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Xu D.,Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control | Xu D.,Nanjing University of Information Science and Technology | Gu J.,Nanjing University of Information Science and Technology | Li Y.,Nanjing University of Information Science and Technology | And 5 more authors.
Environmental Science and Pollution Research | Year: 2016

The response of purifying capability, enzyme activity, nitrification potentials, and total number of bacteria in the rhizosphere in December to wetland plants, substrates, and earthworms was investigated in integrated vertical flow constructed wetlands (IVFCW). The removal efficiency of total nitrogen (TN), NH4–N, chemical oxygen demand (COD), and total phosphorus (TP) was increased when earthworms were added into IVFCW. A significantly average removal efficiency of N in IVFCW that employed river sand as substrate and in IVFCW that employed a mixture of river sand and Qing sand as substrate was not found. However, the average removal efficiency of P was higher in IVFCW with a mixture of river sand and Qing sand as substrate than in IVFCW with river sand as substrate. Invertase activity in December was higher in IVFCW that used a mixture of river sand and Qing sand as substrate than in IVFCW which used only river sand as substrate. However, urease activity, nitrification potential, and total number of bacteria in December was higher in IVFCW that employed river sand as substrate than in IVFCW with a mixture of river sand and Qing sand as substrate. The addition of earthworms into the integrated vertical flow constructed wetland increased the above-ground biomass, enzyme activity (catalase, urease, and invertase), nitrification potentials, and total number of bacteria in December. The above-ground biomass of wetland plants was significantly positively correlated with urease and nitrification potentials (p < 0.01). The addition of earthworms into IVFCW increased enzyme activity and nitrification potentials in December, which resulted in improving purifying capability. © 2015, Springer-Verlag Berlin Heidelberg.


Zheng Y.,Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control | Zheng Y.,Nanjing University of Information Science and Technology | Xu W.,Nanjing University of Information Science and Technology | Wu R.,Nanjing University of Information Science and Technology | And 4 more authors.
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2012

During the last several decades, significant reductions in the concentrations of stratospheric ozone(O3) have been reported. This reduced ozone concentration causes an increment in ultraviolet-B radiation approaching to the surface earth. The elevated UV-B radiation and increased tropospheric O3 concentrations maybe occur together and cause reductions in physiological and biochemical characteristics of crops and economic plants. The effects of UV-B and O3 on plant growth and productivity have been reported separately for a large number of species by filed experiment, but only few experiments have focused on their interaction, it is not clear whether UV-B and O3 induced damages are brought about with similar mechanisms. This uncertainty has largely been due to the lack of an experimental approachs to investigate the responses of a single species exposed to UV-B and O3 under well-defined experimental conditions. Studies were conducted under the open-top-chambers conditions so as to assess photosynthesis changes of soybean (Glycine max, Bayuehuang) with supplemental UV-B radiation (10% -10. 9% higher than control group, T1) and enhanced ozone [(100 ±9) nmol/ mol, T2], separately and in combination (combination treatment, T3), by investigating photosynthetic pigment, flavonoid content and gas exchange parameters with application of LCpro + Portable Photosynthesis System. Results indicate that net photosynthetic rate(Pn),maximum photosynthetic rate(Pmax), somatic conductance(Gs), half-saturation light intensity (Ik)and stomatal limitation (Ls)of T1 treatment decreased significantly compared with CK (control group, natural air and UV-B radiant intensity condition). With same references, inter-cellular CO2 concentration (Ci) and flavonoid content increased, the apparent quantum yield(AQY) and the dark respiration rate (Rd)raised first and then decreased, and the cartenoid content decreased first and then raised while the content of chlorophyll had faint decrease if compared with CK. The change pattern of Pn, Pmax, Ik, Gs, Ci and Ls of T2 treatment was similar to those of T1 treatment while the content of chlorophyll and cartenoid decreased significantly compared with CK; flavonoid content of T2 showed slightly decrease at early stages, but sharp increase at latter stages. The change pattern of Pn, Pmax, Ik, Gs, Ls, Ci and Rd of T3 treatment was also similar to those of T1 treatment while the content of cartenoid and chlorophyll decreased obviously compared with CK with lower chlorophyll content than that of T1 and T2. Obviously, enhanced ozone caused significant decrease in chlorophyll content, but supplemental UV-B radiation had no impressive effect on it. Compared with UV-B and O3 alone, UV-B and O3 in combination enhanced the negative effects on soybean chlorophyll content, and ozone stress dominated the combination stress effect of O3 and UV-B. The decrease of photosynthesis was mainly due to non-stomatal factors. UV-B and O3 in combination enhanced the negative effects on soybean compared with UV-B and O3 alone.


