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Iron-rich sludge produced during textile wastewater treatment has brought serious environmental burden, and usually undergoes incineration disposal without creating added value. In this work, novel adsorbents were fabricated through sintering treatment with dried iron-rich sludge (denoted as B) as precursor, aiming at the deep Sb(V) removal from textile wastewater. Structural characterization confirmed the presence of various iron oxides including α-Fe 2 O 3 and amorphous ferrihydrite in the as-prepared adsorbents. Screening tests indicated that adsorbent obtained after sintering at 400 °C for 2 h (B-400) exhibited a significantly improved maximum adsorption capacity (161.36 mg g−1) as compared to B (51.72 mg g−1). The B-400 possesses lager specific surface area, and more favorable phases for Sb(V) adsorption as compared to B. Satisfying Sb(V) removal efficiency of B-400 is accomplished within a wide pH window ranging from 4 to 10, at varying ionic strengths. The co-existing ions, dyes and surfactants in textile wastewater trigger different degrees of negative impacts on Sb(V) adsorption by B-400, except for Cl− and cetyltrimethylammonium bromide. The Sb(V) adsorption by B-400 is a heterogeneous surface adsorption process, which can be well described by the Freundlich and Elovich models. The possible mechanisms include electrostatic interaction, inner-sphere complexation, and hydrogen bonding. The findings in this study fulfill the 'waste control by waste' strategy by removing Sb(V) from textile wastewater with textile sludge derived adsorbent materials, which achieves the self-recycling of waste during textile wastewater treatment, and contributes to sustainable development goals. [Display omitted] • Self-recycling of waste during textile wastewater treatment is achieved. • Textile sludge is sintered to fabricate novel adsorbents for Sb(V) removal. • Novel adsorbents contain abundant α-Fe 2 O 3 and amorphous ferrihydrite. • Satisfying Sb(V) removal is fulfilled at various pH and ionic strengths. • The co-existing ions, dyes, and surfactants show negative impacts on adsorption. [ABSTRACT FROM AUTHOR]

The ubiquitous heavy metal(loid)s (HMs) contamination has triggered great concern about food safety, while sequestration and separation of trace HMs from herbal extracts still calls for appropriate sorbent materials. In this work, gum acacia was modified by cysteine to form a cysteine-acacia intermolecular complex (Cys-GA complex) via facile mechanochemical synthesis, aiming at capturing multiple HMs simultaneously. Preliminary screening confirms the superiority of Cys-CA complex for both cationic and anionic HMs, and determines an optimum Cys/GA mass ratio of 9:1 to achieve high removal capacities for Pb(II) (938 mg g−1), Cd(II) (834 mg g−1), As(V) (496 mg g−1), and Cr(VI) (647 mg g−1) in simulated aqueous solution. The analysis on HMs-exhausted Cys-GA complex indicates that Pb(II), As(V), and Cr(VI) tend to be removed through chelation, electrostatic attraction, and reduction, while Cd(II) can only be chelated or adsorbed by electrostatic interaction. The batch experiments on commercial herbal (e.g. Panax ginseng , Glycine max , Sophora flavescens , Gardenia jasminoides , Cyclocarya paliurus , and Bamboo leaf) extracts indicate that Cys-GA complex can reduce HMs concentration to attain acceptable level that comply with International Organization for Standardization, with negligible negative effect on its active ingredients. This work provides a practical and convenient strategy to purify HMs-contaminated foods without introducing secondary pollution. [Display omitted] • Cysteine-gum acacia intermolecular complex was fabricated by mechanochemistry. • Cys-GA achieves heavy metal(loid)s sequestration for both cationic/anionic species. • Sequestration mechanism includes chelation, electrostatic attraction, and reduction. • Cys-GA reduces the heavy metal(loid)s in herbal extract to an acceptable level. • Cys-GA triggers negligible negative effect on active ingredient of herbal extract. [ABSTRACT FROM AUTHOR]

Abstract Sulfidation of nanoscale zerovalent iron (nZVI) has attracted increasing interest for improving the reactivity and selectivity of nZVI towards various contaminants, such as aqueous Cr(VI) removal. However, the benefits derived from sulfide modification that govern the removal of Cr(VI) remains unclear, which was studied in this work. S-nZVI with higher S/Fe molar ratio showed higher surface area, the discrepancy between the surface-area-normalized removal capacity of Cr(VI) by S-nZVI with different S/Fe indicated that the removal of Cr(VI) was also affected by other factors, such as electron transfer ability, surface-bounded Fe(II) species, and surface charges. High specific surface area would provide more active site for Cr(VI) removal, and as an efficient electron conductor, acicular-like FeS x phase would also favor electron transfer from Fe0 core to Cr(VI). Low initial pH also enhanced the Cr(VI) removal, and the Cr(VI) removal capacity by S-nZVI and nZVI was not affected by aging process, these results confirmed that the Fe(II) species also played an important role in the Cr(VI) removal. Other influence factors were also investigated for potential application, including temperature, initial Cr(VI) concentration, ionic strength, and co-existed ions. The removal mechanism of Cr(VI) by S-nZVI involved the sulfide modification to increase the specific surface area and provide more active sites, the corrosion of Fe0 to produce surface-bounded Fe(II) species to adsorb Cr(VI) species, followed by the favored reduction of Cr(VI) to Cr(III) due to the electron transfer ability of FeS x , then the formation of Cr(III)/Fe(III) hydroxides precipitates. Graphical abstract Image 1 Highlights • S-nZVI showed better reactivity than pristine nZVI towards Cr(VI). • S/Fe molar ratio had significant effects on the reactivity of S-nZVI. • Cr(VI) was removed through adsorption, reduction, and co-precipitation. • FeS x on S-nZVI facilitated the electron transfer and acted as reducing agent. • S-nZVI maintained high Cr(VI) removal efficiency after aged 12 days. [ABSTRACT FROM AUTHOR]

Highlights • A new fluorophore release strategy was developed based on chemiluminescence as a signal transduction trigger. • Chemiluminescence as a signal transduction trigger was successfully realized in vivo imaging. • The approach modulated a recognition unit via 'click' reaction, making it generalizable to other biomarkers of interest. • The set-up is easily prepared and stored during the processing of in vivo imaging. Abstract Chemiluminescence (CL) of luminol is a well-established technology for in vitro biochemical analysis of hydrogen peroxide (H 2 O 2). However, applications of chemiluminescence as a signal transduction trigger for fluorophore release still remain to be exploited. In this paper, we rationally design a chemiluminescence-triggered fluorophore release approach for imaging of H 2 O 2 in vivo. The o-benzyl alcohol-decorated block poly(carbonate)s copolymer, viz. PMPC−ONA, was synthesized affording the final formation of the H 2 O 2 responsive micelles, in which luminol, fluorophore, and hemin were wrapped forming L/H/S@PMPC−ONA nanoprobe. The presence of H 2 O 2 diffuses into the nanoparticles and reacts with the hemin, generating high-energy reactive oxygen that could chemically excite the luminol triggering the chemiluminescence for cleaving nitrosobenzaldehyde recognition sites. The process could lead to destabilize the micelles and release the fluorescent indicator for imaging of H 2 O 2. The concentration of H 2 O 2 can be determined from 0.02 to 100 μM with a detection limit of 0.01 μM. The feasibility of L/H/S@PMPC−ONA is demonstrated for investigating fluorescence imaging of endogenous H 2 O 2 in cells and mice. As far as we know, this is the first paradigm of rationally designed chemiluminescence as a signal transformation trigger for fluorophore release. [ABSTRACT FROM AUTHOR]

