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In this paper, it is shown that if T=Tri(A,M,B) is a triangular algebra and ϕ is an additive operator on T such that (m+n+k+l)ϕ(T2)-(mϕ(T)T+nTϕ(T)+kϕ(I)T2+lT2ϕ(I))∈FI for any T∈T, then ϕ is a centralizer. It follows that an (m,n)- Jordan centralizer on a triangular algebra is a centralizer. [ABSTRACT FROM AUTHOR]

Let A and B be two factor von Neumann algebras. For A,B∈A, define by [A,B]* = AB − BA* the skew Lie product of A and B. In this article, it is proved that a bijective map Φ:A→B satisfies Φ([[A,B]*,C]*) = [[Φ(A),Φ(B)]*,Φ(C)]* for all A,B,C∈A if and only if Φ is a linear *-isomorphism, or a conjugate linear *- isomorphism, or the negative of a linear *-isomorphism, or the negative of a conjugate linear *-isomorphism. [ABSTRACT FROM AUTHOR]

Let A be a CSL subalgebra of a von Neumann algebra acting on a Hilbert space H. It is shown that any Jordan (α,β)-derivation on A is an (α,β)-derivation, where α,β are any automorphisms on A. Moreover, the nth power (α,β)-maps on A are investigated. [ABSTRACT FROM AUTHOR]

The objective of this work was to investigate the feasibility and effectiveness of silica fume on stabilizing heavy metals in municipal solid waste incineration (MSWI) fly ash. In addition to compressive strength measurements, hydrated pastes were characterized by X-ray diffraction (XRD), thermal-analyses (DTA/TG), and MAS NMR ( 27 Al and 29 Si) techniques. It was found that silica fume additions could effectively reduce the leaching of toxic heavy metals. At the addition of 20% silica fume, leaching concentrations for Cu, Pb and Zn of the hydrated paste cured for 7 days decreased from 0.32 mg/L to 0.05 mg/L, 40.99 mg/L to 4.40 mg/L, and 6.96 mg/L to 0.21 mg/L compared with the MSWI fly ash. After curing for 135 days, Cd and Pb in the leachates were not detected, while Cu and Zn concentrations decreased to 0.02 mg/L and 0.03 mg/L. The speciation of Pb and Cd by the modified version of the European Community Bureau of Reference (BCR) extractions showed that these metals converted into more stable state in hydrated pastes of MSWI fly ash in the presence of silica fume. Although exchangeable and weak-acid soluble fractions of Cu and Zn increased with hydration time, silica fume addition of 10% can satisfy the requirement of detoxification for heavy metals investigated in terms of the identification standard of hazardous waste of China. [ABSTRACT FROM AUTHOR]

Highlights: [•] The frontier molecular orbital theory was applied to explain the oxidation. [•] Initial rates of TOC reduction and oxalic acid production related to E HOMO and χ. [•] The NH4 + production related to the electron density on the α-carbon atom of –NH2. [•] The electron withdrawing effect of –SO3H groups affected the oxidation significantly. [Copyright &y& Elsevier]

This paper is concerned with strictly cyclic functionals of operator algebras on Banach spaces. It is shown that if X is a reflexive Banach space and ... is a norm-closed semisimple abelian subalgebra of B(X) with a strictly cyclic functional ƒ ∈ X*, then ... is reflexive and hereditarily reflexive. Moreover, we construct a semisimple abelian operator algebra having a strictly cyclic functional but having no strictly cyclic vectors. The hereditary reflexivity of an algbra of this type can follow from theorems in this paper, but does not follow directly from the known theorems that, if a strictly cyclic operator algebra on Banach spaces is semisimple and abelian, then it is a hereditarily reflexive algebra. [ABSTRACT FROM AUTHOR]

Abstract: The object of this work was to explore the feasibility of using the sludge derived from dyestuff-making wastewater coagulation for the preparation of unfired bricks with four typical cements including Portland cement, ground silicate cement clinker, alumina cement and slag cement. The interaction between the sludge and cement were studied based on X-ray diffraction, thermal analyses, compressive strength measurements, freeze–thaw tests and leaching tests. The experimental results showed that the cement solidified sludge was capable of reaching all performance criteria for unfired bricks at a cement/dry sludge/water ratio of 1:0.5–0.8:0.5–0.8. The compressive strengths of alumina cement solidified sludge overpass 40MPa, higher than those of other cement solidified sludges. It is expected that the unfired bricks of the sludge and alumina cement can be used for the pave of pedestrian road. [ABSTRACT FROM AUTHOR]

The efficient remediation of heavy metal-bearing sediment has been one of top priorities of ecosystem protection. Cement-based solidification/stabilization (s/s) is an option for reducing the mobility of heavy metals in the sediment and the subsequent hazard for human beings and animals. This work uses sodium carbonate as an internal carbon source of accelerated carbonation and gaseous CO2 as an external carbon source to overcome deleterious effects of heavy metals on strength development and improve the effectiveness of s/s of heavy metal-bearing sediment. In addition to the compressive strength and porosity measurements, leaching tests followed the Chinese solid waste extraction procedure for leaching toxicity – sulfuric acid and nitric acid method (HJ/T299-2007), German leaching procedure (DIN38414-S4) and US toxicity characteristic leaching procedures (TCLP) have been conducted. The experimental results indicated that the solidified sediment by accelerated carbonation was capable of reaching all performance criteria for the disposal at a Portland cement dosage of 10wt.% and a solid/water ratio of 1:1. The concentrations of mercury and other heavy metals in the leachates were below 0.10mg/L and 5mg/L, respectively, complying with Chinese regulatory level (GB5085-2007). Compared to the hydration, accelerated carbonation improved the compressive strength of the solidified sediment by more than 100% and reduced leaching concentrations of heavy metals significantly. It is considered that accelerated carbonation technology with a combination of Na2CO3 and CO2 may practically apply to cement-based s/s of heavy metal-bearing sediment. [Copyright &y& Elsevier]

