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Zheng D.,Peking University | Wang X.,Peking University | Zhou J.,Ningbo Environmental Monitoring Center | Ying H.,Ningbo Environmental Monitoring Center | And 2 more authors.
Huanjing Kexue Xuebao/Acta Scientiae Circumstantiae | Year: 2015

To investigate PM2.5 pollution characteristics and its major affecting factors, the Models-3/CMAQ modeling system was applied to simulate PM2.5 pollution in Ningbo in January, 2013. The results showed that high levels of PM2.5 occurred in the downtown, the north region and the east coastal region of Ningbo. Besides local emissions, aerosol formation and transport processes of PM2.5 were enhanced during the non-attainment days compared with the attainment days, especially horizontal transport process. The contribution of aerosol formation process was significant near the ground, and decreased gradually with the height. Nitrate accounted for ~70% of secondary fine particulate matter. Sulfate was mainly from the atmospheric transports and primary emissions of Ningbo, accounting for 40% and 44% of sulfate level, respectively. PM2.5 pollution of Ningbo was mainly influenced by the transport of northern coastal air mass (54%), northwestern continental air mass (21%) and western local air mass (25%). The highest PM2.5 concentration was primarily related to short-distance transport from the northwest. When East China suffered from fine particle pollution (haze) on a large scale, long-distance transport from the northwest and the north would also lead to PM2.5 pollution in Ningbo. ©, 2015, Science Press. All right reserved.

Du B.-H.,University of Science and Technology of China | Huang X.-F.,University of Science and Technology of China | He L.-Y.,University of Science and Technology of China | Hu M.,Peking University | And 6 more authors.
Huanjing Kexue/Environmental Science | Year: 2015

To investigate the seasonal and spatial variations of carbon fractions in PM2.5 in Ningbo, PM2.5 samples were collected at 5 sites in typical periods of 4 seasons from December 2012 to October 2013. The concentrations of organic carbon (OC) and elemental carbon (EC) were determined and the contribution of secondary organic carbon (SOC) was estimated. The result shows that: (1) the annual average of PM2.5 in Ningbo is 51.6 μg·m-3. OC and EC account for 17% and 6% respectively. According to the result of the backward trajectory model, the concentrations of PM2.5 in winter and spring are higher mainly because of regional transport from inland China. (2) the OC/EC ratio and the correlation between OC and EC indicate that in summer a large sum of SOC is generated while in winter the influence of coal burning emission for heating in North China may be the main reason for high OC/EC ratio. (3) the contribution of SOC was estimated using an EC tracer method. The result shows that this method is not suitable for both winter and spring because of significant regional transport. The average concentrations of SOC in summer and autumn are 2.5 μg·m-3 and 2.3 μg·m-3, accounting for 42% and 28% of total OC respectively. ©, 2015, Science Press. All right reserved.

Tang J.,Chinese Institute of Urban Environment | Tang J.,Chinese Academy of Sciences | Feng J.,Ningbo Environmental Monitoring Center | Li X.,Chinese Institute of Urban Environment | And 2 more authors.
Environmental Sciences: Processes and Impacts | Year: 2014

Hexabromocyclododecanes (HBCDs) and tetrabromobisphenol A (TBBPA) are of increasing concern because of their potential environmental persistence, bioaccumulation and toxicity. Tris-(2,3-dibromopropyl)isocyanurate (TBC) is another brominated flame retardant (BFR) which has recently been found in the environment and begun to attract attention. The objective of this study is to determine the concentration of these three BFRs in surface soil samples collected from a heavily industrialized and urbanized region in East China. Levels of ∑HBCDs ranged from below detection limits (0.020 ng g -1) to 102.6 ng g-1 on a dry weight basis (dw) with a median level of 15.8 ng g-1 dw. For TBBPA, the concentration ranged from below detection limits (0.025 ng g-1) to 78.6 ng g-1 dw with a median level of 9.17 ng g-1 dw. TBC was found at relatively lower concentrations ranging from below detection limits (0.024 ng g -1) to 16.4 ng g-1 dw with a median level of 0.95 ng g-1 dw. The concentrations of these three BFRs are significantly positively correlated, indicating a common source. Variable BFRs levels were found in different types of soils, with significantly higher concentrations observed at waste dumping sites and industrial areas. The diastereoisomer profiles of HBCDs in most of the soil samples differed from those of the commercial products. The mass inventories of HBCDs, TBBPA and TBC in this region gave preliminarily estimates of 6.68, 2.67 and 0.85 kg, respectively. Therefore, the ubiquitous contamination of soils by these BFRs may well reflect their widespread usage in the study area. This journal is © the Partner Organisations 2014.