Abstract Exhaust air insulation building envelope can recover and utilize the low-grade energy inherent in the exhaust air to prevent the heat transfer through the building envelope. The study investigates a triple glazed exhaust-air window (TGEW), which can switch its operation mode between the cooling and heating season. A two-dimensional numerical model was proposed to analyze the conjugated heat transfer in the TGEW. The experiment test of the TGEW was conducted and used to validate the proposed two-dimensional numerical model. The utilization efficiency of exhaust air within the TGEW was experimentally investigated under real outdoor weather condition. Numerical simulations were carried out to investigate the thermal performance improvement of the triple-glazed window by utilizing the exhaust air. Hourly and accumulated cooling/heating loads of the TGEW were calculated and compared with that of a conventional triple-glazed window (TGW). Results indicate that compared to the conventional TGW, the TGEW can reduce 25.3% and 50.1% of the annual accumulated cooling and heating loads. This demonstrates that the TGEW is applicable to the buildings installed with the fresh air supply system and can potentially contribute to decrease the cooling and heating loads through the window by utilizing the exhaust air. Highlights • Experimental test of a triple glazed exhaust-air window was conducted. • Two-dimensional numerical model of the exhaust-air window was verified. • The air temperature increment within the exhaust-air window was investigated. • The use of exhaust air can reduce the cooling and heating loads through the window. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • TiC doped palladium/nickel foam cathode was synthesized via electroless deposition. • Pd/TiC/Ni foam show superior activity for 2,4-DCBA dechlorination to Pd/Ni foam. • Optimized conditions on 2,4-DCBA dechlorination were investigated. • Possible promotion mechanism by doped TiC over Pd/Ni foam cathode was proposed. Abstract Titanium carbide (TiC) with excellent electrical conductivity, chemical and thermal stabilities has been recognized as one of the most promising electrocatalysts. A novel cathode, titanium carbide doped palladium/nickel foam (TiC-Pd/Ni foam), was synthesized via electroless deposition to improve the performance of Pd/Ni foam in electrocatlytic hydrodechlorination (ECH). TiC can be co-precipitated onto the surface of cathode during galvanic replacement reaction between Pd(II) solution and Ni foam. Both constant potential and constant current tests proved that TiC-Pd/Ni foam cathode performed remarkably higher activity for 2,4-dichlorobenzoic acid (2,4-DCBA) than Pd/Ni foam cathode, owing to the excellent conductivity of TiC and enhanced water dissociation over TiC-Pd/Ni foam cathode. Under the optimized reaction conditions of –0.85 V (vs Ag/AgCl), electrolyte of 10 mM and initial pH of 4, 99.8% of aqueous 2,4-DCBA (0.2 mM) was removed within 90 min. The removal process of the aqueous 2,4-DCBA obeyed first-order decay kinetic model. Over 86.3% of 2,4-DCBA can still be removed by TiC-Pd/Ni foam cathode in the fifth consecutive run within 120 min, which was much higher than that of Pd/Ni foam cathode (37.5%). Consequently, TiC-Pd/Ni foam cathode was a promising design for enhanced ECH activity and reduced operation cost. [ABSTRACT FROM AUTHOR]

Polychlorinated dibenzo- p -dioxins (PCDDs), as a group of notorious anthropogenic environmental toxicants, are arguably ubiquitous in nature. In this study, we investigated the photocatalytic reductive dechlorination of 2-chlorodibenzo- p -dioxin (2-CDD) over Pd/g-C 3 N 4 catalysts under UV–vis irradiation. The g-C 3 N 4 and a series of Pd/g-C 3 N 4 catalysts were prepared by thermal polymerization and mechanical mixing-illumination method and characterized by XRD, TEM, BET, SEM and UV–vis DRS analyses. Among all the samples, the Pd/g-C 3 N 4 (5 wt%) yielded the optimal dechlorination activity with a total 2-CDD conversion of 54% within 4 h, and 76% of those converted 2-CDD were evolved to dibenzo- p -dioxin (DD). The kinetics of dechlorination could be described as pseudo-first-order decay model (R 2  > 0.84). Corresponding rate constants (k) increased from 0.052 to 0.17 h −1 with Pd contents up to 5 wt% and decreased to 0.13 h −1 with a 10 wt% of Pd. The enhanced activities originated from the surface plasmonic resonance (SPR) effect of Pd nanoparticles and the formation of Schottky barrier between Pd and g-C 3 N 4 , which extend the spectrum responsive range and suppress the charge recombination of g-C 3 N 4 . This is the first report on the photocatalytic reductive removal of PCDDs and may provide a new approach for PCDDs pollution control. [ABSTRACT FROM AUTHOR]

Nanoscale zero-valent iron (nZVI) has high removal efficiency and strong reductive ability to organic and inorganic contaminants, but concerns over its stability and dispersity limit its application. In this study, nZVI was modified with sulfide to enhance Cd(II) removal from aqueous solutions. TEM and SEM analyses showed that sulfide-modified nZVI (S-nZVI) had a core-shell structure of nano-sized spherical particles, and BET results proved that sulfide modification doubled the specific surface area from 26.04 to 50.34 m 2  g −1 and inhibited the aggregation of nZVI. Mechanism analysis indicated that Cd(II) was immobilized through complexation and precipitation. Cd(II) removal rate on nZVI was only 32% in 2 h, while complete immobilization could be achieved in 15 min on S-nZVI, and S-nZVI with an optimal S/Fe molar ratio of 0.3 offered a cadmium removal capacity of about 150 mg g −1 at pH 7 and 303 K. The process of Cd(II) immobilization on S-nZVI was fitted well with pseudo-second-order kinetic model, and the increase of temperature favored Cd(II) immobilization, suggesting an endothermic process. The presence of Mg 2+ and Ca 2+ hindered Cd(II) removal while Cu 2+ did the opposite, which led to the order as Cu 2+  > control > Mg 2+  > Ca 2+ . The removal rate of 20 mg L −1 Cd(II) maintained a high level with the fluctuation of environmental conditions such as pH, ion strength and presence of HA. This study demonstrated that S-nZVI could be a promising adsorbent for Cd(II) immobilization from cadmium-contaminated water. [ABSTRACT FROM AUTHOR]

CuO x –NiO bimetallic oxides modified TiO 2 catalysts were prepared via a precipitation-photoreduction approach for photocatalytic H 2 production. 0.9%Cu0.1%Ni/TiO 2 exhibited the highest H 2 evolution rate (about 55.4 μmol/g/min) under UV–visible light irradiation (350–780 nm), which is higher than the sum of CuO x /TiO 2 and NiO/TiO 2 catalyst. Cu species exhibited more reducing valence state including Cu 0 when deposited on NiO/TiO 2 compared with deposited on TiO 2 . The polyvalent Cu species lead to enhanced photocurrent and reduced transfer resistance confirmed by photoelectron chemical analysis. CuO x –NiO modification of the TiO 2 surface is beneficial for the photoexcited electron transfer, which suppresses electrons recombination. The lifetime of photoexcited electrons was enhanced greatly from 1.16 (TiO 2 ) to 5.15 ns (CuO x –NiO/TiO 2 ). A multiple electrons transfer mechanism for polyvalent bimetallic oxides co-modified TiO 2 was proposed based on careful analysis. This work demonstrated a polyvalent bimetallic oxides modified TiO 2 system with efficient photocatalytic H 2 production which can provide some insightful understanding for bimetallic metal oxides co-catalyst design and H 2 evolution mechanism. [ABSTRACT FROM AUTHOR]

