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Phenolic compounds are problematic byproducts generated from lignocellulose pretreatment. In this study, the feasibility degradation of syringic acid (SA), vanillic acid (VA), and 4-hydroxybenzoic acid (HBA) by Bio-Electro-Fenton (BEF) system with a novel Fe–Mn/graphite felt (Fe–Mn/GF) composite cathode were investigated. The nano-scale Fe–Mn multivalent composite catalyst with core shell structure distributed more evenly on GF surface to form a catalyst layer with higher oxygen reduction reaction performance. Accordingly, the maximum power density generated with Fe–Mn/GF cathode was 48.1% and 238.9% higher than Fe/GF and GF respectively, which further enhanced the in situ generation of H2O2 due to the superiority of nano-scale core shell structure and synergistic effect of Fe and Mn species. The degradation efficiency of the three phenolic compounds in the BEF system could reached 100% after optimization of influencing parameters. Furthermore, a possible SA degradation pathway by BEF process in the present system was proposed based on the detected intermediates. These results demonstrated an efficient approach for the degradation of phenolic compounds derived from lignocellulose hydrolysates.

Adenosine, which is produced mainly by microbial fermentation, plays an important role in the therapy of cardiovascular disease and has been widely used as an antiarrhythmic agent. In this study, guanosine 5′-monophosphate (GMP) synthetase gene (guaA) was inactivated by gene-target manipulation to increase the metabolic flux from inosine 5′-monophosphate (IMP) to adenosine in B. subtilis A509. The resulted mutant M3-3 showed an increased adenosine production from 7.40 to 10.45 g/L, which was further enhanced to a maximum of 14.39 g/L by central composite design. As the synthesis of succinyladenosine monophosphate (sAMP) from IMP catalysed by adenylosuccinate synthetase (encoded by purA gene) is the rate-limiting step in adenosine synthesis, the up-regulated transcription level of purA was the potential underlying mechanism for the increased adenosine production. This work demonstrated a practical strategy for breeding B. subtilis strains for industrial nucleoside production.

Due to the promising applications, the demand to enhance poly-γ-glutamic acid (γ-PGA) production while decreasing the cost has increased in the past decade. Here, xylose/glucose mixture and corncob hydrolysate (CCH) was evaluated as alternatives for γ-PGA production by Bacillus amyloliquefaciens C1. Although both have been validated to support cell growth, glucose and xylose were not simutaneously consumed and exhibited a diauxic growth pattern due to carbon catabolite repression (CCR) in B. amyloliquefaciens C1, while the enhanced transcription of araE alleviated the xylose transport bottleneck across a cellular membrane. Additionally, the xyl operon (xylA and xylB), which was responsible for xylose metabolism, was strongly induced by xylose at the transcriptional level. When cultured in a mixed medium, xylR was sharply induced to 3.39-folds during the first 8-h while reduced to the base level similar to that in xylose medium. Finally, pre-treated CCH mainly contained a mixture of glucose and xylose was employed for γ-PGA fermentation, which obtained a final concentration of 6.56 ± 0.27 g/L. Although the glucose utilization rate (84.91 ± 1.81%) was lower than that with chemical substrates, the xylose utilization rate (43.41 ± 2.14%) and the sodium glutamate conversion rate (77.22%) of CCH were acceptable. Our study provided a promising approach for the green production of γ-PGA from lignocellulosic biomass and circumvent excessive non-food usage of glucose.

In this study, a double E strategy (enzymes and enhancer) characterized by high efficiency for enhancing sewage sludge anaerobic digestion (AD) is proposed. This strategy combines addition of trace elements (TEs) enhancer and enzyme pretreatment, inducing a synergistic effect on AD, and it is more effective and economical compared with TEs addition or enzyme pretreatment in isolation. When adding 400 U/g cocktail enzymes and 1.24% trance elements enhancers, the cumulative methane production and the maximum daily methane increased yield by 45.29% and 84.7%, respectively. According to microbial community analysis, the double E strategy significantly motivate the growth of acetogens and protein fermenting bacterium. The relative abundance of Fermentimonas and Lutispora increased by 6.15% and 5.4%, respectively. Archaeal community analysis and changes in the mcrA gene abundance demonstrate enrichment of hydrogenotrophic methanogens, with the methanogens exhibiting high vitalities and stress resistance. The double E strategy could be a promising way to improve industrial sewage sludge AD efficiency.

The impacts of different S/N molar ratios and fillers (polyurethane foam, multi-surface hollow spheres, and pall rings) on the process of simultaneous desulfurization and denitrification (SDD) were studied by using anaerobic biotrickling filer (BTF). Furthermore, the SDD mechanism was described by dividing the SDD process into three stages based on pH changes: (I) increase (II) decrease and (III) stable state. The maximum desulfurization and denitrification efficiency (13.5 g-S m−3 h−1 and 3.7 g-N m−3 h−1, respectively) was achieved by applying polyurethane foam as filler. When S2− and S0 coexist as electron donors in the SDD system, the functional microbes degrade S2− preferentially. The S/N molar ratios of the influent were higher, and the relative content of sulfate in the products was less. Considering the efficiency and economic benefits, polyurethane foam is suggested as fillers for practical implementations of SDD systems. The S/N molar ratios should be controlled in a 5/3 to 5/2 range and HS−/S2− concentration should be

The aim of this work was to study the acetate separation from fresh vinegar residue (FVR) to avoid inhibition of methanogenesis and hydrothermal treatment on washed vinegar residue (WVR) to enhance methane production. The optimal liquid-solid ratio was 10:1mL/g for the washing of FVR. The methane yields of the FVR, WVR, and washed leachate (WL) were 273L/kgVS, 199L/kgVS, and 306.9L/kgCOD, respectively. The optimal hydrothermal temperature was 160°C for WVR, with maximum methane yield of 258.38L/kgVS. Hydrothermal pretreatment destroyed the structure of lignocellulose and improved the hydrolysis of hemicellulose. Compared with thermophilic digestion of FVR, thermophilic digestion of 160°C treated FVR, and thermophilic digestion of WVR with mesophilic digestion of WL, the thermophilic digestion of 160°C treated WVR with mesophilic digestion of WL obtained the maximum total methane yield of 102.5L/kgFVR.