Lime is a preferred precipitant for the removal of heavy metals from industrial wastewater due to its relatively low cost. To reduce heavy metal concentration to an acceptable level for discharge, in this work, fly ash was added as a seed material to enhance lime precipitation and the suspension was exposed to CO2 gas. The fly ash¿lime-carbonation treatment increased the particle size of the precipitate and significantly improved sedimentation of sludge and the efficiency of heavy metal removal. The residual concentrations of chromium, copper, lead and zinc in effluents can be reduced to (mgL¿1) 0.08, 0.14, 0.03 and 0.45, respectively. Examination of the precipitates by XRD and thermal analysis techniques showed that calcium¿heavy metal double hydroxides and carbonates were present. The precipitate agglomerated and hardened naturally, facilitating disposal without the need for additional solidification/stabilization measures prior to landfill. It is suggested that fly ash, lime and CO2, captured directly from flue gas, may have potential as a method for wastewater treatment. This method could allow the ex-situ sequestration of CO2, particularly where flue-gas derived CO2 is available near wastewater treatment facilities. [Copyright &y& Elsevier]

Portland cement (PC) and blended cements containing pulverized fuel ash (PFA) or granulated blast-furnace slag (GGBS) were used to solidify/stabilize an electroplating sludge in this work. The acid neutralization capacity (ANC) of the hydrated pastes increased in the order of PC>PC/GGBS>PC/PFA. The GGBS or PFA replacement (80wt%) reduced the ANC of the hydrated pastes by 30–50%. The ANC of the blended cement-solidified electroplating sludge (cement/sludge 1:2) was 20–30% higher than that of the hydrated blended cement pastes. Upon carbonation, there was little difference in the ANC of the three cement pastes, but the presence of electroplating sludge (cement/sludge 1:2) increased the ANC by 20%. Blended cements were more effective binders for immobilization of Ni, Cr and Cu, compared with PC, whereas Zn was encapsulated more effectively in the latter. Accelerated carbonation improved the immobilization of Cr, Cu and Zn, but not Ni. The geochemical code PHREEQC, with the edited database from EQ3/6 and HATCHES, was used to calculate the saturation index and solubility of likely heavy metal precipitates in cement-based solidification/stabilization systems. The release of heavy metals could be related to the disruption of cement matrices and the remarkable variation of solubility of heavy metal precipitates at different pH values. [Copyright &y& Elsevier]

Adsorption-based processes are widely used in the treatment of dilute metal-bearing wastewaters. The development of versatile, low-cost adsorbents is the subject of continuing interest. This paper examines the preparation, characterization and performance of a micro-scale composite adsorbent composed of silica gel (15.9w/w%), calcium silicate hydrate gel (8.2w/w%) and calcite (75.9w/w%), produced by the accelerated carbonation of tricalcium silicate (C3S, Ca3SiO5). The Ca/Si ratio of calcium silicate hydrate gel (C–S–H) was determined at 0.12 (DTA/TG), 0.17 (29Si solid-state MAS/NMR) and 0.18 (SEM/EDS). The metals-retention capacity for selected Cu(II), Pb(II), Zn(II) and Cr(III) was determined by batch and column sorption experiments utilizing nitrate solutions. The effects of metal ion concentration, pH and contact time on binding ability was investigated by kinetic and equilibrium adsorption isotherm studies. The adsorption capacity for Pb(II), Cr(III), Zn(II) and Cu(II) was found to be 94.4mg/g, 83.0mg/g, 52.1mg/g and 31.4mg/g, respectively. It is concluded that the composite adsorbent has considerable potential for the treatment of industrial wastewater containing heavy metals. [Copyright &y& Elsevier]

Diesel removal of contaminated soil by washing/flushing was enhanced with micro-bubbles and selected surfactants based on their solubilization properties and decontamination capacities. The influencing factors were studied to aim for increasing washing/flushing efficacy. The mixture solution of saponin and cyclodextrin increased the removal efficiency significantly compared to the single-agent solution flushing with an increasing range of 20%–31%. Meanwhile, micro-bubble enhancement increased over 20% of the diesel removal for the sandy soil flushing. As the flushing process may cause soil eroded, the TDS and soil solute in flushing solution were measured to evaluate the circulation time. The 90 min flushing time ensured the cleaning goal and reserved the soil solute by circulation flushing. The soil solute, especially the electron acceptor (NO 3 -) , was remained in the soil, which was highly demanded for residual diesel biodegradation of loam soil. It is concluded that mixed agents, circulation of flushing solution, and micro-bubbles increased the diesel removal, and the circulation flushing could be very promising in practical applications. [Display omitted] • Surfactant/cyclodextrin foam enhanced diesel contaminated soil flushing. • Treated and untreated loam soils were analyzed by TG and XRD. • Aging time was crucial factor influencing diesel removal efficiency. • Circulation of flushing solution was effective for soil remediation. [ABSTRACT FROM AUTHOR]

Let A and B be two factors with dim A > 4 . In this article, it is proved that a bijective map Φ : A → B satisfies Φ ([ A ∙ B , C ]) = [ Φ (A) ∙ Φ (B) , Φ (C) ] for all A , B , C ∈ A if and only if Φ is a linear ∗ -isomorphism, or a conjugate linear ∗ -isomorphism, or the negative of a linear ∗ -isomorphism, or the negative of a conjugate linear ∗ -isomorphism. [ABSTRACT FROM AUTHOR]

