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1.
珠江三角洲地区大气气溶胶中有机污染物背景研究   总被引:9,自引:1,他引:8       下载免费PDF全文
选择肇庆市鼎湖山自然保护区为珠江三角洲大气气溶胶有机污染评价的区域性环境背景.研究结果表明,珠江三角洲地区大气气溶胶中优控多环芳烃背景值萘、苊、二氢苊、芴、菲、蒽、荧蒽、芘、苯并(a)蒽、、苯并(b)荧蒽、苯并(k)荧蒽、苯并(a)芘、茚并(1,2,3-cd)芘、二苯并(a,h)蒽、苯并(ghi)分别为n.d.、n.d.、tr.、0.14、tr.、0.39、0.53、0.19、1.05、1.82、1.41、0.02、2.29、0.53和2.44ng/m3,总量为10.80ng/m3,其来源主要为高等植物排放.  相似文献   

2.
城市隧道汽车尾气中多环芳烃排放特征的研究   总被引:2,自引:0,他引:2       下载免费PDF全文
对广州市珠江隧道进行了汽车尾气中颗粒相多环芳烃(PAHs)的排放因子测试,研究了汽车组成、交通流量、隧道内微气象及PAHs成分和浓度水平,采用质量平衡模型和多元线性回归方法计算了8种车型共14种PAHs的综合排放因子.结果表明,汽车尾气颗粒相PAHs的主要检出物为萘、苊烯、苊、蒽、菲、荧蒽、芘、苯并(a)蒽、、苯并[a]芘、苯并(k)荧蒽、茚并(1,2,3-c,d)、二苯并(a,h)蒽、苯并(g,h,I)苝等14种成分,隧道进口处PM10中∑PAHs浓度为(5.000±1.762)μg/m3,隧道出口处PM10中∑PAHs浓度为(27.067±3.602)μg/m3,其中四环以上的PAHs含量占74.9%.在平均车速为46km/h条件下,隧道内机动车尾气颗粒物中∑PAHs平均排放因子高达16.203mg/(km·辆),其中各PAHs化合物排放因子均超出欧洲或美国的100倍以上.  相似文献   

3.
混合表面活性剂对多环芳烃的增溶作用及机理   总被引:43,自引:5,他引:43  
比较了研究了单一和混合表面活性剂对萘、苊、蒽、菲、芘的增溶作用及其机理。混合表面活性剂/单一表面活性对多环芳烃协同增溶/增溶作用的大小与水溶液中表面活性剂的结构、浓度、组成及有机溶质本身的性质有关。在临界胶束浓度(CMC)以上,单一表面活性剂对多环芳烃的增溶作用顺序为TritonX100>Brij35>TritonX305,与其亲水亲油平衡值(HLB)呈负相关;混合表面活性剂对多环芳烃能产生显著的增溶作用,其协同增溶作用顺序为SDS-TritonX305>SDS-Brij35>SDS-TritonX100,协同增溶作用的大小与其中的非离子表面活性剂的HLB值及多环芳烃的辛醇-水分配系数呈正相关。混合表面活性剂溶液的CMC值降低、溶质在胶束相/水相间分配系数Kmc的增大是产生协同增溶作用的主要原因。  相似文献   

4.
本文研究了象山港多环芳烃(PAHs)在沉积物-海水中的分布特征,于2017年1月对港口9个采样点的沉积物和海水中16种优先控制PAHs进行分析,采用同分异构比值法和逸度方法进行来源分析和扩散行为研究。沉积物中PAHs范围为17.51×10–9~84.41×10–9,主要为高环PAHs,处于轻度污染等级。沉积物中多环芳烃主要来自高温燃烧源。表层水体、中层水体和底层水体中PAHs范围分别为41.78~105.72 ng/L、41.51~106.34 ng/L和9.18~145.17 ng/L,主要由低环PAHs组成。表层水体中PAHs主要来源于石油泄漏和石油燃烧。利用逸度系数判断PAHs扩散行为,萘(Nap)、苊(Ace)和芴(Flo)由沉积物向海水释放;苊烯(Acy)、菲(Phe)、蒽(Ant)和芘(Pyr)在沉积物和海水中处于动态平衡;荧蒽(Flu)、苯并[a]蒽(BaA)、?(Chr)和苯并[b]荧蒽(BbF)主要从海水向沉积物扩散并富集。  相似文献   

