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Massive amounts of biogas slurry are produced due to the development of biogas plants. The pollution features and the risk of biogas slurry were fully evaluated in this work. Thirty-one biogas slurry samples were collected from sixteen different cities and five different raw materials biogas plants (e.g. cattle manure, swine manure, straw-manure mixture, kitchen waste and chicken manure). The chemical oxygen demand (COD), ammonia nitrogen ( NH 4 + - N ), anions (e.g. Cl−, SO 4 2 - , NO 3 - and PO 4 3 - ), antibiotics (e.g. sulphonamides, quinolones, β2-receptor agonists, macrolides, tetracyclines and crystal violet) and heavy metals (e.g. Cu, Cd, As, Cr, Hg, Zn and Pb) contents from these biogas slurry samples were systematically investigated. On this basis, risk assessment of biogas slurry was also performed. The concentrations of COD, NH 4 + - N and PO 4 3 - in biogas slurry samples with chicken manure as raw material were significantly higher than those of other raw materials. Therefore, the biogas slurry from chicken manure raw material demonstrated the most serious eutrophication threat. The antibiotic contents in biogas slurry samples from swine manure were the highest among five raw materials, mostly sulphonamides, quinolones and tetracyclines. Biogas slurry revealed particularly serious arsenic contamination and moderate potential ecological risk. The quadratic polynomial stepwise regression model can quantitatively describe the correlation among NH 4 + - N , PO 4 3 - and heavy metals concentration of biogas slurry. This work demonstrated a universal potential threat from biogas slurry that can provide supporting data and theoretical basis for harmless treatment and reuse of biogas slurry.

Improving the biodegradation efficiency of terephthalic acid (TA) wastewater processes is highly challenging, particularly in large-scale up-flow anaerobic sludge blanket (UASB) reactors.

In this work, Friedel-Crafts alkylation was successfully applied to prepare a magnetic ionic liquid hypercrosslinked polymer composite (Fe

effects of HHP on the texture properties of eel surimi, eel myofibrillar protein (MP) structure, and angiotensin-converting enzyme (ACE) inhibitory activity were studied. In this study, eel surimi samples were treated with HHP at 100, 200, 300, 400, 500, and 600 MPa. Texture profiling analysis results of eel surimi under HHP (> 400 MPa) showed that the hardness, adhesiveness, and chewiness of surimi had significantly increased compared to control, which greatly improved the quality of surimi. HHP could convert the α-helix and β-sheet to random coil and β-turn, enhancing the contents of the interior hydrophobic and reactive sulfhydryl groups. The hardness, adhesiveness, chewiness, and springiness of surimi showed a negative relationship with the α-helix and β-sheet, and a positive correlation with random coil and β-turn. The ACE inhibitory activity of MP after HHP treatment increased, and the ACE inhibitory activity was highly (76.9%) observed at 300 MPa, which was increased by 16.5% compared with that of the control group. A positive relationship between the hydrophobic and ACE inhibitory activity of MP, and a negative relationship with the β-sheet structure were observed. The overall results suggested that structurally induced changes can be a major cause of the significant enhance of texture of surimi and ACE inhibitory activity of MP under HHP.

Amorphous and irregular nanoparticles of CoSx were anchored on regular CaTiO3 nanocubes by the method of in situ growth, and the S-scheme heterojunction for photocatalytic hydrogen production was c...

In this study, a new method comprising graphene oxide (GO) and amino group modifications of carbon felt (CF) electrode material surfaces was employed to improve the initial adhesion capacities of b...

An effective method to reduce the recombination rate of photogenerated electron–hole pairs was developed by the construction of heterojunctions with rationally designed photocatalysts having a matched band structure. Herein, g-C3N4 hexagonal tubes possessing a lower conduction band were coupled with Co3S4 ultra-fine nanoparticles having relatively higher positions for their conduction band. A step-scheme heterojunction was constructed between these two materials, and through this heterojunction, the spatial charge separation was boosted. The boosted spatial charge separation led to more useful electrons with a higher reduction ability that participated in a photocatalytic H2 evolution reaction. The Co3S4 ultra-fine nanoparticles act as a mirror to repeatedly scatter and reflect incident light and thus enhance light utilization, and they also accelerate the spatial charge separation. The photocatalytic H2 evolution activity of the composite catalyst reached 2120 μmol g−1 h−1, which was 176 times higher than that of pristine g-C3N4 tubes. A series of characteristics were determined to investigate the interaction that occurred between the g-C3N4 hexagonal tubes and the Co3S4 ultra-fine nanoparticles, and to study the mechanism of the formed step-scheme. This work will guide the design of step-scheme heterojunction-based photocatalysts to produce H2 from photocatalytic water splitting.