Monometallic and bimetallic Pd-Au catalysts supported on multi-walled carbon nanotubes (CNTs) with varied Au cooperation amounts were prepared using the complexing-reduction method in the presence of tetrahydrofuran (THF). The liquid phase catalytic hydrodechlorination (HDC) of 2,4-dichlorophenol (2,4-DCP) was investigated over these bimetallic catalysts. The catalysts were characterized by N 2 adsorption-desorption isotherms, X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, and H 2 chemisorption. Characterization results showed that the co-reduction of Pd and Au mainly formed alloy-like structure. The bimetallic catalysts had smaller metal particles and larger numbers of exposed active site than that of monometallic catalysts. In addition, compared with Pd(1.7)/CNTs and Au(0.4)/CNTs, the binding energies of Pd 3d 5/2 shifted to higher positions while that of Au 4f 7/2 had negative shifts in the Pd-Au bimetallic catalysts, which can be ascribed to the electrons transferred from metal Pd to Au and the cationization of Pd particles was enhanced. Accordingly, the bimetallic Pd-Au particles with different Au contents in the catalysts exhibited varied synergistic effects for the catalytic HDC of 2,4-DCP, with Pd(1.8)Au(0.4)/CNTs having the highest catalytic activity. For the bimetallic catalysts, a disproportional increase of turnover frequency (TOF) was observed with increasing Au content due to the enhanced cationization of Pd particles. Moreover, the dechlorination of 2,4-DCP over the supported monometallic and bimetallic catalysts proceeded via both the stepwise and concerted pathway, and the concerted pathway became predominant with Au decoration amount in the catalyst. [ABSTRACT FROM AUTHOR]

• The removal of BrO 3 − could proceed on Pt clusters rather than the single atoms. • H 2 was dissociated in a heterolytical manner on the isolated Pt atoms. • The reduction of BrO 3 − and high-valent Mo need consecutive active H. • The introduction of Mo promoted BrO 3 − reduction remarkably. • The co-anions had faint effect on BrO 3 − removal. Here, we prepared microporous carbon (PC) supported Pt catalysts with different isolated Pt atoms and designed pathways to introduce Mo into the catalysts. Bromate (BrO 3 −) was applied as the model oxyanion to evaluate the hydrogenation decontamination efficiency and catalyst activity. At a catalyst dosage of 0.05 g l−1, BrO 3 − was reduced by 98.3 % after reaction for 30 min over Pt 2 -PC with Pt atomic clusters, much higher than that of single atom (Pt 0.5 -PC, 5.1 %) and nanoparticle (Pt n -PC, 43.2 %) counterparts. H 2 was dissociated in a heterolytical manner on the highly isolated Pt active sites and the formed active H+/H− pairs dominated the removal of BrO 3 − supported by the experimental data and density functional theory (DFT) calculation. High-valent Mo in the solution could be reduced to lower valent by consecutive active H, which further joined BrO 3 − reduction directly. In comparison, Mo atoms anchored on PC substrate scrambled N ligands with Pt, favoring the enrichment of BrO 3 − anions on the catalyst surface, thus the generated active H could react with the nearby BrO 3 − instantly. This study highlights the role of few-atomic Pt clusters for H 2 activation and provides a strategy to boost the liquid phase catalytic hydrogenation reaction. [ABSTRACT FROM AUTHOR]

Acacia Senegal waste (ASW) is remaining biomass following gum Arabic harvesting and has no use mentioned in the literature as of yet. This study aims to convert ASW into valuable biochar via two comparative thermal and hydrothermal techniques, which include pyrochar ASW at 300 °C (PC ASW300) and hydrochar ASW at 180 °C (HC ASW180), respectively, for Cu (II) adsorption from aqueous solutions. SEM-EDS, FTIR, XRD, and XPS were used to characterize the biochar. Adsorption performance was studied as a function of pH, contact time, and adsorbent concentration. Adsorption kinetics were best fit for a pseudo-second-order model. And thermodynamics studies revealed that Cu (II) on biochar was endothermic, spontaneous, and best fitted to the Langmuir isotherm model. Pyrochar adsorption capacity (31.93 mg g−1) was seven times that of hydrochar (5.45 mg g−1). ASW treated with phosphorus (PC H 3 PO 4 and HC H 3 PO 4) prior to the carbonization altered the pore structure and surface functional groups as well (O–P–O, P–CH 3 , and P–OH) of biochar. It was found that treating with phosphorous acid increased adsorption capacity to 141.7 mg g−1 and 22.24 mg g−1 for PC H 3 PO 4 and HC H 3 PO 4 , respectively. The surface functional groups of biochar resulted from lignin, alkaloids, and polysaccharides combined with Cu (II) during the adsorption process via surface complexation accompanied by π-electron interaction and Cu (II) reduction. These findings shed light on the ASW biochar potential as a new green cost-effective adsorbent and drew an insightful understanding of Cu (II) adsorption performance and mechanism. It is concluded that ASW-derived biochar is highly effective and a promising alternative for Cu (II) decontamination from wastewater. [Display omitted] • Acacia Senegal waste biochar has a potential as Cu(II) cost-effective adsorbents. • Phosphorous activated biochar grew Cu(II) adsorption capacity up to five times. • Copper adsorption on surface of biochar was accompanied by Cu(II) reduction. • Surface complexation and π electron interaction played a key role on adsorption. • Pyrochar show greater adsorption capacity and removal efficiency than hydrochar. [ABSTRACT FROM AUTHOR]

