浅基质层干植草沟对道路径流中PAHs的去除效果

上海市道路径流中的多环芳烃(PAHs)平均浓度达到3 996ng/L,与其他国家相比污染较严重。以前期已稳定运行1年的浅基质层干植草沟中试系统为处理设施进行现场试验,研究设施对道路径流中美国EPA提出的16种优先控制PAHs的控制效果及去除机制。结果表明,监测期内设施出水PAHs浓度显著低于进水浓度(p0.05),∑16PAHs和具有致癌性或可疑致癌性的∑6PAHs的出水浓度范围分别为172.40～365.05 ng/L和9.70～99.97 ng/L。前置沉淀池对PAHs的去除效果不佳。干植草沟设施对高分子质量PAHs的去除率与TSS呈显著正相关,主要伴随基质对TSS的过滤、拦截而被去除;低分子质量PAHs主要依靠吸附作用被去除,水力负荷的升高影响其去除效果。干植草沟设施对苯并[a]芘的去除率达到98.00%,出水浓度低于《污水综合排放标准》(GB 8978—1996)规定的限值(30 ng/L),达标率为100%,干植草沟即使基质层较浅也可有效控制路面径流对受纳水体的PAHs污染。     

我国主要流域饮用水中PAHs浓度分布及风险评价

研究了我国5个主要流域即黄河、长江、辽河、珠江和海河流域的城市自来水厂原水和出水中多环芳烃(PAHs)的分布特征和健康风险。结果表明,原水和出水中的PAHs总浓度分别为(41.19~429.97)、(17.51~408.32)ng/L,PAHs总浓度呈现北方高于南方的趋势。与我国主要流域地表水中PAHs污染情况相比,自来水厂原水中的PAHs浓度较低,且出水中PAHs总浓度并未超过《生活饮用水卫生标准》(GB 5749—2006)的限值。自来水厂出水中PAHs的致癌风险为10-6a-1、非致癌风险为10-4a-1,处于可接受水平。分析发现,我国水厂出水中的PAHs总浓度与健康风险相关性较差,因此我国现行饮用水标准中的PAHs总浓度指标难以反映其健康风险。     

SPE/LC/MS/MS检测水中痕量二甲基亚硝胺

二甲基亚硝胺(NDMA)是水处理领域新近发现的一种氯化消毒副产物,确定了采用LC/MS/MS方法分析NDMA的色谱条件和饮用水中痕量NDMA的固相萃取浓缩方法.试验表明,采用ESI源的LC/MS/MS检测方法可有效检出小分子NDMA,通过优化梯度洗脱可获得良好的分离效果,仪器最低检测浓度可达到1μg/L;使用粉末活性炭作为固相萃取小柱吸附剂,在浓缩500倍的条件下,NDMA回收率可达81%～108%,方法检出限为2 ng/L.该方法检测浓度水平低、精度高、操作简单,完全可满足水中痕量NDMA的分析要求.应用该方法测得管网末端自来水样的NDMA浓度为78.93 ng/L,其浓度远高于发达国家报道的数值.     

大气细颗粒物(PM_(2.5))中多环芳烃的检测方法研究

目的建立一种便捷、高效的方法来检测大气细颗粒物(PM_(2.5))中的16种多环芳烃(PAHs)。方法乙腈—超声水浴萃取样品中的PAHs,经过ENV固相萃取柱净化,多环芳烃专用色谱柱分离,再用液相色谱—荧光—紫外检测器串联进行检测。结果 16种PAHs在线性范围内有良好的线性关系,相关系数均≥0.999 9,检出限范围为(0.04～0.26) ng/m~3,平均回收率为85%～114.1%,相对标准偏差均小于8.0%。结论本方法提取过程简单、灵敏度高、精密度高,适用于PM_(2.5)中PAHs的污染分析。     

