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51.
An intensive campaign was conducted in September 2012 to collect surface water samples along the tributaries of the Pearl River in southern China. Thirteen perfluoroalkyl acids (PFAAs), including perfluorocarboxylates (PFCAs, C4–C11) and perfluorosulfonates (PFSAs, C4, C6–C8, and C10), were determined using high-performance liquid chromatography/negative electrospray ionization–tandem mass spectrometry (HPLC/(-)ESI–MS/MS). The concentrations of total PFAAs (ΣPFAAs) ranged from 3.0 to 52 ng L−1, with an average of 19 ± 12 ng L−1. The highest concentrations of ΣPFAAs were detected in the surface water of the Dong Jiang tributary (17–52 ng L−1), followed by the main stream (13–26 ng L−1) and the Sha Wan stream (3.0–4.5 ng L−1). Perfluorooctanoate (PFOA), perfluorobutane sulfonate (PFBS), and perfluorooctane sulfonate (PFOS) were the three most abundant PFAAs and on average accounted for 20%, 24%, and 19% of ΣPFAAs, respectively. PFBS was the most abundant PFAA in the Dong Jiang tributary, and PFOA was the highest PFAA in the samples from the main stream of the Pearl River. A correlation was found between PFBS and PFOA, which suggests that both of these PFAAs originate from common source(s) in the region. Nevertheless, the slope of PFBS/PFOA was different in the different tributaries sampled, which indicates a spatial difference in the source profiles of the PFAAs.  相似文献   
52.
Ciguatera is food poisoning caused by human consumption of reef fish contaminated with ciguatoxins (CTXs). The expanding international trade of tropical fish species from ciguatera-endemic regions has resulted in increased global incidence of ciguatera, and more than 50 000 people are estimated to suffer from ciguatera each year worldwide. The Republic of Kiribati is located in the Pacific Ocean; two of its islands, Marakei and Tarawa, have been suggested as high-risk areas for ciguatera. The toxicities of coral reef fish collected from these islands, including herbivorous, omnivorous and carnivorous fish (24% [n = 41], 8% [n = 13] and 68% [n = 117], respectively), were analyzed using the mouse neuroblastoma assay (MNA) after CTX extraction. The MNA results indicated that 156 fish specimens, or 91% of the fish samples, were ciguatoxic (CTX levels >0.01 ng g−1). Groupers and moray eels were generally more toxic by an order of magnitude than other fish species. All of the collected individuals of eight species (n = 3-19) were toxic. Toxicity varied within species and among locations by up to 10 000-fold. Cephalapholis argus and Gymnothorax spp. collected from Tarawa Island were significantly less toxic than those from Marakei Island, although all individuals were toxic based on the 0.01 ng g−1 threshold. CTX concentrations in the livers of individuals of two moray eel species (Gymnothorax spp., n = 6) were nine times greater than those in muscle, and toxicity in liver and muscle showed a strong positive correlation with body weight. The present study provides quantitative information on the ciguatoxicity and distribution of toxicity in fish for use in fisheries management and public health.  相似文献   
53.
本研究利用红外光谱(FTIR)、扫描电镜(SEM)和X射线粉末衍射(XRD)观察了共沉淀法合成羟基磷灰石(HAP)的形貌及其晶型结构,并探讨了Ca/P摩尔比、反应时间及反应温度等因素对羟基磷灰石吸附水中氟离子性能的影响。结果表明,n(Ca/P)=1.5/1、反应时间1 h、反应温度40℃、陈化时间48 h、煅烧温度200℃、煅烧时间2 h时,HAP除氟效果最佳,吸附效率和吸附容量分别达到68.8%和6.88 mg/g。实验数据Langmuir等温模式拟合效果优于Freundlich模式,热力学参数计算可知,HAP对氟离子的吸附是自发(ΔG00),吸热(ΔH00),熵增(ΔS00)的过程。HAP对氟离子的吸附符合拟二级反应动力学过程。  相似文献   
54.