Abstract: A photocatalyst comprising nano-sized TiO2 particles on granular activated carbon (GAC) was prepared by a sol-dipping–gel process. The TiO2/GAC composite was characterized by scanning electron microscopy (SEM), X-ray diffractiometry (XRD) and nitrogen sorptometry, and its photocatalytic activity was studied through the degradation of humic acid (HA) in a quartz glass reactor. The factors influencing photocatalysis were investigated and the GAC was found to be an ideal substrate for nano-sized TiO2 immobilization. A 99.5% removal efficiency for HA from solution was achieved at an initial concentration of 15mg/L in a period of 3h. It was found that degradation of HA on the TiO2/GAC composite was facilitated by the synergistic relationship between surface adsorption characteristics and photocatalytic potential. The fitting of experimental results with the Langmuir–Hinshelwood (L–H) model showed that the reaction rate constant and the adsorption constant values were 0.1124mg/(Lmin) and 0.3402L/mg. The latter is 1.7 times of the calculated value by fitting the adsorption equilibrium data into the Langmuir equation. [Copyright &y& Elsevier]

[Display omitted] • CNT/NCB assembly GDE was fabricated for 2e− ORR and recalcitrant pollutant degradation. • Gradient hydrophobic three-phase-boundary favored for oxygen transport and reduction. • CNTs assisted transfers of electrons and O 2 to active sites (pyridinic and pyrrolic N) in GDE. • CNT/NCB co-catalytic electro-Fenton systems involved ROS such as 1O 2 and •OH. The generation of H 2 O 2 on cathode is a pivotal and rate-limiting step in the electrocatalytic oxygen reduction reaction process. In this work, carbon nanotube (CNT) and nitrogen-doped carbon black (NCB) was assembled on carbon fiber cloth to achieve high oxygen reduction reaction (ORR) efficiency in gas diffusion electrode (GDE). An excellent and stable H 2 O 2 generation capacity of 42.15 mg L−1h−1 cm−2 was achieved, and 39.6% TOC removal and complete decolorization over a wide pH range were realized for recalcitrant Reactive Red X-3B in modeling wastewater. The involved reactive oxygen species were found to be H 2 O 2 , 1O 2 and •OH. Besides density functional theory calculations, the coupling effect of various components in the GDE on electrocatalytic activity was investigated based on characterization and electrochemical examinations. It was revealed that pyridinic N and pyrrolic N in NCB and electron transfer of CNT increased the electrocatalytic activity and selectivity for two-electron ORR. In addition, the gradient hydrophobic three-phase-boundary increased oxygen retention and ORR activity for H 2 O 2 generation. The reusability test of CNT/NCB-GDE showed its great applicability for H 2 O 2 electro-generation and wastewater treatment. [ABSTRACT FROM AUTHOR]

B, N co-doping could modulate both the adsorption and activation of PMS on the carbon catalyst surface. • B, N co-doped CNTs exhibited much higher catalytic activity than single doped CNTs. • The adsorption of PMS on the catalyst surface favored the degradation of 2,4-D. • Synergistic effect between N and B dopants was observed. • Both the pyrrolic N and B-N complex played roles in the AOPs of 2,4-D. B, N co-doped CNTs were synthesized by a simple one-step thermal process and the advanced oxidation processes (AOPs) of 2,4-dichlorophenoxyacetic acid (2,4-D) over the catalyst involved peroxymonosulfate (PMS) activation was investigated. The co-doped catalysts showed higher isoelectric points (IEPs) than those of CNTs and single doped CNTs, facilitating the adsorption of PMS anion (HSO 5 −) on the catalyst surface, and the AOPs of 2,4-D depended on PMS concentration could be illustrated by the Langmuir-Hinshelwood model. The removal efficiency of 2,4-D over CNTs, CB450, CN450 and CBN450-2 was 20%, 23%, 34% and 68%, respectively. The enhancement of catalytic activity was due to the synergistic effect between B and N dopants and both the pyrrolic N and B-N complex played roles in the catalytic reaction. The quenching test and electron paramagnetic resonance (EPR) results showed that 1O 2 contributed most to the oxidation of 2,4-D and the reaction experienced both the free radical and non-radical pathways. Additionally, the DFT calculation results showed that the adsorption energy of PMS on the surface N dopants decreased by B co-doping, implying that a moderate adsorption energy may facilitate the release of active species generated by PMS activation. [ABSTRACT FROM AUTHOR]

The Pd/CMK-3 catalyst reflected a good advanced oxidation ability based on PMS activation in situ after the highly effective catalytic hydrodechlorination of 2,4-D. • The HDC, AOPs and combined HDC-AOPs of 2,4-D were conducted over Pd/CMK-3. • Active Pd species exhibited distinct effects in the HDC and AOPs. • HDC product could be further degraded in the presence of PMS in situ. • Surface-bound free radicals contributed most to the AOPs of 2,4-D. • Metal Pd was more stable after HDC than that of AOPs. The eliminate of 2,4-dichlorophenoxyacetic acid (2,4-D) was achieved via individual and combination of catalytic hydrodechlorination (HDC) and AOPs involved peroxymonosulfate activation. The CMK-3 supported monometallic Pd catalysts with varied Pd loadings were prepared and applied in the reactions. The results showed that Pd/CMK-3 were highly active and competitive in both the HDC and AOPs of 2,4-D, and the removal efficiencies were 91.6 and 95.2% over Pd 3 /CMK-3 respectively after reaction for 90 min. The dechlorination of 2,4-D was completed via both the stepwise and concerted pathways while the reactant experienced free radical oxidation processes in the AOPs. For the combined HDC-AOPs reaction, Pd/CMK-3 reflected a good advanced oxidation ability after the effective HDC of 2,4-D. Additionally, the catalysts exhibited higher Pdn+/Pd0 ratios after reactions and metal Pd was more stable after the reductive dechlorination than that of advanced oxidation. [ABSTRACT FROM AUTHOR]