太原市冬季PM_(2.5)中多环芳烃、硝基多环芳烃、SO_4~(2-)和NO_3~-的污染特征

以太原市2013年冬季大气细颗粒物(PM2.5)为研究对象,定性与定量分析了其中多环芳烃(PAHs)、硝基多环芳烃(NPAHs)、硫酸盐(SO2-4)和硝酸盐(NO-3)的浓度及其昼夜变化。采用特征比值法分析了PAHs、SO2-4和NO-3的来源,并通过PEFs毒性评价法评价了PM2.5中PAHs的BaP等效毒性,估算出个体致癌指数。结果显示,太原市PM2.5中16种PAHs总含量、3种NPAHs总含量及SO2-4和NO-3含量分别在102~153 ng/m3、0.41~0.48 ng/m3、4.89~5.87μg/m3和1.69~1.71μg/m3范围内,且其夜间浓度均高于白天。PAHs的BaP等效毒性和个体致癌指数超过标准值。结果提示,太原市PM2.5中PAHs、NPAHs、SO2-4和NO-3污染主要是由于燃料燃烧和固定源引起的,且颗粒物上的PAHs浓度高,对人体健康有潜在的风险。     

城市污水中典型多环麝香的分布

以两种典型的多环麝香--佳乐麝香(HHCB)和吐纳麝香(AHTN)为目标物,对其在北京市3个污水处理厂工艺流程中的分布、迁移进行了研究.结果表明,HHCB和AHTN在进水中的浓度分别为(1 251.4～3 003.8)和(111.9～435.4)ng/L,在出水中的浓度分别为(457.2～729.9)和(35.5～190.9)ng/L,平均去除率分别为62.2%和53.1%.污泥中HHCB和AHTN的含量分别为(2.5～17.0)和(0.7～13.9)μg/g.生物处理阶段是目标物从污水中去除的主要阶段,其去除机理主要是污泥的吸附作用.因此,应关注污水处理厂麝香排放可能带来的水环境风险,尤其是对剩余污泥中该类物质的有效削减应引起足够的重视.     

污水中8种雌激素化合物的定量测定

采用固相萃取-气相色谱-质谱法(GC-MS)测定污水中辛酚(OP)、壬酚(NP)、双酚A(BPA)、己烯雌酚(DES)、雌酮(E1)、17β-雌二醇(E2)、17α-乙炔雌二醇(EE2)和雌三醇(E3)8种具有雌激素活性的化合物。被测组分的加标回收率为(65.4±4.0)%～(110.0±4.5)%,检出限为1.0～7.5ng/L(相对标准偏差为5.2%～15.6%)。经检测,武汉某城市污水处理厂进水中的目标化合物(除EE2外)浓度为6.5～8954.9ng/L;除EE2和E3外,出水中的浓度为3.2～2473.5ng/L,表明现有的污水处理工艺还有待进一步改进。     

固相萃取液相色谱法测定水中6种多环芳烃

建立了通过固相萃取前处理进行富集、高效液相色谱法测定水中痕量6种多环芳烃的方法,色谱条件为流动相乙腈和水的梯度洗脱、荧光检测器检测。选用玻璃纤维膜对水样进行过滤处理,过滤后用异丙醇洗涤滤膜,避免目标物被截留。固相萃取步骤中待上样完成后用50%异丙醇进行润洗,提高了回收率。方法的标准曲线线性良好,相关系数均可达到0. 999以上,各项最低检测浓度为1～6 ng/L,加标回收率为80. 4%～117. 9%,RSD均小于15%,适用于测定水体中的痕量PAHs。     