As a new bioremediation technology for toxic metals, microbiologically induced calcite precipitation (MICP) is gradually becoming a research focus. This study investigated the application of MICP to mineralize toxic metals (lead and cadmium) in landfill leachate for the first time. In the experiment of remediating synthetic landfill leachate (SLL) contaminated by Pb2+, 100% of the 20 mg/L Pb2+ was removed when the maximum urease activity was only 20.96 U/ml. Scanning electron microscopy and energy dispersive spectroscopy (SEM-EDS) and laser particle size characterizations of the precipitates indicate the formation of agglomerated square particles, 76.9% of which had sizes that ranged from 33.93 to 57.06 μm. Fourier transform infrared spectroscopic and X-ray diffraction analyses confirmed that the precipitates consisted predominantly of calcite crystals, and the unit cell lattice constants of the precipitates (a = b = 4.984 A, c = 17.171 A) matched those of calcite, while lead was fixed as hydrocerussite. In addition, the Pb-MICP precipitates were stable under continuous acid degradation (pH = 5.5), and only 1.76% of the lead was released after 15 days. In the verification test of toxic metals remediation in a real landfill leachate (RLL), all of the Pb2+ and Cd2+ (initial concentrations: Pb2+ = 25 mg/L; Cd2+ = 5.6205 mg/L) was mineralized simultaneously, which further confirmed the feasibility of MICP for toxic metal remediation in landfill leachate. However, optimizing the urea dosage and combining the ammonium recovery are necessary strategies required for improving the economic and environmental benefits of the MICP process.

Microbial fuel cell (MFC) is a promising device for energy generation and organic waste treatment simultaneously by electrochemically active bacteria (EAB). In this study, an integrated aerobic-anaerobic strategy was developed to improve the performance of P. aeruginosa-inoculated MFC. With an aerobic start-up and following an anaerobic discharge process, the current density of MFC reached a maximum of 99.80µA/cm2, which was 91.6% higher than the MFC with conventional constant-anaerobic operation. Cyclic voltammetry and HPLC analysis showed that aerobic start-up significantly increased electron shuttle (pyocyanin) production (76% higher than the constant-anaerobic MFC). Additionally, enhanced anode biofilm formation was also observed in the integrated aerobic-anaerobic MFC. The increased pyocyanin production and biofilm formation promoted extracellular electron transfer from EAB to the anode and were the underlying mechanism for the MFC performance enhancement. This work demonstrated the integrated aerobic-anaerobic strategy would be a practical strategy to enhance the electricity generation of MFC.

This study investigated methane productions and the microbial communities in the batch anaerobic digestion process with the mono-digestion of corn stalk (CS) and pig manure (PM), and the co-digestion of them. Co-digestion showed the best methane performance, the cumulative methane yield, 256.57 mL·gVS −1 ; methane production potential, 281.55 mL·gVS −1 ; maximum methane production rate, 10.17 mL·d −1 ·gVS −1 ; and lag phase, 4.24 d. Moreover, co-digestion achieved a more suitable microenvironment including pH, FA and FVFA compared to mono-digestions. Results of high-throughput sequencing indicated that in co-digestion the dynamic changes of relative abundances of phyla and predominant genera were very small and community structure presented a stable status. Acetoclastic pathway was the main biochemical pathway of methanogenesis in co-digestion and mono-digestion of PM, and the growth rate of Methanosaeta in co-digestion was higher. So suitable microenvironment in co-digestion resulted in high growth rate of methanogens and stable microbial community, and leaded to the high methane production.

The intensive use of triphenyltin chloride (TPTC) has caused serious environmental pollution. In this study, an effective method for TPTC degradation was proposed based on the Bio-Electron-Fenton process in microbial fuel cells (MFCs). The maximum voltage of the MFC with graphite felt as electrode was 278.47% higher than that of carbon cloth. The electricity generated by MFC can be used for in situ generation of H2O2 to a maximum of 135.96μmolL-1 at the Fe@Fe2O3(*)/graphite felt composite cathode, which further reacted with leached Fe2+ to produce hydroxyl radicals. While 100μmolL-1 TPTC was added to the cathodic chamber, the degradation efficiency of TPTC reached 78.32±2.07%, with a rate of 0.775±0.021μmolL-1h-1. This Bio-Electron-Fenton driving TPTC degradation might involve in SnC bonds breaking and the main process is probably a stepwise dephenylation until the formation of inorganic tin and CO2. This study provides an energy saving and efficient approach for TPTC degradation.

One-step hydroxylation of C-H (sp 2 ) of aromatic ring synchronized with the oxidation of C-H (sp 3 ) of side-chain of p -xylene to 2,5-dihydroxyterephathalic acid was performed using M-MCM-41 (M = Fe, Fe/Cu, Cu) as the catalysts. Cu-MCM-41 (Cu:Si = 1:100) catalyst exhibited good selectivity (73.0%) of 2,5-dihydroxyterephathalic acid and conversion (21.7%) of p -xylene using acetic acid and acetonitrile (V:V = 3:7) as the solvents at 80 °C for 5 h. The possible mechanism of the oxidation of p -xylene to 2,5-dihydroxyterephathalic acid was proposed and would guide us to design high performance catalyst for sp 2 and sp 3 C-H oxidation. This procedure is also expected to be an alternative method to Kolbe-Schmitt Process for the synthesis of o -hydrobenzoic acids and their derivatives.

