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1.
探讨了白腐菌射脉侧菌Phlebia radiateI-5-6对3种含氯量不同的二类物质———二苯并呋喃(DF)、2,7-二氯二苯并二(2,7-diCDD)和八氯二苯并呋喃(OCDF)的降解情况,并研究了不同培养条件对二降解的影响.在液体混合培养基中,在培养期内P.radiataI-5-6对3种二类物质的降解量分别为:DF>2,7-diCDD>OCDF;在培养的初始阶段,白腐菌对珠江江水/CEH漂白废水的加入需要一个适应期,然后开始降解这些污染物质.实验表明,在江水/CEH漂白废水处于一定浓度时,污染底物有更大的降解量;选择适当的培养基,可影响白腐菌对二类污染物的降解量.图3表3参17  相似文献   

2.
珠江河口沉积物中拟除虫菊酯类农药污染及毒性评价   总被引:2,自引:0,他引:2  
拟除虫菊酯农药是一种广谱、高效、低毒、低残留的亲脂性杀虫剂,它会随农田排水、降雨淋洗进入水体,最终进入沉积环境,故沉积物是其最终归宿之一。本研究针对珠江河口沉积物中菊酯类农药的污染状况进行调查,研究它们的含量、组成比例、污染来源及其潜在毒性,为珠江渔业水生生态环境管理及掌握环境中有机污染情况提供依据,对保护渔业环境安全有十分重要的意义。2012年5月采集珠江河口表层沉积物,采用气相色谱法-电子捕获法(GC-ECD)对表层沉积物中联苯菊酯、甲氰菊酯、高效氯氟氰菊酯、氯菊酯、氯氰菊酯、氰戊菊酯、溴氰菊酯进行残留检测,并利用其对钩虾的生物毒性来评价沉积物的潜在毒性。结果显示,表层沉积物(以干质量计)中7种菊酯类农药质量分数介于ND~6.59μg·kg-1(ND表示未检出),平均值为0.75μg·kg-1,其总质量分数与有机碳质量分数呈现一定的正相关性;组成比例表明,氯菊酯最多,占总量的57.63%,它的检出率为61.90%,甲氰菊酯其次,约占总量的16.39%,检出率为28.57%,氯菊酯占主要组成部分,可能与其在珠江三角洲居民生活中被大量使用及其降解速率有关;珠江桥采样点高浓度的菊酯类农药的检出(6.59μg·kg-1),可能与其靠近人口密集和经济发达的广州有关;与国内外其他地区相比,珠江河口沉积物中菊酯农药处于较低水平;采用毒性单元TU(选用钩虾Hyallela Azteca的LC50)进行毒性评估,∑TU值范围为0~0.09,远远低于1,表明珠江河口拟除虫菊酯不存在生态风险。  相似文献   

3.
● 38 PhACs and 2 pesticides were detected in the three rivers of the Pearl River basin. ● Anti-inflammatory/analgesics drugs were the predominant PhACs. ● The concentrations of PhACs showed seasonal and spatial variation. ● Diazepam and ibuprofen were the two PhACs with a moderate environmental risk. The occurrence, fate, and environmental risk of 40 pharmaceutically active compounds (PhACs) from surface waters and sediments were comprehensively investigated in the Beijiang River, Xijiang River, and Maozhou River of the Pearl River basin, South China. Salicylic acid and diclofenac (anti-inflammatory drugs), gemfibrozil (a lipid regulator), carbamazepine (an antiepileptic drug), diazepam (a psychoactive drug), and 2-methyl-4-chloro-phenoxyacetic acid (MCPA, a pesticide) were the most ubiquitous compounds in the studied region. The average concentrations of detected PhACs in surface waters and sediments ranged from 0.17 to 19.1 ng/L and 0.10 to 10.4 ng/g, respectively. Meanwhile, PhACs concentration in surface waters and sediments varied greatly among and within the Beijiang River, Xijiang River, and Maozhou River. The largest annual flux of PhACs of the Xijiang River and Beijiang River was more than 11 000 kg per annum, whereas only 25.7 kg/a in the Maozhou River. In addition, the estimated emissions of PhACs in the Beijiang River, Xijiang River, and Maozhou River ranged respectively from 0.28 to 4.22 kg/a, 0.12 to 6.72 kg/a, and 6.66 to 91.0 kg/a, and the back-estimated usage varied with a range from 12.0 to 293 kg/a, 6.79 to 944 kg/a, 368 to 17 459 kg/a. Moreover, the emissions of PhACs showed a close relationship with the gross domestic product (GDP) of each city along the Pearl River. The environmental risk assessment suggested that diazepam and ibuprofen had a moderate risk in this region.  相似文献   