Hydrogen production from water splitting is considered as a brand-new and promising way to convert solar energy into recyclable chemical energy. Herein, a core–shell-shaped structure which consisted of Mn0.05Cd0.95S nanorods and flowerlike NiAl-LDH microsphere was constructed via a simple hydrothermal method. The constructed Mn0.05Cd0.95S/ NiAl-LDH core–shell-shaped structure shows superior photocatalytic H2 evolution. The highest photocatalytic H2 evolution rate of the composite is 7.5 mmol g−1 h−1, which is 17 and 6 times higher than those of NiAl-LDH and Mn0.05Cd0.95S respectively. The core–shell like structure is beneficial for the H2 production reaction because NiAl-LDH flowerlike microsphere can provide large surface for the anchoring of Mn0.05Cd0.95S nanorods, which can enhance the interaction between these two materials. A series of characterizations including XRD, FT-IR, SEM, TEM, BET, XPS, UV−vis DRS, etc., were conducted and studied to analyze the reason for the enhanced photocatalytic hydrogen evolution activity. The results of XPS show that an interaction between NiAl-LDH and Mn0.05Cd0.95S has been occurred. The interaction between these two materials is presented through the transfer of electrons, which can be demonstrated by the results of XPS. And, it is found that the rational designed structure can accelerate the transfer of electrons and this is the reason for the enhanced photocatalytic evolution performance. A core-shell like structure consisted of Mn0.05Cd0.95S nanorods and NiAl-LDH nanoflower like sphere was designed rationally via a simple method. The NiAl-LDH nanoflower like sphere with some wrinkles on its surface can provide more areas to contact with Mn0.05Cd0.95S nanorods, which can is beneficial for the interaction between these two materials and accelerate the transfer of electrons.

A mathematical model is developed in this study to simulate the performance and fates of carbon (C), nitrogen (N) and phosphorus (P) in wet and high-total solid (TS) anaerobic digestion (AD) processes. The “Anaerobic Digestion Model No. 1” (ADM1) is improved by adding inorganic components and integrating the inhibition of high-TS and liquid-solid processes. The model's outputs are validated with experimental results obtained from a semi-continuous reactor, with pig manure as a single substrate at wet and high-TS operation stages. The predicted C (methane production and volatile fatty acid concentrations), N (ammonia nitrogen concentrations) and P (phosphorus concentrations) fates are reasonable and exhibit good accuracy. The model is subsequently applied to simulate CH4 production under different hydraulic retention times and organic loading rates. The simulation analysis demonstrates that pret-reatments, such as promoting the hydrolysis and biodegradility of substrate and immobilising strains, are necessary in the high-TS AD process for pig manure to enhance performance. This study provides guidance for the future optimisation of process and nutrient recycling in AD.

Hydrogen production from photocatalytic water splitting has been considered as a promising way to convert solar energy into chemical energy. Herein, a novel photocatalyst was synthesized successful...

The photocatalytic decomposition of water to produce hydrogen is an important process, through which solar energy can be converted to chemical energy. Non-precious metal phosphides have quietly attracted attention as an emerging inexpensive photocatalyst. In this study, we reported that a CoP/CeVO4 hybrid photocatalyst exhibited high hydrogen evolution efficiency owing to EY (eosin Y) sensitization under visible light irradiation for the first time, and the amount of generated hydrogen reached 444.6 μmol in 5 h. The CoP/CeVO4 nanohybrids were synthesized by a simple chemical precipitation method. The coupling of CoP and CeVO4 with ZIF-9 as a precursor could be completed in one step. The CeVO4 particles were firmly attached to the surface of the CoP particles to form a “small point” to “big point” heterojunction. The results of X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, EDX, and transmission electron microscopy showed the formation of CoP and CeVO4 nanoparticles and the structure of the composite. Based on a detailed analysis of the Mott-Schottky plot, the UV-vis diffuse reflectance spectra, photocurrent-time (it) curve, Tafel curve, Nyquist curve (EIS), linear volt-ampere curve (LSV), and steady-state fluorescence spectra were studied. The time-resolved photoluminescence measurements indicated that the reason for the high-efficiency hydrogen evolution of CoP/CeVO4 was that the bands of CoP and CeVO4 were bent due to the existence of the Schottky barrier, and a heterojunction was formed between CoP and CeVO4, which generated an internal electric field and accelerated the charge transfer. In addition, the synergistic effect between CoP and CeVO4 provided a new hydrogen-evolution activity center for each of them. The improved carrier separation efficiency and the decrease in the photo-generated recombination rate led to the excellent photocatalytic hydrogen-evolution activity of the CoP/CeVO4 composite catalyst. This work provides a new strategy for modulating the electronic structure and carrier behavior of transition metal phosphide photocatalysts.

One-dimensional hierarchically superstructured metal-doped titanate and TiO2 materials with coated-nanosheet and interconnected meso-/macropores have been successfully constructed via a general strategy based on the self-evolution of building blocks. The as-fabricated superstructured TiO2-based fibers exhibited remarkable stable cycling performance at a high current rate (5C) in lithium–sulfur (Li–S) batteries.