Stabilized iron sulfide (FeS) nanoparticles have been proven effective in the adsorption of Hg from the water environment. However, previous work with these nanoparticles determined that the separation from the treated water was difficult and time-consuming. In this study, nanoscale FeS-Fe 3 O 4 nanocomposites were firstly synthesized with chitosan as the stabilizer (CTO-MFeS). Then, the Hg adsorption capacity and mechanism were studied. Results showed that the size of the prepared nanoparticles was about 20 nm and the specific surface area was 21.3 m 2 /g. Hg removal by the CTO-MFeS nanoparticles involved both adsorption and precipitation. Further investigation with XPS showed that Hg 2 + was adsorbed on the surface of the CTO-MFeS nanoparticles and reacted with CTO-MFeS to form HgS and [Fe (1 − x) Hg x ]S. It was also found as pH decreased below 4, the adsorption capacity of CTO-MFeS was significantly reduced that might be due to the dissolving of Fe. Additionally, the presence of Cl − resulted in the transformation of Hg 2 + to HgClx 2-x (x = 1, 2, 3, 4) that competed with OH in solution for Hg 2 + and therefore inhibited the adsorption of Hg. Our findings provide additional information that may be useful for a theoretical basis for Hg treatment in water environment. [ABSTRACT FROM AUTHOR]

Carbon-based nanomaterials, especially carbon nanotubes and graphene, have drawn wide attention in recent years as novel materials for environmental applications. Notably, the functionalized derivatives of carbon nanotubes and graphene with high surface area and adsorption sites are proposed to remove heavy metals via adsorption, addressing the pressing pollution of heavy metal. This critical revies assesses the recent development of various functionalized carbon nanotubes and graphene that are used to remove heavy metals from contaminated water, including the preparation and characterization methods of functionalized carbon nanotubes and graphene, their applications for heavy metal adsorption, effects of water chemistry on the adsorption capacity, and decontamination mechanism. Future research directions have also been proposed with the goal of further improving their adsorption performance, the feasibility of industrial applications, and better simulating adsorption mechanisms. [ABSTRACT FROM AUTHOR]

An air-stable mononuclear complex of bis(pentamethylcyclopentadienyl) zirconium pentafluorbezenesulfonate was successfully synthesized by treating C 6 F 5 SO 3 Ag with [(CH 3 ) 5 Cp] 2 ZrCl 2 , which showed the cationic uninuclear structure of [{(CH 3 ) 5 Cp} 2 Zr(CH 3 CN) 2 (H 2 O)][OSO 2 C 6 F 5 ] 2 · CH 3 CN ( 1 ) confirmed by the X-ray analysis. Complex 1 was also characterized by other techniques and found to have the good nature of air-stability, water tolerance, thermally-stability and strong Lewis-acidity. Moreover, the complex showed high catalytic activity and recyclability in catalytic epoxide ring-opening reactions by amines or alcohols. This catalytic system affords a simple and efficient approach for synthesis of β -amino alcohols or β -alkoxy alcohols. [ABSTRACT FROM AUTHOR]

In this study, a novel bamboo activated carbon (BAC) with ethylene diamine tetraacetic acid (EDTA) functionality was prepared by direct grafting in the presence of tetraethyl orthosilicate (TEOS) as a crosslinking agent. The BAC@SiO 2 -EDTA was characterized by SEM, TEM, TGA, FTIR, XPS and its adsorption property for removal of Pb(II) and Cu(II) under various experimental conditions was also investigated. The characterization results reflected that EDTA was successfully assembled on the surface of the BAC and average pore size increased from 4.10 to 4.83 nm as BAC grafted with EDTA. Adsorption data fitted very well in Langmuir isotherm model and pseudo-second-order kinetic model. As compared with the raw BAC, the maximum adsorption capacities of BAC@SiO 2 -EDTA for the Pb(II) and Cu(II) increased from 45.45 to 123.45 mg g −1 and from 6.85 to 42.19 mg g −1 , since the existence of EDTA on modified BAC promoted the formation of chemical complex. The removal of heavy metal ions mainly depended on the complexation with EDTA and the electrostatic attractions with negatively charged surface of BAC@SiO 2 -EDTA. The adsorption of Pb(II)/Cu(II) on the BAC@SiO 2 -EDTA was pH dependent and pH 5–6 was considered an optimum. However, lower temperature favored the adsorption and the maximum adsorption was recorded at 20 °C. In addition, BAC@SiO 2 -EDTA had an excellent reusability with about 40% decline in the adsorption capacity for Pb(II) after fifth reuse. Insignificant influences of co-existing cations and natural organic matter (NOM) were found on the adsorption of Pb(II) and Cu(II). All the results demonstrate that BAC@SiO 2 -EDTA is a potential adsorbent for metal ions in wastewater. [ABSTRACT FROM AUTHOR]

In this study, a comparative evaluation of synthetic FeS and natural pyrite was performed to investigate their adsorptive potentials toward Hg(II) in aqueous system. Characterization analyses such as BET, SEM and TEM suggested that FeS had porous structures with abundant active sites, while pyrite with a hard and smooth surface relied mainly on surface adsorption to immobilize Hg(II). Results of batch tests revealed that FeS offered much greater Hg(II) maximum adsorption capacity (769.2 mg/g) as compared to pyrite (9.9 mg/g). Both iron sulfides showed high removal efficiency (>96%) with the initial Hg(II) concentration (1 mg/L) at pH = 7.0 ± 0.1, and the effluent could meet the permissible effluent concentration (<50 μg/L). Condition experiments (such as pH, co-ions) proved that the adaptive capacity of FeS was significantly higher than that of pyrite. A pseudo-second-order kinetic model was better able to illustrate the sorption kinetics on both FeS and pyrite (R 2 ≥ 0.9992). XRD and XPS analyses supported that precipitation, ion exchange and surface complexation were main reaction mechanisms involved in the adsorption process. In addition, it was also revealed that the structural changes of FeS before and after adsorption was much larger than pyrite. Findings from this study suggest FeS is a promising candidate for treatment of high-concentration Hg(II)-containing wastewater (<20 mg/L), while pyrite can be applied as a long-term adsorbing material in the immobilization of wastewater containing low Hg(II) concentration (<1 mg/L) due to its cost-effective property and local availability. [ABSTRACT FROM AUTHOR]

