Anaerobic digestion (AD) of biodegradable organics depends heavily diverse functional genera, but an attempt to simultaneously enhance the various AD phases including the rate-limiting step (hydrolysis acidification) and methanogenesis has often remained a challenge. Although zero-valent iron (ZVI) supplementation had been proposed by many, its effect on the biomethanation process and microbial community evolution has not been fully explored. In this study, the response of hydrolysis acidification, methanogenesis, kinetics, pollutant removal efficiency, and microbial community evolution to various doses of ZVI employed in AD of food waste leachate was investigated and reported. When 10 g/L ZVI was dosed in the AD system, hydrolysis acidification, COD removal, biomethanation, and methane percentage were elevated by 18.9

Aerofloats, such as aniline aerofloat ((C6H5NH)2PSSH), are extensively employed for collection activities in wastewater particularly in cases where minerals are in flotation. Although this aniline aerofloat has efficient collection properties, they are ordinarily biologically persistent chemicals in which case their residual, as well as their byproducts, pose great environmental risks to water and soils. In this study, the removal efficiency of aniline aerofloat (AAF) by a combined vacuum ultraviolet (VUV) and ozone (O3) process (VUV/O3) was evaluated. Furthermore, the impacts of pH, O3, the concentration of AAF and coexisting ions (SiO32-, CO32-, Cl- (Na+), SO42-, Ca2+) were systematically studied. The experiments revealed that, with an initial AAF of 15 mg/L, AAF removal >88% was feasible with a reaction time of 60 min, pH of 8 and O3 of 6 g/h. The order of influence of the selected coexisting ions on the degradation of AAF by VUV/O3 was Ca2+ > CO32- > SiO32- > Cl- (Na+) >SO42-. Compared with VUV and O3 in terms of pollutant degradation rate, VUV/O3 showed a remarkable performance, followed by O3 and VUV. Additionally, the degradation kinetics of AAF by the VUV/O3 process agreed well with first-order elimination kinetics.

Butane-1,4-bis(dodecyl dimethyl ammonium bromide) (gBDDA) and dodecyl trimethyl ammonium bromide (DTMA) in same stoichiometric amounts were applied to modify montmorillonite (Mt) under microwave and ultrasound conditions. The composition and structure of products were obtained through multiple characterizations including XRD, FTIR, TG/DTG, SEM, TEM, and N2 adsorption/desorption measurements, and the adsorption performance of chromate and phenol on these products were also investigated. Intercalations of gBDDA and DTMA into interlayer space of Mt were observed, but the amount of anchored modifier on the external surface was larger for gBDDA compared with DTMA when the stoichiometric amount of modifier larger than 1.0 times cation exchange capacity of Mt was added. Although there was no significant difference in morphology among products, the interlayer space distance, specific surface area, and pore size distribution were closely associated with the species and amount of applied modifier. Adsorption of phenol on products through partition mechanism relied on not only organic content, but also the configuration of modifier. Meanwhile, adsorption of chromate mainly depended on the presence of counter ion (bromide), which accounted for the high adsorption capacity and initial adsorption rate on gOMt-0.75. The fitting parameters of adsorption results using pseudo-second order model and Freundlich model suggested that gBDDA-modified Mt could sequester phenol or chromate in the faster manner with higher affinity. Compared with the conventional surfactant such as DTMA, the study revealed that, using gemini surfactant such as gBDDA to modify Mt would significantly reduce or even has the potential to eradicate the secondary pollution by modifier release during adsorption process. This study provides a new direction for Mt modification intended to be used as adsorbents to treat polluted water with high standards such as drinking water.

Beneficiation of micro-fine magnetic minerals from reductive iron ore was investigated. Sample characteristics and main force analysis of magnetic floc were conducted. The results indicated that the iron phase in reductive iron ores was predominantly metallic iron (below 20 m). By applying ultrafine grinding-magnetic flocculation separation (MFS) to the raw ore (29.85% Fe), a concentrate assaying 74.12% Fe with 81.45% iron recovery was obtained. The iron recovery increased by 6.68% compared with the conventional magnetic separation (CMS). The high efficiency in beneficiation may be attributed to an increase in magnetic force on the micro-fine iron minerals in the form of flocs.

Thermodynamic analysis of refractory siderite ore during carbothermic reduction was conducted. Microstructure characteristics and phase transformation of siderite ore during sodium-carbonate-added catalyzing carbothermic reduction were investigated. X-ray diffraction (XRD), scanning electron microscopy and energy-dispersive analysis of X-rays were used to characterize the reduced samples. Results indicate that the solid reaction between FeO and SiO2 is inevitable during carbothermic reduction and the formation of fayalite is the main hindrance to the rapid reduction of siderite. The phase transformation of present siderite ore can be described as: siderite-magnetite-metallic iron, complying with the formation of abundant fayalite. Improving the reduction temperature (≤ 1050 °C) and duration is helpful for the formation and aggregation of metallic iron. The iron particle size in the reduced ore was below 20 μm, and fayalite was abundant in the absence of sodium carbonate. With 5% Na2CO3 addition, the iron particle size in the reduced ore was generally above 50 μm, and the diffraction intensity associated with metallic iron in the XRD pattern increased. The Na2O formed from the dissociation of Na2CO3 can catalyze the carbothermic reduction of the siderite. This catalytic activity may be mainly caused by an increase in the reducing reaction activity of FeO.