In this study, a core-shell Fe@Co nanoparticles uniformly modified graphite felt (Fe@Co/GF) was fabricated as the cathode by one-pot self-assembly strategy for the degradation of vanillic acid (VA), syringic acid (SA), and 4-hydroxybenzoic acid (HBA) in the Bio-Electro-Fenton (BEF) system. The Fe@Co/GF cathode showed dual advantages with excellent electrochemical performance and catalytic reactivity not only due to the high electron transfer efficiency but also the synergistic redox cycles between Fe and Co species, both of which significantly enhanced the in situ generation of H2O2 and hydroxyl radicals ( OH) to 152.40 μmol/L and 138.48 μmol/L, respectively. In this case, the degradation rates of VA, SA, and HBA reached 100, 94.32, and 100%, respectively, within 22 h. Representatively, VA was degraded and ultimately mineralized via demethylation, decarboxylation and ring-opening reactions. This work provided a promising approach for eliminating typical recalcitrant organic pollutants generated by the pre-treatment of lignocellulose resources.

Nitrogen loss is the main problem in compost and controlling it is the key to the recovery and utilization of composted materials. This study systematically investigated the effect of nitrogen retaining microbial agent (NRMA) on nitrogen retention and the promotion of decay during manure composting and tested its effect on nitrogen conversion and bacterial community structure. During composting, various parameters were dynamically evaluated, including nitrogen loss and transformation, compost maturity and nutrient, microorganism population and bacteria community variation. Results showed that the inoculation of NRMA significantly reduced ammonia loss by 58.8% with 15 days shorter compost cycle. At the end of the composting, the total nitrogen (TN) and nitrate content of the experimental group were 23.3 g kg−1 and 4.5 g kg−1, 22.6% (p

With polyhedral spheres as the packing, a semi-pilot biological trickling filter reactor (BTF) inoculated by domesticated activated sludge is used to remove Hydrogen Sulphide (H2S) and Ammonia (NH3). The removal rate of H2S and NH3 by BTF was as high as 98.25% and 88.55%, and the maximum removal load was 84.57 g H2S m−3h−1 and 38.77 g NH3 m−3h−1 during the 61-day process. The inlet gas concentration ranges from 0 to 500 ppm, and the empty bed residence time (EBRT) is 31.8 s. When the EBRT reduced from 31.8s to 25.4s, the removal rate of H2S and NH3 decreased significantly, which was 67.21% and 81.36%, respectively. The results showed that EBRT significantly affected the removal rate of H2S and NH3. Microbial analysis indicated that Dokdonella, Ferruginibacter, Nitrosomonas, and Thiobacillus had high abundance at the genus level, showing that these genera play an important role in the degradation of H2S and NH3. When the optimized parameters applied to the on-site biogas residue compost, the removal rate of H2S and NH3 by BTF can reach 91.34%, which provides a feasible process for the deodorization project with compost.

In order to develop a time-saving method for determination of ultimate methane production, obtain the hydrolysis kinetic constant, and identify a determination method for the nonbiodegradable organic fraction of substrate (VSNB) of green and air-dried corn stover, the kinetics of methane production and hydrolysis were studied using batch tests. The results showed that the conventional first-order hydrolysis kinetic model was not suitable for describing the entire hydrolysis process of corn stover, because there were two first-order decay periods for hydrolysis of corn stover. The hydrolysis kinetic constants kH,1 and kH,2 of the first and second periods were 0.1701 and 0.0415 1/d for green stover and 0.1052 and 0.0360 1/d for air-dried stover. The value of VSNB could be obtained by the graphical method rather than by the hydrolysis kinetic model. The obtained VSNB contents were 12.9% and 24.7% of VS (volatile solid) for green and air-dried stover, respectively. The ultimate methane production and corresponding digestion time could be understood through the methane production kinetic model by digestion experiments within a short time. The ultimate methane productions were 347.1 and 319.4 mL/g based on VS and the corresponding digestion times were 69.2 and 182.3 days for green and air-dried stover, respectively.

Intimate coupling of microbial extracellular electron transfer (EET) and photoelectrochemical processes is an emerging research area with great potential to circumvent many disadvantages associated with traditional techniques that depend on independent microbial or photocatalysis treatment. Microbial EET processes involve microorganism oxidation of extracellular electron donors for respiration and synchronous reduction of extracellular electron acceptors to form an integrated respiratory chain. Coupled microbial EET-photoelectrochemical technologies greatly improve energy conversion efficiency providing both economic and environmental benefits. Among substitutes for semiconductor photocatalysts, cadmium sulfide nanoparticles (CdS NPs) possess several attractive properties. Specifically, CdS NPs have suitable electrical conductivity, large specific surface area, visible light-driven photocatalysis capability and robust biocompatibility, enabling them to promote hybrid microbial-photoelectrochemical processes. This review highlights recent advances in intimately coupled CdS NPs-microbial extracellular electron transfer systems and examines the mechanistic pathways involved in photoelectrochemical transformations. Finally, the prospects for emerging applications utilizing hybrid CdS NPs-based microbial-photoelectrochemical technologies are assessed. As such, this review provides a rigorous fundamental analysis of electron transport dynamics for hybrid CdS NPs-microbial photoelectrochemical processes and explores the applicability of engineered CdS NPs-biohybrids for future applications, such as in environmental remediation and clean-energy production.

Nitrogen doping in combination with the brookite phase or a mixture of TiO2 polymorphs nanomaterials can enhance photocatalytic activity under visible light. Generally, nitrogen-dopedanatase/brookite mixed phases TiO2 nanoparticles obtained by hydrothermal or solvothermal method need to be at high temperature and with long time heating treatment. Furthermore, the surface areas of them are low (

This study investigated the possibilities of improving the biogasification from solid-state anaerobic digestion (SS-AD) of composting rice straw (RS) based on the optimized digestion temperature, initial substrate concentration (ISC) and C/N ratio. RS compounds, such as lignin, cellulose, and hemicellulose, were significantly degraded after composting. A significant interactive effect of temperature, ISC and C/N ratio was found on the biogasification of SS-AD of composting RS, and a maximum biogas production was achieved at 35.6°C, with a 20% ISC and a C/N ratio of 29.6:1. The verification experiment confirmed the optimization results. High-throughput sequencing analysis indicated that microbial communities in the SS-AD mainly consist of Methanobacteria, Bacteroidia, Clostridia, Betaproteobacteria, and Gammaproteobacteria. A dominant Methanobacteria was shifted from Methanobacterium to Methanoculleus during the SS-AD process. This study provides novel information about the interdependent effects and microbial behavior of AD.