Seven surfactants were selected as candidate agents for in situ soil column flushing. Column flushing lacks the interaction between surfactants and contaminants, so efficiency is not easy to improve. Microbubbles generated in situ may adhere to the contaminant diesel. Thereafter, the bubbles were mobilized to lift the multi-system oil to the top layer. This process must be attributed to the increased column flushing efficiency of diesel removal. Compared with a single solution, using randomly methylated beta-cyclodextrin (RAMEB) and microbubble enhancement, the diesel removal of column flushing increased by 30.7%. Compared with the existing conditions (5.25 × 10−4 cm s−1), the hydraulic conductivity of loam soil (3.74 × 10−3 cm s−1) increased by 7.1 times after the continued operation of the two processes. The oil layer was collected for further reuse. After three treatments, the effluent for the RAMEB was more than 85%. The collected effluent was treated with a synthetic absorbent and then qualifiedly discharged with a TOC value of only 2.6 mg L−1. By combining surfactant flushing with microbubbles and other equipment, not only can the reaction time be effectively saved, but organic pollutants could be concentrated and reused in the soil, so no additional treatment was required. [ABSTRACT FROM AUTHOR]

Chloroacetic acids could be hydrodechlorinated to acetic acid effectively and the Pd catalyst supported on CeO 2 (1 1 0) plane had the optimum activity. [Display omitted] • MCAA could be completely catalytic removed over Pd/CeO 2 within 6 min. • CeO 2 with (1 1 0) plane supported Pd catalyst had the optimum ability. • Higher Pd dispersion and appropriate Pdn+/Pd0 favored the HDC reaction. • Various chlorinated pollutants can be effectively removed over Pd/CeO 2. • The generation of intermediates can be ignorant during the HDC of TCAA. Chloroacetic acids were frequently detected in the chlorination drinking water. Herein, Pd/CeO 2 catalysts with varied CeO 2 exposed planes were prepared, and the catalysts were applied for the liquid phase hydrodechlorination (HDC) of monochloroacetic acid (MCAA) at ambient temperature and pressure. The CeO 2 nanorod (r-CeO 2) with (1 1 0) plane supported Pd catalysts showed higher Pd dispersion and CO adsorption amount than that of CeO 2 nanocube (c-CeO 2) with (1 0 0) face and octahedron counterparts (o-CeO 2) with (1 1 1) plane. The HDC rate of MCAA reached 99.5% after reaction for 5 min at a catalyst dosage of 0.1 g l−1 under pH 5.6 over the dp-Pd 1 /r-CeO 2 catalyst prepared via the deposition precipitation (dp) method. The MCAA removal efficiencies were only 19.8% and 11.5% over dp-Pd 1 /c-CeO 2 and dp-Pd 1 /o-CeO 2 , respectively. DFT simulation results showed that the adsorption energy between Pd and r-CeO 2 was higher than that of CeO 2 nanocube and octahedron, suggesting that compared with (1 0 0) and (1 1 1) planes, the r-CeO 2 with exposed (1 1 0) plane favored the anchor of Pd nanoparticles. Higher Pd dispersion and appropriate Pdn+/Pd0 ratio (0.86) accounted for the ultra-fast catalytic HDC reaction. Additionally, the pre-adsorption of reactant over the catalyst surface favored the HDC reaction. The HDC of polychlorinated acetic acids over c-CeO 2 and o-CeO 2 supported Pd catalysts were significantly accelerated compared with that of MCAA, while the dechlorination of trichloroacetic acid (TCAA) was remarkably depressed over dp-Pd 1 /r-CeO 2 due to the weak affinity of the catalyst surface for TCAA. [ABSTRACT FROM AUTHOR]

Abstract Traditional powder/film-shaped photocatalysts suffer some serious limitations (such as recycling difficulty or high-cost) in the degradation of flowing wastewater. Herein, we report a novel filter-membrane-shaped photocatalyst by constructing MoS 2 /Bi 2 S 3 heterojunctions on carbon-fiber cloth (CF/MoS 2 /Bi 2 S 3 cloth). CF/MoS 2 /Bi 2 S 3 cloth consists of carbon-fibers (diameter: ∼15 μm) which are decorated with numerous MoS 2 nanosheets (thickness: ∼2 nm) and Bi 2 S 3 nanorods (length: 500–600 nm), and it exhibits a broad-spectrum photoabsorption from ultraviolet to near-infrared region (>1200 nm). Under visible-light irradiation, CF/MoS 2 /Bi 2 S 3 cloth (area: 4 × 4 cm2) exhibits the highest photocurrent (∼1.44 mA cm−2) and can photocatalytically remove 95.1% rhodamine B (RhB), 91.8% methylene blue (MB), 74.5% tetracycline (TC) and 75.5% hexavalent chromium (Cr(VI)) after 100 min, better than those by CF/MoS 2 cloth (37.0% RhB, 39.9% MB, 29.6% TC, 21.6% Cr(VI)) and CF/Bi 2 S 3 cloth (26.9% RhB, 27.4% MB, 20.9% TC, 25.9% Cr(VI)). Importantly, when flexible CF/MoS 2 /Bi 2 S 3 cloth (diameter: 10 cm) is used as the filter-membrane to degrade the flowing wastewater (rate: ∼1 L h−1), the removal efficiency of RhB increases from 19.7% at 1st to 94.6% at 8th filtering/degrading grade. Thus, CF/MoS 2 /Bi 2 S 3 cloth has excellent potential as a novel filter-membrane-shaped photocatalyst to degrade the flowing wastewater. Graphical abstract Image 1 Highlights • The growth of MoS 2 /Bi 2 S 3 on CF cloth have been realized. • CF/MoS 2 /Bi 2 S 3 cloth exhibits broad-spectrum photoabsorption and strong visible-light photocatalytic activity. • CF/MoS 2 /Bi 2 S 3 cloth was used as filter-membrane for degrading flowing wastewater. • The dominant active species are superoxide and the photogenerated holes. • CF/MoS 2 /Bi 2 S 3 cloth can be easily recycled and remains good stability. [ABSTRACT FROM AUTHOR]