To mitigate the toxicity of tetracycline (TET) to functional microorganisms and avoid the exceeded discharge of tetracycline-resistant bacteria (TRB), a novel combined iron-carbon micro-electrolysis-anoxic/oxic biofilter (Fe–C-AOBF) system for treatment of pharmaceutical wastewater with high TET concentration was successfully established. Results showed that Fe–C-AOBF had the higher maximum tolerated concentration and the stronger degradation ability for TET than normal biological treatment system. When influent COD, NH 4 –N and TET were 4000, 200 and 100 mg/L, their removal efficiencies via Fe–C-AOBF could reach 96%, 86% and 90%, respectively. Microbial community analysis revealed micro-electrolysis pretreatment in Fe–C-AOBF system improved the microbial diversity compared to up-flow anaerobic/oxic biological aerated filter (UAF–UBAF). The relative abundance of dominate bacteria with tetracycline resistance genes (TRGs) in the biofilm of Fe–C-AOBF, such as Comamonadaceae , Thauera, Sinobacteracea, Acidaminobacter, and Enterobacteriaceae , was also decreased. Moreover, the absolute concentrations of five normal TRGs in effluent of Fe–C-AOBF were reduced by about 16 orders of magnitude as compared to UAF-UBAF. Due to approximately 70% of original TET has been degraded in micro-electrolysis process and lost its selective pressure to microorganisms, Fe–C micro-electrolysis played a key role in restraining the formation and reproduction of TRB and eliminating the potential risk of pathogenic bacteria (e.g., Arocobacter) in AOBF. Fe–C-AOBF system provided an efficient, stable and green method for antibiotic wastewater treatment with the function of inhibiting the emergence of antibiotic-resistant bacteria. [Display omitted] • Total COD, NH 4 –N and TET removal rate in Fe–C-AOBF could reach 96%, 86% and 90%. • Fe–C micro-electrolysis enhanced TET tolerated level and degradability of Fe–C-AOBF. • Absolute concentration of 5 normal TRGs in AOBF was reduced by 16 orders of magnitude after Fe–C pretreatment. • Potential risk of pathogenic bacteria like Arocobacter was effectively eliminated in Fe–C-AOBF. [ABSTRACT FROM AUTHOR]

Iron sulfide (FeS) nanoparticles were known for their excellent ability to scavenge aqueous Hg(II). However, the aggregation and oxidizability of FeS nanoparticles greatly restricted their practical application. This study developed an Al 2 O 3 -supported nanoscale FeS (FeS/Al 2 O 3 ) which effectively optimized the material performance. Characteristic data suggested that FeS/Al 2 O 3 (mass ratio of FeS to FeS/Al 2 O 3 is 30%) with a large specific surface area (142.7 m 2 g −1 ) could evenly distribute FeS, suppressing the aggregation of FeS successfully. The maximum enrichment capacity of Hg(II) on FeS/Al 2 O 3 achieved ∼313 mg/g at pH 6 and 30 °C. The pH studies indicated that alkaline environment strongly inhibited mercury uptake, while removal rate of 1 mg/L Hg(II) maintained a high level (>97.5%) over the pH range of 3–9. However, FeS/Al 2 O 3 loss was observed at low pH due to the acid corrosion. Additionally, the rates of Hg(II) reduction were almost unaffected over the range of 0.1–100 mM NaCl, but greatly inhibited by the presence of humid acid (HA). The synthetic FeS/Al 2 O 3 remained high mercury removal efficiency (over 95% in 1 mg/L Hg(II)) and low iron dissolution rate when preserved for 30 days, showing good long-term stability and remarkable application potential. [ABSTRACT FROM AUTHOR]

In this study, reduced graphene oxide (RGO) and different stabilizers (hexadecyltrimethylammonium bromide, starch, and carboxymethyl cellulose) were applied to simultaneously support and stabilize Fe-Mn binary oxide (FeMnO x ) nanohybrids, and enhanced removal of As(III)/(V) from water was achieved. TEM images shows that the aggregation of FeMnO x on RGO was effectively inhibited after the starch stabilization, meanwhile, the loading of FeMnO x on RGO was also increased. The adsorption capacity of As(III) and As(V) on starch-FeMnO x /RGO via Langmuir isotherm model was 78.74 mg g −1 and 55.56 mg g −1 , respectively, which was 1.99 and 2.39 times higher than bare FeMnO x . The adsorption kinetics was well fitted by the pseudo-second-order model. The effects of initial pH and coexisted anions were investigated. Over 90% of As(III) and As(V) could be removed by starch-FeMnO x /RGO during the five consecutive adsorption-desorption cycles. The results revealed the potential of the RGO supported and starch stabilized FeMnO x as an efficient adsorbent for arsenic removal from water. [ABSTRACT FROM AUTHOR]

Multilayer Zn-doped SnO 2 nanospheres are successfully synthesized by using Sn/Zn bimetal-organic nanoparticles as precursor. These multilayer spheres are found to be very suitable for solving the critical volume expansion problem and mass transfer property due to its high surface area, small crystal size and hollow structure, which is critical for high capacity metal oxide electrodes for lithium-ion batteries. Moreover, the covalently interconnected three-dimensional graphene foams encapsulated these multilayer spheres are successfully obtained through self-assembly effect and chemical cross-linking of graphene oxide nanosheets. The graphene network could further greatly improve the cycling stability and rate capability of the Zn-doped SnO 2 spheres electrode due to its flexible buffering matrix and high electric conduction. As a result, the graphene encapsulating multilayer Zn-doped SnO 2 spheres anodes exhibit excellent rate capacity and a high reversible capacity of 446 mA h g −1 even after 1000 cycles at the current density of 1 A g −1 . These excellent electrochemical performances are ascribed to its large specific surface area, fast electron/ion transfer, and stable electrode structure. Furthermore, this strategy using covalently interconnected 3D graphene foams encapsulate the Zn-doped SnO 2 spheres not only develops a high performance anode material with long cycle life but also holds great promise for binder-free lithium ion batteries. [ABSTRACT FROM AUTHOR]

In this study, SiO 2 -EDTA was prepared by silanization reaction between N-(trimethoxysilylpropyl) ethylenediamine triacetic acid, trisodium salt (EDTA-silane) and hydroxyl groups for enhanced removal of Pb(II), Pb(II)-Cit (the clathrate generated by Pb(II) and trisodium citrate dehydrate(Cit)) and Pb(II)-EDTA(20%) from aqueous solutions. SiO 2 -EDTA composites were characterized using SEM, TEM, EDX-mapping, FTIR, XPS and TGA analyses. The influence of solution pH, initial concentration, contact time and co-existing interferents were also studied. Results demonstrated that the composite successfully adsorbed 147.52, 107.65 and 124.18 mg g −1 of Pb(II), Pb(II)-Cit, and Pb(II)-EDTA (20%), respectively with the initial Pb(II) concentration of 100 mg L −1 . Kinetics study revealed that the adsorption rate was significantly high at the beginning and then reached to equilibrium within 1.0 h. Moreover, Pb(II) adsorption capacities were found to considerably affected by co-existing cations and not inhibited by natural organic matter (NOM). Characterization analyses confirmed that EDTA was successfully assembled on SiO 2 which had been used as a supporting matrix due to its huge specific surface area. Findings from this study suggested that the present composite could be considered as a promising adsorbent for large scale treatment of wastewater containing elevated Pb(II) concentration. [ABSTRACT FROM AUTHOR]

A novel one-pot approach for the synthesis of ( Z )-vinylic selenosulfides is demonstrated through the thioselenation of a wide range of alkynes with unsymmetrical diorganoyl dichalcogenides (RSSePh) catalyzed by cesium hydroxide monohydrate, avoiding the use of the transition metal catalyst and the previous preparation of chalcogen alkynes. Other outstanding features include mild reaction conditions, high regio- and stereo-selectivity, excellent yields and wide functional group tolerance. [ABSTRACT FROM AUTHOR]