5.
有机膨润土吸附水中多环芳烃的性能及机理研究   总被引:32,自引:4,他引:32  
分别用溴化十二烷基三甲铵(DTMAB),溴化十四烷基苄基二甲基铵(TPAC),溴化十六烷基三甲铵(CTMAB),溴化十八烷基三甲铵(OTMAB)改性膨润土研究了有机膨润土中吸附水中菲,萘,苊的适宜条件,性能及机理,结果表明,有机膨润土的层间距,有机碳含量,对多环芳烃的吸附能力与改性时所用表面活性剂的碳链长度及其在制德时的用量成正比;多环芳烃的去除效果还与其本身的性质有关;  相似文献   

6.
丰、沛、铜重氟病区,禽、畜体内氟主要积聚在骨骼中(羊骨1096×10-6~2001.9×10-6,鸡骨335×10-6~378×10-6)及生理功能强的内脏(肝、心、肾等)器官中,氟的含量3.3×10-6~7.17×10-6,肌肉和蛋、奶品中氟的含量大多接近或低于氟的卫生标准,显然肉、蛋、奶食品不是该区地氟病的致病因子。研究表明,动物体内氟含量与环境水氟及叶菜和树叶(含水分高)中的氟含量呈明显的正相关。因而造成食草动物比以食粮食为主的家禽体内的氟含量明显偏高。说明水是氟的传播媒界,为该区地氟病的主要致病因子。  相似文献   

7.
超临界水氧化法降解氧乐果的研究   总被引:36,自引:0,他引:36       下载免费PDF全文
实验研究了有机磷农药氧乐果在超临界水中的氧化降解.结果表明,超临界水氧化技术能有效地降解氧乐果废水.随着反应温度的升高、压力的增大、停留时间的延长,COD去除率也随之提高氧乐果在超临界水中氧化降解的动力学方程为:-d[COD]/dτ=1.60exp(-2.25×104/RT)[COD]0.90[O20-0.38[H2O00.053.  相似文献   

8.
硝基芳烃对鲤鱼鱼鳃ATPase的活性抑制和QSARs   总被引:5,自引:0,他引:5       下载免费PDF全文
在离体实验条件下,测定了20种硝基芳烃化合物对鲤鱼鱼鳃ATPase活性的半抑制浓度-logIC50值,以一阶价分子连接性指数1XV,取代基常数总和∑σ、指示变量I、分子分支指数1Ka、分子最低空轨道能ELUMO及辛醇─水分配系数logP为参数,进行定量结构活性相关性(QSAR)研究。结果表明,硝基芳烃的毒性和∑σ、I、ELUMO3个参数密切相关。在上述基础上,成功地建立了20种硝基芳烃的QSAR方程,其相关系数为0.927。  相似文献   

9.
北京东南郊污灌区PAHs垂向分布规律   总被引:8,自引:3,他引:5  
采用Eijkelkamp土壤采样器对北京东南郊污灌区进行了3个钻孔剖面采样,分析了土壤样品的理化参数,并且采用气相色谱-质谱联用仪对土壤样品的多环芳烃(PAHs)进行了定量分析,研究了土壤理化参数和16种PAHs从表层到5.5 m深的范围内垂向变化规律.结果表明,污灌区表层土壤中有14种PAHs检出,检出浓度在4~428 μg/kg之间,表层以下PAHs的检出种类显著减少,主要以2环和3环的萘、菲、芴、苊烯、二氢苊、荧蒽6种为主.粘粒含量、粘土矿物总量、阳离子交换容量以及总有机碳4个理化参数相互之间在垂向变化上具有一致性,均在0.05水平上显著相关.表层以下粘粒含量与低环PAHs在垂向含量变化也有较好的一致性,粘粒含量高的层位,PAHs含量也较高.从剖面PAHs含量变化可以判断,低环PAHs较易迁移,它们的迁移性强弱顺序为:二氢苊>芴>萘>菲>苊烯>荧蒽,其它高环PAHs难以迁移,仅在表层土壤中检出,说明在长期污灌条件下,迁移性较好的低环PAHs能够迁移到较深的土层中,有可能导致浅层地下水的污染.  相似文献   