Pd-Au/TiO 2 bimetallic catalysts with varied Au contents were prepared by the sequential photocatalytic deposition method and the liquid phase catalytic hydrogenation reduction of bromate over these catalysts was investigated. The catalysts were characterized using X-ray diffraction, transmission electron microscope, UV–vis diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy, H 2 chemisorption and energy dispersive spectroscopy. Characterization results showed that Pd atoms were site-deposited on the surface of varied size Au cores and formed Pd-on-Au core-shell like bimetallic nanoparticles on TiO 2 . The bimetallic catalysts showed higher Pd dispersions and more exposed active sites than that of Pd/TiO 2 , and the amount of exposed active sites first increased then decreased with Au content. For a similar Pd loading, the bimetallic catalyst exhibited volcano-shape activity as a function of Au loading and the highest activity was identified on Pd-Au(1.0)/TiO 2 with Au core size around 8.4 nm. In addition, the catalytic reduction of bromate could be well-fitted by the Langmuir-Hinshelwood model, reflecting an adsorption controlled mechanism. [ABSTRACT FROM AUTHOR]

The limited regeneration of Fe2+ in the Fe-catalyzed advanced oxidation processes (AOPs) constrained its application for the removal of organic pollutants. Herein, MoSe 2 was introduced to promote the degradation of 2,4-dichlorophenoxyacetic acid (2,4-D) in the Fe2+/PMS system. Compared with Fe2+/PMS processes, the 2,4-D degradation efficiency and PMS decomposition rate respectively increased by 73.8% and 84.2% in the MoSe 2 /Fe2+/PMS system. DFT simulation results suggested that Se atoms acted smoothly as the bridge supporting the charge transfer from Mo to adjacent Fe atoms, which led to the reduction of Fe3+. The rapid regeneration of Fe2+ boosted the activation of PMS and the degradation of pollutants. Additionally, the electron paramagnetic resonance (EPR) and quenching experiments results indicated that SO 4 ∙−, ∙OH, and 1O 2 accounted for 2,4-D degradation, and SO 4 ∙− and 1O 2 predominated the reaction. The Mo based co-catalysts showed better co-catalytic effect than the W counterparts, and the moderate adsorption for PMS and lower electron transfer electron transfer resistance accounted for the more excellent co-catalytic performance of MoSe 2 than that of WSe 2. In addition, the degradation efficiency of 2,4-D was up to 95.5% after five cycles of MoSe 2 in the co-catalytic system. The coexistent humic acid (HA) and Cl− showed ignorant negative effect on the degradation, while HCO 3 − would depress the oxidation reaction. The acidic etching wastewater can be applied as the Fe ions source in this co-catalytic process to remove 2,4-D effectively. MoSe 2 accelerated the Fe(III)/Fe(II) redox cycle and resulted in enhanced PMS activation and 2,4-D degradation. [Display omitted] • MoSe 2 showed better co-catalytic effect than the W counterpart. • Fe2+ can be rapidly regenerated by the assistance of MoSe 2. • The electron transfers between edge Mo, Se and Fe atoms were well clarified. • MoSe 2 /Fe2+/PMS system was highly stable during cyclic runs. • Etching wastewater can be used as Fe ions source in the co-catalytic system. [ABSTRACT FROM AUTHOR]

Heterogeneous Fenton-like systems were exploited for the degradation of Reactive Red X–3B (RR X–3B) using iron-carbon composite, sponge iron, chalcopyrite and pyrite as catalysts. The effect of operational variables on the catalytic activity and metal leaching behavior of catalysts was evaluated and the catalytic mechanism was discussed. The experimental results showed that under the optimum conditions, chemical oxygen demand (COD) removals by Fenton-like systems could reach 89.91%, 86.84%, 80.11% and 60.02% with iron-carbon composite, sponge iron, chalcopyrite and pyrite, respectively. Micro-electrolysis of iron-carbon composite and sponge iron resulted in higher COD removal at acid pH range. Electron Paramagnetic Resonance (EPR) analysis and quenching tests showed that •OH was the main reactive oxygen species responsible for the degradation of RR X–3B. A large amount of Fe2+ leached from iron-carbon composite and sponge iron, which served as a homogeneous Fenton catalyst during the degradation of RR X–3B. In contrast, much lower amount of Fe2+ was leached from chalcopyrite and pyrite, and surface catalysis of the minerals played more important role in the generation of •OH. Surface characterization and density functional theory (DFT) calculation results illustrated that ≡Fe(II) was the primary surface catalytic site during the reaction. The reduction of ≡Fe(III) and ≡Cu(II) can be facilitated by sulfides on the mineral surface. The Fenton-like systems catalyzed by iron-based materials exhibited higher H 2 O 2 utilization and COD removal than classical Fenton system. With the lower metal leaching concentration and stable surface property, chalcopyrite and pyrite may be more practical applicable from a long-term catalytic activity point of view. [Display omitted] • Catalytic activity and metal leaching behavior of iron-based materials were compared. • Iron-carbon micro-electrolysis enhanced pollutant removal in Fenton-like systems. • H 2 O 2 conversion mechanism on the surface of pyrite and chalcopyrite was studied. • Chalcopyrite and pyrite with little metal leaching were more efficient as Fenton-like catalysts. [ABSTRACT FROM AUTHOR]