Spent mushroom compost (SMC), a spent mushroom substrate (SMS) derived compost, is always applied to agriculture land to enhance soil organic matter and nutrient contents. However, nitrogen, phosphate and organic matter contained in SMC can leach out and contaminate ground water during its application. In this study, biochars prepared under different pyrolytic temperatures (550 °C, 650 °C or 750 °C) from SMS were applied to soil as a nutrient conservation strategy. The resultant biochars were characterized for physical and mineralogical properties. Surface area and pore volume of biochars increased as temperature increased, while pore size decreased with increasing temperature. Calcite and quartz were evidenced by X-ray diffraction analysis in all biochars produced. Results of column leaching test suggested that mixed treatment of SMC and SMS-750-800 (prepared with the temperature for pyrolysis and activation was chosen as 750 °C and 800 °C, respectively) could reduce 43% of TN and 66% of COD Cr in leachate as compared to chemical fertilizers and SMC, respectively. Furthermore, increasing dosage of SMS-750-800 from 1% to 5% would lead to 54% COD Cr reduction in leachate, which confirmed its nutrient retention capability. Findings from this study suggested that combined application of SMC and SMS-based biochar was an applicable strategy for reducing TN and COD Cr leaching. [ABSTRACT FROM AUTHOR]

Harmful algal blooms frequently occur globally, and forecasting could constitute an essential proactive strategy for bloom control. To decrease the cost of aquatic environmental monitoring and increase the accuracy of bloom forecasting, a novel single-parameter approach combining wavelet analysis with artificial neural networks (WNN) was developed and verified based on daily online monitoring datasets of algal density in the Siling Reservoir, China and Lake Winnebago, U.S.A. Firstly, a detailed modeling process was illustrated using the forecasting of cyanobacterial cell density in the Chinese reservoir as an example. Three WNN models occupying various prediction time intervals were optimized through model training using an early stopped training approach. All models performed well in fitting historical data and predicting the dynamics of cyanobacterial cell density, with the best model predicting cyanobacteria density one-day ahead ( r = 0.986 and mean absolute error = 0.103 × 10 4 cells mL −1 ). Secondly, the potential of this novel approach was further confirmed by the precise predictions of algal biomass dynamics measured as chl a in both study sites, demonstrating its high performance in forecasting algal blooms, including cyanobacteria as well as other blooming species. Thirdly, the WNN model was compared to current algal forecasting methods (i.e. artificial neural networks, autoregressive integrated moving average model), and was found to be more accurate. In addition, the application of this novel single-parameter approach is cost effective as it requires only a buoy-mounted fluorescent probe, which is merely a fraction (∼15%) of the cost of a typical auto-monitoring system. As such, the newly developed approach presents a promising and cost-effective tool for the future prediction and management of harmful algal blooms. [ABSTRACT FROM AUTHOR]

Active pipe-embedded building envelope can allow for substantial heat flow for relatively small temperature difference due to the embedded pipes in the external wall/roof. This structure can directly utilize the low-grade sources for reducing building cooling/heating load and improving indoor thermal comfort by intercepting the heat gain/loss through the building envelope due to the circular water inside the embedded pipe. This paper presents the experimental validation of a semi-dynamic simplified model of the active pipe embedded building envelope. The experiment test rig consists of two environment chambers with one for simulating the ambient environment and one for indoor environment with a pipe-embedded building envelope sample separating both chambers. A small chiller and a buffer tank are installed to provide stable water temperature for the test sample. The temperatures and heat fluxes on both sides of the test sample, the inlet and outlet water temperature as well as flow rate are measured. The measured boundary conditions are used as the inputs of the semi-dynamic simplified model for calculating the thermal performance of the active structure. The results show the semi-dynamic simplified model can predict the semi-steady or pure dynamic thermal performance of the pipe-embedded building envelope very well by comparing with the measurement. [ABSTRACT FROM AUTHOR]

A novel polypyrrole (PPy) coated three-dimensional (3D) SnO 2 nanotube arrays (SnO 2 @PPy) is synthesized via a template-assisted method followed by a chemical vapor-phase polymerization process as a high performance anode for lithium-ion batteries. In this new type electrode material, the hollow interiors of SnO 2 are able to provide enough spaces for the accommodation of large volume expansion during the insertion of lithium-ion, making for the improvement of the stability of electrode. Meanwhile, the addition of conductive PPy layer could facilitate the electron transport, prevent the aggregation of active materials and warrant the stability of as-formed solid electrolyte interface (SEI) films. As a result, the integration of 3D hybrid nanostructure electrode is capable of retaining a high capacity of 646 mA h g −1 after 150 cycles with a coulomb efficiency above 98% and a capacity retention of 221 mA h g −1 even at a high current density of 5000 mA g −1 , revealing better cycling and rate properties compared with bare SnO 2 nanotube arrays anode. This nanoengineering strategy can provide a facile and controllable way to synthesize other anode materials for lithium-ion batteries. [ABSTRACT FROM AUTHOR]

In this study, EDTA-functionalized Fe 3 O 4 (Fe 3 O 4 @SiO 2 -EDTA) was prepared by silanization reaction between N-(trimethoxysilylpropyl) ethylenediamine triacetic acid (EDTA-silane) and hydroxyl groups for Pb(II) and Cu(II) removal from aqueous solutions. Fe 3 O 4 @SiO 2 -EDTA composites were characterized using SEM, TEM, EDX, FTIR, XPS, TGA and saturated magnetization techniques. Maximum Pb(II) adsorption capacity was found to be 114.94 mg g −1 with SiO 2 /EDTA molar ratio of 2.5:1. The adsorption rate was significantly fast and the equilibrium was reached within 10 min. The optimum pH was recorded to be 5.0. The maximum adsorption capacity of the studied heavy metal ions calculated by Langmuir model followed the order: Cu(II) (0.58 mmol g −1 ) > Pb(II) (0.55 mmol g −1 ) ≈ Ni(II) (0.55 mmol g −1 ) > Cd(II) (0.45 mmol g −1 ). Moreover, Pb(II) and Cu(II) adsorption capacities were not significantly affected by co-existing cations and NOM. These results suggested that this adsorbent can be considered as a promising adsorbent to remove Pb(II) and Cu(II) from wastewaters. [ABSTRACT FROM AUTHOR]

Nitrite-dependent anaerobic methane oxidation (n-damo) is a potential bioprocess for treating nitrogen-containing wastewater. This process uses methane, an inexpensive and nontoxic end-product of anaerobic digestion, as an external electron donor. However, the low turnover rate and slow growth rate of n-damo functional bacteria limit the practical application of this process. In the present study, the short- and long-term effects of variations in trace metal concentrations on n-damo bacteria were investigated, and the concentrations of trace metal elements of medium were improved. The results were subsequently verified by a group of long-term inoculations (90 days) and were applied in a sequencing batch reactor (SBR) (84 days). The results indicated that iron (Fe(II)) and copper (Cu(II)) (20 and 10 μmol L −1 , respectively) significantly stimulated the activity and the growth of n-damo bacteria, whereas other trace metal elements, including zinc (Zn), molybdenum (Mo), cobalt (Co), manganese (Mn), and nickel (Ni), had no significant effect on n-damo bacteria in the tested concentration ranges. Interestingly, fluorescence in situ hybridization (FISH) showed that a large number of dense, large aggregates (10–50 μm) of n-damo bacteria were formed by cell adhesion in the SBR reactor after using the improved medium, and to our knowledge this is the first discovery of large aggregates of n-damo bacteria. [ABSTRACT FROM AUTHOR]