Although a few systems prepared by using biotemplates have been employed as mesoporous photocatalysts, the natural latex secreted by plants has not been used as a template to synthesize porous materials, let alone for the achievement of high photocatalytic activity under solar light. Herein, one of the most important biosynthesized polymers, natural rubber latex from the rubber tree, Hevea brasiliensis in Xishuangbanna was directly used as a structure-directing agent in synthesis of thermally stable mesostructured TiO2. The as-prepared samples were characterized by XRD, FT-IR, XPS, N2 adsorption/desorption, TEM and UV-vis DRS. The synthesized TiO2 exhibited highly effective photocatalytic activity for the degradation of phenol and rhodamine B under solar light. Furthermore, addition of acetylacetone (ACA) during the synthesis significantly enhanced the photocatalytic activity. The reported strategies provide a new direction of using natural rubber latex as a template to prepare highly effective photocatalysts.

Cobalt doped and undoped mesoporous titania were synthesized using resin acid as template. Moreover, without adding extra cobalt source, cobalt doped mesoporous titania was also synthesized by using cobalt resinate as both template and cobalt source. These mesoporous samples were characterized by a combination of various physicochemical techniques, such as N2 adsorption/adsorption isotherm, UV–vis diffuse reflectance, X-ray diffraction, high resolution transmission electron microscopy, XPS, and FT-IR. They were used for the photodegradation of methyl blue and Rhdamine B under visible light. It was found that P25 and mesoporous TiO2 synthesized using resin acid as template did not exhibit any meaningful activity for the photodegradation of two dyes under visible light. By contrast, cobalt doped mesoporous titania synthesized by using resin acid as template exhibited more significant photocatalytic yield (94%) for Rhdamine B. Moreover, cobalt doped mesoporous titania synthesized by using cobalt resinate as template also exhibited similar high photocatalytic activity for methyl blue to the former.

In this work, mesoporous TiO 2 compose of anatase and brookite phases (M-TiO 2 ) has been synthesized using 2,4,5-triphenylimidazole as template. The physical features of the as-prepared catalyst was measured by X-ray diffraction (XRD), low-temperature nitrogen adsorption/desorption, UV–visible diffuse reflectance spectrum, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The photocatalytic performance of the catalyst was evaluated in terms of the degradation of organic dyes. It is found that M-TiO 2 exhibits reasonable activity under UV light and can significantly degrade methylthionine chloride, rhodamine B, gentian violet, safranine T, methyl violet and fuchsine basic under visible-light irradiation ( λ ≥420 nm).

The use of metal-organic frameworks (MOFs) in the polymerization field remains comparatively rare up to now, let alone studies on the fabrication of polymer microstructures through a MOFs-catalyzed assembly process. Zeolitic imidazolate framework-8 (ZIF-8), a well-known MOF for its chemical and thermal stabilities, was used to induce a polymerization reaction of saturated alkylsilanes for the first time. The reaction temperature was found to be critical for morphology control of the polymerized ZIF-siloxane composites. The polymerization of alkylsilanes by ZIF-8 at room temperature resulted in siloxane microspheres while rose petal-like microstructures were obtained at higher temperature. The effects of the reaction time on the structures of the polymerization products were also investigated and the polymerization reaction process was proposed. This work expands the field of MOFs’ applications and develops a reasonable method for the multidimensional assembly of MOFs building blocks into required structures or platforms for designing new kinds of hierarchical morphologies, which to our knowledge has not been previously investigated.

Production of upgraded biogas is required to remove as much carbon dioxide as possible. It was found that by coupling microbial electrolysis cell (MEC) and anaerobic digestion (AD) in a single-chamber, barrel-shape stainless steel reactor, compared with common anaerobic digestion (control), CH4 content in excess of 98% was achieved and CH4 yield was increased 2.3 times. Meanwhile, the COD removal rate was tripled and carbon recovery was increased by 56.2%. In this new process, unwanted CO2 was in situ converted into CH4 on anode by the dominant microbes, hydrogenotrophic electromethanogens (e.g. Methanospirillum). These microbes could utilize hydrogen gas generated at the inner surface of stainless steel reactor, which itself served as cathode of MEC through small voltage addition (1.0 V). The overall energy efficiency was 66.7%. Keywords: Upgraded biogas, Carbon dioxide, MEC–AD coupling system, Stainless steel reactor

Liquid-phase catalytic oxidation of limonene was carried out under mild conditions, and carvone was produced in the presence of ZIF-67(Co), cobalt based zeolitic imidazolate framework, as catalyst, using t-butyl hydroperoxide (t-BHP) as oxidant and benzene as solvent. As a heterogeneous catalyst, the zeolitic imidazolate framework ZIF-67(Co) exhibited reasonable substrate&ndash, product selectivity (55.4%) and conversion (29.8%). Finally, the X-ray diffraction patterns of the catalyst before and after proved that ZIF-67(Co) acted as a heterogeneous catalyst, and can be reused without losing its activity to a great extent.