Yu H.,Nanjing University of Information Science and Technology | Yu H.,Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control | Zhou L.,Nanjing University of Information Science and Technology | Dai L.,Nanjing University of Information Science and Technology | And 8 more authors.
Atmospheric Chemistry and Physics | Year: 2016

Particle size distribution down to 1.4 nm was measured in the urban atmosphere of Nanjing, China, in spring, summer, and winter during 2014-2015. Sub-3 nm particle event, which is equivalent to nucleation event, occurred on 42 out of total 90 observation days, but new particles could grow to cloud condensation nuclei (CCN)-active sizes on only 9 days. In summer, infrequent nucleation was limited by both unfavorable meteorological conditions (high temperature and relative humidity - RH) and reduced anthropogenic precursor availability due to strict emission control measures during the 2014 Youth Olympic Games in Nanjing. The limiting factors for nucleation in winter and spring were meteorological conditions (radiation, temperature, and RH) and condensation sink, but for the further growth of sub-3 nm particles to CCN-active sizes, anthropogenic precursors again became limiting factors. Nucleation events were strong in the polluted urban atmosphere. Initial J1.4 at the onset and peak J1.4 at the noontime could be up to 2.1 × 102 and 2.5 × 103 cm-3 s-1, respectively, during the eight nucleation events selected from different seasons. Time-dependent J1.4 usually showed good linear correlations with a sulfuric acid proxy for every single event (R2 = 0.56-0.86, excluding a day with significant nocturnal nucleation), but the correlation among all eight events deteriorated (R2 = 0.17) due to temperature or season change. We observed that new particle growth rate (GR) did not increase monotonically with particle size, but had a local maximum up to 25 nm h-1 between 1 and 3 nm. The existence of local maxima GR in sub-3 nm size range, though sensitive to measurement uncertainties, gives new insight into cluster dynamics in polluted environments. In this study such growth rate behavior was interpreted as the solvation effect of organic activating vapor in newly formed inorganic nuclei. © Author(s) 2016.


Yao L.,Nanjing University of Information Science and Technology | Yao L.,Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control | Yao L.,Fudan University | Ma Y.,Nanjing University of Information Science and Technology | And 12 more authors.
Atmospheric Environment | Year: 2014

Atmospheric ozonolysis of sesquiterpenes is an important source of secondary organic aerosols (SOA). The mechanisms by which Criegee Intermediates (CIs) react to form SOA precursors and the influence of environmental conditions, however, remain unclear. On the basis of environmental chamber experiments coupled with detailed characterization of gas-phase and particle-phase products, we present evidence that a significant fraction of CIs from ozonolysis of α-cedrene are stabilized and bimolecular reactions of these stabilized CIs (SCIs) play a key role in the formation of SOA precursors. Ozonolysis experiments were conducted in a 4.5m3 collapsible fluoropolymer chamber under various conditions in the presence of the OH radical and SCI scavengers. The size and mass of SOA particles produced during ozonolysis were measured directly and used for calculation of particle effective density and mass yield. Gaseous and particulate products were analyzed by several mass spectrometry methods. A total of 14 compounds in gas phase and 17 compounds in particle phase were tentatively identified. The major gas-phase products are secondary ozonides (SOZ) from intramolecular reactions of SCIs. Multifunctional organic acids are dominant particle-phase products. The measured density of aerosol particles is 1.04±0.03 to 1.38±0.03g/cm3, and the aerosol mass yield is (23.7±0.4)% to (46.4±6.5)%, depending on reaction conditions. The presence of acetic acid, an SCI scavenger, inhibits new particle formation, but leads to increased aerosol mass yield. In contrast, the addition of SO2 dramatically enhances new particle formation and total aerosol yield. The calculated OH formation yield decreases from (62.4±4.9)% to (9.0±1.6)% upon addition of SCI scavengers CH3COOH and SO2, indicating that a large fraction of excited CIs are collisionally stabilized and unimolecular decomposition of SCIs via the hydroperoxide channel can be suppressed by bimolecular reactions. The reaction of SCIs with SO2 leads to the formation of sulfuric acid, an important nucleation precursor. From the consumption of SO2 added as SCI scavenger, a lower-limit yield of SCIs from α-cedrene ozonolysis is estimated at ~88%. Our work underscores the key role of SCIs in SOA formation and observed composition of gas- and particle-phase products from α-cedrene ozonolysis. Bimolecular reactions of sesquiterpene CIs with atmospherically relevant species (e.g. SO2, H2O) need to be considered when assessing the atmospheric relevance of ozonolysis of sesquiterpenes. © 2014 Elsevier Ltd.