The binding order of sorbent, sediment and organic compounds, as well as binding time is important factors determining the potential success of sorbent amendment, which should be considered when the practicability of sorbents was assessed. But until now, relevant research was rare. In this study, desorption in three practical conditions were simulated, by three mixing spiking orders among nonylphenol (NP), rice straw black carbon (RC) and sediment (the order of mixing spiking is (RC + Sediment) + NP, (Sediment + NP) + RC and (RC + NP) + Sediment, for situation I, II and III, respectively), to discuss the feasibility of using RC to remedy NP pollution. Results demonstrated that amendment of RC into sediment decreased desorption fractions of NP, and increased the resistant desorption fraction ( F r ), implying strong affinity of NP to RC and efficient sequestration by RC. No significant differences were observed for desorption among the three fresh situations, meaning NP may be adsorbed on RC exterior surface sites and inter-phase diffusion is faster than desorption. However, F r for three aged situations was in the order: situation I < II < III, due to NP diffusion into the inter-pores or irreversible sorption sites of RC, reducing the releasing risk of NP. Regardless of time, F r of three situations were all > 0.5, suggesting RC is an effective sorbent for remedying NP pollution in the aquatic environment. Overall, we proposed a practical and analytical method for properly assessing the validity of a sorbent. [ABSTRACT FROM AUTHOR]

A novel and efficient method for the synthesis of O -allenes and N -allenes via isomerization of terminal alkynes catalyzed by cesium hydroxide monohydrate is described. The advantages of this method include: mild reaction conditions, high yields and wide tolerance toward functional groups. The protocol provides an efficient route to O -allenes and N -allenes, which are important intermediates in organic synthetic chemistry. [ABSTRACT FROM AUTHOR]

Two air-stable novel Lewis acids of triphenylantimony(V) pentafluorbezenesulfonates ( 2 ) and perfluorooctanesulfonates ( 3 ) were successfully synthesized and characterized. X-ray studies and thermo-gravimetric analysis found that these complexes showed high anti -hydrolyzability and thermal stability. The high catalytic activity and excellent recyclability of these complexes were achieved in the Michael addition reaction and the allylation reaction. On account of their stability, storability, as well as catalytic efficiency, these complexes should find a broad range of utility in organic synthesis. [ABSTRACT FROM AUTHOR]

An air-stable uninuclear complex of bis(isopropylcyclopentadienyl) zirconium perfluorooctane sulfonate ( 1a · H 2 O · 3THF ) was successfully synthesized by the reaction of ( i -PrCp) 2 ZrCl 2 with C 17 SO 3 Ag. The compound 1a · H 2 O · 3THF was characterized by different techniques (such as X-ray single crystal diffraction, TG-DSC, conductivity measurement and acid strength) and found to have the similar nature of water tolerance, air-stability, thermally-stability and strong Lewis-acidity with that of our previously reported binuclear and uninuclear zirconocenes perfluorooctanesulfonate. This novel complex was confirmed to be an effective catalyst with good recyclability and reusability for the direct benzylation of 1,3-dicarbonyl derivatives using alcohols as alkylating agents. Various 1,3-dicarbonyl and alcohols derivatives can participate in the reaction, affording the corresponding monobenzylated products in competitive yields as compared to its counterparts, such as Cp 2 Zr(OSO 17 ) 2 ·3H 2 O·THF and the traditional Lewis-acid catalysts. [ABSTRACT FROM AUTHOR]

Wet flue gas desulfurization (WFGD) system has been increasingly recognized to be effective in Hg removal. But the generated secondary pollution due to Hg re-emission from desulfurization solutions or solid byproducts has received researchers’ attention. In this paper, the distribution of captured Hg 2+ (L) in the simulated WFGD slurry was studied as a function of various environmental factors. Experimental results indicated that the pH value had a strong effect on Hg 2+ reduction but had negligible influence on the Hg 2+ retention by the grained fraction of gypsum. Increasing in pH value resulted in higher Hg 2+ reduction and over 46% of Hg 2+ was found to be reduced into Hg 0 at pH 5.0. Besides, increased slurry temperature also promoted the Hg 2+ reduction and Hg 0 re-emission as well as the Hg 2+ retention efficiency by gypsum. Other factors including S (IV), Cl − and NO 3 − concentration was found to inhibit Hg 2+ transformation into Hg 0 but slightly promoted the Hg 2+ retained in gypsum. Moreover, the addition of sodium sulfide (Na 2 S), 2,4,6-trimercaptotiazine, trisodium salt nonahydrate (TMT), and sodium dithiocarbamate (DTCR) prevented the Hg 2+ reduction and precipitated out as insoluble HgS, Hg 3 (TMT) 2 and Hg(DTCR) 2 on gypsum. The findings presented in this study could provide theoretical basis for Hg removal in coal-fired power plants. [ABSTRACT FROM AUTHOR]

Anaerobic oxidation of methane coupled to nitrite reduction (n-damo) plays an important role in global carbon and nitrogen cycles and also is a potential bioprocess in wastewater treatment. In this work, the effects of environmental conditions – temperature, pH and salinity – on the metabolic activity and growth rate of n-damo bacteria were investigated by short-term batch test and long-term bacterial incubation. Quantitative PCR and 16S rRNA and pmo A gene sequencing were applied to detect the microbial community in the long-term incubation. The results indicated that all the three environmental factors significantly affected the metabolic activity and growth rate of n-damo bacteria and the optimum temperature, pH and salinity were 35 °C, 7.6 and 0 g NaCl L −1 , respectively. Notably, salinity adaption of n-damo bacteria was first observed under salinity stress of 20 g NaCl L −1 . It's predicted that n-damo process might occur in saline environments and future work could focus on this. [ABSTRACT FROM AUTHOR]

Magnetic biochar is increasingly known as a multi-functional material and the appropriate synthesis method further increase its efficient applications. In this study, the effects of synthesis methods on the fabrication of Kans grass straw/biochar (KGS/KGB) with Fe 3+ /Fe 2+ by chemical co-precipitation and subsequently pyrolyzing at 500 °C for 2 and 4 h were studied in details, and compared their As(III, V) adsorption potentials under different operating conditions. Magnetic biochars (MKGB3 and MKGB4) prepared from KGS revealed of superior Fe 3 O 4 loading, higher As(III, V) adsorption efficiency and saturation magnetization (45.7 Am 2 kg −1 ) than that of KGB (MKGB1 and MKGB2). Moreover, Thermogravimetric analysis (TGA) demonstrated three stages of decomposition and the MKGB3 and MKGB4 generated higher residual mass (>60%) at stage 3 (1000 °C) due to greater Fe 3 O 4 composite in biochar matrix and turned to be thermally more stable. As(III) and As(V) adsorption equilibrium data well fitted in Langmuir model and followed the order: MKGB4 > MKGB3 > MKGB2 > MKGB1. The maximum As(III) and As(V) adsorption capacities were about 2.0 mg g −1 and 3.1 mg g −1 , respectively. The data best fitted in pseudo-second-order ( R 2 > 0.99) rather than pseudo-first-order kinetics model indicating of more complex mechanism. The adsorption of As(III) and As(V) was found to decrease with increasing in ionic strength of competing ions and PO 4 3− was found to strongly inhibit arsenic adsorption. Highest desorption was achieved at pH 13.5 using NaOH. This study suggests that selective adsorbent synthesis method could be useful to prepare effective adsorbent for toxic metals immobilization. [ABSTRACT FROM AUTHOR]