黄浦江源水中藻类和微囊藻毒素状况调查

对黄浦江源水中的藻类和微囊藻毒素-LR和-RR的含量进行了检测,结果表明:黄浦江源水中的微囊藻毒素浓度和藻类数目相对较低,藻类数目为(30~700)×104个/L,总MC-LR浓度为100~250 ng/L,总MC-RR浓度为450~650 ng/L;黄浦江源水中的MC-RR浓度比MC-LR浓度高两倍左右,总MC-RR浓度最高为650 ng/L,总MC-LR浓度最高为250 ng/L;受黄浦江水力和环境条件的影响,藻类在河道内大量死亡、裂解导致黄浦江源水中溶解性微囊藻毒素与总微囊藻毒素浓度的比值比一般源水的高很多。     

超高效液相色谱-串联质谱法测定再生水中5种雌激素

建立了同时测定再生水中双酚A、17β-雌二醇、炔雌醇、雌酮和4-壬基酚含量的超高效液相色谱-串联质谱法。5种雌激素在0.2~250μg/L浓度范围内线性关系良好,回归方程相关系数均大于0.997 6,检出限(S/N=3)和定量限(S/N=10)范围分别为0.09~0.28 ng/L和0.30~0.87 ng/L。在添加水平分别为1、10、100 ng/L时,低浓度(1 ng/L)平均回收率为78%~109%,RSD为5.5%~20%;中浓度(10 ng/L)平均回收率为75%~115.3%,RSD为6.7%~15%;高浓度(100 ng/L)平均回收率为89.2%~107.3%,RSD为3.3%~15.5%。该方法操作简单高效、灵敏度高,适用于再生水中5种雌激素的定量分析。     

Absorbability of estrone and 17beta-estradiol in water onto activated carbon

With a view to reducing pollution in the aquatic environment, estrone (E1) and 17beta-estradiol (E2) were tested for their absorbability in water onto activated carbons (ACs) with various pore-size distributions. In batch-type adsorption measurements, all adsorption isotherms obtained were found to fit a Freundlich equation. In case of eight different kinds of commercial AC in pure water, the amount adsorbed at equilibrium concentration of 1 microg/L was in the range of 25.6-73.5mg/g for E1 and 21.3-67.6 mg/g for E2. In case of pre-used ACs in water sand-filtered for use as drinking water, the amount adsorbed at 1 microg/L was in the range of 3.5-8.2mg/g for E2. In the case of two commercial ACs in river water and in effluent from secondary clarifier at municipal sewage treatment plant (MSTP), both originally containing E2, was in the range of 0.1-0.2 and 0.3-1 microg/g, respectively, at 1 ng/L. The difference of amount adsorbed onto AC was discussed in view of hydrophobicity of target chemicals, specific surface area and mean pore diameter of AC, and the difference in the absorbability and the ratios of co-present substances for the target compound.     

Distribution of polycyclic aromatic hydrocarbons in snow of Mount Nanshan,Xinjiang

Polycyclic aromatic hydrocarbon (PAH) in snow samples collected from Mount Nanshan (Xinjiang, China) was investigated for eight stations. Fourteen PAHs were detected in these samples. The total PAH concentration ranged from 70.15 ng/L to 155.67 ng/L, with an average of 113.02 ng/L. Human carcinogens, such as fluoranthene, chrysene, benzo(a)pyrene, dibenzo(a,h)anthracene, indeno(1,2,3‐cd)pyrene and benzo(ghi)perylene in snow were assessed based on risk quotient. Preliminary assessment showed that these PAHs posed a moderate risk. Component analysis showed that the PAHs found in the snow samples were mainly three‐ring PAHs, which comprised 34.51–90.81% of the total PAHs. Phenanthrene, fluorene and anthracene accounted for 35.08, 11.90 and 11.13% of the total PAHs, respectively. The ΣPAH content increased with the increasing altitude, and the highest concentration of 155.67 ng/L was observed in snow samples from the N7 station, which was located near the top of the mountain. This high PAH concentration in N7 was possibly due to more frequent human activities in the area and long‐distance transportation of PAHs. Isomer ratios were used to determine the possible sources of PAHs in the samples. The results indicate that coal and biomass combustion made a larger contribution than emissions from petroleum consumption. It is therefore of utmost importance to develop new fuels taking the place of coal and to achieve as complete as possible for the burning of carbon‐containing materials.     

