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In this article, foam zero‐valent nickel (FZVN) was put forward as a promising zero‐valent metal for the pretreatment of azo dye wastewater (MO as a model contaminant). The characteristics of FZVN were evaluated by methods of Barrett‐Emmett‐Teller, scanning electron microscopy, X‐ray diffraction, and X‐ray photoelectron spectroscopy. Moreover, influence of key experimental parameters, including oxygen concentration, presence of different acid, pH, and temperature on the MO decolorization were systematically ascertained. Furthermore, possible mechanism of MO removal by FZVN was investigated by using Liquid chromatography‐mass spectrometry (LC‐MS). Results showed that FZVN was a three‐dimensional pore material with a specific surface area of 3 m2 g−1. Moreover, anoxic condition, presence of acetic acid, higher temperatures and acid conditions were beneficial to decolorize MO by FZVN while the decolorization process obeyed the first order kinetic model with an apparent rate constant (kapp) of 0.162 min−1 at pH value of 4 (25°C). The activation energy Ea obtained from the decolorization reaction was 83.1 kJ mol−1. Based on LC‐MS results, the role of FZVN in the decolorization reaction process was suggested as follows: strong reductive, catalysis, and adsorption. © 2017 American Institute of Chemical Engineers Environ Prog, 37: 686–694, 2018 [ABSTRACT FROM AUTHOR]

The lowest energy structures of Au and AuNi ( = 2-9) clusters have been researched using the CALYPSO structure searching method in conjunction with the density functional theory. It is found that the most stable structures of Au, Au8Ni and Au9Ni clusters reported by Tang et al. [C. M. Tang, X. X. Chen and X. D. Yang, Int. J. Mod. Phys. B 28, 1450138 (2014)] are low-lying isomers. The correct ground states and vibrational spectra are given in this paper. [ABSTRACT FROM AUTHOR]

Abstract: The density functional method PW91P86 with relativistic effective core potentials (RECP) and LANL2DZ basis set have been used to investigate the possible stable geometrical configurations and relative stabilities of the lowest-lying isomers of iridium-doped gold clusters, Au n Ir (n =1–8). Several low-lying isomers were determined. The results indicate that the ground-state Au n Ir, n =1–8, clusters have planar structures except for n =7. The stability trend of the Au n Ir clusters shows that even-numbered Au n Ir clusters are relatively more stable than the neighbouring odd-numbered ones, and indicating the Au2Ir clusters are magic cluster with high chemical stability. [ABSTRACT FROM AUTHOR]

Abstract: The density functional method PW91P86 with relativistic effective core potentials (RECPs) and LANL2DZ basis set has been used to investigate the possible stable geometrical configurations and relative stabilities of the lowest-lying isomers of rhodium-doped gold clusters, Au n Rh (n=1–8). Several low-lying isomers were determined. The results indicate that the ground-state Au n Rh, n=1–8, clusters have planar structures except for n=5 and 8. The stability trend of the Au n Rh clusters shows that the clusters with even numbers of atoms are more stable than the clusters with odd numbers of atoms, indicating that the Au5Rh cluster is a magic cluster with high chemical stability. [Copyright &y& Elsevier]

To accurately regulate the production of active substances with demulsification characteristic by biological demulsification bacteria, the effects of different culture time, different components of culture solution and different types of carbon source and nitrogen source on a Bacillus mojavensis sp., which was isolated by our laboratory, were determined by demulsifying the O/W model emulsions, respectively. Results show that when the culture time is 14 -- 24 h, the highest demulsification activity of culture solution can be achieved. The culture and cell -- free culture have the high efficiency of demulsification while the bacterial cells do not. Hydrocarbons carbon source can induce this strain to produce the metabolites with demulsification activity and carbohydrate carbon source can promote the growth of cells. The mix carbon source containing fructose and liquid paraffin is most favorable for the growth and demulsification. Compared with the single nitrogen source, the mix nitrogen source containing ammonium nitrate and yeast extract is more beneficial to the growth and the demulsification production of this strain. The level of demulsifying activity of metabolites from this strain can be controlled by regulating the culture time, carbon source and nitrogen source. [ABSTRACT FROM AUTHOR]