Highlights: [•] Nano-Ni/Fe were synthesized in the presence of ultrasonic irradiation. [•] Ultrasonic irradiation can improve nano-Ni/Fe′ disparity and avoid agglomeration. [•] 2,4-DCP was first adsorbed by nano-Ni/Fe, then was quickly dechlorinated. [•] Factors of reductive dechlorination by nano-Ni/Fe were studied. [ABSTRACT FROM AUTHOR]

Highlights: [•] Hg was mainly distributed in strong complex phase in FGD gypsum. [•] Chlorine content in coal might influence water soluble Hg in FGD gypsum. [•] Hg release ability from FGD gypsum was related to its speciation. [•] Water soluble Hg was easily to release, while residual Hg was relatively stable. [•] Hg emission from FGD gypsum during its disposal in Zhejiang province was estimated. [Copyright &y& Elsevier]

Abstract: Flue gas desulfurization system used for SO2 removal has co-beneficial removal of Hg, which has resulted in Hg-laden gypsums. With growing beneficial reuse applications of the FGD gypsum, it has been recognized as a potential source of Hg pollution. In this paper, the fate and mobility of Hg were investigated. The Hg content in four samples varied widely and it showed a significant correlation between Hg and sulfite contents in gypsum. In leachate, Hg concentration varied during the leaching process. The Hg extraction rate generally increased with decreasing pH value, which suggested that the environmental risk of FGD gypsum increased during the multipurpose utilization processes, resulted from severe acid rain. The released Hg from FGD gypsum used in this study exhibited biphasic kinetics. Hg in FGD gypsum samples not only appeared in the leachate but also re-emitted into the air. The Hg reduction kinetics followed the pseudo-first-order kinetic model well. Our results provide the theoretical understanding for the co-removal of highly soluble oxidized Hg in WFGD systems and also in the recycling of the FGD gypsum. [Copyright &y& Elsevier]

Abstract: Air-stable binuclear complex of bis(methylcyclopentadienyl)zirconium perfluorooctanesulfonate (1a) was successfully synthesized by the reaction of (CH3Cp)2ZrCl2 with C8F17SO3Ag. The compound 1a was characterized by different techniques and found to have the nature of air-stability, water tolerance, thermally-stability and strong Lewis-acidity. In addition, its solubility was higher than that of our previously reported uninuclear zirconocene bis(perfluorooctanesulfonate). It showed high catalytic efficiency in the Friedel–Crafts acylation of alkyl aryl ethers and the Mannich reaction and could be reused. [Copyright &y& Elsevier]

Abstract: An air-stable Lewis acidic binuclear complex of bis(ethylcyclopentadienyl)zirconium perfluorooctanesulfonate (1a) was successfully synthesized by the reaction of (CH3CH2Cp)2ZrCl2 with C8F17SO3Ag. The complex 1a was characterized by different techniques and found to have the nature of air-stability, water tolerance, thermal-stability, and strong Lewis-acidity. In addition, its solubility was higher than that of our previously reported uninuclear zirconocene bis(perfluorooctanesulfonate). This complex showed high catalytic efficiency, good recyclability, and reusability in the one-pot three-component aza-Friedel–Crafts reactions of indoles with aldehydes and N,N-dimethylaniline. The yields of the corresponding 3-diarylmethyl indoles are higher than those from the traditional Lewis acidic catalysts. [Copyright &y& Elsevier]

Highlights: [•] Fe0-Fe3O4 nanocomposites are embedded in polyvinyl alcohol/sodium alginate beads;. [•] Acidification and reduction after bead molding greatly improve beads performance;. [•] High stability, Cr(VI) removal efficiency and reusability of these beads;. [•] Easy and complete separation after reaction. [Copyright &y& Elsevier]

Highlights: [•] Arsenic removal performance of SSFs containing HBC and Fe-HBC (50% w/w) is studied. [•] Over 99% and 98% arsenic removals were achieved in SSF(a) and SSF(b) under oxic-environment. [•] Two steps in situ mechanism is proposed to convert As(III) into As(V) and subsequent adsorption. [•] Low levels of influent co-occurring ions did not significantly interfered arsenic removal. [•] Filter with low-cost adsorbents could be proposed as feasible and efficient method for arsenic removal. [ABSTRACT FROM AUTHOR]

Highlights: [•] Sensitivity analysis of energy performance is performed for residential envelope. [•] EETP method is introduced to calculate cooling and heating energy use. [•] Shading coefficient and window to wall ratio are the most vital factors in summer. [•] Wall heat transfer coefficient and shape coefficient have crucial effect in winter. [•] Wall heat transfer coefficient and window to wall ratio weight the most in a year. [ABSTRACT FROM AUTHOR]

Abstract: Palladium/Iron (Pd/Fe) nanoparticles were prepared by using ultrasound strengthened liquid phase reductive method to enhance dispersion and avoid agglomeration. The dechlorination of 2,4-dichlorophenol (2,4-DCP) by Pd/Fe nanoparticles was investigated to understand its feasibility for an in situ remediation of contaminated groundwater. Results showed that 2,4-DCP was first adsorbed by Pd/Fe nanoparticles, then quickly reduced to o-chlorophenol (o-CP), p-chlorophenol (p-CP), and finally to phenol (P). The induction of ultrasound during the preparation of Pd/Fe nanoparticles further enhanced the removal efficiency of 2,4-DCP, as a result, the phenol production rates increased from 65% (in the absence of ultrasonic irradiation) to 91% (in the presence of ultrasonic irradiation) within 2h. Our data suggested that the dechlorination rate was dependent on various factors including Pd loading percentage over Fe0, Pd/Fe nanoparticles availability, temperature, mechanical stirring speed, and initial pH values. Up to 99.2% of 2,4-DCP was removed after 300min reaction with these conditions: Pd loading percentage over Fe0 0.3wt.%, initial 2,4-DCP concentration 20mgL−1, Pd/Fe dosage 3gL−1, initial pH value 3.0, and reaction temperature 25°C. The degradation of 2,4-DCP followed pseudo-first-order kinetics reaction and the apparent pseudo-first-order kinetics constant was 0.0468min−1. [Copyright &y& Elsevier]

Abstract: This study describes the chromium (VI) removal in aqueous solution by nanoscale zero-valent iron (nZVI)-Fe3O4 nanocomposites, which were prepared by a novel in situ reduction method. The effects of several factors, including ionic strength, temperature, co-existing anions and cations and natural organic matters were evaluated. The ionic strength was found to be insignificant to the removal efficiency, while temperature was critical. With the increase in temperature from 10–40°C, 32% removal efficiency increased within 2h from 49.96%. Most anions hindered the reaction, especially in high concentration, such as and , causing a drop of the removal efficiency from 66.48% to 57.47% and 59.93% respectively. In contrast, both cations and moderate natural organic matter facilitated the removal of Cr(VI). It is noteworthy that calcium hardness can greatly promote the reaction, 100% removal efficiency was achieved within 90min and the rate constant k 2 reached 0.528gmg−1 min−1 after adding 40mgL−1 Ca2+, which was ten times more than that in other cases. Possible mechanism was presented, and TEM, SEM and FITR analyses were used to verify these speculations. Hopefully, these results can contribute to a better development of the water treatment facilitates for nZVI-Fe3O4 composites, maintaining its high efficiency in real aqueous environment. [Copyright &y& Elsevier]