Insulin administration at mealtimes for the control of postprandial glucose is a major part of basal-bolus insulin therapy; however, painful subcutaneous (SC) injections lead to poor patient compliance. The microneedle (MN) patch, which allows painless transdermal drug delivery, is a promising substitute; however, it remains a big challenge to deliver insulin as rapidly as by SC injection. Here a novel MN patch is designed in which the MNs are coated with insulin/poly-l-glutamic acid (PGA) layer-by-layer (LBL) films at pH 3.0. This coating is pH-sensitive because the net charge of insulin turns from positive to negative when the pH increases from 3.0 to 7.4. As a result, when transferred to pH 7.4 media, e.g., when inserted into skin, the coating dissociates instantly and releases insulin rapidly. A brief epidermal application (

BackgroundThis study aims to investigate the effects of ω-3, ω-6 polyunsaturated fatty acids (PUFAs), and their middle metabolites prostaglandin (PGE)2 and PGE3 on proliferation, invasion, and angiogenesis formation of gastric cancer cells and to explore associated mechanism.MethodsRT-PCR and ELISA were used to detect the expression of cyclooxygenase (COX)-1 and COX-2 in gastric cancer cell lines. The effect of ω-3, ω-6, PGE2, and PGE3 on the proliferation, invasion, and angiogenesis of gastric cancer cells were measured by cell proliferation, invasion, and angiogenesis assay in vitro. COX-2 small interfering RNA (siRNA) was transfected into gastric cancer cells, and the expression of COX-2 protein was detected by Western blot. COX-2 gene silencing influencing proliferation, invasion, and angiogenesis potential of gastric cancer cells was detected by WST-1, transwell chamber, and angiogenesis assay, respectively.ResultsCOX-2 was only expressed in MKN74 and MKN45 cells. In gastric cancer cell lines with positive COX-2 expression, ω-6 and PGE2 could significantly enhance the proliferation, invasion, and angiogenesis of gastric cancer cells, and after transfection with COX-2 siRNA, the effects of ω-6 and PGE2 on enhancing the proliferation, invasion, and angiogenesis of gastric cancer cells were significantly attenuated; ω-3 and PEG3 could inhibit the proliferation, invasion, and angiogenesis of gastric cancer cells. In gastric cancer cell lines with negative COX-2 expression, ω-6 and PGE2 had no significant effect on the proliferation, invasion, and angiogenesis of gastric cancer; ω-3 and PGE3 could significantly inhibit the proliferation, invasion, and angiogenesis of gastric cancer.Conclusionω-6 PUFAs reinforce the metastatic potential of gastric cancer cells via COX-2/PGE2; ω-3 PUFAs inhibit the metastatic potential of gastric cancer via COX-1/PGE3 signaling axis.

In this study, an integrated and assembled recyclable biofilm material was prepared by loading Herminiimonas arsenicoxydans (H. arsenicoxydans) onto electrospun biomass-activated carbon nanofibers (denoted as H. arsenicoxydans-BACFs films). The H. arsenicoxydans-BACFs biofilms showed an approximately 50% increase in As(III) removal rate for 50 mg/L during a 48-h incubation. Furthermore, the biofilms demonstrated satisfactory biocompatibility, ideal catalytic As(III) oxidation and excellent recyclability in cyclic reactions (at least 5 runs). The improved catalytic efficiency is mainly due to a large amount of biomass accumulation and biofilms formation on the surface of the BACF films. More important, the BACF films as an electron transport medium from an oxidized state to a reduced state promote the electron transfer of As(III) oxidation of H. arsenicoxydans. The dual factors can synergistically promote As(III) oxidation efficiency. The oxidation process of As(III) in the H. arsenicoxydans-BACFs composite biofilm reactor was more in line with the first-order kinetic equation, and the oxidation rate of As(III) by H. arsenicoxydans-BACF

Microbe-photocatalyst biohybrids, integrating the optimal attributes of whole-cell catalysts and nanometer photocatalysts, have emerged as a promising strategy for environment-associated applications. However, few such biohybrids have been tested for complex pollution systems. Herein, we constructed an outer membrane photosensitized Geobacter sulfurreducens (G. sulfurreducens)-CdS biohybrid, which enabled to generate stronger photocurrent in response to irradiation and meanwhile achieved an significant promotion for the redox transformation of Cr(VI) and tetracycline compared with that of bare G. sulfurreducens or CdS counterparts. Further analysis revealed that the outer membrane played a significant role in photoelectron transfer. Differential pulse voltammetry (DPV) tests demonstrated that CdS enhanced the catalytic activity of C-type cytochromes on the outer membrane under irradiation, resulting in the increase of electron-hole pairs separation efficiency. The possible degradation pathway of tetracycline was proposed based on determined intermediates, whose toxicities were well evaluated. Importantly, the toxicity of the final detected intermediates was apparently decreased. Overall, this work aims to explore the working mechanisms of the novel G. sulfurreducens-CdS biohybrid system and opens up a new avenue to purifying combined wastewater by microbe-photocatalyst biohybrids.