In sharp contrast to conventional photosensitization methods in which the organic pigments were often adsorbed, herein we present a study on natural vegetable pigment inserted TiO2 aerogel nanocomposites and we directly use red cabbage anthocyanin (RCP) as a structure-directing agent. It was found that pure TiO2 aerogel nanocomposite did not exhibit any meaningful activity for photocatalytic reduction of Cr(VI). However, the photocatalytic reduction activity was greatly improved by the RCP inserted TiO2 aerogel nanocomposites under visible-light irradiation, which was approximately 2- and 12.3-fold higher than that of TiO2 aerogel conventionally photosensitized by RCP and pure TiO2 aerogel nanocomposites, respectively. It also exhibited good stability and could be reused at least three times without losing a significant amount of its activity.

The siliceous frustules with sophisticated optical structure endow diatoms with superior solar light-harvesting abilities for effective photosynthesis. The preserved frustules of diatom (Cocconeis placentula) cells, as biophotonic crystals, were thus employed as both hard templates and silicon resources to synthesize TiO2 photocatalyst. Characterizations by a combination of physicochemical techniques proved that the bio-inspired sample is TiO2-coated SiO2 with biogenic C self-doped in. It was found that the synthesized composites exhibited similar morphologies to the original diatom templates. In comparison with commercial Degussa P25 TiO2, the C-doped TiO2/SiO2 catalyst exhibited more light absorption in the visible region and higher photocatalytic efficiency for photodegradation of rhodamine B under visible light due to the biomorphic hierarchical structures, TiO2 coating and C-doping.

With the transition of livestock production from the traditional small household farming to large-scale centralized breeding, the odor pollution caused by livestock manure has become pressing in China. In this study, two yeast strains Y1 and Y2 with high deodorization efficiency were isolated from the sample collected from an outlet in a swine farm in Shuangliu County, Sichuan Province. The scale-up deodorization experiments were carried out for strains Y1, Y2, and their mixture Y1+Y2. The results showed that the reduction rate of treatments on NH3 was in the sequence of Y1+Y2 (35.6 ∼ 68.7%) >Y1 (20.3 ∼ 63.7%) >Y2 (−11.7 ∼ 53.8%). The reduction rate of treatments on H2S was in the sequence of Y1+Y2 (47.2 ∼ 70.1%) > Y2 (36.6 ∼ 60.8%) > Y1 (27.6 ∼ 42.0%). The reduction rate of treatments on total volatile organic compounds (TVOC) was in the sequence of Y1+Y2 (49.1 ∼ 68.3%) > Y1 (36.2 ∼ 54.6%) >Y2 (20.8 ∼ 48.6%). The reduction rate of treatments on odor intensity was in the sequence of Y1+Y2 (27.2–60.3%) > Y1 (16.3 ∼ 38.5%) >Y2 (−0.4 ∼ 35.2%). Furthermore, the concentrations of VFAs, indole, skatole, total nitrogen (TN), organic nitrogen (ON), total sulfur (TS), and ammonium nitrogen (AN) in swine manure during deodorization by yeast strains Y1, Y2, and their mixture Y1+Y2 were assayed. The results showed the concentrations of VFAs, indole, and skatole in the manure with Y1, Y2, and Y1+Y2 treatments were all lower than those of the control group. The concentrations of TN, ON, and TS in treatments were all higher than that of the control group. The concentrations of AN in the treatment groups were all lower than those of the control group.

Odor pollution is a big environmental problem caused by large-scale livestock production in China, and developing a practical way to reduce these odors is pressing. In this study, a combination of 0.2-1.0 U/mL lignin peroxidase (LiP) and one of three peroxides (H2O2, CaO2, 2Na3CO3·3H2O2) was examined for its efficiency in reducing the release of eight chemicals (propionic acid, isobutyric acid, isocaproic acid, isovaleric acid, phenol, p-cresol, indole, and skatole), NH3, H2S, and odor intensity from pig manure. The results showed an approximately 90% reduction in p-cresol, 40-60% reduction in odor intensity, 16.5-40% reduction in indolic compounds, and 25-40% reduction in volatile fatty acids. Being the electron acceptors of LiP, 2Na3CO3·3H2O2 and CaO2 performed better than H2O2 in reducing the concentration of eight chemicals, NH3, H2S, and odor intensity from pig manure. The effect of deodorization can last for up to 72 hr.In China, one of the major environmental problems caused by confined feeding is odor pollution, which brings a major threat to the sustainability, profitability, and growth of the livestock industry. To couple the LiP with the electron acceptors, a low-cost, simple, and feasible method for odor removal was established in this study. Based on the study results, a practical treatment method was provided for odor pollution and supply the farm operators a more flexible time to dispose treated manure.

BACKGROUND: This work investigated the monokaryogenesis of dikaryon strains of Trametes hirsuta by protoplasts regeneration for extracellular ligninolytic enzyme production. Saccharification of corn straw was enhanced by alkali pretreatment combining crude ligninolytic enzymes. RESULTS: Effectiveness of alkali pretreatment of corn straw on delignification was evaluated under different concentrations. About 45% lignin loss was achieved at the concentration of 1.5% NaOH. In addition, 79.0% sugar yield was obtained after combined pretreatment with NaOH and crude ligninolytic enzyme produced from monokaryotic strains of Trametes hirsuta. Scanning electron microscopy (SEM) images showed that the porosity and surface area increased significantly after combined pretreatment. The FTIR spectra indicated that great intensity changes occurred at the 890900 cm-1, 15091513 cm-1 and 1595 cm-1 bands. CONCLUSION: The proposed combined pretreatment removes lignin and enhances saccharification of corn straw effectively. Copyright (c) 2012 Society of Chemical Industry

Mesoporous TiO2 with anatase crystalline structure (MTiO2/F2319) has been synthesized by using vinylidene fluoride/chlorotrifluoroethylene copolymer (1:9 in mole, F2319) as template. The synthesized mesoporous titania samples were characterized by a combination of various physicochemical techniques, such as X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, and N2 adsorption/desorption. It was found that without any external doping, MTiO2/F2319 exhibited significantly higher photocatalytic activities for the degradation of rhodamine B (RhB) dye than P25 TiO2 under visible light irradiation. Furthermore, the UV-Vis absorption maximum of the dye solution exhibited a gradual hypsochromic shift due to de-ethylation and degradation of RhB dye.