Abstract: Global warming is increasingly challenging for wetland ecological function. A temperature controlled microcosm system was developed to simulate climate change scenarios of an ambient temperature (control) and an elevated temperature (+5°C). The effects and associated mechanisms of warming on phosphorus (P) fluxes at the sediment–water interface of six subtropical wetlands were investigated. The results indicated that P fluxes were generally enhanced under the experimental warming as measured by higher P concentrations in the porewater and overlying water as well as higher benthic P fluxes. The release of P from sediment to porewater occurred more strongly and quickly in response to experimental warming compared to the subsequent upward transfer into overlying water. The average accumulative benthic P output from the tested wetlands under the experimental warming was greater by 12.9μgcm−2 y−1 (28%) for total P and 8.26μgcm−2 y−1 (25%) for dissolved reactive P, compared to the ambient scenarios. Under warming the redistribution of P fractions in sediments occurred with greater NH4Cl–P and lower BD–P (extracted by a bicarbonate buffered dithionite solution) accompanied by greater NaOH–P. The higher temperature enhanced total phospholipid fatty acids. A shift in the microbial community was also observed with a relative dominance of fungi (a 4.7% increase) and a relative decline (by 18%) in bacterial abundance, leading to the higher secretion of phosphatase. Comparing between wetlands, the potential P fluxes in the nutrient-enriched wetlands were less impacted by warming than the other wetland types investigated. Thus wetlands characterized by low or medium concentrations of P in sediments were more susceptible to warming compared to P-rich wetlands. [Copyright &y& Elsevier]

Abstract: A small solar energy collector was run to heat lignocellulosic hydrolyzates through an exchanger, and the heated hydrolyzate was concentrated by vacuum membrane distillation (VMD). Under optimal conditions of velocity of 1.0m/s and 65°C, glucose rejection was 99.5% and the flux was 8.46Lm−2 h−1. Fermentation of the concentrated hydrolyzate produced 2.64 times the amount of ethanol as fermentation using the original hydrolyzate. The results of this work indicated the possibility to decrease the thermal energy consumption of lignocellulosic ethanol through using VMD. [Copyright &y& Elsevier]

Abstract: Water pollution caused by ammonia nitrogen has attracted a great attention as its toxicity affects both the environment and human health. The objective of this paper was to investigate the adsorption behavior of NH4 +-N from aqueous solution by activated carbons prepared from rice husk. The physico-chemical properties of the activated carbon were characterized by Brunauer-Emmett-Teller (BET) test, Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). It was found that the NH4 +-N adsorption on the rice husk derived carbons was dependent on adsorbent dosage and solution pH. The adsorption kinetics and isotherms of NH4 +-N by rice husk carbon were also investigated, and good correlation coefficients were obtained for the pseudo-second order kinetic equation. Dubinin-Radushkevitch (D-R) adsorption isotherm model could better describe the adsorption behavior of NH4 +-N on the rice husk carbon. Calculated by D-R model, the adsorption course of NH4 +-N on the rice husk carbon was favored chemical ion-exchange mechanism. Moreover, the activated carbon adsorbed NH4 +-N was highly fertilizer conservation especially for the nitrogen element. It was proposed that the amount of removed NH4 +-N from aqueous solutions would increase evidently treated by rice husk carbon if combined with biological method. [Copyright &y& Elsevier]

Abstract: To investigate the feasibility of using black carbon (BC) in the control of hydrophobic organic contaminants (HOCs) in sediment, we added BCs from various sources (rice straw charcoal (RC), fly ash (FC) and soot (SC)) to sediment to create different BC-inclusive sediments and studied the release of pentachlorophenol (PCP) in the sediments under different condition. Different pH values had no obvious effect on the release of PCP in BC-inclusive sediment, but solid/liquid ratio, temperature, salinity and dissolved organic matter (DOM) content had significant influences on the release of PCP in all sediments except the RC-inclusive sediment. Adding 2% RC to sediment resulted in a 90% decrease in PCP release, which was a greater decrease than observed with FC- and SC-inclusive sediments. Therefore, from the standpoint of HOC release, the application of RC is feasible for organic pollution control in the water environment. [Copyright &y& Elsevier]

Abstract: Black carbon (BC) is a potential material for controlling hydrophobic organic contaminants in sediment because it has a high sorption capacity. In the present study, the sorption of pentachlorophenol (PCP) onto sediments supplemented with rice straw biochar (RC) and fly ash (FC) aged for different times and at temperatures were investigated. The sorption of PCP increased with increasing amounts of BC and decreased with aging time and storage temperature of the BC-supplemented sediments. The sorption of PCP onto RC-supplemented sediments was higher than those supplemented with FC regardless of whether or not BCs were aged in sediments. For aged sediments containing 2% BCs, the sorption capacity was 9.15- and 2.87-fold higher than that of FC when supplemented with RC aged at 25 and 45°C, respectively. Therefore, biochar is better than fly ash for controlling organic pollutants even when the RC was present in sediment for a long time. [Copyright &y& Elsevier]

Abstract: The electrochemical reductive dechlorination of 2,4-dichlorophenoxyacetic acid (2,4-D) in an aqueous solution was investigated at ambient temperature using a palladium/nickel foam (Pd/Ni foam) electrode in batch mode experiments. The catalytic electrode prepared using the standard chemical deposition method was further characterized using X-ray diffraction and scanning electron microscopy. It was observed that the reaction followed a pseudo-first-order kinetics model, the magnetic agitator-supported system could achieve 87% removal of 2,4-D within 4h, which is 16% higher than the efficiency obtained under a nitrogen atmosphere. No organic intermediates other than phenoxyacetic (PA), o-chlorophenoxyacetic acid (o-CPA) and p-chlorophenoxyacetic acid (p-CPA) were observed to be generated during the reaction. The dechlorination efficiency depended on several factors including the current density, the palladium loading and the initial concentrations of the supporting NaCl electrolyte and the 2,4-D. The palladium loading and the NaCl concentration had a greater effect on the dechlorination kinetics of 2,4-D. Furthermore, the efficiencies of dechlorination and PA formation could be improved by optimizing the reaction system by modifying the ventilation conditions. [Copyright &y& Elsevier]

Abstract: Activated sludge dewatering is of great importance in sludge treatment and disposal. To enhance the dewaterability, a novel method was performed by treating the sludge under mild temperature (50–90 °C) in CaCl2 solution (3.7–1110.0 mg/g dry sludge). The capillary suction time, zeta potential, Fourier-transformed infrared spectra, concentration of soluble protein and carbohydrates were employed to characterize the dewaterability and influencing mechanism. The sludge dewaterability was deteriorated with single thermal treatment, but significantly promoted in CaCl2 solution and advanced further together with thermal treatment. An increasing CaCl2 dosage reduced the surface charge remarkably, and a higher temperature could strengthen this impact. The spectra indicate that Ca2+ could interact with the protein, phenols and O–H functional group in the flocs. The thermal treatment could cause the solubilization of protein and carbohydrates, providing more binding sites for Ca2+ to establish a strong bridging among the flocs. As CaCl2 dosage elevated, the soluble carbohydrates showed a reduction trend, while the soluble protein lowered firstly and then bounced back except that remained unchanged at room temperature. A bridging equilibrium is presumed to exist between Ca2+ and the soluble protein. And the bridging between Ca2+ and the soluble carbohydrates plays a more important role in the dewatering. The sludge dewaterability was successfully and economically improved by thermal treatment in CaCl2 solution. [Copyright &y& Elsevier]