6-二硝基甲苯等化合物的检出率为超过50%;在平水期、丰水期、枯水期,被检出的有机污染物种类分别为12,9,14种,被检出污染物的浓度范围分别为0.05~4.26,0.01~0.20,0.01~1.00μg/L。     

Phthalate Esters in Sediments Near a Sewage Treatment Plant Outflow in Hamilton Harbour,Ontario: SFE Extraction and Environmental Distribution

Esters of phthalic acid are ubiquitous environmental contaminants as a result of their use as plasticizers and as constituents in many other commercial products. Although the acute toxicity of phthalates is low, recent concerns over their potential to disrupt the gonadal development of vertebrates has prompted interest in determining the distribution of these compounds in the environment. However, trace analysis of phthalates in environmental samples has been hampered by their presence as ubiquitous laboratory contaminants. In this study, the problem of high background contamination was addressed by developing an analytical method using supercritical fluid extraction (SFE), which was used to extract phthalates from sediment samples collected near the outflow of a sewage treatment plant (STP) in Hamilton Harbour at the western end of Lake Ontario. GC-MS-SIM analysis of sediment samples indicated that di(2-ethylhexyl) phthalate (DEHP)was present at very high concentrations; ranging from a mean of 29.7 μg/g dry weight at a site near the STP outflow to a mean of 6.5 μg/g dry weight at a site 300 m away. Di-n-butyl phthalate (DBP), and benzylbutyl phthalate (BBP) were judged to be present in some sediment samples but at concentrations below the Method Detection Limits (< 0.3 μg/g). Di-isononyl phthalate (DINP) and diethyl phthalate (DEP) were not detected in any of the sediment samples. This study indicates that SFE can be an efficient extraction method for phthalates in sediments, which avoids the extensive use of glassware and organic solvents that may contaminate environmental samples. In addition, STP effluents are sources of phthalates in the aquatic environment; in particular, DEHP.     

Simulation of DEHP biodegradation and sorption during the anaerobic digestion of secondary sludge.

Di-ethylhexyl phthalate (DEHP) has commonly been found in the sludge of municipal wastewater treatment plants especially during anaerobic processing. It is slowly biodegradable under anaerobic conditions. Due to its high hydrophobicity, sorption-desorption processes can be rate-limiting for the compound biodegradation. In this study, the anaerobic biodegradation of DEHP was investigated through batch kinetic experiments and dynamic transitions of a continuous stirred tank reactor (CSTR) fed with secondary sludge contaminated with DEHP. A widely accepted model (ADM1) was used to fit the anaerobic digestion of secondary sludge and was properly extended to account for DEHP removal, in which mass transfer processes are also involved. It was shown that DEHP removal was limited by the transfer of DEHP within the solid fraction. The criterion selected for the distinction of the two sites was whether the compound sorbed in those sites was bioavailable for biodegradation or not. Thus, the aqueous phase and the surface of the biosolids were considered as suitable sites for the compound to be bioavailable and the main bulk of the solid matrix was regarded as sites, where the compound remains "protected" against biodegradation. The model, fitted to the batch experimental data, was able to predict DEHP removal in the CSTR operated at various HRTs.     

Mobility of 4-nonylphenol and di(2-ethylhexyl) phthalate in three agricultural soils irrigated with untreated wastewater

Agricultural irrigation using raw wastewater is a popular practice in developing countries. However, as endocrine disrupting chemicals have been found in this water, the potential pollution of soil and water sources has become a source of concern. Such pollutants may be removed during the passage of wastewater through the soil by degradation and/or sorption. In this study the sorption and mobility of bis-2-ethyl(hexyl)phthalate (DEHP) and 4-nonylphenol (4-NP) in three different soils (Leptosol, Phaeozem and Vertisol) was compared. The distribution coefficients showed that DEHP is rapidly sorbed onto the three tested soils (K(d) between 1.8 × 10(4) and 4.2 × 0(4) L/kg), while sorption of 4-NP (K(d) between 15 and 80 L/kg) was weaker. In batch experiments the soil sorption capacity observed was as follows: Vertisol > Phaeozem > Leptosol for both compounds. However, in column experiments the retardation factor (R(F)) for 4-NP was higher than for the DEHP in the three soils. This suggests the possible migration of DEHP through the soil via colloids. The column results were found consistent with those observed in the field. It was concluded that the risk of groundwater contamination is higher for Leptosol soil than for Phaeozem and Vertisol soils and that DEHP can reach the aquifer prior to 4-NP.     