Ara h 1 is recognized as a major peanut allergen. The effects of high hydrostatic pressure (HHP) on the immunoreactivity and structure of Ara h 1 were investigated in this study. The immunoreactivity of Ara h 1 was considerably reduced (P

Background: To investigate the effect of polyunsaturated fatty acids ω-3 and ω-6 and their metabolites prostaglandin PGE2 and PGE3 on the proliferation, invasion and neovascularization of gastric cancer.Methods: RT-PCR and ELISA were used to detect the gene and protein expression of COX-1 and COX-2 in gastric cancer cell lines, respectively. The effects of ω-3, ω-6, PFG2 and PEG3 on the proliferation, invasion and neovascularization of gastric cancer cells were detected by cell proliferation, invasion and neovascularization assay in vitro. COX-2 siRNA was synthesized by short gene interfering RNA (siRNA) technique and transfected into gastric cancer cells, and the expression of COX-2 protein in gastric cancer cell lines was detected again by Western blot. The effects of COX-2 gene silencing on proliferation, invasion and neovascularization of gastric cancer cells were detected by WST-1 assay, transwell chamber assay and gastric cancer neovascularization assay, respectively.Results: COX-2 was only expressed in MKN74 and MKN45 cell lines, while COX-1 was expressed in four gastric cancer cell lines. In gastric cancer cell lines with positive COX-2 expression, ω-6 and PEG2 could significantly enhance the proliferation, invasion and neovascularization of gastric cancer cells, and after transfection with COX-2 siRNA, the effects of ω-6 and PEG2 on enhancing the proliferation, invasion and neovascularization of gastric cancer cells were significantly attenuated; ω-3 and PEG3 could inhibit the proliferation, invasion and neovascularization of gastric cancer cells. In gastric cancer cell lines with negative COX-2 expression, ω-6 and PEG2 had no significant effect on the proliferation, invasion and neovascularization of gastric cancer; ω-3 and PEG3 could significantly inhibit the proliferation, invasion and neovascularization of gastric cancer.Conclusion: ω-6 PUFAs reinforce the metastatic potential energy of gastric cancer cells via COX-2/PGE2; ω-3 PUFAs inhibit the metastatic potential energy of gastric cancer via COX-1/PGE3.

A clear understanding of the physicochemical, compositional, morphological properties and heavy metal leaching behaviours of municipal solid waste (MSW) incinerated fly ash (FA) and bottom ash (BA) are essential to guide their respective re-utilizations. In this study, FA and BA collected from three MSW incinerator plants located in Xiamen were systematically exploited. Results indicated that FA in the three plants exhibited more porous structures than BA, and the particle sizes of FA and BA were 45–295 μm and >3000 μm, respectively. However, both ashes showed similar main mineralogical crystalline phases of Ca(OH)2, CaCO3 and SiO2, indicative of high feasibilities in manufacturing cement, bricks or construction materials. Additionally, the heavy metal migration of MSW into leachate, flue gas, FA and BA were all specifically measured in this study to provide full data analyses and in-depth understandings of heavy metal migrations, manifesting that the heavy metals of MSW majorly migrated into the FA and BA with clearly discrepant metal ratios and only a very small fraction migrated into the leachate and flue gas. To maximumly reuse both FA and BA, importantly, the green degree and cost-benefit analysis methods were integrated into this study to evaluate their re-utilization alternatives on environmental impacts and economic benefits, and results implied that FA was beneficial for re-utilizing as aggregates in bricks while BA was optimum as paving materials. This study provides overall systematic perspectives on guiding the re-utilization of FA/BA from the MSW incinerators and also considers their environmental and economic benefits for future long-term management.

To develop a new utilization approach of biogas residues, mesoporous activated biochar (MB) was prepared from biogas residues and used for adsorption of As(III) from aqueous solution. MB-ZnCl2-600,...

Considering the importance of removing toxic Cr(VI) from practical wastewater containing complex pollutants, this study presented for the first time the utilization of the live heterotrophic microalgae (Botryocossuss sp. NJD-1) to achieve a concurrent abatement of Cr(VI), TOC, NO3-N and PO4-P, through a comprehensive biochemical process. The experimental results showed that the Cr(VI) removal efficiencies in the culture with different types of organic descended in the order of sodium acetate, ethanol and methanol. The highest removal efficiencies were achieved as 94.2%, 98.2%, 66.9% and 99.2% for Cr(VI), TOC, NO3-N and PO4-P, respectively, in the culture with 5 mg L−1 Cr(VI) and sodium acetate of equivalent to 2.92 g C L−1. Through mass balance calculation and characterization, the fate of Cr(VI) and Cr(III) was tracked and quantified in the culture system, which indicates that 87.17% of initial Cr(VI) were reduced to Cr(III) and then adsorbed in algal biomass for the optimal removal case. Consequently, the mechanism demonstrating the correlation among the removal process of Cr(VI), the biological activity of microalgae and the effect of organic compounds was proposed.

Organic dyes have been considered as persistent pollutants to the water environment and remain a challenge for industrial wastewater treatment. Here we integrated environmental biotechnology and ad...