基于变异系数法的安徽省节能减排评价研究   总被引:1,自引:0,他引:1  
以行政区域为单位进行节能减排评价研究,分析其中的影响因素,便于因地制宜地采取措施开展节能减排工作。本文以安徽省为研究对象,运用变异系数法对节能减排作评价研究。研究表明,节能减排总体成效显著,但减排问题突出,其中污染物排放与产业结构存在密切关系,进一步的关联分析得出影响减排的主要行业因素。据此,提出从调整产业结构、加强科技创新、完善法规政策方面推进节能减排。  相似文献   
55.
Determining the destructions of both ozone and odd oxygen, Ox, in the nocturnal boundary layer (NBL) is important to evaluate the regional ozone budget and overnight ozone accumulation. This work develops a simple method to determine the dry deposition velocity of ozone and its destruction at a polluted nocturnal boundary layer. The destruction of Ox can also be determined simultaneously. The method is based on O3 and NO2 profiles and their surface measurements. Linkages between the dry deposition velocities of O3 and NO2 and between the dry deposition loss of Ox and its chemical loss are constructed and used. Field measurements are made at an agricultural site to demonstrate the application of the model. The model estimated nocturnal O3 dry deposition velocities from 0.13 to 0.19 cm s?1, very close to those previously obtained for similar land types. Additionally, dry deposition and chemical reactions account for 60 and 40% of the overall nocturnal ozone loss, respectively; ozone dry deposition accounts for 50% of the overall nocturnal loss of Ox, dry deposition of NO2 accounts for another 20%, and chemical reactions account for the remaining 30%. The proposed method enables the use of measurements made in typical ozone field studies to evaluate various nocturnal destructions of O3 and Ox in a polluted environment.  相似文献   
56.
赖正华 《化工环保》1999,19(4):240-242
着重论述了株洲化工集团有限责任公司废水污染物排放总量控制指标的确定方法,并简述了排放总量控制对策。  相似文献   
57.
58.
化学工业固体废物毒性鉴别分析   总被引:2,自引:0,他引:2  
该文介绍了对硫酸烧渣和磷石膏两种固体废物进行急性毒性和浸出毒性鉴别试验的过程与结果 ,并对磷石膏由危险废物转变为非危险废物的原因进行了探讨 ,为硫酸烧渣和磷石膏的处置和利用提供了依据  相似文献   
59.
In April 1998, two intense dust storms were generated in CentralAsia and transported eastward across East Asia (15 and 19 April). This article presents the chemical characterization ofHong Kong (HK) aerosols during the dust storms. During the 15 Aprildust storm, hourly respiratory suspended particles (RSP)(particle diameter smaller than 10 m) concentrationsmonitored at 7 sites in Hong Kong reached the peak valuessynchronously between 9 and 11 a.m. on 17 April, in which thehighest concentration was 267 g m-3. Analysis ofthe RSP samples showed that concentrations of crustalelements (Ba, Ca, Cd, Cr, Fe, Mg, K+) and anthropogenicspecies (As, Ni, Pb, Zn, NH4 +, NO3 -,SO4 2- and total carbon) were substantiallyenhanced. Enhancement of these species was more than afactor of 2 to 14 relative to the non dust period. The totalcarbon content was high, at 59 g m-3 (notincluding carbonate), and the enrichment factors of Asand Pb on 17 April were 122 and 117, respectively. Thisimplied that anthropogenic materials together with mineraldust were transported to HK from Mainland China. Based onmaterial balance calculations, mineral dust contributed41% to the observed RSP mass on 17 April, which was 2 times thatof the nondust sample (22%). From the 5-day backwardtrajectory analysis, this storm was transported directlyfrom Northwest China to HK. However, there was nocorresponding observation for the 19 April dust stormaerosol. Consequently, 15 April storm had stronger impact onHK's atmosphere than 19 April storm. Compared to the HK AirQuality Objective, 15 April dust storm did not cause seriousair pollution in HK.  相似文献   
60.
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