4.
A study was conducted to investigate the occurrence and behavior of six endocrine-disrupting chemicals (EDCs) in sewage, river water, and seawater from the Pearl River Delta (PRD). The six EDCs under study were 4-nonylphenol (NP), bisphenol A (BPA), 17α-ethynylestradiol (EE2), estrone (E2), 17β-estradiol (E2), and estriol (E3). These EDCs, predominated by BPA, were found in high levels in the influents and the effluents of sewage treatment plants in the area. The relatively high concentrations (0.23–625 ng/L) of the EDCs detected in the receiving river water suggested that the untreated sewage discharge was a major contributor. The EDCs detected in eight outlets of the Pear River and the Pear River Estuary were in the ranges of 1.2–234 and 0.2–178 ng/L, respectively. The estrogen equivalents in the aquatic environments under study ranged from 0.08 to 4.5 ng/L, with E1 and EE2 being the two predominant contributors. As the fluxes of the EDCs from the PRD region to the nearby ocean are over 500 tons each year, the results of this study point to the potential that Pearl River is a significant source of the EDCs to the local environment there.  相似文献   

5.
The accurate quantification of enantiomers is crucial for assessing the biodegradation of chiral pharmaceuticals in the environment. Methods to quantify enantiomers in environmental matrices are scarce. Here, we used an enantioselective method, high-performance liquid chromatography with fluorescence detection (HPLC-FD), to analyze two beta-blockers, metoprolol and atenolol, and the antidepressant fluoxetine in an activated sludge consortium from a wastewater treatment plant. The vancomycin-based chiral stationary phase was used under polar ionic mode to achieve the enantioseparation of target chiral pharmaceuticals in a single chromatographic run. The method was successfully validated over a concentration range of 20–800 ng/mL for each enantiomer of both beta-blockers and of 50–800 ng/mL for fluoxetine enantiomers. The limits of detection were between 5 and 20 ng/mL and the limits of quantification were between 20 and 50 ng/mL, for all enantiomers. The intra- and inter-batch precision was lower than 5.66 and 8.37 %, respectively. Accuracy values were between 103.03 and 117.92 %, and recovery rates were in the range of 88.48–116.62 %. Furthermore, the enantioselective biodegradation of atenolol, metoprolol and fluoxetine was followed during 15 days. The (S)-enantiomeric form of metoprolol was degraded at higher extents, whereas the degradation of atenolol and fluoxetine did not show enantioselectivity under the applied conditions.  相似文献   

6.
磺胺嘧啶在水中的微生物降解研究   总被引:2,自引:0,他引:2  
张从良  王岩  王福安 《生态环境》2007,16(6):1679-1682
为了探明磺胺嘧啶在水中的环境行为,通过室内模拟降解实验分别研究了磺胺嘧啶在湖水和猪场废水中的好氧和厌氧微生物降解,考察了供氧方式和有机质含量对磺胺嘧啶微生物降解的影响。结果表明:磺胺嘧啶在猪场废水中厌氧微生物降解速率高于其好氧组,而磺胺嘧啶在湖水中厌氧微生物降解速率低于其好氧组。磺胺嘧啶在湖水和猪场废水中的好氧或厌氧微生物降解均较缓慢,这可能与其较强的抑菌性和微生物的营养状况有关。通过微生物培养还研究了好氧降解时磺胺嘧啶对湖水中微生物种群生长的影响,数据显示:磺胺嘧啶对湖水和猪场废水中细菌的生长具有一定的刺激作用,而对真菌和放线菌的生长影响不明显。  相似文献   

7.
The occurrence and removal efficiency of seven pharmaceuticals (norfloxacin, trimethoprim, roxithromycin, sulfamethoxazole, ibuprofen, diclofenac and carbamazepine) were determined in three sewage treatment plants (STPs) with anaerobic/anoxic/oxic, anoxic/oxic and oxidation ditches processes in Xuzhou City, Eastern China. The results showed that seven pharmaceuticals were detected in the influent samples with concentrations ranging from 93 to 2540 ng·L−1. The removal of these substances among the three different STPs varied from 36 to 84%, with the highest performance obtained by the wastewater treatment works with tertiary treatment (sand filtration). Most of the compounds were removed effectively during biologic treatment while sand filtration treatment also made a contribution to the total elimination of most pharmaceuticals. The efficiency comparison of the three sewage treatment processes showed that the STP which employed anaerobic/anoxic/oxic was more effective to remove pharmaceuticals than the oxidation ditches and anoxic/oxic.  相似文献   