Image-based visual servoing (IBVS) can reach a desired position for a relatively stationary target using continuous visual feedback. Proper feature extraction and appropriate servoing control laws are essential to performance for IBVS. IBVS control can be interrupted or interfered abruptly if no features are extracted when the observed object is occluded. To address the problem of missing feature points in current images during a visual navigation task, a homography method that uses a priori visual information is proposed to predict all of the missing feature points and to ensure the execution of IBVS. The mixture parameter for the image Jacobian matrix can also affect the control of IBVS. The settings for the mixture parameter are heuristic so there is no a systematic approach for most IBVS applications. An adaptive control approach is proposed to determine the mixture parameter. The proposed method uses a reinforcement learning (RL) method to adaptively adjust the mixture parameter during the robot movement, which allows more efficient control than a constant parameter. A logarithmic interval state-space partition for RL is used to ensure efficient learning. The integrated visual servoing control system is validated by several experiments that involve wheeled mobile robots reaching a target with a desired configuration. The results for simulation and experiment demonstrate that the proposed method has a faster convergence rate than other methods.

To understand PHAs accumulation process well in the stand point of the sludge characteristics, polyhydroxyalkanoates (PHAs) accumulation by activated sludge was investigated in correlation with sludge properties, such as particle size, mixed liquor suspended solids (MLSS) and extracellular polymeric substances (EPS) under different carbon sources (e.g., acetate, propionate and mixed carbons) at 2, 4, 6 and 8 g/L. The efficiency of PHAs synthesis from sludge with sodium acetate as carbon source was superior to that with sodium propionate as carbon source and mixed carbon sources in the sequencing biological reactors, while EPS and sludge characteristics showed similar trends for each carbon source. Various carbon sources did not induce significant differences in the correlations. Polyhydroxybutyrate (PHB) showed good correlation with MLSS (R = 0.782) and sludge floc size (R = −0.58). In the reactors with carbon sources of propionate and mixed carbons, polyhydroxyvalerate (PHV) and PHBV correlated with MLSS (R = 0.480 and 0.489, respectively), sludge floc size (R = −0.921 and −0.666, respectively) and concentrations of polysaccharides (R = 0.726, 0.557, respectively). According to the correlations, improving the concentration of sludge, promoting the production of extracellular polymeric substances (EPS) and decreasing the sludge floc size were supposed to be effective approaches for further accumulation of the PHAs. This study is the first to systematically establish the correlations among EPS, characteristics of activated sludge and PHAs accumulation, can provide a theoretical foundation for the engineering design and the operational parameters selection of PHAs production by activated sludge.

Microbially mediated bioreduction of iron oxyhydroxide plays an important role in the biogeochemical cycle of iron. Geobacter sulfurreducens is a representative dissimilatory iron-reducing bacterium that assembles electrically conductive pili and cytochromes. The impact of supplementation with γ-Fe2O3 nanoparticles (NPs) (0.2 and 0.6 g) on the G. sulfurreducens-mediated reduction of ferrihydrite was investigated. In the overall performance of microbial ferrihydrite reduction mediated by γ-Fe2O3 NPs, stronger reduction was observed in the presence of direct contact with γ-Fe2O3 NPs than with indirect contact. Compared to the production of Fe(II) derived from biotic modification with ferrihydrite alone, increases greater than 1.6- and 1.4-fold in the production of Fe(II) were detected in the biotic modifications in which direct contact with 0.2 g and 0.6 g γ-Fe2O3 NPs, respectively, occurred. X-ray diffraction analysis indicated that magnetite was a unique representative iron mineral in ferrihydrite when active G. sulfurreducens cells were in direct contact with γ-Fe2O3 NPs. Because of the sorption of biogenic Fe(II) onto γ-Fe2O3 NPs instead of ferrihydrite, the addition of γ-Fe2O3 NPs could also contribute to increased duration of ferrihydrite reduction by preventing ferrihydrite surface passivation. Additionally, electron microscopy analysis confirmed that the direct addition of γ-Fe2O3 NPs stimulated the electrically conductive pili and cytochromes to stretch, facilitating long-range electron transfer between the cells and ferrihydrite. The obtained findings provide a more comprehensive understanding of the effects of iron oxide NPs on soil biogeochemistry.

The technical applicability of hydrochar-derived pyrolysis char-supported Cu nanoparticles composite (Cu NPs/HDPC) to the degradation of octocrylene (OC) was investigated in aqueous solutions in the presence of H2O2. The physico-chemical properties of the Cu NPs/HDPC composite before and after degradation reaction were described. The role of OH in this H2O2-led degradation was examined using electron spin resonance (EPR) technique. The possible degradation mechanisms of OC by the Cu NPs/HDPC-H2O2 system and its degradation pathways were investigated. A relatively large surface area and pore volume of the HDPC (191.4 m2 g−1 and 0.11 cm3 g−1, respectively) resulted in well-dispersed Cu NPs loading on the surface. The degradation efficiency of OC (50 μM) was 97.0% in the presence of Cu NPs/HDPC composite (0.5 g L−1) and H2O2 (20 mM) at pH 5.6 in 4 h, which was significantly higher than in Cu NPs/biochar and the integrated HDPC-Cu NPs, i.e., 62.4% and 79.7%, respectively, under the same conditions (ANOVA test; p ≤ 0.05). Several oxidation by-products of the OC included benzophenone, 3,3-diphenylacrylonitrile, and others. The OH, which resulted from the Fenton-like oxidation between the Cu species and H2O2 on the HDPC surface, was the predominant factor responsible for the OC degradation in the solution. The OH formation was facilitated by a single-electron transfer process from the HDPC surface, in which the Cu NPs/HDPC composite with its C OH functional group promoted the decomposition of H2O2. These findings contribute to a novel approach of cost-effective wastewater treatment by adding value to unused waste materials from agricultural industries.

