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Huang Z.,South China Agricultural University | Huang Z.,South China University of Technology | Wu P.,South China University of Technology | Wu P.,Key Laboratory of Pollution Control | And 7 more authors.
PLoS ONE | Year: 2016

To achieve a satisfactory removal efficiency of heavy metal ions from wastewater, silane-functionalized montmorillonite with abundant ligand-binding sites (-NH2 ) was synthesized as an efficient adsorbent. Ca-montmorillonite (Ca-Mt) was functionalized with 3-aminopropyl triethoxysilane (APTES) to obtain the APTES-Mt products (APTES1.0CEC -Mt, APTES2.0CEC -Mt, APTES3.0CEC -Mt, APTES4.0CEC -Mt) with enhanced adsorption capacity for Co2+ . The physicochemical properties of the synthesized adsorbents were characterized by spectroscopic and microscopic methods, and the results demonstrated that APTES was successfully intercalated into the gallery of Ca-Mt or grafted onto the surface of Ca-Mt through Si-O bonds. The effect of solution pH, ionic strength, temperature, initial concentrations and contact time on adsorption of Co2+ by APTES-Mt was evaluated. The results indicated that adsorption of Co2+ onto Ca-Mt, APTES1.0CEC -Mt and APTES2.0CEC -Mt can be considered to be a pseudo-second-order process. In contrast, adsorption of Co2+ onto APTES3.0CEC -Mt and APTES4.0CEC -Mt fitted well with the pseudo-first-order kinetics. The adsorption isotherms were described by the Langmuir model, and the maximum adsorption capacities of APTES1.0CEC -Mt, APTES2.0CEC -Mt, APTES3.0CEC -Mt and APTES4.0CEC -Mt were 25.1, 33.8, 61.6, and 61.9 mgg-1 , respectively. In addition, reaction temperature had no impact on the adsorption capacity, while both the pH and ionic strength significantly affected the adsorption process. A synergistic effect of ion exchange and coordination interactions on adsorption was observed, thereby leading to a significant enhancement of Co2+ adsorption by the composites. Thus, APTES-Mt could be a cost-effective and environmental-friendly adsorbent, with potential for treating Co2+ -rich wastewater. © 2016 Huang et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Hu W.C.,South China University of Technology | Hu W.C.,Key Laboratory of Pollution Control | Wu C.D.,South China University of Technology | Wu C.D.,Key Laboratory of Pollution Control | And 3 more authors.
Water Science and Technology: Water Supply | Year: 2015

The effects of raw diatomite on coagulation performance (CP) and the contents of residual aluminum (RAl) during the Pearl River water treatment with polyaluminum chloride (PAC) were investigated. Results demonstrated that the addition of raw diatomite could significantly improve the CP. The removal efficiencies (REs) of turbidity, dissolved organic carbon and UV254 could achieve 97.63%, 44.31% and 52.31%, respectively, at PAC dose of 20 mg/L and diatomite dose of 40 mg/L. Furthermore, adding appropriate dose of diatomite (less than 40 mg/L) could greatly reduce the RAl contents. The residual total aluminum and residual total dissolved aluminum both reached the lowest concentrations (0.185 mg/L and 0.06 mg/L, respectively) when the PAC dose was 15 mg/L and diatomite dose was 40 mg/L. © 2015 IWA Publishing.

Wu Y.,South China University of Technology | Wu Y.,Key Laboratory of Pollution Control | Luo H.,South China University of Technology | Luo H.,Key Laboratory of Pollution Control | And 5 more authors.
RSC Advances | Year: 2015

To improve the utilization efficiency of the Bi25FeO40 catalyst, Bi25FeO40-reduced graphene oxide (rGO) composite photo-catalysts were prepared by a facile hydrothermal method. The photocatalysts afforded fast degradation performance and high photocatalytic efficiency for degradation of phenol and p-chlorophenol under exposure to visible light irradiation. © The Royal Society of Chemistry 2015.