8.
Titanium dioxide photocatalysis for pharmaceutical wastewater treatment   总被引:1,自引:0,他引:1  
Heterogeneous photocatalysis using the semiconductor titanium dioxide (TiO2) has proven to be a promising treatment technology for water purification. The effectiveness of this oxidation technology for the destruction of pharmaceuticals has also been demonstrated in numerous studies. This review highlights recent research on TiO2 photocatalytic treatment applied to the removal of selected pharmaceuticals. The discussions are tailored based on the therapeutic drug classes as the kinetics and mechanistic aspects are compound dependent. These classes of pharmaceuticals were chosen because of their environmental prevalence and potential adverse effects. Optimal operational conditions and degradation pathways vary with different pharmaceutical compounds. The main conclusion is that the use of TiO2 photocatalysis can be considered a state-of-the-art pharmaceutical wastewater treatment methodology. Further studies are, however, required to optimize the operating conditions for maximum degradation of multiple pharmaceuticals in wastewater under realistic conditions and on an industrial scale.  相似文献   

9.
The global consumption and production of pharmaceuticals is increasing concomitantly with concern regarding their environmental fate and effects. Active pharmaceutical ingredients are mainly released into the aquatic environment through wastewater effluent discharge. Once in the environment, pharmaceuticals can undergo processes of natural attenuation, i.e. dilution, sorption, transformation, depending on physico-chemical properties of the compound, such as water solubility, lipophilicity, vapour pressure, and environmental conditions, such as pH, temperature and ionic strength. A major natural attenuation process is the sorption on dissolved organic matter, colloids, suspended solids and sediments, which in turn control pharmaceuticals distribution, residence time and persistence in aquatic systems. Here we review studies of sorption capacity of natural sorbents to pharmaceuticals. These report on the importance of several environmental and sorbent-specific properties, such as the composition, quality, and amount of the sorbent, and the environmental pH, which determines the speciation of both the sorbent and compound. The importance of accounting for distribution processes on freshwater sorbents for any determination of environmental concentrations of pharmaceuticals is apparent, while the reliability of surrogate standards for measuring dissolved organic matter (DOM) distribution is evaluated in the context of the need for robust environmental risk assessment protocols.  相似文献   

10.
珠江入海口水体中多溴联苯醚及其来源分析   总被引:3,自引:0,他引:3  
2005年3月至2006年2月,选取珠江8个入海口,进行每月1次为期1周年的水样采集。检测了96个水样的多溴联苯醚(PBDEs,包括BDE 28、47、66、85、99、100、138、153、154、183、196、197、203、206、207、208和209)的残留状况。水体中PBDEs的质量浓度为0.344~68.0 ng·L-1。PBDEs的组成分析结果表明:珠江水体PBDEs的来源以土壤和沉积物源为主,而目前珠三角陆地环境中PBDEs仍不断蓄积,其通过珠江地表径流迁移转换的PBDEs将逐年增多,给珠三角水生态环境带来的压力逐日增加,所造成的生态环境及公众健康影响将是深远的。  相似文献   

11.
Chiral pharmaceuticals in the environment   总被引:1,自引:1,他引:0  
Many pharmaceutical pollutants are chiral, existing in the environment as a single enantiomer or as mixtures of the two enantiomers. In spite of their similar physical and chemical properties, the different spatial configurations lead the enantiomers to have different interactions with enzymes, receptors or other chiral molecules, which can give diverse biological response. Consequently, biodegradation process and ecotoxicity tend to be enantioselective. Despite numerous ongoing research regarding analysis and monitorization of pharmaceutical ingredients in the environment, the fate and effects of single enantiomers of chiral pharmaceuticals (CP) in the environment are still largely unknown. There are only few chiral analytical methods to accurately measure the enantiomeric fraction (EF) in environmental matrices and during biodegradation processes. Furthermore, the ecotoxicity studies usually consider the enantiomeric pair as unique compound. We reviewed the current knowledge about CP in the environment, as well as the chiral analytical methods to determine the EF in environmental matrices. The degradation and removal processes of CP of important therapeutic classes, usually detected in the environment, and their toxicity to aquatic organisms were also reviewed. On the other hand, this review demonstrate that despite the great importance of the stereochemistry in pharmaceutical science, pharmacology and organic chemistry, this is normally neglected in environmental studies. Therefore, CP in the environment need much more attention from the scientific community, and more research within this subject is required.  相似文献   