Exploratory experiments were conducted according to the property of a siderite mineral composition and structure has the advantages of simple structure, low grade theory. The siderite Contain Fe 27.46%, Pb 0.97%. First magnetic Fe separation, because of the lower grade ore, for the two stages selection, In 90% of the fineness, good beneficiation indexes, Fe concentrate grade reaches 45.49%, the recovery reached 96.21%. The Fe tailings of magnetic separation in the 90% fineness of flotation tailings Pb test, The tailings in without further grinding conditions, after two stages of cleaning grade is still difficult to improve, Pb concentrate grade of 2.64%, recovery reached 46.96%, Observed in the tests of carbon in tailings interference, because well floatability of carbon, and the dissemination too small it is difficult to remove, so lead to difficulty for improving the grade of the lead concentrate.

Non-oriented electrical steels with different amounts of copper were prepared and the microstructure and magnetic properties of each kind of steel were studied. The results show that there exist a large number of Cu-rich metastable precipitates in the hot-rolled bands of the steels containing copper. They not only can decrease the sensitivity of the microstructures and magnetic properties of the steels to the change of process parameters but also can significantly reduce the core loss of the steels by improving the recrystallization textures without obviously decreasing the magnetic induction. Therefore, it is possible to control the microstructures and then magnetic properties of non-oriented electrical steels by the copper precipitates.

Small quantities of copper were added to non-oriented electrical steels to produce a metastable Cu-rich phase with a different structure from a twinned 9R or 3R and an average size on the order of 20 nm. These precipitates were observed in hot-rolled bands coiled at 650 degrees C for between 1 and 3 h. The coiling time and copper content have little effect on the average size of the precipitates, but the amount of the precipitates increases significantly with the Cu content, and the particles appear to coalesce when the copper level rises to 0.35%. The influence of the precipitates on the recrystallization textures and magnetic properties of non-oriented electrical steels was investigated, and it can be concluded that the Cu-rich precipitates can improve the recrystallization textures of soft magnetic materials by inhibiting the {111} texture component and promoting the Goss component. However, this beneficial effect is weakened when the Cu-rich particles coalesce or the coiling time is extended. Furthermore, the Cu-rich precipitates can significantly reduce the core loss of non-oriented electrical steels by improving the recrystallization textures without obviously decreasing the magnetic induction. (C) 2013 Elsevier B. V. All rights reserved.

VOx/TiO2 catalysts were prepared by wetness of TiO2 with anatase and rutile structures and tested in the catalytic combustion of CB, DCB, DCM and TCE. The characterization by XRD, TPR and XPS shows that VOx catalyst supported on anatase (VOx/TiO2-SG) possesses more V5+–O–V5+ and hence higher mobility of oxygen than VOx catalyst supported on rutile (VOx/TiO2-HY). VOx/TiO2-SG presents lower T50 and T90 for CVOC. High activity of VOx/TiO2-SG is related to high mobility of oxygen which weakens the adsorption of Cl species, and enhances the removal of Cl species from the surface of catalysts.

A series of MnxCey/Al2O3 mixed oxides catalysts with different compositions prepared by wet impregnation method were tested for catalytic combustion of chlorobenzene (CB), as a model of volatile organic compounds of chlorinated aromatics. MnxCey/Al2O3 mixed oxides catalysts present high activity for the low temperature catalytic destruction of CB and Mn8Ce2/Al2O3 catalyst is identified as the most active catalyst, on which the temperature of complete combustion of CB is 338°C. Effects of systematic variation of reaction conditions, including space velocity and inlet CB and oxygen concentration on the reaction were investigated. Additionally, the stability and deactivation of MnxCey/Al2O3 mixed oxides catalysts were studied by various characterization methods and other assistant experiments. MnxCey/Al2O3 mixed oxides catalysts with high Mn/Ce ratios present a stable high activity, which is related to their better reducibility.

Mn–Ce–Mg/Al2O3 catalyst prepared by a wet impregnation method was investigated in the catalytic combustion of chlorobenzene. The addition of Mg decreased the interaction of Mn and Ce species with Al2O3 and promotes the dispersion of Mn and Ce species and the formation of Ce–Mn–O solid solution. High activity, good selectivity and desired stability of Mn–Ce–Mg/Al2O3 catalyst were observed.