Zhang Z.,Tongji University |
Zhang Z.,State Key Laboratory of Pollution Control and Resource Reuse |
Zhou Y.,Tongji University |
Zhou Y.,State Key Laboratory of Pollution Control and Resource Reuse |
Xia S.,State Key Laboratory of Pollution Control and Resource Reuse
Environmental Science and Pollution Research | Year: 2014
The extracellular polymeric substance (EPS) extracted from waste activated sludge (WAS) after short-time aerobic digestion was investigated to be used as a novel biosorbent for Cu2+ removal from water. The EPS consisted of protein (52.6 %, w/w), polysaccharide (30.7 %, w/w), and nucleic acid (16.7 %, w/w). Short-time aerobic digestion process of WAS for about 4 h promoted the productivity growth of the EPS for about 10 %. With a molecular weight of about 1.9 × 106 Da, the EPS showed a linear structure with long chains, and contained carboxyl, hydroxyl, and amino groups. The sorption kinetics was well fit for the pseudo-second-order model, and the maximum sorption capacity of the EPS (700.3 mg Cu2+/g EPS) was markedly greater than those of the reported biosorbents. Both Langmuir model and Freundlich model commendably described the sorption isotherm. The Gibbs free energy analysis of the adsorption showed that the sorption process was feasible and spontaneous. According to the complex results of multiple analytical techniques, including scanning electron microscopy, Fourier transform infrared spectroscopy, atomic force microscopy, etc., the adsorption process took place via both physical and chemical sorption, but the electrostatic interaction between sorption sites with the functional groups and Cu2+ is the major mechanism. © 2013 Springer-Verlag Berlin Heidelberg.
Huang L.,State Key Laboratory of Pollution Control and Resource Reuse |
Huang L.,Nanjing University |
Ban J.,State Key Laboratory of Pollution Control and Resource Reuse |
Ban J.,Nanjing University |
And 8 more authors.
Safety Science | Year: 2013
This paper aims to identify factors underlying public risk acceptance of the chemical industry in a case study of Jiangsu Province, China and to explore the diverse views of various demographic groups and in various regions using the psychometric paradigm method. The surveys were conducted between August and December 2010 in three representative cities: Changzhou, Nanjing and Yancheng, located in the southern, central and northern parts of Jiangsu, respectively. Based on 1190 valid questionnaires, the results show that public acceptance of the risk related to the chemical industry could be predicted by four factors: the public perception of their personal knowledge about the chemical industry, the perceived effect of accidents related to the chemical industry, the perceived benefit obtained from the chemical industry, and trust in the government's risk management abilities. Additionally, the study found that respondents' demographic characters, such as gender, age, education level, occupation, and household income, influenced the effect of the four factors on risk acceptance at different degrees. The Effect factor more significantly affected risk acceptance among lower-income residents than that among higher-income persons, and people over age 50 with lower education levels were more sensitive to Knowledge than others. Moreover, Trust was an important factor for risk acceptance among people with various demographic characteristics or regional characteristics. These findings can assist governments and policy makers to select target groups for effective risk communication, and also guide the public to improve their rational judgment on risk acceptability of the chemical industry. © 2012 Elsevier Ltd.
Wei Y.,Tongji University |
Wei Y.,Changzhou University |
Chu H.-Q.,Tongji University |
Dong B.-Z.,State Key Laboratory of Pollution Control and Resource Reuse |
And 3 more authors.
Desalination | Year: 2011
A new PVDF-TiO2 nanowire hybrid ultrafiltration membrane was prepared via phase inversion by dispersing TiO2 nanowires in PVDF casting solutions. The characteristics of the hybrid membranes, i.e., crystal structure, thermal stability, morphology, hydrophilicity, permeation performance, and mechanical properties, were investigated. Results of X-ray diffraction (XRD), thermal gravitational analysis (TGA) and Fourier transform infrared spectroscopy (FTIR) analysis showed that the interaction existed between TiO2 nanowires and PVDF and the thermal stability of the hybrid membrane had been improved by the addition of TiO2 nanowires. Concurrently, dynamic contact angles indicated that the hydrophilicity of the hybrid membranes was enhanced by the addition of TiO2 nanowires. The effects of the TiO2 nanowires in the PVDF on the permeation properties, membrane strength, and antifouling performance were examined. The experimental results indicated that PVDF-TiO2 nanowire hybrid membranes exhibited significant differences in surface properties and intrinsic properties due to TiO2 nanowires addition. Most importantly, PVDF-TiO2 nanowire hybrid membrane can avoid some of the drawbacks of PVDF-TiO2 nanoparticle hybrid membrane, such as, aggregate and leak out of TiO2 nanoparticles, also declining elongation ratio. © 2011.