To investigate the effects of organic loading rate (OLR) on performance and stability of mesophilic co-digestion of rice straw (RS) and chicken manure (CM), benchtop experiments (40 L) were carried out at OLRs of 3.0, 3.6, 4.2, 4.8, 6.0, 8.0, and 12.0 kg volatile solid (VS)/(m(3)·day) with volatile solid (VS) ratio of 1:1 (RS/CM) which was based on batch tests. Anaerobic co-digestion was slightly and severely inhibited by the accumulation of ammonia when the digester was overloaded at an OLR of 6 and 12 kg VS/(m(3)·day), respectively. The recommended OLR for co-digestion is 4.8 kg VS/(m(3)·day), which corresponds to average specific biogas production (SBP) of 380 L/kg VS and volumetric biogas production rate (VBPR) of 1.8 m(3)/(m(3)·day). An OLR of 6-8 kg VS/(m(3)·d) with SBP of 360-440 L/kg VS and VBPR of 2.1-3.5 m(3)/(m(3)·day) could be considered, if an Anaerobic digestion (AD) system assisted by in situ removal of ammonia was adopted.

Mesophilic-hydrothermal (80-160 °C, 30 min)-thermophilic (M-H-T) digestion and control tests of mesophilic (M), thermophilic (T), hydrothermal-mesophilic (H-M), and mesophilic-thermophilic digestion (M-T) of green corn straw were conducted for a 20-day fermentation period. The results indicate that M-H-T is an efficient method to improve methane production. A maximum methane yield of 371.74 mL/g volatile solid was obtained by the M (3 days)-H (140 °C)-T (17 days) process, which was 20.44%, 16.55%, 31.44%, and 14.31% higher than the yields of the M, T, 140-M, and M-T processes. The enhanced methane production was attributed to (1) the improved hemicellulose degradation and lignin disorganization; (2) prevention of the degradation of soluble sugar, easily hydrolyzed hemicellulose and cellulose into furfural and methylfurfural; and (3) lack of formation of Maillard reaction products during initial hydrothermal treatment.

In this study, a newly isolated Trametes hirsuta yj9 was used to pretreat corn stover in order to enhance enzymatic digestibility. T. hirsuta yj9 preferentially degraded lignin to be as high as 71.49% after 42-day pretreatment. Laccase and xylanase was the major ligninolytic and hydrolytic enzyme, respectively and filter paper activity (FPA) increased gradually with prolonged pretreatment time. Sugar yields increased significantly after pretreatment with T. hirsuta yj9, reaching an enzymatic digestibility of 73.99% after 42 days of pretreatment. Scanning electron microscopy (SEM) showed significant structural changes in pretreated corn stover, the surface of pretreated corn stover became increasingly coarse, the gaps between cellulose fibers were visible, and many pores were developed. Correlation analysis showed that sugar yields were inversely proportional to the lignin contents, less related to cellulose and hemicellulose contents.

In this work, focal cerebral ischemia/reperfusion was induced by the model of middle cerebral artery occlusion. The dialysates of extracellular fluid in hypothalamus were obtained by using brain microdialysis technique. An efficient and sensitive chiral capillary electrophoresis with laser-induced fluorescence detection procedure was developed for the simultaneous determination of multiple amino acids neurotransmitter including Arg, Lys, Trp, GABA, l-Ser, Ala, Tau, Gly, Glu and Asp; catcholamine (dopamine) and neuromodulator (d-Ser and O-phosphoethanolamine) in microdialysate. Different parameters that influenced CE separation were optimized. The optimal method was used to investigate the dynamic changes of neurotransmitters and neuromodulators during cerebral ischemia/reperfusion. The results indicated that extracellular levels of multiple neurotransmitters and neuromodulators were elevated during cerebral ischemia/reperfusion. The dynamic changes and functional status of releasable neurotransmitters and neuromodulators during ischemia/reperfusion were discussed.

The present study was carried out to elucidate the neuroprotective effect and influence of resveratrol on the extracellular levels of neurotransmitter and neuromodulator during ischemia/reperfusion in rats. Male rats were divided into three groups: sham operation, ischemia treatment, and ischemia combined with resveratrol treatment (resveratrol-treated group, 30 mg/kg intraperitoneally for 7 days). Cerebral ischemia was induced by using the model of middle cerebral artery occlusion. The dialysates in hypothalamus were obtained by brain microdialysis technique. The levels of sixteen amino acids and amines in microdialysate were monitored by capillary electrophoresis analysis. This study shows that the ischemic infarcts were significantly reduced and neurological functions were improved in resveratrol-treated group compared to ischemia group. The analysis results demonstrate that chronic treatment with resveratrol remarkably reduced the release of excitatory neurotransmitter glutamate, aspartate and neuromodulator d-Serine during ischemia and reperfusion; and significantly increased the basal extracellular levels of inhibitory neurotransmitter gamma-amino-n-butyric acid, glycine and taurine. Chronic treatment with resveratrol also ameliorated O-phosphoethanolamine levels and excitotoxic index during ischemia and reperfusion. This study provides the first in vivo evidence that resveratrol could exert neuroprotective effect against ischemia injury by modulating the release of multiple neurotransmitters and neuromodulators during ischemia/reperfusion.