Wu R.,Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control | Wu R.,Nanjing University of Information Science and Technology | Ge Q.,Nanjing University of Information Science and Technology | Zhan X.,The Center for Satellite Applications and Research | And 2 more authors.
Journal of Natural Disasters | Year: 2014

To construct effective drought monitoring and evaluation index, the moderate resolution imaging spectrometer (MODIS) data and the NCEP/NCAR reanalysis data were utilized, and on the basis of remote sensing process model (BEPS), the surface evapotranspiration was simulated in this paper. At the same time, using the data of flux observation network AmeriFlux, the reliability and adaptability of this model was validated. On this basis, relative moisture index (BMI) was constructed to analyze the temporal and spatial distribution characteristics of regional dry and wet conditions in 2007-2009, and was compared with other drought index. The findings suggest that, BEPS model has a good effectiveness for terrestrial ecosystem evapotranspiration in the United States of America. The correlation coefficient of 12 sites reaches 0. 8568 (p < 0.01). Spatial distribution characteristics of BMI value is obvious, and is consistent with latitudinal change and longitude of the precipitation and evapotranspiration. The temporal distribution characteristic of BMI values shows that, its seasonal variation is significant too. It is closely linked with the terrain, climatic characteristic and vegetation distribution. Affected by precipitation, good indication effectiveness of BMI on drought monitoring is in the month scale or seasonal scale. The correlation coefficients of BMI and USDM show that, the constructed index based on the BEPS model simulating ET is feasible in drought monitoring.


Han Y.,Nanjing University of Information Science and Technology | Zheng Y.-F.,Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control | Wu R.-J.,Nanjing University of Information Science and Technology | Yin J.-F.,Nanjing University of Information Science and Technology | Sun X.,Nanjing University of Information Science and Technology
Huanjing Kexue/Environmental Science | Year: 2014

Employing floating static chamber-chromatography method, the N2O diurnal fluxes at the water-air interface of four rivers(Tuanjie River, Jinchuan River, Inner and Outer Qinhuai River)and Jinniu Lake were monitored in Nanjing during summer. The results show that four rivers act as the sources of N2O emission, but Jinniu Lake is characterized by the absorption of N2O. The highest N2O flux from Inner Qinhuai presented at 20:00 because of the changing of hydrodynamic conditions. Both Jinchuan and Tuanjie rivers' minimum N2O fluxes were detected when the content of dissolved oxygen was extremely low. The tendency of N2O from Outer Qinhuai showed a double-peak because of its daytime nitrification and nocturnal denitrification. The flux of N2O from Jinniu Lake had been noted as being generally higher at night than that during light hours due to the effect of wind. For natural rivers, the proper sampling period is from 08:00 to 12:00, but for the river subjected to interference, the sampling period is different.