In this work, a novel photocatalyst Ni(OH)2&Ce(OH)3@P-CdS was synthesized successfully by phosphorization of CdS and in situ loading of Ni(OH)2&Ce(OH)3 on the surface of P-CdS. It was found that the introduction of the element P can expand the absorption range of light, prolong the lifetime of the photoinduced carriers of CdS and enhance photocatalytic hydrogen evolution activity. Importantly, we found that Ni(OH)2&Ce(OH)3 can play the role of storing holes, which can efficiently inhibit the recombination of photoinduced electron–hole pairs, thus enhancing hydrogen evolution activity, the hydrogen evolution activity of Ni(OH)2&Ce(OH)3@P-CdS is 11.36 mmol g−1 h−1, which is 4.2 times greater than that of P-CdS. A series of characterization methods, including XRD, SEM, TEM, XPS, BET, UV-vis DRS, PL and TRPL spectroscopy and electrochemical methods (IT, LSV, EIS, MS), were performed, aimed at studying the behavior of Ni(OH)2&Ce(OH)3@P-CdS. The BET result showed that coupling Ni(OH)2&Ce(OH)3 with P-CdS can enhance the specific surface area of the compound catalyst. Also, the UV-vis DRS results showed that the introduction of Ni(OH)2&Ce(OH)3 can expand the absorption range of light. Importantly, photoluminescence spectroscopy (PL) showed that the recombination of photoinduced electron–hole pairs was hindered greatly after adding Ni(OH)2&Ce(OH)3 into the system.

The redistribution process of arsenate (As(V)) and the variation in As(V) content in different locations must be clarified to ensure low mobility of As(V) during microbial ferrihydrite reduction. In this study, we investigated As(V) immobilization and redistribution processes when ferrihydrite was incubated with Geobacter sulfurreducens in the presence of titanium dioxide (TiO

Salmon calcitonin (sCT) was developed as an antiresorptive for the management of osteoporosis, a major public health threat worldwide. However, its clinical application was severely limited by its short half-life. Herein, an injectable drug carrier, that is, polylactic acid (PLA) microspheres coated with TA/PEG-sCT (TA: tannic acid. PEG-sCT: PEGylated sCT) layer-by-layer (LBL) films, was designed. An in vitro test demonstrated that, unlike previously developed drug carriers, the new carrier released PEG-sCT at a constant rate. The unique zero-order release kinetics originates from its unique drug release mechanism, that is, drug release via gradual disintegration of the dynamic TA/PEG-sCT LBL film. The small size of the PLA microspheres allows the carrier to be administrated via subcutaneous injection. An in vivo test demonstrated that a single injection of the carrier could maintain the plasma level of PEG-sCT stable for an extended period and thus induced a stable reduction in the plasma calcium level in rats. Using a rat model of osteoporosis induced by ovariectomy, it was further demonstrated that a single injection of the new carrier gave better therapeutic outcomes than daily injection of sCT of the same dose, thanks to the improved pharmacokinetic profile. Given the advantages of the new carrier, including facile subcutaneous administration, less frequent dosing, no initial burst release, no peak plasma drug level, and improved therapeutic outcomes, it is expected to have potential in long-term management of osteoporosis and other metabolic bone diseases.

Cellular internalization of nanomaterials to endow cells with more functionalities is highly desirable. Herein, a straightforward strategy for internalizing red-emission carbon dots (CDs) into Shewanella xiamenensis is proposed. This suggests that the internalized CDs not only afford enhanced conductivity of bacteria but also trigger the cellular physiological response to secrete abundant electron shuttles to aid the boosting of extracellular electron transfer (EET) efficiency. Additionally, once illuminated, internalized CDs can also serve as light absorbers to allow for photogenerated electrons to be transferred into cellular metabolism to further facilitate light-enhanced EET processes. Specifically, the findings advance the fundamental understanding of the interaction between internalized carbon-based semiconductor and cells in the dark and light, and provide a facile and effective strategy for enhancing EET efficiency.