12.
检测了珠江三角洲河流及南海近海表层沉积物中25种多环芳烃的含量.其含量范围为138-6793ng·g-1.主成分分析/多元回归分析结果表明,珠江三角洲水体沉积物中多环芳烃来源主要有石油排放,煤、木柴等低温燃烧排放,机动车尾气排放及生物成因.其相对贡献分别为石油排放占36%、煤、木柴燃烧占27%、机动车尾气占25%,自然来源占12%.珠江、东江河流沉积物中多环芳烃主要来源于区域内工业和生活废物的直接排入和机动车尾气的近距离沉降.西江沉积物中多环芳烃大气沉降是主要输入途径.南海沉积物中多环芳烃河流输入是主要途径.在多环芳烃由河流向海洋的输送过程中,茈可以作为一个有效指标示踪河流输送的多环芳烃.风险评价表明,东江及珠江部分河段沉积物可能存在着对生物的潜在危害,其它区域多环芳烃的生态风险处于较低水平.  相似文献   

13.
采用高通量分析方法对长江干流重庆段11个流域断面、2个市政污水处理厂进水和6个养殖场废水的潜在抗生素进行筛查,并结合抗生素使用调查探讨其来源。结果表明,(1)共检出83种抗生素,其中流域内检出36种,污水处理厂和养殖场废水中检出70种;磺胺间甲氧嘧啶检出率最高,在流域水体和废水的检出率分别为91%和55%,喹诺酮类是检出抗生素的主要类型;(2)长江干流重庆段下游检出抗生素数量高于上游检出抗生素;(3)有20种抗生素可能由上游携带和重庆市内排放2种方式进入流域,7种抗生素可能由上游携带入境,9种抗生素可能由重庆市内排放引入长江。  相似文献   

14.
Water pollution by pharmaceutically active compounds is an emerging issue. Toxicological studies reveal that pharmaceuticals are indeed toxic for living organisms. The lack of suitable treatment technology for the complete removal of pharmaceuticals is therefore a major challenge. Advanced oxidation processes are emerging removal techniques that have many advantages versus conventional technologies. Many studies indicate that advanced oxidation processes, either in single or in combination with other degradation techniques, can enhance the degradation of pharmaceuticals in aqueous solutions. Here, we review the degradation of pharmaceuticals by sonolysis, an oxidation processes using ultrasound. In this technique, hydroxyl radicals are generated by pyrolytic cleavage of water molecules. We review the influence of operational parameters, additives and hybrid techniques on the degradation of pharmaceuticals. The maximum degradation of organic compounds was observed in the frequency range of 100–1000 kHz, which is in the high-frequency medium-power ultrasound. Even though almost all the experiments presented more than 90 % removal and good biodegradability of the target compound, good mineralization and the toxicity removal were hardly achieved. The efficiency of the degradation varies with water matrixes and varying pH. Major pathways of degradation are hydroxylation, dehalogenation, demethylation, decarboxylation, deamination, etc. More hybrid techniques have to be developed to scale up the application of ultrasound.  相似文献   

15.
变化环境下北江下游年径流量的加权马尔可夫链预测   总被引:2,自引:0,他引:2  
在气候变化和人类活动的影响下,西北江的水文环境发生了重大变化,导致北江下游的来水条件发生变化。采用斯波曼检验(Spearman’s rho test)和Mann-kendall法系统地分析了北江下游的年径流量的变化趋势和变异情况,在此基础上建立了北江下游变化环境下年径流量的加权马尔可夫链预测模型。结果表明:西北江近50年来的大规模联围筑闸、大规模无序采掘河床泥沙等剧烈的人类活动,导致北江下游三水水文站年径流量在1990年左右发生了变异;所建立的加权马尔可夫链预测结果表明,从变异后的序列中统计出来的状态"转移概率"矩阵,能准确地反映出环境变化后年径流量之间的关系,所建立的加权马尔可夫链法预测变化环境下的年径流量是可行的,预测效果也比较好;按文章确定的分级标准,依现有的资料信息推断,环境发生变化后,在未来长期过程中,北江下游出现平水年的机会最大,但年际间的丰枯波动概率也不小。这一结果值得水资源管理部门注意。  相似文献   

16.
于海霞  徐礼强  张强  陈晓宏 《生态环境》2010,19(10):2515-2520
建立珠江三角洲区域一体化的水利政策法规体系是珠江三角洲国民经济社会发展和水利现代化建设的需要。从珠江三角洲地区现行水利政策法规存在的问题入手,开展珠江三角洲区域一体化的政策法规体系研究。结果表明:珠江三角洲地区现行水利政策法规体系仍很不完善,许多立、改、废工作亟待进行,2008年水政执法有效率总体较高,但很少在珠江三角洲层面开展区域一体化的联合执法,珠江三角洲水利政策法规体系建设应重点加强与水利现代化建设、水资源一体化配置、保护及管理相关的政策法规,进而建立统一协调、快速高效的区域一体化的联合执法体系。  相似文献   