10.
尝试利用英国的污染土地暴露评价模型(CLEA模型)获取了典型石油化工污染场地中几种多环芳烃(PAHs)的土壤指导限值(SGVs),并用所得到的土壤指导限值对该场地的污染物风险进行了评价.结果表明,研究区域内萘、蒽、苯并[a]芘、苊、芴、芘的土壤指导限值分别为3.57×103,6.12×107,0.874,6.81×104,6.24×104和5.84×106 ng/g.特定场地表层土壤中萘、蒽、苊、芴、芘的实测浓度(MECs)大于其相应土壤指导限值的概率均趋于0,而苯并[a]芘的为0.225.这几种PAHs的风险从大到小依次为:苯并[a]芘萘>苊>芴>芘>蒽,说明该场地的优先控制污染物为苯并[a]芘.   相似文献   

11.
The potential harm of heavy metals is a primary concern in application of sludge to the agricultural land. A pot experiment was conducted to evaluate the effect of two sludges on fractionation of Zn and Cu in soil and their phytotoxicity to pakchoi. The loamy soil was mixed with 0%, 20%, 40%, 60% and 80% (by weight) of digested sewage sludge (SS) and composted sludge (SC). The additions of both sludges caused a significant raise in all fractions, resulting in that exchangeable (EXCH) and organic bound (OM) became predominance of Zn and organic bound Cu occupied the largest portion. There was more available amount of Zn and Cu in SS treatments than SC treatments. During the pot experiment, the concentration of Zn in EXCH, carbonate (CAR) and OM and Cu in EXCH and OM fractions decreased in all treatments, so their bioavailability reduced. Germination rate and plant biomass decreased when the addition rate was high and the best yield appeared in 20% mixtures at the harvest of pakchoi. The two sludges increased tissue contents of Zn and Cu especially in the SS treatments. Zn in pakchoi was not only in relationship to ΔEXCH and ΔCAR forms but also in ΔOM forms in the sludge-soil mixtures. Tissue content of Cu in pakchoi grown on SC-soils could not be predicted by ΔEXCH. These correlation rates between Zn and Cu accumulation in pakchoi and variation of different fractions increased with time, which might indicate that sludges represented stronger impacts on the plant in long-term land application.  相似文献   

12.
A hydroponic experiment was carried out to study intraspecific differences in the effects of different concentrations of cadmium (Cd)(0-10 mg/L) and arsenate (As(V)) (0-8 mg/L) on the growth parameters and accumulation of Cd and As in six wheat varieties Jing-9428, Duokang-1, Jingdong-11, Jing-411, Jingdong-8 and Zhongmai-8. The endpoints of wheat seedlings, including seed germination,biomass, root length and shoot height, decreased with increasing the Cd and As concentrations. Significant differences in seed germination, biomass, root length, shoot height and the accumulation of Cd and As were observed between the treatments and among the varieties (p < 0.05). The lethal dosage 50% were about 20, 80, 60, 60, 80 and 20 mg As/L for Jing-9428, Duokang-1, Jingdong-11,Jing-411, Jingdong-8 and Zhongmai-8, respectively, and the corresponding values for Cd were about 30, 80, 20, 40, 60 and 10 mg Cd/L, respectively. Among the six varieties, Duokang-1 was found to be the most resistant to Cd and As toxicity, and Zhongmai-8 was the most sensitive to Cd and As co-contamination. The resistance of the six varieties was found dependant on the seedling uptake of Cd and As. Duokang-1 was the most suitable for cultivation in Cd and As co-contaminated soils.  相似文献   

13.
Phytoremediation is a potential cleanup technology for the removal of heavy metals from contaminated soils.Bidens maximowicziana is a new Pb hyperaccumulator,which not only has remarkable tolerance to Pb but also extraordinary accumulation capacity for Pb.The maximum Pb concentration was 1509.3 mg/kg in roots and 2164.7 mg/kg in overground tissues.The Pb distribution order in the B. maximowicziana was:leaf>stem>root.The effect of amendments on phytoremediation was also studied.The mobility of soil Pb and the Pb concentrations in plants were both increased by EDTA application.Compared with CK(control check),EDTA application promoted translocation of Pb to overground parts of the plant.The Pb concentrations in overground parts of plants was increased from 24.23-680.56 mg/kg to 29.07-1905.57 mg/kg.This research demonstrated that B.maximowicziana appeared to be suitable for phytoremediation of Pb contaminated soil,especially,combination with EDTA.  相似文献   