Basal insulin therapy plays a key role in diabetes management. An ideal therapy should mimic the steady physiologic basal insulin secretion, and provide a peak-free, prolonged and steady insulin supply. Herein, a new drug carrier was designed by first PEGylating insulin and then incorporating the conjugate into layer-by-layer assembled films with tannic acid (TA). Because PEG-insulin and TA in the films were linked with reversible, dynamic hydrogen bonds, the films disintegrate gradually when soaked in aqueous solutions, and thus release PEG-insulin into the media. In vitro release tests revealed that the release of PEG-insulin follows a zero-order kinetics. Theoretical analysis based on the unique release mechanism also supports a zero-order kinetics. In vivo tests using a streptozotocin-induced diabetic rat model demonstrated that subcutaneous implantation of the film could maintain a steady plasma drug level and hence maintain a fasting blood glucose level (BGL) close to normal. The duration of action depends on the thickness of the film. Using a 50-bilayer film, fasting BGL was kept within the normoglycemic range for ∼16 days. Initial burst release, a severe problem for other release systems, was successfully avoided.

The redistribution process of arsenate (As(V)) and the variation in As(V) content in different locations must be clarified to ensure low mobility of As(V) during microbial ferrihydrite reduction. In this study, we investigated As(V) immobilization and redistribution processes when ferrihydrite was incubated with Geobacter sulfurreducens in the presence of titanium dioxide (TiO2) nanoparticles. Our study results showed that, As(V) in the aqueous phase and ferrihydrite were redistributed on light minerals (goethite), heavy minerals (ferrihydrite and magnetite), and extracellular polymeric substances (EPS) induced by G. sulfurreducens during ferrihydrite reduction. Interestingly, we found that As(V) in the form of arsenate ion (AsO43-) was adsorbed by the functional groups of the EPS, while the formed FeII3(AsVO4)2 was wrapped in the network structure of EPS. Moreover, the addition of TiO2 nanoparticles did not promote but delayed the entire ferrihydrite reduction, As(V) immobilization and redistribution processes. Furthermore, changes in the aqueous arsenic and iron concentrations are closely related to the formation time of secondary minerals. Our study findings provide new insights into the As(V) immobilization process mediated by G. sulfurreducens under anaerobic conditions.

Three-dimensional (3D) printing technology has received remarkable attention in manufacturing catalysts with tailored shapes and high precision, particularly facilitating catalyst recovery, maximizing heat/mass transfer, as well as enhancing catalytic performance. Herein, an engineered recombinant Escherichia coli strain (denoted as e-E. coli) with overexpressing metallothionein (a metal-binding protein) was explored to synthesize Au nanoparticles serving as both reducing and stabilizing agents. Then, the mixed inks containing e-E. coli/Au composite and biocompatible polymers (sodium alginate and gelatin) were extruded based on a direct ink writing method followed by chemical crosslinking to form robust 3D grids with square symmetry. To boost the mass transfer and minimize pressure drop, the monolith catalysts were assembled into agitating paddles and used for liquid-phase batch reactions (volume: 1 L). As such, the reaction solutions were mixed internally via the powered “catalytic paddles” with high mechanical strength, excellent reactivity, and easy recyclability, which could be reused at least 7 cycles without performance loss. Our work provides a novel strategy for the fabrication of supported Au catalysts, and the proof-of-concept “catalytic paddles” by 3D printing technology can be applied to other industrial solution-based reactions.

The main purpose of photocatalytic hydrogen evolution is to fundamentally solve the problem of energy shortage and environmental pollution. In this experiment, based on the adjustment of the density of MoC quantum dots (MoC-QDs) on carbon film and the morphology of 3D porous g-C3N4, this exploring aimed at exploring the influence of various morphology combinations on the hydrogen evolution performance. Using bulk g-C3N4 (CN-B) as a reference, the tubular and honeycomb g-C3N4 were prepared by solvothermal and chemical vapor deposition methods. The experimental results show that the hydrogen production of MoCT-7 and MoCH-5 composite catalysts are 1.54 and 1.76 times that of MoCB-15, respectively, which proves that the ingenious morphology matching is an effective strategy to improve the catalytic performance. It is believed that CN-H and CN-T have unique slow photo effect and directional electron transfer characteristics, respectively. The well-dispersed MoC-QDs provide abundant active sites, and the thin carbon film is conducive to the adsorption of dye molecules and electrons transfer. This experiment is expected to provide some references for the in-depth study of g-C3N4 and the design of novel photocatalysts.

The effects of octanoic acid/nonanoic acid and acclimation time on the synthesis of short-chain-length and medium-chain-length PHA blends from activated sludge were investigated. An increased concentration (847-1366 mg/L) of PHAs resulted from 4-month acclimation compared with the concentration derived from 2-month acclimation (450-1126 mg/L). The content of octanoic acid had a positive linear relationship with the content of even-numbered carbon monomers among the PHAs. The blending products were identified mainly with scl-PHAs during the 2-month acclimation period and were thereafter dominated by mcl-PHAs until 4 months of acclimation. Thermal properties analysis demonstrated that the products derived from 4-month acclimation were a mixture of scl-PHAs and mcl-PHAs rather than a copolymer of scl-PHAs and mcl-PHAs. High-throughput sequencing results indicated that Pseudofulvimonas, Paracoccus, and Blastocatella were the dominant genera that might be responsible for scl-PHAs production during the 2-month acclimation period, whereas Comamonas and Pseudomonas that were responsible for mcl-PHAs production then became the dominant genera after 4-months acclimation.

