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Xu W.,Peking University | Li Q.,Peking University | Li Q.,POTEN Environment Group Co. | Shang J.,Peking University | And 3 more authors.
Journal of Environmental Sciences (China) | Year: 2015

Ozone (O3) is an important atmospheric oxidant. Black carbon (BC) particles released into the atmosphere undergo an aging process via O3 oxidation. O3-aged BC particles may change their uptake ability toward trace reducing gases such as SO2 in the atmosphere, leading to different environmental and health effects. In this paper, the heterogeneous reaction process between O3-aged BC and SO2 was explored via in-situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). Combined with ion chromatography (IC), DRIFTS was used to qualitatively and quantitatively analyze the sulfate product. The results showed that O3-aged BC had stronger SO2 oxidation ability than fresh BC, and the reactive species/sites generated on the surface had an important role in the oxidation of SO2. Relative humidity or 254nm UV (ultraviolet) light illumination enhanced the oxidation uptake of SO2 on O3-aged BC. The oxidation potentials of the BC particles were detected via dithiothreitol (DTT) assay. The DTT activity over BC was decreased in the process of SO2 reduction, with the consumption of oxidative active sites. © 2015.

He S.,Donghua University | Gu C.-C.,Donghua University | Wei X.,Donghua University | Huang S.-L.,POTEN Environment Group Co. | And 3 more authors.
Huanjing Kexue/Environmental Science | Year: 2016

Effect of low-concentration ciprofloxacin (CIP) on nitrification and nitrifying microorganisms of biofilms was studied in biological aerated filters (BAF). Quantitative PCR (qPCR) was used to determine the abundance variance of four ciprofloxacin resistance genes (CIP-ARGs) during nitrification in biofilms. The correlations between the abundances of CIP-ARGs and nitrifying microorganisms were also discussed. The results showed that CIP had little influence on the ammonium oxidation process of biofilm microorganisms, whereas inhibition of the nitrite oxidation process was found. The quantitative results of ammonium-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) including Nitrobacter and Nitrospira indicated that the inhibition on the transformation of nitrite was resulted from the inhibition on Nitrobacter and Nitrospira. In addition, little influence of CIP on the relative abundance of aac and qepA in biofilms was found, but the influence on parC and oqxB was great. The abundance of Nitrobacter exhibited significant positive correlation with the abundance of parC. Similar significant correlation was also found between the abundances of Nitrospira and oqxB. It could be speculated that the genetic elements of different nitrifying microorganisms in biofilms possibly carried CIP-ARGs. © 2016, Science Press. All right reserved.

Zhao X.,Lanzhou University of Technology | Zhao X.,Harbin Institute of Technology | Qiu H.,Lanzhou University of Technology | Zhao Y.,POTEN Environment Group Co. | And 3 more authors.
Environmental Science and Pollution Research | Year: 2015

The concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) in water, suspended particulate matters (SPMs), and sediments in the Lanzhou reach of the Yellow River were investigated in this study. The total PAH concentrations ranged from 548 to 2598 ng/L in water, 1502 to 11,562 ng/g in SPMs, and 181 to 1583 ng/g in sediments. The compositions of PAHs showed that 2- to 3-ring PAHs were abundant in water, 2- to 4-ring PAHs were predominant in SPMs, and 2- to 5-ring PAHs were abundant in sediments. The spatial distribution of PAHs was site-specific and PAHs varied at different sampling locations. The diagnostic ratio analysis indicated that the PAHs mainly had a pyrolytic source. The ecological risk assessment showed that the ecosystem risk of PAHs was low in the Lanzhou reach of the Yellow River. © 2014, Springer-Verlag Berlin Heidelberg.

Liu C.-Z.,Poten Environment Research & Development Center | Wang C.-Y.,Poten Environment Research & Development Center | Qiao R.-P.,Poten Environment Research & Development Center | Yu B.,Poten Beijing Environment Design & Research Institute Co. | And 4 more authors.
Huaxue Gongcheng/Chemical Engineering (China) | Year: 2014

The iron-carbon micro-electrolysis process was used to treat goal gasification wastewater. The influences of initial pH value, reaction time, iron-carbon catalyst dosage and types on the treatment effect were investigated. The results show that Poten-ICME05 can exhibit higher CODCr, turbidity and chromaticity removal performance. The experimental factors were optimized. When the initial pH value was 3.01, the Poten-ICME05 dosage was 80 g/L, and the reaction time was 60 min, the concentration of CODCr in the wastewater after the treatment decreased from 133.6 mg/L to 27.0 mg/L, and the removal efficiency of CODCr was 79.79%; the turbidity of wastewater decreased from 0.63 NTU to 0.29 NTU, and the corresponding removal efficiency was 53.97%; the chromaticity decreased from 260 to 10 unit, and the removal of chromaticity was 96.15%; the biodegradability of the effluent was improved by increasing the ratio of BOD5/CODCr from 0.166 to 0.353.The wastewater treated could meet the local drainage standard of CODCr≤40 mg/L. Thus, the Poten-ICME05 is a micro-electrolysis integration with a good performance on removal of CODCr, turbidity and chromaticity, which can be effectively used for advanced treatment of coal gasification wastewater. ©, 2014, Editorial Office of Chemical Engineering (China). All right reserved.

Li Q.,Peking University | Li Q.,POTEN Environment Group Co. | Shang J.,Peking University | Liu J.,Peking University | And 4 more authors.
Atmospheric Research | Year: 2015

Black carbon (BC) particles play important roles in climate change, visibility impairment, atmospheric reaction process, and health effect. The aging processes of BC alter not only atmospheric composition, but also the physicochemical characteristics of BC itself, thus impacting the environment and health effects. Here, three types of BC including sulfate-coated, 1,4-naphthoquinone (1,4-NQ)-coated, and O3-aged BC are presented. The morphologies, structures, extraction components, the amount of water-soluble organic carbon (WSOC) and free radical intensities of the three types of BC particles are examined by transmission electron microscopy, diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), ultraviolet-visible spectrophotometry, total organic carbon detector and electron paramagnetic resonance, respectively. Dithiothreitol (DTT) and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide assays are utilized to assess the changes in oxidative capacity and cytotoxicity towards murine alveolar macrophage cells. The orders of DTT activities and cytotoxicities of the particles are both arranged as follows: BC/1,4-NQ>BC/O3>BC>BC/sulfate, mainly because 1,4-NQ owned high oxidative potential and cytotoxicity, while sulfate did not exhibit oxidative capacity and cytotoxicity. The insoluble components of particles contribute most of the total DTT activity, whereas either water or methanol extract is minor contributor. DTT activity was positively correlated with both WSOC content and free radical intensity, with the correlation between DTT activity and WSOC content was stronger than that between DTT activity and free radical intensity. © 2014 Elsevier B.V.

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