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This paper reports the preparation of zein nanoribbons and their application in the removal of Pb(II) from polluted water. A modified coaxial electrospinning process was conducted permitting the smooth and continuous generation of zein nanoribbons. The process utilized sodium lauryl sulfate ethanol aqueous solution as the sheath fluid to overcome protein–metal interactions and the corresponding spinneret clogging. Scanning electron microscopic images demonstrated that the zein nanoribbons created using the modified processes had a flatter and narrower morphology than the analogous materials from a single-fluid process. By exploiting the favorable interactions between metal and protein, these zein nanoribbon mats were used to treat Pb(II)-polluted water. Adsorption results indicated that equilibrium was obtained in 60 min for Pb(II) solutions with initial concentrations of 100, 150 and 200 mg/L. The process can be described using the pseudo-second-order model. Isotherm data fitted well to the Langmuir isotherm model, with a maximum adsorption of 89.37 mg/g. Desorption results showed that the adsorption capacity can remain up to 82.3% even after 5 cycles of re-use. Mechanisms underlying both the preparation and application of the zein nanoribbons were proposed. [ABSTRACT FROM AUTHOR]

Abstract: In this study, Bi2O3 with band gap energy of 2.6eV was coated on a Ti disk and used in a rotating disk reactor to treat 10mgL−1 Rhodamine B (RB) solution under UV and visible light irradiation. The effects of different inorganic anions (including , S2−, , F− and Cl−) were investigated and the results shown that the color removal efficiency could be greatly improved in the presence of Cl−. RB adsorption capacity could be enhanced when Cl− was added and RB could further be degraded due to indirect dye self-photosensitization under visible light irradiation. The radicals generated during the reaction were detected by adding radical trapping agents and other experimental conditions like Cl− concentration, rotating speed and pH of the process were investigated and optimized. [Copyright &y& Elsevier]

Nanoscale zero-valent iron (nZVI) and nickel/nanoscale zero-valent iron (Ni/nZVI) bimetallic particles were explored for tetrabromobisphenol A (TBBPA) and tetrachlorobisphenol A (TCBPA) dehalogenation under ambient condition. The characteristics of the fresh and aged nanoparticles were analyzed by SEM, BET, XRD, XPS and FTIR, and found out that bimetal nanoparticles accelerated the corrosion of Fe 0 in the synthesized particles during the reaction. The results shows that the addition of Ni to nZVI particles with low Ni loading (⩽0.5 wt%) significantly enhanced dehalogenation of TBBPA and TCBPA compared to the pure nZVI, while high Ni loading (>0.5 wt%) did less favor. The observed pseudo first-order rate constant ( k obs ) of 0.5%Ni/nZVI for TBBPA and TCBPA were 3.74 (±0.29) × 10 −2 and 0.95 (±0.04) × 10 −2 min −1 , which were about 27 and 20 times higher than that of nZVI, respectively, probably due to the formation of highly activated hydrogen atom (H * ) and galvanic cells. Ni/nZVI with lower Ni loading (<0.5 wt%) resulted in partial dehalogenation of TBBPA and TCBPA, while with higher Ni loading (⩾0.5 wt%) curtailed the accumulation of intermediates and completely transformed them to bisphenol A (BPA). A dramatic decrease in oxidation–reduction potential (ORP) values from about +300 to −750 mV after Ni/nZVI addition indicates that Ni/nZVI is an effective material to achieve highly reducing conditions. Both ORP and pH shows a correlative tendency with TBBPA and TCBPA removal efficiency. This suggests that ORP and pH can serve as indicators for the reductant reactivity. [ABSTRACT FROM AUTHOR]