Occurrence of nine nitrosamines and secondary amines in source water and drinking water: Potential of secondary amines as nitrosamine precursors

Due to their high carcinogenicity, the control of nitrosamines, a group of disinfection by-products (DBPs), is an important issue for drinking water supplies. In this study, a method using ultra-performance liquid chromatography-electrospray ionization tandem mass spectrometry was improved for simultaneously analyzing nine nitrosamines in source water and finished water samples of twelve drinking water treatment plants (DWTPs) in China. The method detection limits of the nine target analytes were 0.2-0.9 ng/L for the source water samples and 0.1-0.7 ng/L for the finished water samples. Of the nine nitrosamines, six (N-nitrosodimethylamine (NDMA), nitrosodiethylamine (NDEA), N-nitrosomorpholine (NMor), N-nitrosodi-n-butylamine (NDBA), N-nitrosomethylethylamine (NMEA), and N-nitrosodiphenylamine (NDPhA)) were detected. The total nitrosamine concentrations in source water and finished water samples were no detection-42.4 ng/L and no detection-26.3 ng/L, respectively, and NDMA (no detection-13.9 ng/L and no detection-20.5 ng/L, respectively) and NDEA (no detection-16.3 ng/L and no detection-14.0 ng/L, respectively) were the most abundant. Meanwhile, the occurrence of nine secondary amines corresponding to the nine nitrosamines was also investigated. All of them except for di-n-propylamine were detected in some source water and finished water samples, and dimethylamine (no detection-3.9 μg/L and no detection-4.0 μg/L, respectively) and diethylamine (no detection-2.4 μg/L and no detection-1.8 μg/L, respectively) were the most abundant ones. Controlled experiments involving chloramination of four secondary amines confirmed that dimethylamine, diethylamine, morpholine and di-n-butylamine in water can form the corresponding nitrosamines, with diethylamine and morpholine showing significantly higher yields than dimethylamine which has already been identified as a precursor of NDMA. This study proved that diethylamine, morpholine and di-n-butylamine detected in raw water would be one of the important the precursors of NDEA, NMOR and NDBA, respectively, in drinking water.     

Characterization and distribution of polycyclic aromatic hydrocarbon contaminations in surface sediment and water from Gao-ping River, Taiwan

The concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) in water and sediment samples collected from 12 locations in Gao-ping River, Taiwan were analyzed. Molecular ratios and principal component analysis (PCA) were used to characterize the possible pollution sources. Concentrations of total 16 PAHs (SigmaPAHs) in water samples ranged from below method detection limits (相似文献   

Chemical and ecotoxicological assessment of polycyclic aromatic hydrocarbon--contaminated sediments of the Niger Delta, Southern Nigeria

The extent of environmental contamination and sources of polycyclic aromatic hydrocarbons (PAHs) compounds to sediments of the Niger Delta, Nigeria were assessed using combined chemical analysis and toxicity bioassay techniques. Concentrations of two- to six-ring PAHs of molecular mass 128-278 and toxicity to Vibrio fischeri and Lemna minor are considered in this investigation. Levels of the sum of the 16 USEPA priority pollutant PAHs varied from 20.7 to 72.1 ng/g dry weight. Sediment PAH levels were highest in samples collected from Delta Steel located at the outskirts of Warri, and Quality control centre, Ughelli West; with total PAH concentrations of 72.1 and 67.5 ng/g dry weight, respectively. The overall levels of PAHs in this study are low compared to other regions and reveal moderate PAHs pollution in the sediments of the Niger Delta. Two- and three-ring aromatic hydrocarbons predominated in almost all the sediments, which indicate a petrogenic origin. The sediment total PAH (PAHtot) concentration, normalized to organic carbon content (OC), ranged from 120.2 to 1.99 ng PAHtot/mg OC; and showed distinctively that the sedimentary organic matter of the sample from Delta Steel is highly contaminated with PAHs, and had a value of 120.2 ng PAHtot/mg OC. The toxicity bioassays indicated that the sample collected from Warri Refinery Area (SDWRR) was the most toxic to V. fischeri, with an EC50 value of 0.45 mg sediment equiv./mL test medium; and samples from Ogunu (SDOGN) and Warri Refinery area (SDWRR) showed high toxicity to L. minor, with percent inhibitions of 42.6% and 33.67%, respectively, after 7 days of exposure. The total PAH concentrations showed no correlation with toxicity bioassays, and thereby implied that chemical analysis of PAHs cannot be an indicator of sediment toxicity.     