Pure rutile and rutile-anatase composite TiO(2) nanoparticles have been successfully synthesized via an ionic liquid-assisted method by hydrolysis of titanium tetrachloride in hydrochloric acid. It is found that the phase composition (ratio of rutile to anatase) of the products increases with increasing the content of ionic liquid [Emim]Br (1-ethyl-3-methyl-imidazolium bromide), therefore, TiO(2) nanoparticles with controlled phase compositions can be obtained in high yields. The structural and morphological characterizations of the resulting samples are investigated by means of X-ray powder diffraction (XRD), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), and Brunauer-Emmett-Teller (BET) analysis, and the results indicate that the diameters of the anatase nanoparticles are in the range of 4-6 nm and the well-defined rutile nanorods are about 3-6 nm in diameter and 20-60 nm in length. More importantly, we find that the [Emim](+) ions can serve as capping agents based on their strong interactions with the (110) facets of rutile, and the [Emim]Br favors the formation of the rutile structure with a rod-like shape due to the mutual pi-stacking interactions of imidazole rings. We believe that this method can be developed into a general way to synthesize other metal oxide nanoparticles on a large scale.

Selective oxidation of 4-tert-butyltoluene (TBT) to 4-tert-butylbenzaldehyde (TBBZ) and 4-methylacetophenone (MAP) is reported for the first time using aqueous hydrogen peroxide as oxidant and Co/MCM-41 as the catalyst under mild conditions for the first time. Co/MCM-41 presented reasonable selectivity (82%) of TBBZ with a conversion rate of 15% of TBT without any initiator. Under the suitable reaction conditions, Co/MCM-41 also presented reasonable selectivity (58%) of MAP with a conversion rate of 12% of the substrate. The catalysts can be reused once with almost the same activity.

Aims To reveal the microbial communities from Qinghai–Tibetan Plateau wetland soils that have the potential to be used in the utilization of cellulosic and chitinous biomass at low temperatures (≤25°C). Methods and Results Soil samples collected from six wetlands on Qinghai–Tibetan Plateau were supplemented with or without cellulose and chitin flakes, and anaerobically incubated at 25 and 15°C; high-throughput 16S rRNA gene sequencing was used to access the composition and localization (in the slurry and on the surface) of enriched microbial communities; a hypothetical model was constructed to demonstrate the functional roles of involved microbes mainly at genus level. Overall, microbial communities from Qinghai–Tibetan Plateau wetlands showed significant potential to convert both cellulose and chitin to methane at low temperatures; Clostridium III, Clostridium XIVa, Paludibacter, Parcubacteria, Saccharofermentans, Pelotomaculum, Methanosaeta, Methanobrevibacter, Methanoregula, Methanospirillum and Methanosarcina participated in methanogenic degradation of both cellulose and chitin through the roles of hydrolytic, saccharolytic and secondary fermenters and methanogens respectively. Acetotrophic methanogens were mainly enriched in the slurries, while hydrogenotrophic methanogens could be both in the slurries and on the surface. Conclusions The composition and localization of microbial communities that could effectively convert cellulose and chitin to methane at low temperatures have been revealed by high-throughput 16S rRNA gene sequencing methods, and reviewing the literatures on the microbial pure culture helped to elucidate functional roles of significantly enriched microbes. Significance and Impact of the Study This study will contribute to the understanding of carbon and nitrogen cycling of cellulose and chitin in cold-area wetlands and provide fundamental information to obtain microbial resources for the utilization of biomass wastes at low temperatures.

A CdS embedded metal-organic framework (MIL-100) composite was synthesized and used for photocatalytic degradation of nitrite ions. The obtained samples were characterized by a series of techniques such as X-ray diffraction (XRD), N2 adsorption/desorption, transmission electron microscopy (TEM) and UV-Vis diffuse reflectance spectra (DRS). The results show that CdS nanoparticles were dispread and embedded on the MIL-100 crystals. The CdS/MIL-100 composites exhibited significant activities for photocatalytic degradation of nitrite ions through a disproportionation process in a neutral aqueous solution without any sacrificial reagents. When 20 wt% of CdS was embedded, the highest degradation yield of 92 % was achieved in 10-ppm NaNO2 aqueous solution under simulated solar light irradiation, which was fivefold of bare CdS. The enhancement in photocatalytic activities could be contributed to photosensitization and supporting of metal-organic framework scaffold.

The anaerobic digestion (AD) and microbial electrolysis cell (MEC) coupled system has been proved to be a promising process for biomethane production. In this paper, it was found that by co-cultivating Geobacter with Methanosarcina in an AD-MEC coupled system, methane yield was further increased by 24.1%, achieving to 360.2 mL/g-COD, which was comparable to the theoretical methane yield of an anaerobic digester. With the presence of Geobacter, the maximum chemical oxygen demand (COD) removal rate (216.8 mg COD/(L·hr)) and current density (304.3A/m(3)) were both increased by 1.3 and 1.8 fold compared to the previous study without Geobacter, resulting in overall energy efficiency reaching up to 74.6%. Community analysis demonstrated that Geobacter and Methanosarcina could coexist together in the biofilm, and the electrochemical activities of both were confirmed by cyclic voltammetry. Our study observed that the carbon dioxide content in total gas generated from the AD reactor with Geobacter was only half of that generated from the same reactor without Geobacter, suggesting that Methanosarcina may obtain the electron transferred from Geobacter for the reduction of carbon dioxide to methane. Taken together, Geobacter not only can improve the performance of the MEC system, but also can enhance methane production.

Cobalt-doped mesoporous titania with anatase crystalline structure was prepared using 1-dodecylamine as template by cogellation method and was used as a catalyst for the oxidation of cyclohexane to cyclohexanol and cyclohexanone under mild conditions for the first time.

Cobalt-doped mesoporous titania with a crystalline framework synthesized by surfactant templating method presented highly selective (99%) and reasonable conversion rate (49%) of catalytic oxidation of para-chlorotoluene to para-chlorobenzaldehyde in acetic acid using aqueous hydrogen peroxide as oxidant for the first time. Recycling of the catalyst indicates that the catalyst can be used a number of times without losing its activity to a greater extent. By contrast, cobalt-doped mesoporous titania without a crystalline structure and cobalt doped the commercial titania, Degussa P25 prepared by impregnation method with the similar concentration of cobalt were found inactive. The effects of catalyst concentration, reaction time, reaction temperature, and solvents on the performance of the catalyst were also investigated.