Zhu N.,South China University of Technology | Zhu N.,Key Laboratory of Pollution Control | Xiang Y.,South China University of Technology | Xiang Y.,South China Institute of Environmental Sciences | And 9 more authors.
Journal of Hazardous Materials | Year: 2011

Metal concentrates of printed circuit boards (PCBs) are the residue valuable metals from which non-metallic components are removed. The non-metallic components show bacterial toxicity in bioleaching process and can be recycled as well. In this study, the effects of initial pH, initial Fe(II) concentration, metal concentrate dosage, particle size, and inoculation quantity on the bioleaching were investigated so as to determine the optimum conditions and evaluate the feasibility of bioleaching of metal concentrates of PCBs by mixed culture of acidophilic bacteria (MCAB). The results showed that the initial pH and Fe(II) concentration played an important role in copper extraction and precipitate formation. Under the optimized conditions of initial pH 2.00, 12. g/L initial Fe(II), 12. g/L metal concentrate dosage, 10% inoculation quantity, and 60-80 mesh particle size, 96.8% the copper leaching efficiency was achieved in 45. h, and aluminum and zinc 88.2% and 91.6% in 98. h, respectively. All findings demonstrated that metals could be efficiently leached from metal concentrates of waste PCBs by using the MCAB, and the leaching period was shorten from about 8 days to 45 h. © 2011 Elsevier B.V.

Li X.,South China University of Technology | Zhu N.,South China University of Technology | Zhu N.,Key Laboratory of Pollution Control | Zhu N.,Eco Remediation of Guangdong Regular Higher Education Institutions | And 8 more authors.
Bioresource Technology | Year: 2013

Animal carcass wastewater (ACW) is a kind of typical high concentration organic wastewater. Up-flow tubular air cathode microbial fuel cells (MFCs) were constructed using 0, 4.0 and 8.0mg/cm2 MnO2 as cathodic catalyst, respectively (MFC-0, MFC-4 and MFC-8) to test the feasibility of bioelectricity production from ACW. After a start-up period of around 55d, when hydraulic retention time (HRT) was set at 3d, MFC-4 showed best bioelectricity performance with the maximum power density of 2.19W/m3 and minimum internal resistance of 30.3Ω, as compared to MFC-0 (1.14W/m3, 62.6Ω) and MFC-8 (1.49W/m3, 34.5Ω). Chemical oxygen demand (COD) and nitrate removal efficiencies of MFC-4 were 50.66% and 79.76%, respectively. Switching HRT from 3d to 6d, COD and nitrate removal efficiencies sped up while the increase rates of ammonia slowed down. The results demonstrated that ACW could be the fuel of MFCs to generate bioelectricity. © 2012 Elsevier Ltd.

Yao H.,South China University of Technology | Ren Y.,South China University of Technology | Ren Y.,Key Laboratory of Pollution Control | Ren Y.,Eco Remediation of Guangdong Regular Higher Education Institutions | And 4 more authors.
Journal of Hazardous Materials | Year: 2011

Phenols and N-heterocyclic compounds are found to co-exist in actual wastewater, especially in petrochemical and coking wastewater. Lysinibacillus cresolivorans, a bacterium capable of phenol-biodegradation was used to study the substrate interactions of m-cresol and pyridine as single and dual substrates. The cell growth and substrate biodegradation kinetics were also investigated with initial m-cresol concentrations varying from 0 to 1200mg/L and pyridine concentrations varying from 0 to 150mg/L. The single substrate kinetics was well described by the Haldane kinetic models. The single-substrate parameter values of m-cresol on cell growth were μ max=0.89h -1, K s= 426.25mg/L, K i=51.26mg/L and μ max=0.0925h -1, K s=60.28mg/L, K i=16.17mg/L for cell growth on pyridine. Inhibitory effects of substrates were observed when cells were grown on the mixed substrates. The interaction parameter I m,p (0.76) was greater than I m,p (0.11), which indicated that m-cresol inhibited the utilization of pyridine much more than pyridine inhibited the biodegradation of m-cresol. The study showed a good potential of L. cresolivorans in degrading mixed substrates of m-cresol and pyridine. © 2010 Elsevier B.V.

Wu C.D.,South China University of Technology | Wu C.D.,Key Laboratory of Pollution Control | Zhang J.Y.,South China University of Technology | Zhang J.Y.,Key Laboratory of Pollution Control | And 3 more authors.
Water Science and Technology | Year: 2013

The feasibility of using raw diatomite and aluminum hydroxide-modified diatomite (Al-diatomite) for removal of aniline and phenol from water was investigated. Their physicochemical characteristics such as pHsolution, point of zero charge (pHPZC), surface area, Fourier transform infrared (FT-IR) and scanning electron microscopy was determined. After the raw diatomite was modified, the surface area of Al-diatomite increases from 26.67 to 82.65 m 2 g-1. The pHPZC and pHsolution (10%) occurred around pH 5.2 and pH 8.6, respectively. The removal rates of aniline and phenol on diatomite and Aldiatomite decreased with increasing solution pH, while surface charge density decreased. The adsorption of aniline and phenol on diatomite presented a good fit to the Langmuir and Freundlich models, but the models are not fit to forecast the adsorption of aniline and phenol on Al-diatomite. The study indicated that electrostatic interaction was a dominating mechanism of aniline and phenol sorption onto Al-diatomite. © IWA Publishing 2013.

