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Anaerobic sludge from sewage treatment was employed to derive a microbial colony that is capable of anaerobic oxidation of methane coupled with sulfate reduction and denitrification. Investigations revealed that methane can be oxidized with sulfate reduction and denitrification. When sulfate and nitrite acted as electron acceptors together, the rates and amount of methane conversion were higher than that when sulfate or nitrite alone was employed as an electron acceptor. The oxidation rate and amount of methane conversion reached 1.9 mg/(d•gVSS) and 22.24 mg, respectively. Methanotrophic bacteria, such as M. oxyfera , and Methylocystis sp., sulfate-reducing bacteria (SRB), e.g. Desulfosporosinus sp., and Desulfuromonas sp.; and denitrification bacteria, such as Hyphomicrobium sp. , and Diaphorobacter sp., presented in the bacterial community. Anaerobic methanotrophic archaea (ANME), including Methanosaeta sp. and Methanobacterium sp. were found in the archaeal community. These findings indicate the coexistence of ANME, SRB and denitrification bacteria in the system. Nitrite reduction coupled with methane oxidation was performed independently by M. oxyfera during which limited oxygen generated. The oxygen released may be utilized by methanotrophic bacteria to produce organics, which could be used by denitrifying bacteria to reduce nitrite. Methanotrophic archaea could also oxidize methane to carbon dioxide or organics by reverse methanogenesis whereas sulfate was reduced to sulfide by SRB. This study opens possibility for biotechnological process of sulfate reduction and denitrification with methane as electron donor and provides a method for the synergistic treatment of wastewater containing sulfate/nitrite and waste gas containing methane. • Methane was oxidized coupled with sulfate reduction and denitrification. • Sulfate and nitrite as electron co-acceptors for AOM performed better than alone. • Anaerobic digestion sludge could act as the inoculum for AOM. • Methanotrophic bacteria and archaea, denitrifying bacteria and SRB were dominant. • Transfer pathways of AOM, sulfate reduction and denitrification were speculated. [ABSTRACT FROM AUTHOR]

Abstract: In this study, removal of chromium (VI) from aqueous solution by walnut hull (a local low-cost adsorbent) was studied. The extent of adsorption was investigated as a function of solution pH, contact time, adsorbent and adsorbate concentration, reaction temperature and supporting electrolyte (sodium chloride). The Cr (VI) removal was pH-dependent, reaching a maximum (97.3%) at pH 1.0. The kinetic experimental data were fitted to the first-order, modified Freundlich, intraparticle diffusion and Elovich models and the corresponding parameters were obtained. A 102.78kJ/molEa (activation energy) for the reaction of chromium (VI) adsorption onto walnut indicated that the rate-limiting step in this case might be a chemically controlled process. Both the Langmuir and Freundlich isotherms were suitable for describing the biosorption of chromium (VI) onto walnut hull. The uptake of chromium (VI) per weight of adsorbent increased with increasing initial chromium (VI) concentration up to 240–480mg/L, and decreased sharply with increasing adsorbent concentration ranging from 1.0 to 5.0g/L. An increase in sodium chloride (as supporting electrolyte) concentration was found to induce a negative effect while an increase in temperature was found to give rise to a positive effect on the chromium (VI) adsorption process. Compared to the various other adsorbents reported in the literature, the walnut hull in this study shows very good promise for practical applicability. [Copyright &y& Elsevier]

Abstract: Tuning surface charge property by a floating gate field effect transistor (FGFET) is proposed and analyzed for the first time. The FGFET has an additional floating gate electrode embedded inside the dielectric channel wall and is superior to the conventional FET to tune the surface charge property of a dielectric material in contact with an aqueous solution. [Copyright &y& Elsevier]

Visible light-driven photocatalytic aerobic oxidative coupling processes of amines have been successfully performed in the presence of a flower-like Bi 2 O 2 CO 3 catalyst. • Visible light-driven of benzyl amine is successfully performed. • The flower-like Bi 2 O 2 CO 3 is a preferable catalyst in the presence of O 2. • A 99% yield of N-benzylidenebenzylamine is obtained at room temperature. • The catalyst still keeps a high activity after being recycled for 5 times. The photocatalytic selective transformation of amines is a green and cost-effective technology to obtain value-added products in chemical industry. In this work, a series of bismuth-based photocatalysts including Bi 2 MoO 6 , Bi 2 WO 6 , Bi 5 O 7 Cl, Bi 5 O 7 Br, Bi 5 O 7 I, BiPO 4 , BiVO 4 , Bi 2 O 3 and various morphology Bi 2 O 2 CO 3 (flower-like, sponge-like, plate-like and spherical) were synthesized and employed in the aerobic oxidative coupling of benzylamine. It is found that flower-like Bi 2 O 2 CO 3 exhibited the highest photocatalytic activity, in which a 100% conversion of benzylamine with 99.0% selectivity of N -benzylidenebenzylamine was obtained at room temperature. Moreover, the photocatalytic oxidative coupling processes of various aromatic and aliphatic amines were further investigated, and excellent yields and selectivities of corresponding products are attained. Then, based on characterization results (XRD, SEM, BET and XPS, etc.) of catalyst, high photocatalytic activity of flower-like Bi 2 O 2 CO 3 is attributed to thin nanopetals, low band gap, the morphology and large specific surface area. Finally, a possible reaction mechanism is proposed for the photocatalytic oxidative coupling of benzyl amine. [ABSTRACT FROM AUTHOR]