Removal behavior of organic pollutants such as lignin in cotton pulp black liquor (CPBL) was investigated in precipitation followed by electrochemical oxidation (EO) using FeCl 3 , Fe 2 (SO 4) 3 , FeCl 2 and FeSO 4 as precipitants, electrolyte and catalysts. Based on comparison of precipitation efficacy of iron salts, spectroscopic techniques, thermodynamic equilibrium calculations and molecular dynamics (MD) simulations were used to provide insight into the interaction between iron cations and lignin. The results showed that FeCl 3 achieved the highest removal of chemical oxygen demand (COD, 76.05%), UV 254 (69.21%) and lignin (78.28%). Iron cationic complexation with lignin was identified as the key mechanism in precipitation. Fe3+ was more active in binding to organic ligands mainly due to charge effect compared to Fe2+. The strong Fe−sulphate coordination affected the complexation with lignin. MD simulations showed the formation of inner sphere complexes of iron cations with deprotonated carboxyl and hydroxyl groups via bidentate and monodentate coordination. The removal efficiency of electrochemical oxidation (EO) as a post−treatment of the precipitation was dependent on iron salts. Removals of COD, UV 254 and color can achieve 98.88%, 98.9% and 99.97% by FeCl 3 precipitation and EO processes. The effluent reached the primary discharge standard specified in Integrated Wastewater Discharge Standard of China (GB8978−1996). FeCl 3 demonstrated significant advantages in the removal of organic pollutants from cotton pulp black liquor in the combined process of precipitation and electrochemical treatment and may have practical application potential. [Display omitted] • Iron cations formed inner sphere complexes with carboxyl and hydroxyl groups. • Iron−sulphate coordination affected iron cationic complexation with lignin. • Metal cationic complexation facilitated electro-degradation of organic ligands. • Precipitation−electrooxidation with FeCl 3 was most effective for black liquor purification. [ABSTRACT FROM AUTHOR]

[Display omitted] • Nano-flowered yavapaiite anchored on graphite oxide was firstly fabricated by one-pot. • Electrocatalytic conversion of NO 3 − to N 2 was achieved on cathode with yavapaiite. • Reduction of NO 3 − occurred preferentially at yavapaiite (0 0 1) surface sites. • Nano-flowered yavapaiite showed stability and reusability as an electrocatalyst. Nano-flowered yavapaiite anchored on magnetic graphite oxide (YMGO) was firstly fabricated by one-pot with K 2 FeO 4 as both oxidant and iron source to selectively reduce nitrate to N 2. The assembling cathode of carbon black and YMGO on carbon cloth (YMGO/CB-CC) exhibited complete nitrate conversion with excellent reusability in a wide pH range of 3–11 and Na 2 SO 4 of 25 mM (3.55 g L−1). The corresponding N 2 selectivity was found to be 60.9% and 96.3% in the absence or presence of NaCl. Iron in nano-flowered yavapaiite with empty d -orbital electrons and surrounding oxygen ions provided high-active sites and boosted electron transfer. It was found that Fe(III) active sites and chemical bonding between graphite oxide and yavapaiite (Fe-O-C) reduced iron leaching, which critically dominated reusability and electrocatalytic activity. The catalytic activity of yavapaiite for spontaneously adsorbed nitrate on the Fe(III) activity sites through two-fold coordination and NO 3 − reduction to N 2 pathway were revealed by density functional theory calculations. Experimental results of nitrate removal from domestic wastewater demonstrated that yavapaiite catalyst may have potential for practical application in wastewater treatment for nitrate reduction. [ABSTRACT FROM AUTHOR]

Fe atoms were highly isolated by the edge Mo vacancies and the adjacent Mo atoms could provide electrons smoothly for the regeneration of Fe(II). [Display omitted] • Fe-MoS 2 catalyst with Fe atomically anchored at the edge Mo vacancies was prepared. • Fe(II) can be rapidly regenerated through the Mo-S 2 -Fe-S 2 -Mo edge configuration. • The electron transfer between edge Mo, S and Fe atoms were well clarified. • Both the adsorption and activation of PMS were systemically investigated. • Fe-MoS 2 was highly stable for the AOPs of varied persistent organic pollutants. Here, we designed and prepared edge defect-rich Fe-MoS 2 nanohybrid catalysts via a facile post-confined strategy, in which single Fe atoms were isolated by the newly formed edge Mo vacancies. Evaluation of the decontamination efficiency, using the model herbicide 2,4-dichlorophenoxyacetic acid (2,4-D), showed that the rate constant for the Fe-MoS 2 /peroxymonosulfate (PMS)/2,4-D system was (0.2777 min−1), seven times higher than that of a Fe-MoS 2 nanocluster counterpart (0.0323 min−1). The unique Mo-S 2 -Fe-S 2 -Mo edge configuration of Fe-MoS 2 promoted the regeneration of active sites during the activation reaction in which Fe(III) was reduced to Fe(II), Mo(IV) was oxidized to Mo(V), and the adjacent S atoms acted as bridges for electron transfer. Thus, PMS could be constantly activated by low valence Fe atoms resulting in superior catalytic performance. Quenching experiments and Electron Paramagnetic Resonance (EPR) signals indicated that hydroxyl radicals, sulfate radicals (SO 4 •-), superoxide anion radicals and singlet oxygen (1O 2) were all involved in the oxidative degradation of 2,4-D, in which 1O 2 and SO 4 •- predominated. In addition, PMS adsorption and its activation were identified as key steps in the process, and the Fe-MoS 2 /PMS system demonstrated good robustness during continuous operation. This study provides new insights into the Fe-MoS 2 edge coordination mechanism for the PMS activated decontamination of organic pollutants. [ABSTRACT FROM AUTHOR]