New chlorinated amphetamine-type-stimulants disinfection-by-products formed during drinking water treatment

Previous studies have demonstrated high removal rates of amphetamine-type-stimulants (ATSs) through conventional drinking water treatments; however the behaviour of these compounds through disinfection steps and their transformation into disinfection-by-products (DBPs) is still unknown. In this work, for the first time, the reactivity of some ATSs such as amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxymethamphetamine (MDMA) and 3,4-methylenedioxyethylamphetamine (MDEA) with chlorine has been investigated under simulated and real drinking water treatment conditions in order to evaluate their ability to give rise to transformation products. Two new DBPs from these illicit drugs have been found. A common chlorinated-by-product (3-chlorobenzo)-1,3-dioxole, was identified for both MDA and MDEA while for MDMA, 3-chlorocatechol was found. The presence of these DBPs in water samples collected through drinking water treatment was studied in order to evaluate their formation under real conditions. Both compounds were generated through treatment from raw river water samples containing ATSs at concentration levels ranging from 1 to 15 ng/L for MDA and from 2.3 to 78 ng/L for MDMA. One of them, (3-chlorobenzo)-1,3-dioxole, found after the first chlorination step, was eliminated after ozone and GAC treatment while the MDMA DBP mainly generated after the postchlorination step, showed to be recalcitrant and it was found in final treated waters at concentrations ranging from 0.5 to 5.8 ng/L.     

Pharmaceuticals and personal care products (PPCPs) in surface and treated waters of Louisiana,USA and Ontario,Canada

A newly developed analytical method was used to measure concentrations of nine pharmaceuticals and personal care products (PPCPs) in samples from two surface water bodies, a sewage treatment plant effluent and various stages of a drinking water treatment plant in Louisiana, USA, and from one surface water body, a drinking water treatment plant and a pilot plant in Ontario, Canada. The analytical method provides for simultaneous extraction and quantification of the following broad range of PPCPs and endocrine-disrupting chemicals: naproxen; ibuprofen; estrone; 17beta-estradiol; bisphenol A; clorophene; triclosan; fluoxetine; and clofibric acid. Naproxen was detected in Louisiana sewage treatment plant effluent at 81-106 ng/l and Louisiana and Ontario surface waters at 22-107 ng/l. Triclosan was detected in Louisiana sewage treatment plant effluent at 10-21 ng/l. Of the three surface waters sampled, clofibric acid was detected in Detroit River water at 103 ng/l, but not in Mississippi River or Lake Pontchartrain waters. None of the other target analytes were detected above their method detection limits. Based on results at various stages of treatment, conventional drinking-water treatment processes (coagulation, flocculation and sedimentation) plus continuous addition of powdered activated carbon at a dosage of 2 mg/l did not remove naproxen from Mississippi River waters. However, chlorination, ozonation and dual media filtration processes reduced the concentration of naproxen below detection in Mississippi River and Detroit River waters and reduced clofibric acid in Detroit River waters. Results of this study demonstrate that existing water treatment technologies can effectively remove certain PPCPs. In addition, our study demonstrates the importance of obtaining data on removal mechanisms and byproducts associated with PPCPs and other endocrine-disrupting chemicals in drinking water and sewage treatment processes.     