Guo Z.-B.,Nanjing University of Information Science and Technology | Guo Z.-B.,Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control | Chen T.,Nanjing University of Information Science and Technology | Chen T.,Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control | And 3 more authors.
Zhongguo Huanjing Kexue/China Environmental Science | Year: 2011

Modification of wasted eggshell using ferric salt and phosphorus adsorption behaviors on the iron-coated eggshell are investigated. The results show that phosphorus adsorption capacity can be markedly improved on iron-coated eggshell compared to that on eggshell without modification. Phosphorus adsorption on iron-coated eggshell is an endothermal process, and its adsorption isotherms can be well described by Freundlich equation. The time-resolved curves of phosphorus adsorption on iron-coated eggshell follows pseudo-second-order kinetic model. In addition, solution initial pH values have a significant effect on phosphorus adsorption. the maximum phosphorus adsorption amount on iron-coated eggshell can be achieved at pH value of 3.


Guo Z.,Nanjing University of Information Science and Technology | Guo Z.,Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control | Dong Q.,Huazhong University of Science and Technology | He D.,Nanjing University of Information Science and Technology | And 3 more authors.
Chemical Engineering Journal | Year: 2012

The treatment of bisphenol A (BPA)-contaminated solution has attracted more and more interests recently. In this contribution, BPA removals using gamma radiation in presence of different additives were carried out. It can be observed that absorbed dose, BPA initial concentration, solution pH, dissolved oxygen and organic matters were the important factors in influencing BPA decomposition during gamma radiation. Based on the results of quantum chemical calculations and GC-MS analysis, we suggested BPA degradation pathway to produce ortho-position monohydroxylated BPA and meta-position monohydroxylated BPA via OH radical oxidation. In addition, gamma radiation resulted in a slight decrease in pH and TOC data of BPA-containing aqueous solution. © 2011 Elsevier B.V.


Guo Z.,Nanjing University of Information Science and Technology | Guo Z.,Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control | Zhou F.,Nanjing University of Information Science and Technology | Zhou F.,Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control | And 9 more authors.
Chemical Engineering Journal | Year: 2012

Gamma irradiation-induced removal of sulfadiazine (SD) under different conditions was investigated. The results show that SD can be effectively degraded using gamma irradiation. The removal efficiencies of low-concentration SD can be remarkably improved in an acid solution, and SD degradation was in accordant with the pseudo-first-order kinetic model. The additives, such as H 2O 2 and Fenton reagent, were favorable for removing SD during gamma irradiation. However, SD removal was restrained with the addition of Na 2CO 3. Adding CH 3OH in solution, we found that SD removal was restrained at low-irradiation dose while markedly promoted at high-irradiation dose. Based on the results of quantum chemical calculations and LC-MS analysis, SD degradation using gamma irradiation in aqueous solution is mainly ascribed to OH oxidation and the direct decomposition of SD molecules. © 2012 Elsevier B.V.


PubMed | Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Nanjing University of Information Science and Technology and University of Reading
Type: Journal Article | Journal: Environmental science and pollution research international | Year: 2016

The response of purifying capability, enzyme activity, nitrification potentials, and total number of bacteria in the rhizosphere in December to wetland plants, substrates, and earthworms was investigated in integrated vertical flow constructed wetlands (IVFCW). The removal efficiency of total nitrogen (TN), NH4-N, chemical oxygen demand (COD), and total phosphorus (TP) was increased when earthworms were added into IVFCW. A significantly average removal efficiency of N in IVFCW that employed river sand as substrate and in IVFCW that employed a mixture of river sand and Qing sand as substrate was not found. However, the average removal efficiency of P was higher in IVFCW with a mixture of river sand and Qing sand as substrate than in IVFCW with river sand as substrate. Invertase activity in December was higher in IVFCW that used a mixture of river sand and Qing sand as substrate than in IVFCW which used only river sand as substrate. However, urease activity, nitrification potential, and total number of bacteria in December was higher in IVFCW that employed river sand as substrate than in IVFCW with a mixture of river sand and Qing sand as substrate. The addition of earthworms into the integrated vertical flow constructed wetland increased the above-ground biomass, enzyme activity (catalase, urease, and invertase), nitrification potentials, and total number of bacteria in December. The above-ground biomass of wetland plants was significantly positively correlated with urease and nitrification potentials (p<0.01). The addition of earthworms into IVFCW increased enzyme activity and nitrification potentials in December, which resulted in improving purifying capability.

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