Zhang J.Y.,South China University of Technology | Wu C.D.,South China University of Technology | Wu C.D.,Key Laboratory of Pollution Control | Zhang Z.L.,South China University of Technology
Asian Journal of Chemistry | Year: 2014

The adsorption behaviour of p-nitrophenol on variable charge soil was studied in simulated micropolluted surface water through batch adsorption experiments. It was observed that the adsorption of p-nitrophenol decreased with increasing the pH values of solution, whereas it increased with increasing of ionic strength content, temperature and adsorbent dose and the presence of heavy metal ions depressed the adsorption of p-nitrophenol. Langmuir and Freundlich models were used to describe the adsorption isotherms. Results indicated that Freundlich model was fit to experimental data well, revealing the possibility of more than just one monomolecular layer of coverage on the soil surface. The pseudo-first-order and pseudo-second-order kinetic model were applied to describe the kinetic data. The experimental data agreed with pseudo-second-order kinetic model well. Scanning electron microscope and Fourier transform infrared spectroscopy were used to characterize the soil before and after adsorption of p-nitrophenol.

Zhang H.-Z.,South China University of Technology | Zhang H.-Z.,Key Laboratory of Pollution Control | Pan W.-B.,South China University of Technology | Pan W.-B.,Key Laboratory of Pollution Control | And 4 more authors.
Fundamental and Applied Limnology | Year: 2012

Growth of cyanobacteria can easily cause cyanobacterial blooms. Cyanobacteria-algicidal bacteria interactions are a major regulatory factor of cyanobacteria growth during the entire cyanobacterial bloom period. Interactions between algicidal bacteria (Bacillus cereus strain L7) and cyanobacteria (Anabaena flos-aquae) during cyanobacterial blooms were investigated in different axenic microcosms. Changes in the Bacillus cereus strain L7 and Anabaena flos-aquae cell concentrations, malondialdehyde concentrations, and concentrations of NH4 +-N and NO3 -N in microcosms were evaluated. Lower concentrations of Bacillus cereus strain L7 stimulated growth of Anabaena flos-aquae, while higher concentrations inhibited cyanobacterial growth. Bacillus cereus strain L7 growth was inhibited by extracellular metabolites of Anabaena flos-aquae but promoted by intracellular metabolites of the cyanobacteria. Bacillus cereus strain L7 may promote transformation of nitrate nitrogen into ammonium nitrogen that could be directly and easily utilized by Anabaena flos-aquae. However, higher Bacillus cereus strain L7 concentration (1.75× 108 CFUs/mL) increased malondialdehyde concentration, suggesting it could damage cyanobateria via peroxidation. Thus, we concluded that cyanobacteria and algicidal bacteria have both mutualistic and antagonistic effects on each other. We also propose a model to illustrate the interactions between both populations during the bloom. This study allows us to better understand the interactions between algicidal bacteria and cyanobacteria during a cyanobacterial bloom and the role of algicidal bacteria during the development and declining stages of the bloom. In addition, this study will support the direct utilization of algicidal bacteria to control a cyanobacterial bloom. © 2012 E. Schweizerbart'sche Verlagsbuchhandlung.

Chen S.,Jinan University | Yin H.,South China University of Technology | Yin H.,Key Laboratory of Pollution Control | Ye J.,Jinan University | And 3 more authors.
Chemosphere | Year: 2013

Benzo[a]pyrene (BaP) biodegradation by Stenotrophomonas maltophilia was studied under the influence of co-existed Cu(II) ions. About 45% degradation was achieved within 3d when dealing with 1mgL-1 BaP under initial natural pH at 30°C; degradation reached 48% in 2d at 35°C. Efficacy of BaP biodegradation reached the highest point at pH 4. In the presence of 10mgL-1 Cu(II) ions, the BaP removal ratio was 45% on 7th day, and maintained stable from 7 to 14d at 30°C under natural pH. The favorable temperature and pH for BaP removal was 25°C and 6.0 respectively, when Cu(II) ions coexisted in the solutions. Experiments on cometabolism indicated that S. maltophilia performed best when sucrose was used as an additional carbon source. GC-MS analysis revealed that the five rings of BaP opened, producing compounds with one or two rings which were more bioavailable. © 2012 Elsevier Ltd.

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