Sources of pharmaceutical pollution in the New York City Watershed

An investigation was carried out in the New York City Watershed for the presence of selected pharmaceuticals. In four seasonal sampling events between August 2003 and May 2004, surface water was collected from eight reservoir keypoints and effluent was collected from four wastewater treatment plants. We evaluated the following twelve compounds: amoxicillin, atenolol, caffeine, carbamazepine, cephalexin, estrone, 17alpha-ethinylestradiol, 17beta-estradiol, ibuprofen, sulfamethoxazole, trimethoprim, and valproic acid. In the treated effluents, carbamazepine was detected most frequently (100%; concentration range: 22-551 ng/L), followed by atenolol (94%; ND - 14,200 ng/L), trimethoprim (83%; ND - 37,000 ng/L), ibuprofen (61%; ND - 14,600 ng/L), and caffeine (49%; ND - 37,200 ng/L), while estrone was detected once (56 ng/L). In the reservoir keypoint samples, only ibuprofen (2.5%; ND - 932 ng/L) and caffeine (2.9%; ND - 177 ng/L) were detected. The other analytes were not detected in any sample. It is expected that investigation of other wastewater treatment plants in the New York City Watershed would show that their effluents are also a potential source of pharmaceuticals, but that these pharmaceuticals are unlikely to be detected in the Watershed's surface waters.     

Stirring bar sorptive extraction in the determination of PAHs in drinking waters

The application of a new extraction technique which is known as stir bar sorptive extraction (SBSE), followed by high-performance liquid chromatography with a fluorescence detector, was assessed for determining eight polycyclic aromatic hydrocarbons (PAHs) in water samples. The extraction conditions such as acetonitrile addition; effects of temperature and salt; and finally, extraction and desorption time profiles were studied. Once SBSE was optimized, analytical method parameters such as linearity (r(2)>0.991), precision (<9%), detection (0.5-7.3 ng/L) and quantitation (1.0-22 ng/L) limits were estimated. To correct for the 43-57% absolute recovery depending on the PAH, calibration was done with a line obtained submitting standard-spiked blank tap waters to the complete sample treatment and analysis. Consequently, relative recovery was about 100% because all water samples (those for calibration purposes and those for recovery estimation) were processed in the same way and the absolute recovery remained constant. SBSE method characteristics were checked with the analysis of real drinking waters in the search for PAHs.     

A nationwide survey of NDMA in raw and drinking water in Japan

A nationwide survey of N-nitrosodimethylamine (NDMA) in both raw and finished water samples from drinking water treatment plants (DWTPs) in Japan was conducted. NDMA was analyzed by solid-phase extraction (SPE) followed by ultra performance liquid chromatography (UPLC) coupled with tandem mass spectrometry (MS/MS). NDMA was detected in 15 of 31 raw water samples collected in the summer at concentrations up to 2.6 ng/L, and in 9 of 28 raw water samples collected in winter at concentrations up to 4.3 ng/L. The NDMA concentrations were higher in raw water samples collected from treatment plants with catchment areas that have high population densities. The NDMA concentrations were higher in river water samples collected from the east and west of Japan than in those collected from other areas. NDMA was detected in 10 of 31 finished samples collected in summer at reduced concentrations of up to 2.2 ng/L, while 5 of 28 finished samples collected in winter showed NDMA concentrations up to 10 ng/L. The highest NDMA levels were detected in finished water samples collected from the Yodo River basin DWTP, which uses ozonation. Furthermore, evaluation of the process water produced at six advanced water treatment plants was conducted. Influent from the Yodo River indicated that the NDMA concentration increased during ozonation to as high as 20 ng/L, and then decreased with subsequent biological activated carbon treatment. To our knowledge, this is the first nationwide evaluation of NDMA concentrations in water conducted in Japan to date.