Zheng W.-W.,Nankai University | Bi X.-H.,Nankai University | Wu J.-H.,Nankai University | Feng Y.-C.,Nankai University | And 3 more authors.
Research of Environmental Sciences | Year: 2014

Ambient volatile organic compound (VOCs) samples were collected from three sites (urban area, Zhenhai and Beilun) in Ningbo during 2010. A total of 36 VOC species were determined. The chemical composition and spatiotemporal variations of ambient VOCs were investigated. Key reactive species of VOCs were identified based upon OH radical reaction rate (LOH). The average mass concentration of the total VOCs (sum of 36 VOCs) was 198.2 μg/m3, and the major components were alkanes (48.6%), aromatics (33.6%) and alkenes (17.8%). Seasonal concentrations of the total VOCs (ρ (VOCs)) were ordered as winter (298.5 μg/m3) 〉 autumn (174.1 μg/m3) 〉 spring (122.0 μg/m3). ρ (VOCs) in the urban area (161.3 μg/m3) was lower than those in Zhenhai (225.0 μg/m3) and Beilun (208.2 μg/m3). The relative compositions of the total VOCs were stable. Having the similar LOH to ethylene, the chemical reactivity of total VOCs was relatively strong. Alkenes, being only 22% of the mixing ratio of VOCs, contributed the most to LOH and accounted for over 64% of chemical reactivity. The key reactive species of ambient VOCs were 1-butene, trans-2-butene, m, p-xylene, ethylene and pentene. ©, 2014, Editorial Department of Molecular Catalysis. All right reserved.

Shao L.-N.,Lanzhou Jiaotong University | Ren Z.-M.,CAS Yantai Institute of Coastal Zone Research | Zhang G.-S.,CAS Yantai Institute of Coastal Zone Research | Chen L.-L.,CAS Yantai Institute of Coastal Zone Research | And 3 more authors.
Huanjing Kexue/Environmental Science | Year: 2011

To evaluate the contamination of Sn and Hg in the seafood in Yantai coastal areas, three kinds of wild shrimps and crabs were collected from three zones located in the coast in July, 2009. At the same time, seven kinds of mollusks were purchased from the local market. The concentrations of Sn and Hg in the samples were analyzed using an Agilent 7500i inductively coupled plasma-mass spectrometer (ICP-MS). The results showed that Sn and Hg concentrations in all the samples were different, with the ranges of 0.375-0.570 mg·kg-1 and 0.060-0.340 mg·kg-1(d. w.) and the average values of 0.470 and 0.140 mg·kg-1, respectively. For the mollusk samples, Concha ostreae was highly enriched with Sn, with the value of 0.570 mg·kg-1, while Mytilus edulis was obviously enriched with Hg, with the value of 0.340 mg·kg-1. The value of Pi was 1.13, which indicated that Mytilus edulis was seriously polluted. The concentrations of Sn and Hg in Chamys farreri and Sol sricus were the lowest, respectively. For the collected samples, the average concentrations of Sn and Hg in Oratosquilla oratoria, Alpheus brevicristatus and Carpilius convexus in the background area were all lower than those in sewage outfall area and port area, the average concentrations of Sn were 0.520 mg·kg-1(port area), 0.470 mg·kg-1(sewage outfall area) and 0.290 mg·kg-1(background area), the average concentrations of Hg were: 0.160 mg·kg-1(port area), 0.157 mg·kg-1(sewage outfall area) and 0.137 mg·kg-1(background area). Compared with other reports, the Sn level in the studied marine organisms was moderate, but the Hg level was a little higher. However, the concentrations of Sn and Hg in the studied marine seafood were all below the limit for agriculture product safety requirements for non-environmental pollution products, except Hg in Mytilus edulis (the national standards of Sn haven't been established).The results suggested that the coastal areas studied were not significantly polluted by the heavy metals of Sn and Hg. However, from the view of human health, people should consume the seafood away from the sewage outfall area and port area.