Denitrifying anaerobic methane-oxidizing (DAMO) processes, which link anaerobic methane oxidation (AMO) and denitrification, have a promising prospect in anaerobic wastewater treatment. In bioelectrochemical systems (BES), DAMO consortium presented potent metabolic activity. However, the extracellular electron transfer (EET) in BES was poorly understood. This study investigated the EET mechanisms and modes of electron transport in BES dominated by anaerobic methanotrophic bacteria. In the bioreactors with the auxiliary voltage of 0.5 and 1.1 V, named EMN-0.5 and EMN-1.1, respectively, biological voltages of 0.198 and 0.329 V were generated with power densities of 0.6 and 1.20 mW/m2, after removing the voltage. High throughput and metagenome analyses demonstrated that main methanotrophs were DAMO bacteria and Methylocystis sp. The electroactive bacteria detected were Pseudomonas sp., Hypomicrobium sp., Thiobacillus sp, and Rhodococcus sp. The pil , cytochrome c , hdr , and he / fp genes related to EET were present on the electrode surfaces. Carbon 13 isotope tracing and chemicals analysis by GC-MS exhibited that methanol was an intermediate product released to extracellular environment and acted as the electronic carrier to drive the EET in methane oxidation. Extracellular electron transfer was achieved through the collaboration of DAMO bacteria, Methylocystis sp., and Pseudomonas sp. Anthraquinone 2-sulfonic acid ester (AQS) could improve the rate of electron transfer to the extracellular space, especially in the EMN-0.5 reaction system. This study provides a new understanding of AMO consortium metabolism in BES and may provide a scientific basis for developing methane control technology. [Display omitted] • 1.20 mW/m2 was generated in the bioelectrochemical systems driven DAMO bacteria. • Electroactive bacteria and EET genes were identified on the surface of electrodes. • Methanol was likely the electron carrier of methanotrophs and electroactive bacteria. • AQS, as an electron shuttle, enhanced the EET process in the system of EMN-0.5. • DAMO bacteria, Methylocystis sp. and Pseudomonas sp. might jointly complete EET. [ABSTRACT FROM AUTHOR]

4-Carboxyphenoxybutanoic acid (H 2 cpob) and its monosodium salt (NaHcpob) are synthesized and characterized. The crystal structure of NaHcpob shows that the sodium atoms are connected by the carboxyl group of Hcpob−, forming a three-dimensional coordination polymer network. NaHcpob reacts with metal salts and N -containing ligands produced following complexes: [Co(cpob)(H 2 O) 2 ] n 1 , [Zn(cpob)(phen)(H 2 O)] 2 2 , [Cd(cpob)(phen)] n 3 , [Mn(cpob)(phen)·4H 2 O] n 4 , and [Cd 2 (cpob) 2 (bimb)] n 5 (phen ​= ​1,10-phenanthroline, bimb ​= ​1,4-bis(imidazole-1-ylmethyl)benzene). Single-crystal X-ray diffraction analysis showed that these complexes have different metal-organic frameworks, ranging from binuclear (2) to one-dimensional (3 and 4), two-dimensional (1), and three-dimensional (5) arrangements. When only H 2 cpob forms a complex with metal ions, the ligand connects the metal ions into a higher-dimensional structure. In contrast, the terminal ligand (phen) added as an auxiliary ligand forms a low-dimensional complex. And when the bridging auxiliary ligand (bimb) is added, the high-dimensional complex can still be formed. The flexible conformation of H 2 cpob and the different N -containing ligands may be responsible for the structural diversity of binary H 2 cpob metal complexes. These metal complexes also displayed many differences in their fluorescence properties in the solid state. NaHcpob reacts with M(II) salts and N -containing ligands produced five complexes. Single-crystal X-ray diffraction analysis showed that these complexes have different metal-organic frameworks, ranging from binuclear to one-dimensional, two-dimensional, and three-dimensional arrangements. [Display omitted] • H 2 cpob and its monosodium salt (NaHcpob) have been synthesized. • Five M(II) complexes are constructed from NaHcpob and N -donor ligands. • These complexes have different metal-organic frameworks. • Luminescence properties and lifetime of solid state are documented. [ABSTRACT FROM AUTHOR]