17.
环境水体中检测到大量药物的存在,主要包括抗生素,抗惊厥抗抑郁药物,解热和非甾体消炎药,血脂调整剂,β-阻滞剂等。传统的水处理技术并不能有效地去除这些药物,存在于水体中的环境药物对公共健康的潜在危害引起了广泛的关注。文中简要地介绍了近年来光催化技术在降解环境药物动力学和机理方面的研究进展,试图找出水体中环境药物降解的一般规律,为环境水体中该类物质的迁移和转化提供理论依据。  相似文献   

18.
It is well known that soluble microbial products (SMP) derived from biological systems found in wastewater treatment plant effluent are responsible for chemical oxygen demand (COD). Aerobic granular sludge (AGS) is recognized as an efficient and innovative approach for wastewater treatment. Acetate and propionate as two dominant organic substances in wastewater need to be effectively removed before discharge. The aim of this study was to investigate the effectiveness of acetate and propionate to interfere with the accumulation, molecular weight (MW) distribution and composition of SMP in aerobic granular sludge (AGS) system using two identical sequencing batch reactors (SBR) named R1 and R2, respectively, thus reducing the COD. The results demonstrated that more SMP accumulated in R1 in presence of acetate compared to R2 treated with propionate. A positive correlation for SMP formation was detected as evidenced by aeration rates, but a negative correlation with hydraulic retention time (HRT). The MW distribution analysis suggested that small molecules (MW <3?kDa) were the dominant fraction of SMP in R1 and R2, accounting for 57–79% and 39–61%, respectively. In addition, gas chromatography-mass spectrometry (GC-MS) demonstrated that esters, alkanes, alkenes and alcohols were the predominant low-MW SMP in R1 and R2. More peaks were present in R2 (61) than R1 (46). Esters were the predominant SMP (39%) in R1, while alkanes were the predominant SMP (31%) in R2. Further, microbial community analysis indicated that more α- and γ-Proteobacteria groups which readily utilize low-MW SMP were found in R2 compared to R1-granules which may have contributed to less SMP accumulated in R2. The abundant genera in the granules were Zoogloea and Azoarcus, in particular, a greater quantity of Azoarcus was detected in R2 than R1-granules, which may be associated with higher degradation of aromatics in SMP.  相似文献   

19.
The Ili River is a very important river to the northwest of China and Kazakhstan. The Axi Goldmine is located in the upstream of a branch of the Ili River. The cyanide from the goldmine effluent is a threat to the downstream areas. According to our study, the natural degradation of cyanide conforms to a negative exponential equation in the tailings impoundment, second wastewater pond and even in the receiving streams if the dilution action from other streams were deducted. In the combined action of dilution and natural decomposing, the cyanide from the goldmine effluent does not pose a hazard to the trunk of the Ili River in the normal producing states. The equations of cyanide degradation in the streams and the hydrology parameters could be used to assess the environmental impact on the downstream areas if accidental discharges of cyanide occurred. The available way of decreasing the cyanide impact on the streams is to increase the rate of recycled water so that the lower the wastewater level in the tailing impoundment and the second wastewater pond, the lower is the amount of leakage of wastewater to the streams.  相似文献   

20.
Biodegradation experiments of various polycyclic aromatic hydrocarbons were studied with mixed bacteria culture under aerobic conditions. An easy‐to‐handle clean‐up procedure was developed for PAH and their metabolites simultaneously as well as a gc‐ms‐method to identify and quantify these compounds.

Anthracene and dibenzothiophene are completely degradable in an aqeous system, whereas biodegradation of benzo(k)fluoranthene and benzo(h)quinoline is possible only in an oil‐in‐water‐system with dodecane as cosubstrate. No degradation of nitronaphthalene was observed in aqueous systems. New metabolites are 2,3‐dihydroxybenzothiophene, hydroxybenzothiophenecarbonic acid and benzothiophenequinone for dibenzothiophene and hydroxyfluoranthenic acid for benzo(k)flouranthene. Whereas the former metabolites are degradable under the experimental conditions, the latter accumulates during the degradation experiment.

The results are important for microbiological wastewater treatment, since knowledge of biodegradation processes is indespensable for the successful treatment of PAH‐containing wastewater.  相似文献   

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