Zhang G.,CAS Yantai Institute of Coastal Zone Research | Chen L.,CAS Yantai Institute of Coastal Zone Research | Liu Y.,Pusan National University | Chon T.,Pusan National University | And 5 more authors.
Water Science and Technology | Year: 2011

Due to urgency of the accidental pollution events (APE) on one side and the variability in water quality data on the other side, a new online monitoring and management system (OMMS) was developed for the purpose of sustainable water quality management and human health protection as well. The Biological Early Warning System (BEWS) based on the behavioral responses (behavior strength) of medaka (Oryzias latipes) were built in combination with the physico-chemical factor monitoring system (PFMS) in OMMS. OMMS included a monitoring center and six monitoring stations. Communication between the center and the peripheral stations was conducted by the General Packet Radio Service (GPRS) network transmission complemented by a dial-up connection for use when GPRS was unavailable. OMMS could monitor water quality continuously for at least 30 days. Once APEs occurred, OMMS would promptly notify the administrator to make some follow up decisions based on the Emergency Treatment of APE. Meanwhile, complex behavioral data were analyzed by Self-Organizing Map to properly classify behavior response data before and after contamination. By utilizing BEWS, PFMS and the modern data transmission in combination, OMMS was efficient in monitoring the water quality more realistically. © IWA Publishing 2011.

Leng Y.,Ningbo Institute of Materials Technology and Engineering | Zhang F.,Ningbo Institute of Materials Technology and Engineering | Zhang F.,Anhui Normal University | Zhang Y.,Ningbo Institute of Materials Technology and Engineering | And 4 more authors.
Talanta | Year: 2012

We previously reported a colorimetric assay method for Co 2+ based on the thioglycolic acid (TGA) functionalized hexadecyl trimethyl ammonium bromide (CTAB) modified Au NPs. However, the detection limit of 3 × 10 -7 M was still higher than that of the sanitary standard for drinking water (6.8 × 10 -8 M). In addition, the interactions between the modifier and Au NPs, and between the modifier-Au NPs and Co 2+ remain to be clarified and confirmed. Thus, in the present study, the modified Au NPs solution was dialyzed and its detection limit was optimized to be 5 × 10 -10 M. The interactions between the modifier and Au NPs, and between the modifier-Au NPs and Co 2+ were investigated in both experimental characterizations and theoretical calculations, consistently confirming that the Au NPs were modified by the negatively charged anions of [SCH 2CO 2] 2- through Au-S bonds and Co 2+ was recognized by the modifier-Au NPs through CoO chelate bonds. The results of X-ray photoelectron spectroscopy (XPS) suggest that there were no chemical bonds formed between CTAB and Co 2+. Moreover, the colorimetric assay of Co 2+ using the modified Au NPs has been proved to be a rapid, very sensitive and highly selective method. The validation of the method was carried out by analysis of a certified reference material, GSBZ 50030-94. © 2012 Elsevier B.V. All rights reserved.

Wang T.,CAS Research Center for Eco Environmental Sciences | Han S.,CAS Research Center for Eco Environmental Sciences | Ruan T.,CAS Research Center for Eco Environmental Sciences | Wang Y.,CAS Research Center for Eco Environmental Sciences | And 2 more authors.
Chemosphere | Year: 2013

Hexabromocyclododecane (HBCD) is a high production volume brominated flame retardant (BFR) which has been of increasing environmental and public health concern due to its potential environmental persistency, bioaccumulation and toxicity. Tris-(2,3-dibromopropyl) isocyanurate (TBC) is another BFR which has recently been found in environmental matrices near a manufacturing plant, but its production volume and environmental distribution is currently not well known. This study was conducted to investigate the presence and distribution of these two BFRs in farm soils at a region in southeast Beijing. Total HBCD levels ranged from 0.17 to 34.5ngg-1 on a dry weight basis (dw) with a median level of 2.97ngg-1dw. The composition profile of HBCD diastereoisomers was, on average, 28%, 13% and 59% for α-, β- and γ-HBCD, respectively. Detection frequency of TBC was only 25% in 2010 but was detected in all soil samples in 2011, and the median level was 0.19ngg-1dw with the range between below detection limit to 1.62ngg-1dw. There were no significant differences of HBCD and TBC levels among different irrigation sources in the region. The soil HBCD and TBC levels in samples collected in 2011 were significantly higher than in 2010. The increasing short-term temporal levels in farm soil might be due to the rapid urbanization in this region or could also reflect the increasing usage of HBCD and TBC after the phase out of other BFRs. © 2012.

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