The combined anammox (anaerobic ammonium oxidation) and autotrophic desulfurization–denitrification (AADD) process represents a promising innovative technology for biological nitrogen and sulfur removal. In this study, an up-flow anaerobic sludge blanket reactor, which was started with anammox and methanogenic granules, was operated for 245 days to evaluate the co-treatment of wastewater containing nitrogen and sulfur. The reactor demonstrated good performance in terms of nitrogen and sulfide removal and exhibited excellent behavior for removal of NH 4 + -N, NO 2 − -N and S 2− -S exceeding 252, 333 and 330 mg L −1 , respectively. The highest nitrogen removal rate and sulfide removal rate attained were 4.00 kgN m −3 d −1 and 2.39 kgS m −3 d −1 , respectively, which were also the highest reported values for a coupling-system. The influent NH 4 + -N:S 2− -S and NO 2 − -N:S 2− -S ratios set at 1.74 and 2.20–2.27 are suitable for maintaining system stability. The specific activities of anammox and autotrophic desulfurization–denitrification (SAA and SADD), extracellular polymeric substance (EPS), heme c (an important cofactor of some anammox bacterial enzymes) and the diversity of anammox and autotrophic desulfurization–denitrification (ADD) bacteria were investigated during the operation. The SAA and SADD are regarded as key factors for high efficiency. The granules contained many EPS (128.4–204.5 mg g −1 VSS) and minor heme c content (1.17 μmol g −1 VSS). The dominant bacteria belonged to members of Brocadiaceae and Hydrogenophilaceae , a majority of which were anammox bacteria and ADD bacteria, respectively. These observations suggest a new removal process for ammonia, nitrite and sulfide utilizing an uncommon mechanism involving simultaneous anammox and ADD. [ABSTRACT FROM AUTHOR]

• SCR effectively active site and non-selective oxidation site are coexisting on Mn-Co catalysts. • Co 3 O 4 acted as non-selective site has positive influences for the "fast SCR" and activation of NH 3. • Co 3 O 4 phase also has negative influences, which can add N 2 O and NO 2 by O 2 oxidation. • Both oxidation of NH 3 by O 2 and the redox reaction of NH 3 with NO x can produce N 2 O. In order to explore the generation of NO 2 and N 2 O on the Mn-Co catalysts in the NH 3 -SCR process, Mn 2 Co 1 O x (PEG) and Mn 2 Co 1 O x (PA) catalysts, prepared by two different complexing agents, i.e., polyethylene glycol (PEG) and urea as double complexing agents, and ammonia (PA), were further investigated by NO + O 2 and NH 3 + O 2 experiments, besides NH 3 -SCR test. Catalytic activity and physicochemical properties of the catalysts were compared and analyzed through NH 3 -TPD, O 2 -TPD, H 2 -TPR, XRD, Raman and XPS. The NH 3 -SCR results show that the Mn 2 Co 1 O x (PEG) exhibits higher NO conversion than Mn 2 Co 1 O x (PA) due to larger amount of lattice oxygen accompanied with more Con+, and surface adsorbed oxygen species, as well as the improvement of surface acidity, proved by O 2 -TPD, XPS and NH 3 -TPD, respectively. Furthermore, the separate oxidation experiments show that Mn 2 Co 1 O x (PEG) effectively exhibits the oxidation of NH 3 to N 2 O and also the oxidation of NO to NO 2 by O 2 respectively, which can influence the catalytic performance. The XRD, XPS and Raman characterization results indicate that Mn 2 Co 1 O x (PEG) contains more Co 3 O 4 than Mn 2 Co 1 O x (PA), that can produce non-selective pure oxidation reaction by the NO + O 2 and NH 3 + O 2 experiments of Co 3 O 4 phase. Information from in situ infrared experiments is that the strongly adsorbed NH 3 species on the Mn 2 Co 1 O x (PEG) is susceptible to deep dehydrogenation and react with NO x to produce N 2 O in the presence of O 2. Meanwhile, the oxidation site (Co 3 O 4) can also oxidize NO to more NO 2 , thereby improving the "fast SCR" reaction. However, if the proportion of oxidation sites is high, NO and NH 3 can be oxidized to more N 2 O will be produced by the reaction between NO and NH 3. [ABSTRACT FROM AUTHOR]