The application of compound bioflocculant (CBF) in the treatment of low temperature and low turbidity water was studied in this work. The jar test was adopted to examine the effects of hydrogen ion concentration (pH), the CBF dosage and the cationic flocculant dosage on the removal efficiency of turbidity. Coagulation test shows that CBF has an effective performance with dosage of 5.0 - 17.5 mg/L in alkalescence environment. The optimal conditions for treatment of low temperature and low turbidity water by CBF are the dosage of 7.5 mg/L and pH of 8.0. The cationic flocculant can increase the production of flocs. Based on an overall analysis of removal efficiency and economic sectors, the optimal dosages for treatment of low turbidity water are CBF of 4 mg/L and PAFC of 10 mg/L, then the turbidity removal rate is 73. 0% and the CODMn, removal is 60.7%. [ABSTRACT FROM AUTHOR]

Abstract: Nickel-doped gold cluster anions, Au n Ni− (n =1–5), were investigated using the density functional method B3LYP with relativistic effective core potentials (RECP) and LANL2DZ basis set. The possible stable geometrical configurations with their electronic states are determined, and many of them in electronic configurations with a high spin multiplicity. The stability trend of the anionic clusters is compared to that of neutral clusters. Our results show that the one excess electron is strong enough to modify the known growth pattern and stability trend of the neutral Au n Ni clusters, and indicate that the stability and electron affinity of the clusters alter with odd-even oscillations as a function of the number of gold atoms. [Copyright &y& Elsevier]

Abstract: Ab initio method based on density-functional theory has been used to investigate the Au n Pd− (n=1–5) cluster anions. The possible stable geometrical configurations with their electronic states are determined, and the energy gaps between the HOMO and LUMO of the ground states are investigated. Our results show that the one excess electron is strong enough to modify the known growth pattern of the neutral Au n Pd clusters, and indicate that the larger is the Au n Pd cluster, the smaller are the distortions by the one excess electron. [Copyright &y& Elsevier]

The process of simultaneous nitrification and denitrification (SND) of immobilized microorganisms in polyurethane form is discussed. The effect of different positions within the polyurethane carrier on microbial community response for the SND process is investigated by a combination of denaturing gradient gel electrophoresis profiles of the 16S rRNA gene V3 region and scanning electron microscopy. Results show that polyurethane, which consists of a unique porous structure, is an ideal platform for biofilm stratification of aerobe, anaerobe and facultative microorganisms in regard to the SND process. The community structure diversity response to different positions was distinct. The distributions of various functional microbes, detected from the surface aerobic stratification to the interior anaerobic stratification of polyurethane, were mainly nitrifying and denitrifying bacteria. Meanwhile aerobic denitrifying bacteria such as Paracoccus sp., Agrobacterium rubi and Ochrobactrum sp. were also adhered to the interior and surface of polyurethane. The SND process occurring on polyurethane foam was carried out by two independent processes: nitrogen removal and aerobic denitrification.

Although the treatment technology of sulfamethoxazole has been investigated widely, there are various issues such as the high cost, inefficiency, and secondary pollution which restricted its application. Bioflocculant, as a novel method, is proposed to improve the removal efficiency of PPCPs, which has an advantage over other methods. Bioflocculant MFX, composed by high polymer polysaccharide and protein, is the metabolism product generated and secreted by Klebsiella sp. In this paper, MFX is added to 1 mg/L sulfanilamide aqueous solution substrate, and the removal ratio is evaluated. According to literatures review, for MFX absorption of sulfanilamide, flocculant dosage, coagulant-aid dosage, pH, reaction time, and temperature are considered as influence parameters. The result shows that the optimum condition is 5 mg/L bioflocculant MFX, 0.5 mg/L coagulant aid, initial pH 5, and 1 h reaction time, and the removal efficiency could reach 67.82%. In this condition, MFX could remove 53.27% sulfamethoxazole in domestic wastewater, and the process obeys Freundlich equation. R(2) value equals 0.9641. It is inferred that hydrophobic partitioning is an important factor in determining the adsorption capacity of MFX for sulfamethoxazole solutes in water; meanwhile, some chemical reaction probably occurs.