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1.
利用高效液相色谱联合荧光检测器分析宝鸡市PM2. 5中16种EPA优控多环芳烃。研究结果表明PM2. 5中高环多环芳烃浓度高于低环多环芳烃,SPSS分析得出PM2. 5的浓度与多环芳烃浓度呈正相关。用比值分析得到宝鸡市多环芳烃的主要来源是煤炭燃烧和汽车尾气。计算多环芳烃的毒性当量(TEQ)和致癌风险评价,结果显示宝鸡市除了婴儿外其他年龄段的人群都存在不同的潜在致癌风险。  相似文献   

2.
本研究合成了水溶性CdZnSeS/ZnS绿光量子点和CdSe/CdS/ZnS红光量子点作为荧光探针,与典型多环芳烃(萘、芘、苯并芘、荧蒽)复合构建荧光共振能量转移体系,探讨了量子点-多环芳烃复合体系的部分参数。数据结果表明,量子点与四种多环芳烃之间存在共振能量转移作用,而且在CdZnSeS/ZnS量子点-芘/苯并芘复合体系中,量子点荧光变化幅度与芘/苯并芘浓度在一定范围内存在线性关系,这证明通过构建量子点-多环芳烃复合物荧光共振能量转移体系,可以实现对地下水中多环芳烃的定量分析。  相似文献   

3.
近年来南京土壤仪器研究所生产的 BNF-2型微电脑浓度分析仪,采用日本 SHARP公司微电脑,应用 BASIC 语言,以各种类型离子选择性电极为传感器,进行离子浓度定量分析,仪器内的微机直接处理数据并打印结果,提高了仪器的分析自动化程度。该仪器具有体积小,携带方便,利于环保监测、农业土壤、化工等部门的化学分析工作者下乡巡回,就地采样进行分析等优点。  相似文献   

4.
国内外清洁燃料技术发展动态分析   总被引:1,自引:0,他引:1  
探讨了清洁燃料发展的可行方向,阐述了汽车燃料主要污染物为硫、烯烃、芳烃和MTBE。对比了国内外汽车尾气排放标准和汽、柴油质量标准,找出了我国油品质量与国际先进水平的差距。在此基础上,针对我国油品面临来自WTO开放政策,原油含硫不断升高,装置结构亟待改造等现实问题,提出了初步的对策措施和建议。  相似文献   

5.
以黄山贡菊离体叶片中过氧化氢酶为研究对象,采用室内模拟方法,研究不同因素处理对黄山贡菊离体叶片中过氧化氢酶活力的影响。结果表明,在30℃时酶活力较高,高温或低温时酶活力均减小;低浓度的K^+和Ca^2+对过氧化氢酶有激活作用,高浓度的K^+和Ca^2+对过氧化氢酶有抑制作用;Mg^2+、Pb^2+、Cu^2+对过氧化氢酶均具有抑制作用,生长素和赤霉素对过氧化氢酶活性的影响不明显。  相似文献   

6.
唐兴玥 《青海环境》2012,22(1):30-32,35
文章选择湟水河流域湟源至乐都段为研究点,采集并分析了湟水河及支流北川河、南川河河道不同地点25个河床泥沙样品的常量元素地球化学特征。结果表明,湟水河河床沉积物相对富Si4+、Al3+和Ca2+,而贫K+、Na+和Mg2+,这可能与河道周围沉积的河湖相碎屑岩和黄土的化学风化有关。通过对河道不同地点泥沙样品的化学风化趋势图分析,发现不同地点泥沙样品具有不同的Al2O3、CaO和Na2O含量,而具有相似的K2O含量,说明不同地点的化学风化强度不同。对比发现湟水河流域上游湟源段的化学风化强度达到最大值,至西宁段达到最小值,到平安和乐都段稍有增加。同时也发现湟水河支流北川河具有较强的化学风化过程。  相似文献   

7.
研究了pH值、吸附接触时间、铜离子的初始浓度及活性炭纤维(ACF)的投加量对活性炭纤维吸附Cu2+的影响,并选取了最佳的实验条件。用Langmuir方程和Freundlich方程拟合活性炭纤维对Cu2+吸附等温线,结果表明:活性炭纤维吸附Cu2+更符合Langmuir等温式,其相关系数为0.9995,以单分子层吸附为主。对活性炭纤维改性能明显提高对Cu2+的吸附,其中效果最佳的吸附量从4.8mg/g增加到17.32mg/g,提高了3.6倍。  相似文献   

8.
硫的氧化物SO_x是有害气体,影响人的健康和农作物生长,腐蚀设备建筑物,形成酸雨等。因此,被列入大气污染要求监测项目之一。目前一般采用分光光度法,仓库法、电导法、容量分析及比浊等方法进行检测。这些方法尚不能满足多方面的要求。随着科学技术的发展,不断地出现了能将化学讯号变为电讯号的各类敏感元件,即化学传感器,其中尤以气体传感器  相似文献   