14.
Laogang landfill near Shanghai is the largest landfill in China, and receives about 10000 t of daily garbage per day, Samples of topsoil and plants were analyzed to evaluate mercury pollution from the landfill. For topsoil samples, there were significant correlations among total mercury (HgT), combinative mercury (Hgc) and gaseous mercury (HgG), and content of total organic carbon (TOC), but, no significantly relationship was found between Hg content and filling time. Hg content changes in vertical profiles with time showed that the average Hgv of profiles 1992, 1996, and 2000 was similar, but their average HgG was quite different. HgT was significantly correlated with Hgc in profile 1992 and 2000, and Hgv was significantly correlated with Hg6 in profile 1996. HgG/Hgv ratio in profile samples decreased in the order of (HgG,/HgT)1992〉(HgG/HgT)1996〉〉(HgG/HgT)2000. A simple outline of Hg release in landfill could be drawn: with increasing of filling time, degradation undergoes different biodegradation, accordingly, gaseous mercury goes through small, more, and small proportion to total mercury. Distribution of Hg in plants was inhomogeneous, following the order of leaf〉root〉stem. The highest value of leaf may be associated with higher atmospheric Hg from landfill. Ligneous plants (e.g. Phyllostachys glanca, Prunus salicina and Ligustrum lucidum) are capable of enriching more Hg than herbaceous plants.  相似文献   

15.
Toxic effects of two agrochemicals on nifH gene in agricultural black soil were investigated using denaturing gradient gel electrophoresis (DGGE) and sequencing approaches in a microcosm experiment. Changes of soil nifH gene diversity and composition were examined following the application of acetochlor, methamidophos and their combination. Acetochlor reduced the nifH gene diversity (both in gene richness and diversity index values) and caused changes in the nifH gene composition. The effects of acetochlor on nifH gene were strengthened as the concentration of acetochlor increased. Cluster analysis of DGGE banding patterns showed that nifH gene composition which had been affected by low concentration of acetochlor (50 mg/kg) recovered firstly. Methamidophos reduced nifH gene richness that except at 4 weeks. The medium concentration of methamidophos (150 mg/kg) caused the most apparent changes in nifH gene diversity at the first week while the high concentration of methamidophos (250 mg/kg) produced prominent effects on nifH gene diversity in the following weeks. Cluster analysis showed that minimal changes of nifH gene composition were found at 1 week and maximal changes at 4 weeks. Toxic effects of acetochlor and methamidophos combination on nifH gene were also apparent. Different nifH genes (bands) responded differently to the impact of agrochemicals: four individual bands were eliminated by the application of the agrochemicals, five bands became predominant by the stimulation of the agrochemicals, and four bands showed strong resistance to the influence of the agrochemicals. Fifteen prominent bands were partially sequenced, yielding 15 different nifH sequences, which were used for phylogenetic reconstructions. All sequences were affiliated with the alpha- and beta-proteobacteria, showing higher similarity to eight different diazotrophic genera.  相似文献   

16.
The influence of the nonionic surfactant Tween 80 on pentachlorophenol (PCP) oxidation catalyzed by horseradish peroxidase was studied. The surfactant was tested at concentrations below and above its critical micelle concentration (CMC). Enhancement of PCP removal was observed at sub-CMCs. The presence of Tween 80 in the reaction mixture reduced enzyme inactivation which occurred through a combination of free radical attack and sorption by precipitated products. A simple first-order model was able to simulate time profiles for enzyme inactivation in the presence or absence of Tween 80. At supra-CMCs, the surfactant caused noticeable reductions in PCP removal, presumably through micelle partitioning of PCP which precluded the hydrophobic PCP molecule from interacting with the enzyme.  相似文献   