Chemical speciation can fundamentally affect the potential toxicity and bioavailability of heavy metals. The transformation of heavy metal speciation and change of bioavailability were investigated in an anaerobic digestion (AD) system using four different substrates (pig manure (PM), cattle manure (CAM), chicken manure (CHM) and rice straw (RS)). The results obtained indicated that the total contents of heavy metals in PM, CHM and CAM were higher than in RS and decreased in the order Zn > Cu > Ni > Pb > As > Cd in all substrates. Moreover, the speciation with the largest proportion for each heavy metal was the same both in the different substrates and the biogas residues. Among them, Zn, Ni, Cd and As were mainly in the reducible fraction (F2), while Cu was mainly in the oxidizable fraction (F3) and Pb occurred predominantly in the residual fraction (F4). Our results further indicated that the AD process had a greater effect on the speciation of heavy metals in CHM and PM, but less on CAM and RS. The rates of change in bioavailability followed the order PM > CHM > CAM > RS. Changes in organic matter, humic acid or local metal ion environment as a result of AD were inferred as likely mechanisms leading to the transformation of heavy metal speciation. These results enhanced our understanding of the behavior of heavy metals in AD and provided a new perspective for the treatment and disposal of the substrates.

The speciation of heavy metals, besides the total concentrations, urgently need to be considered when assessing the eco-toxicity and the bioavailability of heavy metals in environment. This paper aims to investigate the distribution and chemical speciation (e.g. the acid extractable fraction (F1), the reducible fraction (F2), the oxidizable fraction (F3), and the residual fraction (F4)) of heavy metals during the anaerobic digestion process of swine manure. The majority of six heavy metals from the manure was located in biogas residue in the order of decreasing concentration Zn > Cu > Ni > As > Pb > Cd. The transformation of heavy metals among four fractions was observed during the digestion process, and the change of bioavailable fraction of Zn, Cu, Ni, Cd, As and Pb were 9.71%, −6.04%, −19.24%, 13.62%, −16.48% and −7.22%, respectively. The heat map of correlation coefficients and the stepwise linear regressions model were established to describe the correlation between the bioavailability of the metals and the given digestion variables to predict the influence of the selected variables on the bioavailability of heavy metals. The variations of heavy metal bioavailable fractions are attributed to three key digestion variables, NH4+-N concentration, CH4% in biogas daily yield and pH. These results provide a new perspective for analysis and control of heavy metals during the anaerobic digestion process.

BACKGROUND: Microbial reduction of Cr(VI) has been demonstrated as an environmentally friendly remediation protocol in recent years. In this study, the catalytic capability of soluble quinone compounds [i.e. anthraquinone‐2,6‐disulphonate (AQDS), 2‐hydroxy‐1,4‐naphthoquinone (HNQ) and ubiquinone (CoQ)] as well as an immobilized HNQ‐graphene oxide (GO) composite were evaluated for their ability to mediate Cr(VI) bioreduction by Shewanella xiamenensis. Additionally, the mechanism for Cr(VI) bioreduction was rigorously explored. RESULT: At a test concentration of 0.02 mmol L⁻¹, HNQ exhibited the highest efficiency for catalysing Cr(VI) bioreduction compared to AQDS and CoQ. During a 48 h test period, the highest removal efficiency (100%) of Cr(VI) (50 mg L⁻¹) was exhibited in the presence of 0.015 mmol L⁻¹ HNQ compared to biotic supplementations with 0.005, 0.010 and 0.020 mmol L⁻¹ of HNQ. Furthermore, supplementation with 13.0 mg HNQ‐GO composite greatly enhanced Cr(VI) bioreduction compared to the biotic assay without any quinone compounds. Specifically, complete reduction of Cr(VI) was found in the first reaction cycle (following 72 h), compared to

Effects of temperature variations from mesophilic to thermophilic on the performance of UASB reactors with glucose and ethanol as substrate were investigated. The reactor with ethanol as substrate had better resistance to temperature variations with over 93% COD degradation rate and 75% methane content. The conductivity of granular sludge that degraded ethanol was also considerably higher. High-throughput sequencing indicated that the abundance of Methanobacterium decreased, while Methanosaeta increased with increasing temperature. Moreover, the abundance of Geobacter and Methanosaeta were higher in the reactor with ethanol as substrate than that with glucose, whereas a higher abundance of Klebsiella was observed in the glucose reactor. More importantly, significant correlations were observed between granular sludge conductivity and COD removal rate (R2 = 0.73), between the abundance of Geobacter and COD removal rate (R2 = 0.895). These results indicate that the growth of Geobacter and Methanosaeta which promote transfer electrons in the manner of DIET in anaerobic methanogenic systems might alleviate the effect of temperature variation and facilitate reaction rate.