城市再生水利用风险评价指标体系初探

水的再生利用是破解我国水资源短缺问题的重要途径之一,但是再生水利用对人体健康和环境的影响也是生活污水处理必须面对的挑战,从而受到人们普遍关注。根据我国再生水回用途径和天津市纪庄子再生水厂的出水水质情况,构建了再生水利用风险评价指标体系(包括健康风险指标和生态环境风险指标),并对纪庄子再生水厂的出水与景观用水和地表水分别进行了风险评价,得出再生水用在不同用途时存在的不同环境风险。     

Photocatalytic degradation of di(2-ethylhexyl)phthalate adsorbed by chitin A.

Di(2-ethylhexyl)phthalate (DEHP) is a ubiquitous environmental contaminant due to its extensive use as a plasticiser and its persistence. Currently, there is no cost-effective treatment method for its removal from industrial wastewater. In a previous study, DEHP was effectively adsorbed from aqueous solution by biosorption onto chitinous materials. Biosorption can pre-concentrate DEHP from the aqueous phase for further treatment. As biosorption cannot degrade DEHP, in this study the degradation (and detoxification) of DEHP adsorbed onto chitinous material by photocatalytic oxidation (PCO) is attempted. PCO relies on hydroxyl radical (.OH), which is a strong oxidising agent, for the oxidative degradation of pollutants. It is a non-selective process which can degrade DEHP adsorbed onto chitinous material. The first part of this study is the optimisation of the degradation of adsorbed DEHP by PCO. Adsorption was carried out in the physicochemical conditions optimised in the previous study, with 500 mg/L chitin A and 40 mg/L DEHP at initial pH 2, 22+/-2 degrees C and 150 rpm agitation for 5 min. After optimisation of PCO, a 61% removal efficiency of 10 mg/L of DEHP was achieved within 45 min under 0.65 mW/cm2 of UV-A with 100 mg/L TiO2, and 10 mM of H2O2 at initial pH 12. The optimisation study showed that UV-A and TiO(2) are essential for the degradation of DEHP by PCO. The degradation intermediates/products were identified by GC-MS analysis. GC-MS results showed that the di(2-ethylhexyl) side chain was first degraded, producing phthalates with shorter side chains. Further reaction produced phathalic anhydride and aliphatic compounds such as alkanol and ester. The toxicities of parental and degradation intermediates in the solution phase and on chitinous materials were followed by the Microtox test. Results indicated that toxicity can be removed after 4 h treatment by PCO. Thus the decontamination of DEHP by integrating biosorption and PCO is feasible.     

热电厂中水回用深度处理技术与国内应用进展

综述了我国中水深度处理工艺的发展历程、相关工艺在国内电厂的主要研究与应用情况及其主要问题与控制策略。石灰混凝法是热电厂中水回用的第二代处理工艺,应用广泛;双膜法及全膜法具有更高的污染物去除效率,已成为目前热电厂中水回用的主流深度处理工艺。膜污染是膜法深度处理工艺的限制因素,膜污染形成机制与控制策略研究成为中水回用领域的研究热点和难点。随着水处理技术及设备的发展,一些新型的材料、技术和设备也逐渐推广应用于热电厂的中水深度处理;未来城市中水将成为热电厂的第一水源,膜法将成为中水深度处理与回用的最关键工艺,其预处理和深度处理工艺将实现多样化与高效化的发展。     

Plasticizers and related toxic degradation products in wastewater sludges.

Plasticizers can persist during the treatment of wastewaters in sewage treatment plants (STPs) and can be discharged in effluents and/or accumulated in sewage sludges. For example, di-2-ethylhexyl phthalate (DEHP) is a common plasticizer that is now considered a priority pollutant and is known to accumulate in sludges. This may add constraints to the exploitation of the beneficial uses of sludges that contain significant quantities of plasticizers. Recently, it was demonstrated in studies with pure cultures that the biodegradation of plasticizers including DEHP and di-ethylhexyl adipate (DEHA) generates toxic metabolites including 2-ethylhexanoic acid, 2-ethylhexanol, and 2-ethylhexanal. However, the environmental impacts and fate of the degradation products arising from plasticizers are unknown. Therefore, this work investigated the concentrations of DEHP and DEHA and their metabolites in the sludges from several STPs in Quebec, Canada. DEHP and DEHA were found in concentrations ranging from 15 to 346 mg kg(-1) and 4 to 743 mg kg(-1), respectively, in primary, secondary, digested, dewatered or dried sludges. Metabolites were detected in almost all sludges, except those that had undergone a drying process at high temperature. It is concluded that sludges can represent significant sources of plasticizers and their toxic metabolites in the environment.