17.
Decomposition of alachlor by ozonation and its mechanism   总被引:1,自引:0,他引:1  
Decomposition and corresponding mechanism of alachlor, an endocrine disruptor in water by ozonation were investigated. Results showed that alachlor could not be completely mineralized by ozone alone. Many intermediates and final products were formed during the process, including aromatic compounds, aliphatic carboxylic acids, and inorganic ions. In evoluting these products, some of them with weak polarity were qualitatively identified by GC-MS. The information of inorganic ions suggested that the dechlorination was the first and the fastest step in the ozonation of alachlor.  相似文献   

18.
The effects of arbuscular mycorrhizal (AM) fungus (Glomus mosseae) and phosphorus (P) addition (100 mg/kg soil) on arsenic (As) uptake by maize plants (Zea mays L.) from an As-contaminated soil were examined in a glasshouse experiment.Non-mycorrhizal and zero-P addition controls were included.Plant biomass and concentrations and uptake of As,P,and other nutrients,AM colonization,root lengths,and hyphal length densities were determined.The results indicated that addition of P significantly inhibited root colonization and development of extraradical mycelium.Root length and dry weight both increased markedly with mycorrhizal colonization under the zero-P treatments,but shoot and root biomass of AM plants was depressed by P application.AM fungal inoculation decreased shoot As concentrations when no P was added,and shoot and root As concentrations of AM plants increased 2.6 and 1.4 times with P addition,respectively.Shoot and root uptake of P,Mn,Cu,and Zn increased,but shoot Fe uptake decreased by 44.6%,with inoculation, when P was added.P addition reduced shoot P,Fe,Mn,Cu,and Zn uptake of AM plants,but increased root Fe and Mn uptake of the nonmycorrhizal ones.AM colonization therefore appeared to enhance plant tolerance to As in low P soil,and have some potential for the phytostabilization of As-contaminated soil,however,P application may introduce additional environmental risk by increasing soil As mobility.  相似文献   

19.
Several main metabolites of benzo[a]pyrene (BaP) formed by Penicillium chrysogenum, Benzo[a]pyrene-1,6-quinone (BP 1,6- quinone), trans-7,8-dihydroxy-7,8-dihydrobenzo[a]pyrene (BP 7,8-diol), 3-hydroxybenzo[a]pyrene (3-OHBP), were identified by high-performance liquid chromatography (HPLC). The three metabolites were liable to be accumulated and were hardly further metabolized because of their toxicity to microorganisms. However, their further degradation was essential for the complete degradation of BaP. To enhance their degradation, two methods, degradation by coupling Penicillium chrysogenum with KMnO4 and degradation only by Penicillium chrysogenum, were compared; Meanwhile, the parameters of degradation in the superior method were optimized. The results showed that (1) the method of coupling Penicillium chrysogenum with KMnO4 was better and was the first method to be used in the degradation of BaP and its metabolites; (2) the metabolite, BP 1,6-quinone was the most liable to be accumulated in pure cultures; (3) the effect of degradation was the best when the concentration of KMnO4 in the cultures was 0.01% (w/v), concentration of the three compounds was 5 mg/L and pH was 6.2. Based on the experimental results, a novel concept with regard to the bioremediation of BaP-contaminated environment was discussed, considering the influence on environmental toxicity of the accumulated metabolites.  相似文献   

20.
Sorption of chlorotoluron in ammonium sulfate, urea and atrazine multi-solutes system was investigated by batch experiments. The results showed application of nitrogen fertilizers to the soil could affect the behavior of chlorotoluron. At the same concentration of N, sorption of chlorotoluron decreased as the concentration of atrazine increased on the day 0 and 6 in soil, respectively. The sorption of chlorotoluron increased from 0 to 6 d when soils were preincubated with deionized water, ammonium sulfate and urea solution for 6 d. That indicated incubation time was one of the most important factors for the sorption of chlorotoluron in nitrogen fertilizers treatments. The individual sorption isotherms of chlorotoluron in rubbery polymer and silica were strictly linear in single solute system, but there were competition sorption between pesticides or between pesticides and nitrogen fertilizers. That indicated the sorption taken place by concurrent solid-phase dissolution mechanism and sorption on the interface of water-organic matter or water-mineral matter.  相似文献   

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