Wyniki wyszukiwania - Biblioteka Nauki

1

Advanced treatment of leachate secondary effluent by a combined process of MFPFS coagulation and sulfate radical oxidation

100%

Liu Z. , Zhan P. , Nie F.

Polish Journal of Environmental Studies

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2016

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tom 25

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nr 4

EN

Leachate secondary effluent is usually unable to meet the national discharge permit in China and further treatment is a significant challenge because of the residual persistent pollutants. A novel magnetic composite coagulant of MFPFS was prepared from Fe3O4 nanoparticles and polymeric ferric sulfate (PFS). Landfill leachate secondary effluent was treated by MFPFS coagulation combined with sulfate radical oxidation due to Fe2+ activation. Higher COD and color removals were achieved using the MFPFS magnetic coagulant than by adding the coagulant PFS alone. Under the working conditions of 1:3 Fe3O4/PFS mass ratios, 1.2 g/L MFPFS dosage, 50 min sedimentation time, and without pH adjustment, the removals of COD and color reached up to 60% and 80%, respectively. In the oxidation process, Na2S2O8 was activated by Fe2+ to generate sulfate radicals to oxide the residual pollutants in the effluent from MFPFS coagulation. In general, higher temperature, higher dosage, and lower pH were in favor of the oxidation efficiencies. Under the working conditions of 2.4 g/L Na2S2O8 dosage, 0.3 Fe2+/S2O8 2- molar ratio, pH 3.0, and 60ºC temperature, the COD and color removals can reach up to 75% and 95%. After being treated by the combined process, no violation of Chinese effluent standards for landfill leachate was found in respect of each individual parameter, including COD, color, and other parameters like BOD, total nitrogen, and ammonia nitrogen. The combined process was a promising alternative treatment pathway for leachate secondary effluent.

2

Preparation, characterization and coagulation behaviour of a novel inorganic coagulant - polyferric(III)-magnesium(II) sulfate

88%

Liu Z. , Li S. , Zhang H. , Nie F. , Wang Q.

Environment Protection Engineering

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2013

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tom Vol. 39, nr 3

57--71

EN

A novel coagulant, polyferric(III)-magnesium(II) sulfate (PFMS), was prepared. The preparation technology was optimized and the optimized PFMS product was used to treat actual textile wastewater. The performance of PFMS was evaluated and compared with those of conventional coagulants. X-ray diffraction and infrared spectrometry show that PFMS is a macromolecular composite polymer of ferric and magnesium based on -OH bonds. The coagulation performance of PFMS is better than those of PFS, PAC, and PFC. The coagulation mechanism of PFMS in treating actual textile wastewater is primarily driven by charge neutralization at low dosages and co-precipitation netting at high dosages.

3

Characterization of a novel transcript variant of human STAU1 gene

88%

Nie F. , Yao H. , Qi R. , Li X. , Wu C.

Acta Biochimica Polonica

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2008

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tom 55

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nr 3

473-478

EN

Human STAU1 is one member of the family of double-stranded RNA (dsRNA)-binding proteins. It is thought to function in transporting mRNA, controlling translation and eliciting mRNA decay in neurons, and to function in infection of influenza virus and human immunodeficiency virus type 1 (HIV-1). Four transcripts coding two isoforms have been identified before. In this study, we have isolated a novel transcript of STAU1, coding a novel isoform that has six amino acids more (SFPLKQ) than isoform a. In order to examine the tissue distribution of this novel isoform, we have performed RT-PCR experiments and the analysis showed that it was highly expressed in heart, liver, kidney and pancreas.

4

Pollutant removal and PCR-DGGE analysis of microbial community structural changes in an integrated vertical-flow constructed wetland

88%

Nie F. , Zhou Y. , Liu R. , Liu Z. , Huang D.

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nr 2

EN

In this study we measured changes in the CODCr, TN, NH4+-N, TP, and DO concentrations and the pH of different layers in an integrated vertical-flow constructed wetland (IVCW) treating eutrophic water. We also examined the composition and diversity of the bacterial community in the IVCW using PCR-DGGE. Our results showed that most of the contaminants were removed during sewage flow from the down-flow chamber to the up-flow chamber. The removal rates of TN, TP, CODCr, and NH4+-N were, respectively, 63.7%, 66.7%, 72.2%, and 67.9% in the down-flow; consequently, the CODCr and TP concentrations of the effluent fell below 10 mg/L and 0.05 mg/L. There were some common microorganisms and specific microorganisms in the different layers of the constructed wetland because of the changes in environmental factors and nutrient levels. The diversity of the bacterial community was highest in the upper layer of the down-flow system, and the similarity in the down-flow system was higher than that in the up-flow system. From the down-flow system to the up-flow system, the diversity of the bacterial community increased from 2.31 to 1.95 and the structural similarity gradually increased from 65.7% to 70.9%. The higher complexity of the bacterial community in the upper layer of the constructed wetland may be supported by plant oxygenation, rhizodeposition, and litter accumulation.