Ling L.,State Key Laboratory of Pollution Control and Resource Reuse |
Ling L.,Tongji University |
Pan B.,State Key Laboratory of Pollution Control and Resource Reuse |
Pan B.,Nanjing University |
And 2 more authors.
Water Research | Year: 2015
Increasing evidences suggest that nanoscale zero-valent iron (nZVI) is an effective agent for treatment and removal of selenium from water. For example, 1.3mM selenite was quickly removed from water within 3min with 5g/L nZVI. In this work, reaction mechanisms of selenite [Se(IV)] in a single core-shell structured nanoscale zero-valent iron (nZVI) particle were studied with the method of spherical aberration corrected scanning transmission electron microscopy (Cs-STEM) integrated with X-ray energy dispersive spectroscopy (XEDS). This method was utilized to visualize solid phase translocation and transformation of Se(IV) such as diffusion, reduction, deposition and the effect of surface defects in a single nanoparticle. Se(IV) was reduced to Se(-II) and Se(0), which then formed a 0.5nm layer of selenium at the iron oxide-Fe(0) interface at a depth of 6nm from the surface. The results provided near atomic-resolution proof on the intraparticle diffusion-reduction of Se(IV) induced by nZVI. The STEM mapping also discovered that defects on the surface layer accelerate the diffusion of selenium and increase the capacity of nZVI for selenium sequestration. © 2015 Elsevier Ltd.
Liu J.X.,Tongji University |
Dong B.Z.,State Key Laboratory of Pollution Control and Resource Reuse |
Sheng Y.G.,Tongji University |
Wang J.P.,Tongji University
Advanced Materials Research | Year: 2013
The main objective of this study was to investigate foulants in chemical cleaning solutions of membrane(CCSM). Sodium hydroxide (NaOH), sodium hypochlorite (NaOCl), hydrochloric acid(HCl) were used as chemical agents respectively. Hydrophobicity, molecular weight distribution and metal ions of foulants in CCSM were analyzed as the major characters for membrane fouling. Results reveal that alkali cleaning can remove both hydrophobic and hydrophilic fractions of natural organic matters(NOM), and acid cleaning mainly removes hydrophilic organic matters. Medium molecular weight of very hydrophobic acids (1-10 kDa) and different molecular weight of neutral hydrophilic acids (100-1000 Da & >300kDa) in NOM can lead to membrane irreversible fouling. Acid cleaning is relatively effective for the reduction of inorganic foulants. The main metal ions in acid cleaning solutions are K,Ca, Al and Mn, which are responsible for membrane inorganic fouling. © (2013) Trans Tech Publications, Switzerland.
Li B.,State Key Laboratory of Pollution Control and Resource Reuse |
Liu F.,State Key Laboratory of Pollution Control and Resource Reuse |
Wang J.,State Key Laboratory of Pollution Control and Resource Reuse |
Ling C.,State Key Laboratory of Pollution Control and Resource Reuse |
And 4 more authors.
Chemical Engineering Journal | Year: 2012
The high selectivity for the separation of nickel from cobalt-solution by a polyamine chelating resin was explored. As to the sole-component static system, the equilibrium data could be satisfactorily described by the Langmuir isotherm, from which the calculated maximum adsorption capacities for Ni(II) and Co(II) were 0.982. mmol/g and 0.741. mmol/g, respectively. Additionally, in the binary system with high concentration ratio of cobalt and nickel, the uptake amount of resin for both ions decreased, indicating their competitive adsorption behavior on active sites. Separation factors suggested the extremely higher selectivity for Ni(II) against Co(II). The obtained separation factor values indicated the extremely higher selectivity for Ni(II) versus Co(II). The column dynamic breakthrough curves revealed a potential success for the achievement of high-purity cobalt because of the higher initial adsorption rate and capacity toward Ni(II). © 2012 Elsevier B.V.