9.
化学沉淀法处理高浓度氨氮废水的试验研究   总被引:1,自引:0,他引:1  
实验采用磷酸氨镁沉淀法(MAP法)去除垃圾渗滤液中的高浓度氨氮。通过对MgCl2+Na2HPO4^-、MgSO4+Na2HPO4、MgO+Na2HPO4、MgCl2+NaH2PO4、MgSO4+NaH2PO4和MgO+NaH2PO4等六种组合药剂去除氨氮效果的分析比较,得出MgCl2+Na2HPO4对氨氮的去除效果最好。继而对该组合药剂去除氨氮的影响因素进行了优化。结果表明:pH为9.0,反应时1.3为50min,n(Mg^2+):n(NH4^+):n(PO4^3-)为1.2:1:0.9时,氨氮可由原来的2100mg/L降低到317mg/L,去除率达84.9%.  相似文献   

10.
通过实验研究建立了自动固相萃取-高效液相色谱测定炼化废水中16种多环芳烃(PAHs)的方法。研究结果表明,利用Agilent Eclipse XDB-C18色谱分离柱,以乙腈和水为流动相,采用梯度淋洗和变化波长的紫外、荧光程序可测定炼化废水中痕量的16种PAHs。最优固相萃取条件为:15mL甲醇改进剂、10mL萃取柱活化溶剂、5mL/min的萃取流速、分3次共计15mL洗脱溶剂、0.5mL/min洗脱速率。在此优化条件下,方法检出限低于HJ 478—2009《水质多环芳烃的测定液液萃取和固相萃取高效液相色谱法》,精密度相对标准偏差(RSD)小于10%,标准曲线线性系数r≥0.999。  相似文献   

11.
对辉县市城区2006—2011年间环境空气质量监测数据进行了评价,并对城区污染物浓度时空变化进行了分析。结果表明,辉县市城区大气污染主要表现为可吸入颗粒物污染严重,主要是能源结构不合理、锅炉废气污染严重、城区道路保洁方式落后等原因造成的,由此提出了合理规划城市布局、减少结构性污染等对策。  相似文献   

12.
To improve understanding of the factors affecting pesticide occurrence in ground water, patterns of detection were examined for selected herbicides, based primarily on results from the National Water-Quality Assessment (NAWQA) program. The NAWQA data were derived from 2,227 sites (wells and springs) sampled in 20 major hydrologic basins across the USA from 1993 to 1995. Results are presented for six high-use herbicides--atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine), cyanazine (2-[4-chloro-6-ethylamino-1,3,5triazin-2-yl]amino]-2-methylpropionitrile), simazine (2-chloro-4,6-bis-[ethylamino]-s-triazine), alachlor (2-chloro-N-[2,6-diethylphenyl]-N-[methoxymethyl]acetamide), acetochlor (2-chloro-N-[ethoxymethyl]-N-[2-ethyl-6-methylphenyl]acetamide), and metolachlor (2-chloro-N-[2-ethyl-6-methylphenyl]-N-[2-methoxylethyl]acetamide)--as well as for prometon (2,4-bis[isopropylamino]-6-methoxy-s-triazine), a nonagricultural herbicide detected frequently during the study. Concentrations were <1 microg L(-1) at 98% of the sites with detections, but exceeded drinking-water criteria (for atrazine) at two sites. In urban areas, frequencies of detection (at or above 0.01 microg L(-1)) of atrazine, cyanazine, simazine, alachlor, and metolachlor in shallow ground water were positively correlated with their nonagricultural use nationwide (P < 0.05). Among different agricultural areas, frequencies of detection were positively correlated with nearby agricultural use for atrazine, cyanazine, alachlor, and metolachlor, but not simazine. Multivariate analysis demonstrated that for these five herbicides, frequencies of detection beneath agricultural areas were positively correlated with their agricultural use and persistence in aerobic soil. Acetochlor, an agricultural herbicide first registered in 1994 for use in the USA, was detected in shallow ground water by 1995, consistent with previous field-scale studies indicating that some pesticides may be detected in ground water within 1 yr following application. The NAWQA results agreed closely with those from other multistate studies with similar designs.  相似文献   

13.
通过实验室水培试验研究不同浓度处理水平下Cu、Cd、Hg单一及其复合污染对少根紫萍叶绿素及脯氨酸浓度的影响。经观察分析,培养4天后,各处理组均呈现出不同程度的受害症状。同一浓度处理水平下,单一重金属污染对少根紫萍叶绿素的生态毒性效应为Cd>Cu>Hg。复合污染中Cu+Cd和Hg+Cu+Cd对叶绿素的影响则表现为协同作用;Cd+Hg复合浓度≤6.0+4.0mg/L时表现为拮抗作用,复合浓度>6.0+4.0mg/L时表现为协同作用;Cu+Hg复合浓度≤0.4+4.0mg/L时表现为协同作用;复合浓度>0.4+4.0mg/L时表现为拮抗作用。随处理浓度的递增,脯氨酸含量均表现出一显著抗性峰,而后下降。  相似文献   