A stable photoactive metal–organic framework UiO-66(Zr) sensitized by adsorbed or directly added rhodamine B dye exhibited photocatalytic activity for hydrogen evolution under visible-light illumination (λ ≥ 420 nm). Using Pt as a co-catalyst, the adsorbed and directly added dye extremely enhanced the photocatalytic activity to 30 and 26 times the value afforded by bare Pt@UiO-66(Zr), respectively.

Catalytic hydrolysis of biomass over solid catalysts can be one of the most efficient pathways for a future sustainable society dependent on cellulose biomass. In this work metal–organic framework MIL-53(Al) without any functionalization was directly employed as an efficient heterogeneous catalyst for the hydrolysis of carboxymethyl cellulose (CMC) to 5-hydroxymethyl-furaldehyde (5-HMF) in aqueous phase. A 5-HMF molar yield of 40.3% and total reducing sugar (TRS) molar yield of 54.2% were obtained with water as single solvent at 473 K for 4 h. The catalyst could be reused three times without losing activity to a greater extent. With the remarkable advantages such as the use of water as single solvent and MIL-53(Al) as a novel heterogeneous green catalyst, the work provides a new platform for the production of value added chemicals and liquid fuels from biomass.

Agriculture straw is considered a renewable resource that has the potential to contribute greatly to bioenergy supplies. Chemical pretreatment prior to anaerobic digestion can increase the anaerobic digestibility of agriculture straw. The present study investigated the effects of seven chemical pretreatments on the composition and methane yield of corn straw to assess their effectiveness of digestibility. Four acid reagents (H2SO4, HCl, H2O2, and CH3COOH) at concentrations of 1%, 2%, 3%, and 4% (w/w) and three alkaline reagents (NaOH, Ca(OH)2, and NH3·H2O) at concentrations of 4%, 6%, 8%, and 10% (w/w) were used for the pretreatments. All pretreatments were effective in the biodegradation of the lignocellulosic straw structure. The straw, pretreated with 3% H2O2 and 8% Ca(OH)2, acquired the highest methane yield of 216.7 and 206.6 mL CH4 g VS(-1) in the acid and alkaline pretreatments, which are 115.4% and 105.3% greater than the untreated straw. H2O2 and Ca(OH)2 can be considered as the most favorable pretreatment methods for improving the methane yield of straw because of their effectiveness and low cost.

Cyanobacteria, which occurred in eutrophic water harvest solar light to carry out photosynthesis with high efficiency. In this work, cyanobacteria (Microcystis sp.) were used as biotemplate to synthesize titania structure. The synthesized titania sample had similar morphology to that of the original template in spite of the fragile unicellular structures and extremely high water content of cyanobacterial cells. Incorporation of biogenic C, as well as the morphology inherited from biotemplate improved visible-light absorbance of the titania structure. The sample exhibited higher visible-light photocatalytic activity than commercial titania photocatalyst Degussa P25 for Rhodamine B (RhB) degradation. Compared with those C-doped titania photocatalysts prepared by other methods, cyanobacteria templated titania photocatalyst offer some potential for competitive advantages. The reported strategy opened up a new use for the cyanobacteria. It could also be used for titania in applications such as treatment of polluted water, dye-sensitized solar cells, or other regions.

A simple low-temperature solvothermal scheme has been developed to produce pure, well-controlled characteristics in terms of size, morphology, and monodispersity of barium titanate (BaTiO3) nanocub...

Using CMC Congo Red agar plate method,an actinomycetic strain producing cellulase with high temperature tolerance and pH stability was isolated from the sample collected from mushroom plantation.The strain was identified and named as Thermobifida fusca DY3 by morphological,physiological and biochemical characteristics,and 16S rDNA gene sequence analysis.The study on the cellulase showed that the extracellular thermostable cellualse exhibited the maximum activity at 65 ℃ and retained more than 75% of its maximum activity after incubation for 60 minutes at 70 ℃.The enzyme also showed its pH stability between pH 5.5 and 10.0,and retained 80% of its maximum enzymatic activity after treated at pH 10.0.The sodium carboxymethylcellulose was its best zymolyte.All the characteristics of the enzyme provide reference value for its application in biological pretreatment of lignocellulose.

An alkalophilic methanogen T13 was isolated by anaerobic techniques of Hungate from cow muck in Hongyuan county,Sichuan,China enriched in culture for methanogen at 15 ℃.Its optimum pH for producing methane was 8.5,and the temperature for growth was observed at the range of 8~45 ℃.The culture was visible particulate.Cells were aggregated and gram-positive.The colony was pale yellow,mulberry-like and fluoresced.T13 could grow using acetate,methanol or methylamine as sole carbon source,and it was sensitive to chloramphenicol and gentamicin.The optimum temperature and NaCl concentration for its growth were 30 ℃ and 0~0.15 mol L-1,respectively.It grew at the pH range between 6.5 and 9.5.The morphological and physio-biochemical characteristics combined with 16S rDNA sequence analysis of strain T13 demonstrated that it was a strain of Methanosarcina mazei.Since its optimum pH for growth was 8.5,strain T13 therefore was considered preliminarily as a new strain of M.mazei.

Polyvinylpyrrolidone (PVP)-capped silver nanoparticles were used as the catalyst for the oxidative coupling of n -dodecanethiol. The product was characterized to be n -dodecyl disulfide by mass spectrometry, Fourier transform infrared spectroscopy, Raman spectros-copy, and proton nuclear magnetic resonance spectroscopy. The effects of reaction time, temperature, catalyst concentration, and water amount on catalyst performance were examined. The optimum reaction conditions were 0.157 mmol PVP-capped silver nanoparticles, 20 μl distilled water, reaction temperature of 100 °C, and reaction time of 3 h. The PVP-capped silver nanoparticles were also used as the catalyst for the oxidative coupling of n -butanethiol and n -octanethiol to their corresponding disulfides.