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Bao J.,Jiangsu Academy of Environmental Sciences | Fu Y.,Tongji University | Bao Z.,Tongji University
Nanoscale Research Letters | Year: 2013

A thiol-functionalized magnetite/graphene oxide (MGO) hybrid as an adsorbent of Hg2+ was successfully synthesized by a two-step reaction. It exhibited a higher adsorption capacity compared to the bare graphene oxide and MGO due to the combined adsorption of thiol groups and magnetite nanocrystals. Its capacity reached 289.9 mg g-1 in a solution with an initial Hg2+ concentration of 100 mg l-1. After being exchanged with H+, the adsorbent could be reused. The adsorption of Hg2+ by the thiol-functionalized MGO fits well with the Freundlich isotherm model and followed pseudo-second-order kinetics. © 2013 Bao et al.

Chen F.,Nanjing University of Science and Technology | Hu W.,Jiangsu Academy of Environmental Sciences | Zhong Q.,Nanjing University of Science and Technology
Atmospheric Research | Year: 2013

Real-world vehicle emission factors for PM10 (particulate matter with aerodynamic diameter smaller than 10μm) and particle-phase polycyclic aromatic hydrocarbons (PAHs) from mixed vehicles were quantified in the Fu Gui-shan Tunnel of Nanjing during summer and winter of 2010. Concentrations of PM10 and sixteen particle phase polycyclic aromatic hydrocarbons (PAHs) in the entrance and exit of the tunnel were studied. The results showed that the four most abundant particular phase polycyclic aromatic hydrocarbons (PAHs) of motor vehicle were benzo[ghi]perylene, benzo[k]fluoranthene, benz[a]anthracene and benzo[a]pyrene. The emission factors for PM10 and particle-phase PAHs were 687mgveh-1km-1 and 18.853mgveh-1km-1 in summer, 714mgveh-1km-1 and 20.374mgveh-1km-1 in winter. Higher particle-phase PAH emission factors were found to be associated with a high proportion of diesel-fueled vehicles (DV). The estimated PM10 emission factor of gasoline-fueled vehicles (GV) was 513mgveh-1km-1 and the value for DV was 914mgveh-1km-1, while EFDV of particulate PAH (31.290mgveh-1km-1) was nearly 4 times higher than EFGV (9.310mgveh-1km-1). The five highest emission factors of diesel-fueled vehicles (DV) were benzo[ghi]perylene, benzo[k]fluoranthene, Indeno[1,2,3-cd]pyrene, benz[a]anthracene and benzo[a]pyrene, which was similarly found in the gasoline-fueled vehicles (GV). The sum of these five emission factors accounted for ~69% of the total particle-phase PAH of DV and ~67% of GV. © 2013 Elsevier B.V.

Wang N.-X.,Nanjing University | Li Y.,Jiangsu Academy of Environmental Sciences | Deng X.-H.,CAS Nanjing Institute of Soil Science | Miao A.-J.,Nanjing University | And 2 more authors.
Water Research | Year: 2013

In the present study, the toxicity and bioaccumulation kinetics of arsenate in two green algae Chlamydomonas reinhardtii and Scenedesmus obliquus under phosphate-enriched (+P) and limited (-P) conditions were investigated. P-limitation was found to aggravate arsenate toxicity and S. obliquus was more tolerant than C. reinhardtii. Such phosphate-condition-dependent or algal-species-specific toxicity difference was narrowed when the relative inhibition of cell growth was plotted against intracellular arsenate content instead of its extracellular concentration. The discrepance was further reduced when the intracellular ratio of arsenic to phosphorus was applied. It suggests that both arsenate bioaccumulation and intracellular phosphorus played an important role in arsenate toxicity. On the other hand, arsenate uptake was induced by P-limitation and its variation with ambient arsenate concentration could be well fitted to the Michaelis-Menten model. Arsenate transporters of S. obliquus were found to have a higher affinity but lower capacity than those of C. reinhardtii, which explains its better regulation of arsenate accumulation than the latter species in the toxicity experiment. Further, arsenate depuration was facilitated and more was transformed to arsenite in C. reinhardtii or under -P condition. Intracellular proportion of arsenite was also increased after the algae were transferred from the long-term uptake media to a relatively clean solution in the efflux experiment. Both phenomena imply that algae especially the sensitive species could make physiological adjustments to alleviate the adverse effects of arsenate. Overall, our findings will facilitate the application of algae in arsenate remediation. © 2013 Elsevier Ltd.

Shen G.,Jiangsu Academy of Environmental Sciences | Shen G.,Oak Ridge Institute for Science and Education
Biomass and Bioenergy | Year: 2016

Household biomass and coal use is an important source of PM2.5 emission in China due to low efficient burnings and large consumptions. Primary PM2.5 emissions for different fuels are compared based on a compilation of data from emission measurements of Chinese cookstoves in literature. The burning of pellets had low PM2.5 emissions at 0.42 and 0.18 g MJd -1 for straw and wood pellets, respectively. There would be an emission reduction of about 80% compared to ordinary raw biomass fuel burning for cooking. The average emissions of PM2.5 per useful energy delivered were 0.10 and 0.28 g MJd -1 for anthracite briquette and chunk, but as high as 1.2 and 3.2 g MJd -1 for bituminous briquette and chunk, respectively. Coals burned in the form of briquette may lower PM2.5 emission by 60% compared to the burning of raw chunk. The adoption of improved high efficiency cookstoves would have a comparable reduction in primary emissions compared to a fuel switch. Gas should be promoted for cooking as primary PM2.5 emissions are 1,2 orders of magnitude lower compared to those for solid fuels. More emission measurements and fuel consumption survey are needed to fill data gap and to support interventions of advanced fuel-stove combinations. © 2016 Elsevier Ltd.

Jiangsu Academy of Environmental Sciences | Date: 2014-04-24

The present disclosure discloses a method for determining ecological risks of polycyclic aromatic hydrocarbon in a water body. The method may include (1) screening representative species of a water ecological system in a region; (2) obtaining toxicity data of benzoapyrene; (3) calculating benzoapyrene concentration values HC5 of 95% of species in the protected water ecological system; (4) determining types of polycyclic aromatic hydrocarbon pollutants and corresponding environmental concentrations thereof by sampling, and analyzing concentration distribution characteristics of various polycyclic aromatic hydrocarbons; (5) calculating ecological risk quotient values RQi of specific polycyclic aromatic hydrocarbon pollutants; and (6) calculating a total ecological risk quotient value RQt and confirming concrete ecological risks. The method may analyze whether potential risks caused by the polycyclic aromatic hydrocarbon pollutants are acceptable, and determine whether the total level of the ecological risks of the water body needs to be controlled.

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