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Dong Y.,Shenyang University | Dong Y.,Key Laboratory of Regional Environment and Eco Remediation | Hu X.,Northeastern University China | Zhang Y.,Shenyang University | Gao D.,Shenyang University
Zhongnan Daxue Xuebao (Ziran Kexue Ban)/Journal of Central South University (Science and Technology)

In order to enhance degradation efficiency, a strain of o-chlorophenol degrading photosynthetic bacteria, named Rhodopseudomonas palustris PSB-1D, was immobilized with sodium alginate as immobilizing carrier and activated carbon as additive material. The optimal preparation condition of the immobilized cells was determined as follows: 1% of activated carbon, 3% of sodium alginate and 1/20 of the mass ratio of the embedded biomass and investment material. Under the optimal immobilization condition, the removal rate of o-chlorophenol by the immobilized cells is 72.6% after 7 d culture time. The o-chlorophenol degrading efficiency of the immobilized cells and free cells were studied and compared with each other. The immobilized cells were then added to the sequencing batch reactor (SBR) and the effects of reaction parameters (immobilized cells addition, aeration time, aeration rate) on o-chlorophenol degradation efficiency in the reactor were studied. The results indicate that immobilized cells have higher o-chlorophenol degradation ability than free cells. Under the condition of dark aerobic, the optimum technological conditions for the bioreactor with effective volume 5 L are as follows: aeration time 10 h, immobilized cells addition 20 g, and aeration rate 100 L/h. Under the conditions, bioreactor system could treat the o-chlorophenol wastewater effectively and steadily, with the removal rate of 65% or so. Source

Niu Z.-X.,Key Laboratory of Regional Environment and Eco Remediation | Sun L.-N.,CAS Shenyang Institute of Applied Ecology | Sun T.-H.,Key Laboratory of Regional Environment and Eco Remediation | Sun T.-H.,CAS Shenyang Institute of Applied Ecology
Advanced Materials Research

Higher biomass producing crops such as sunflower have already been considered as a hyperaccumulating candidate. In the present study, Cd and Pb accumulation by sunflower (Helianthus annuus L.), biomass and root exudates changes in sand cultures was analyzed during 90 days. Results demonstrated that ratios of aerial biomass/ root biomass (AW/RW) in Cd or Pb treatments declined with concentrations of Cd or Pb. Optical density (OD) of root exudates at 190 nm and 280 nm observed in Cd and Pb treatments were lower than the control. In single Cd or Pb treatments, bioconcentration factors (BCF) of Cd or Pb increased with time and decreased with concentrations, the highest Cd-BCF and Pb-BCF appeared in Cd5 (21) and Pb50 (7.95), respectively. Cd-BCF or Pb-BCF showed positive correlations with AW/RW ratios and OD values, and they were negative correlated with Cd and Pb concentrations. In the complex of Cd and Pb treatments, the highest values of BCFs were observed in Cd10+Pb100. Cd-BCF values negatively correlated with AW/RW ratios and Cd concentrations; besides, Pb-BCFs were negative with both Cd and Pb concentrations. Translocation factors (TF) fluctuated irregularly with time and concentration of metals in most treatments. Cd-TF values in single Cd treatments were positive correlated with concentrations of Cd. In the complex of Cd and Pb treatments, Cd-TF showed positive correlations with OD at 280 nm, but negative with Pb concentration. Results in this paper may supply useful information for phytoremediation of soil contaminated with cadmium and lead in situ. © (2011) Trans Tech Publications. Source

Niu X.,Key Laboratory of Regional Environment and Eco Remediation | Zhou L.,Jilin University | Hu X.,Key Laboratory of Regional Environment and Eco Remediation | Han W.,Jilin University
RSC Advances

Cerium-doped mesoporous spinel-type catalysts were prepared via a solution combustion synthesis method and were investigated for the catalytic combustion of soot and NO. Characterization studies using BET, XRD, SEM, TEM and catalytic activity tests confirmed that these catalysts effectively and simultaneously removed soot and NO, which are the two prevalent pollutants in diesel exhaust in the temperature range of 200-600°C. The results from the characterization indicated that the deformation of a spinel structure might occur in the process of cerium substitution. This deformation would increase the oxygen mobility and affect the catalytic performance of cerium modified spinel-type catalysts. This journal is © The Royal Society of Chemistry. Source

Niu X.,Key Laboratory of Regional Environment and Eco Remediation | Zhang H.,Jilin University | Hu X.,Key Laboratory of Regional Environment and Eco Remediation | Han W.,Jilin University
Applied Surface Science

In this paper, SiO2-Al2O3 coatings were deposited on a NiCrFe alloy by dip-coating with tetraethyl orthosilicate and nitrate as the raw materials. The effects of the main preparative parameters on the coating were investigated using XRD, SEM, FTIR, thermal shock cycling, and ultrasonic vibration. The results show that the morphologies, specific surface area, adhesion and thermal stability of the coating are affected by the SiO 2 content in the SiO2-Al2O3 sol and the pre-oxidation temperature of the NiCrFe support. The optimal treatment conditions for producing high-quality coatings were identified from our experimental results. © 2012 Elsevier B.V. Source

Xiao Y.,Key Laboratory of Regional Environment and Eco Remediation | Yang J.S.,Key Laboratory of Regional Environment and Eco Remediation
Applied Mechanics and Materials

Nitrification and denitrification plays an important role in the nitrogen cycle in wetlands. The nitrification and denitrification potentials of soil from different depths (0-40 cm) in Liaohe estuary wetland were studied with laboratorial batch incubation for three weeks. The results showed that the percent of nitrification and denitrification in soil at different depth were about 25-40% and 31-63% of soil total added nitrogen over three weeks, respectively. Both the denitrification and nitrification of soil at different depth showed an exponential decay trend over the incubation period. The corresponding rates were 0.013–0.021 mg·kg-1·d-1 and 0.017–0.057 mg·kg-1·d-1. The value of surface soil (0-5cm) was significant higher than that of the subsoil (5-40 cm) (p < 0.05) and there was no significant difference between values of the subsoil (p > 0.05). © (2014) Trans Tech Publications, Switzerland. All Rights Reserved. Source

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