Cheng C.,Nanjing University |
Wang J.-N.,Nanjing University |
Wang J.-N.,State Key Laboratory of Pollution Control and Resource Reuse |
Yang X.,State Key Laboratory of Pollution Control and Resource Reuse
Chinese Chemical Letters | Year: 2013
The novel chelating sponge modified with hydroxamic acid groups was prepared by a grafting polymerization followed by a nucleophilic substitution reaction. Elementary analysis, SEM, FT-IR spectroscopy and XPS were used to characterize the spongy adsorbent (PVA-MA-HH). Adsorption isotherm study indicated that PVA-MA-HH had high equilibrium adsorption capacity for Cu 2+. © 2013 Jin-Nan Wang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
Xia S.,State Key Laboratory of Pollution Control and Resource Reuse |
Li J.,State Key Laboratory of Pollution Control and Resource Reuse |
Wang R.,State Key Laboratory of Pollution Control and Resource Reuse |
Zhang Z.,State Key Laboratory of Pollution Control and Resource Reuse
Biochemical Engineering Journal | Year: 2010
A compact suspended carrier biofilm reactor (SCBR) was operated at three different C/N ratios (C/N = 10:1, 5:1 and 3:1) with focus on reactor performance and microbial community composition of nitrifying and denitrifying bacteria. The process was capable of achieving over 90% removal of chemical oxygen demand (COD) and over 83.3% of simultaneous nitrification and denitrification (SND) efficiency. Denaturing gradient gel electrophoresis (DGGE) analysis showed that the diversity of ammonia-oxidizing bacteria (AOB) community decreased with inoculation sludge, C/N ratio 3:1, 10:1 and 5:1 in turn. Phylogenetics analysis indicated that there were three distinct groups of AOB in Betaproteobacteria subdivision, where Nitrosomonas were the dominant members in the biofilm. Fluorescence in situ hybridization-flow cytometry (FISH-FCM) results revealed that Alpha-, Beta- and Gamma-proteobacteria accounted for over 50% of all cells. Additionally, the clusters of Nitrosomonas, Nitrosospira, Nitrobacter, Nitrospira and AOB of Betaproteobacteria yielded a similar distribution pattern about 5-12% of all cells. Nested analysis of variance assay (ANOVA) demonstrated that the C/N ratio did not significantly affect the shift of populations in different groups of nitrifying and denitrifying bacteria detected by FISH-FCM. © 2010 Elsevier B.V. All rights reserved.
Wang Y.,State Key Laboratory of Pollution Control and Resource Reuse |
Wang D.,State Key Laboratory of Pollution Control and Resource Reuse |
Wu J.,State Key Laboratory of Pollution Control and Resource Reuse
Journal of Multiple-Valued Logic and Soft Computing | Year: 2012
Human activities, especially dam construction and river channelizations are changing the river environment and stream habitat in the Yangtze River. Aquatic organisms, especially, the four major Chinese carps are affected. Based on the research on the main eco-factors influencing growth and reproduction of the four major Chinese carps, 6 assessment indexes were selected to reflect habitat suitability. A fuzzy comprehensive evaluation model for the four major Chinese carps habitat suitability was developed. The stream habitat for the carp was assessed with the model. The results show that the proposed model is adaptable for assessing stream habitat suitability. The proposed model could provide an effective tool for the river management department assessing the habitat quality. © 2012 Old City Publishing, Inc.
Yang Z.,State Key Laboratory of Pollution Control and Resource Reuse |
Yuan B.,State Key Laboratory of Pollution Control and Resource Reuse |
Li H.,State Key Laboratory of Pollution Control and Resource Reuse |
Yang Y.,State Key Laboratory of Pollution Control and Resource Reuse |
And 3 more authors.
Colloids and Surfaces A: Physicochemical and Engineering Aspects | Year: 2014
Flocculation is one of the most widely applied techniques in water treatment. Polysaccharide-based flocculants have been paid much attention for their eco-friendliness recently. However, precise molecular structure control is greatly important in improving their flocculation performance. In this work, a series of amphoteric starch-based flocculants with different substitution degrees of functional groups (3-chloro-2-hydroxypropyl trimethyl ammonium chloride modified carboxymethyl starch, denoted as CMS-CTA) was synthesized. The flocculation experiments confirmed that the well-designed CMS-CTA flocculants exhibited improved performance in both optimal dosage and pH sensitivity, for not only kaolin, but also hematite suspensions, which have opposite surface charges. Further quantitative mathematical correlations among the preparation recipe, structural features, and flocculation properties were built, providing operational feasibility in the precise molecular control of the flocculants to achieve their desired flocculation performance. Additional experimental results demonstrated that a suitable flocculant could be designed successfully according to the characteristics of the targeted contaminants and structure-activity relationship, proving the effectiveness of molecular structure control for optimization of the flocculation process. © 2014 Elsevier B.V.