14.
南充市近十年酸雨变化特征及降水化学组成研究   总被引:2,自引:0,他引:2  
依据南充市2003~2012年城区降水环境监测统计资料,分析了酸雨变化特征及降水离子化学组成。研究表明:这十年,酸雨频率平均为50.4%,2007年降雨量为最高,呈波动递减趋势变化,降水年平均pH值为4.88,呈现"低—高—低"的变化特征,城区酸雨频率和降水pH值月均值变化呈现高低交替的波动趋势。城区降水中主要阳离子成分是Ca2+,主要阴离子成分是SO2-4和NO-3。(SO2-4/NO-3)比值逐年下降,平均比值为7.82,酸雨污染类型仍以硫酸型为主;降水(NH+4+Ca2+)/(SO2-4+NO-3)和Ca2+/NH+4比值呈波动性变化,2007年分别达到最高值为6.71和50.27,除2010年比值均较低小于1外,近年来均有增加趋势,表明碱性离子缓冲能力增强了,降水酸度降低,pH值增加,但2007年pH值较低,主要与降雨量有关。综合分析,降水酸度不仅是酸性离子和碱性离子中和作用,也受其他离子浓度和降雨量、风向等气候条件、距离传输以及地形等影响。  相似文献   

15.
以马尾松为指示植物,对韶关的土壤进行了长期淋溶模拟并记录其化学状态。结果发现,土壤溶液的pH值下降到4.0,Bs值下降到几乎为零,有较大量的A1离子溶出。最后选取土壤溶液pn〉4.0、KS〉10%和[Al^3+]〈0.1mmol/L为临界化学指标,参考国内外应用广泛的MAGIC模型和SMART模型,确定韶关酸沉降临界负荷(S的临界负荷)为14.1keq/hm^2.a。  相似文献   

16.
Terbuthylazine [N2-tert-butyl-6-chloro-N4-ethyl-1,3,5-triazine-2,4-diamine] degradation pathways in agricultural soils were evaluated by following the appearance and mobility of its main transformation products: dealkylated and hydroxylated derivatives. Three experimental degradation studies in open field were performed in different hydraulic conditions: constant hydraulic head on topsoil, achieved to simulate the highest-risk situation for the aquifer, intermittent artificial precipitation to simulate a medium-risk situation; and natural precipitation to reproduce the lowest-risk condition. Concentrations of terbuthylazine transformation products derived from dealkylation and hydroxylation reactions were measured in leachates and soil samples collected during the three experiments. Desethylterbuthylazine (DET) and deethylterbuthylazine-2-hydroxide [DETH; 4-amino-6-terbutylamino-(1,3,5)-triazine-2-OH] were found to be the highest-leaching compounds and therefore can be considered as potential pollutants for aquifer contamination.  相似文献   

17.
本文通过实验考查了Cu2+、Co2+、Cd2+、Zn2+和Ni25种重金属离子在二氧化锰上的吸附边.在改良型金属分配模型(MMP模型)的基础上,作者考虑了水解态重金属离子吸附的贡献,构建了MMP-1模型,并分别利用这两种模型去模拟了重金属离子在二氧化锰上的吸附边.两个模型模拟各金属吸附边效果很好且相关系数均达到0.99以上.在pH4.0~6.0范围内,MMP-1模型模拟Cu2+、Co2+吸附边效果要明显优于MMP模型.  相似文献   

18.
There is evidence that degradation of pesticides in simple laboratory systems may differ from that in the field, but it is not clear which of the simplifications inherent in laboratory studies present serious shortcomings. Laboratory experiments evaluated several simplifying assumptions for a clay loam soil and contrasting pesticides. Degradation of cyanazine [2-(4-chloro-6-ethylamino-1,3,5-triazin-2-ylamino)-2-methylpropiononitrile] and bentazone [3-isopropyl-1H-2,1,3-benzothiadiazin-4(3H)-one 2,2-dioxide] at fluctuating temperature and moisture was predicted reasonably well based on parameters derived from degradation under constant conditions. There was a tendency for slower degradation of cyanazine and bentazone in soil aggregates of 3 to 5 mm in diameter (DT50 at 15 degrees C and 40% maximum water holding capacity of 25.1 and 58.2 d, where DT50 is the time for 50% decline of the initial pesticide concentration) than in soil sieved to <3 mm (DT50 of 19.1 and 37.6 d), but the differences were not significant for most datasets. Degradation of cyanazine, isoproturon [3-(4-isopropylphenyl)-1,1-dimethylurea], and chlorotoluron [3-(3-chloro-p-tolyl)-1,1-dimethylurea] was measured in soil amended with different amounts of lignin. The effect of lignin on degradation was small despite considerable differences in sorption. The DT50 values of cyanazine, isoproturon, and chlorotoluron were 16.2, 18.6, and 33.0 d, respectively, in soil without lignin and 19.0, 23.4, and 34.6 d, respectively, in soil amended with 2% lignin. Degradation of bentazone and cyanazine in repacked soil columns was similar under static and flow conditions with 50.1 and 47.2% of applied bentazone and 74.7 and 73.6% of applied cyanazine, respectively, degraded within 20 d of application. Thus, the assumptions underpinning laboratory to field extrapolation tested here were considered to hold for our experimental system. Additional work is required before general conclusions can be drawn.  相似文献   

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