The limited production of Cu+ in the Cu2+/PMS processes constrained its large-scan application for the elimination of organic pollutants. In this study, molybdenum powder (Mo) was applied as the co-catalyst to improve the degradation of 2,4-dichlorophenol (2,4-DCP) in Cu2+/PMS system at pH 5.6. By the assistance of Mo, Cu2+ was rapidly reduced to Cu+ which exhibited super activity for the peroxymonosulfate (PMS) activation. Compared with Cu2+/PMS processes, the PMS decomposition rate and 2,4-DCP degradation efficiency respectively increased by 62.1% and 83.6% in the Mo co-catalytic Cu2+/PMS system after reaction for 20 min. The degradation of 2,4-DCP was completed via both the free radical and non-radical pathways and the free radicals rather than Cu3+ contributed most to the reaction. In contrast to fresh Mo, the ratio of Mo4+ increased and Mo6+ decreased in the used Mo powder, due to the oxidation of Mo0 by Cu2+ and/or ∙OH and the reduction of Mo6+ by O 2 ∙−. Additionally, the coexistence of Cl- and humic acid with low concentrations showed little effects on the Mo/Cu2+/PMS system while HCO 3 − presented an obvious depression for 2,4-DCP degradation. During five cycling runs, all the degradation rates were higher than 92.8%, indicating the good stability of Mo/Cu2+/PMS system. [Display omitted] • Cu2+/Cu+ redox cycles were achieved in the presence of metal Mo. • PMS decomposition was enhanced significantly by adding Mo. • Mo showed better co-catalytic effect than other solid co-catalysts. • The free radicals rather than Cu3+ contributed most to the degradation. • Mo/Cu2+/PMS system was highly stable during cyclic runs. [ABSTRACT FROM AUTHOR]

The cotton pulp black liquor (CPBL) is high alkalinity wastewater generated in the production of cotton pulp dreg. In the present work, CPBL was treated by a coupling process of alkaline precipitation and alkali-activated hydrogen peroxide (H 2 O 2) oxidation to remove colorants, so that the water and alkali can be reused in cotton linters cooking for cleaner production of cotton pulp dreg. The influence of main operating parameters of alkaline precipitation and alkali-activated H 2 O 2 oxidation was investigated. The reactive oxygen species (ROS) tests in alkali-activated H 2 O 2 combined with analyses of degradation products were conducted to explore the possible reaction mechanism. Experimental results showed that alkaline precipitation was more effective compared to traditional acid precipitation. The removal efficiencies of COD, UV 254 and color were 30.83%, 40.69% and 65.21%, when 13 g L−1 CaCl 2 was added. Removal efficiencies of UV 254 of 30.22% and color of 80.78% can be achieved for the alkali-activated H 2 O 2 process (H 2 O 2 dosage of 30 mmol L−1, 2 h reaction time, and temperature 60 °C). Consequently, total removals of UV 254 , lignin and color were 61.4%, 67.8% and 92.79% in the integrated process. The quality of the effluent after treatment satisfied requirements of recycling for cotton pulp dreg production. It was found that superoxide radical (O 2 −·) was the dominant ROS and hydroxyl ion (OH−) was mainly responsible for activation of H 2 O 2 in the oxidation process. Image 1 • Alkaline precipitation was more effective than acid precipitation in CPBL treatment. • OH− was main activator of H 2 O 2 for the oxidation of lignin and hemicellulose. • O 2 −· and HO 2 − played a crucial role in the alkali-activated H 2 O 2 oxidation process. • Treated CPBL can be reuse in the cooking process of cotton pulp dreg production. [ABSTRACT FROM AUTHOR]

Electro-catalytic activities of carbonaceous cathodes including graphite plate, graphite felt, carbon felt, activated carbon felt (ACF) and carbon fiber felt (CFF) for degradation of Reactive Red X–3B (RRX-3B) in residual dyeing liquid were compared. The best electrochemical performance was obtained using dimensional stable anode (DSA) and CFF cathode due to the higher capacity for electro-generation of H 2 O 2 by selective two-electron oxygen reduction. The CFF/DSA electrolysis system realized 78.2% COD removal and complete decolorization over a wide pH range. The efficacy of RRX-3B degradation was found to be dependent on the nature of carbonaceous materials. Electrochemical measurements showed that CFF possessed higher electrochemical surface area and hydrogen evolution reaction over-potential. Furthermore, the intrinsic graphitic N in CFF was proved to be catalytic active site by DFT calculations. Reactive Red X–3B degradation intermediates with benzene structures and carboxylic acids via hydroxylation in RRX-3B oxidation were identified by GC-MS. It was found that S/Cl/N-containing groups in RRX-3B molecule were mineralized to SO 4 2−, NO 3 − and Cl− ions in the electrolysis. Image 1 • Performances of carbonaceous cathodes for reactive dye removal were investigated. • CFF cathode was effective for H 2 O 2 generation and reactive dye electro-degradation. • Intrinsic graphitic N in CFF was proved to be active site by DFT calculations. • Contributions of H 2 O 2 and ·OH to dye oxidation were determined. • S/Cl/N-containing groups in reactive dye were mineralized to SO 4 2−, NO 3 −, Cl− ions. [ABSTRACT FROM AUTHOR]

The greatest constraint in the advanced oxidation processes involved Fe(II)/PMS was the low utilization of Fe(II) and PMS. In the present study, the co-catalytic effect of WS 2 on the Fe(II)/PMS system for the degradation of organics was investigated. In the presence of WS 2 , Fe(III) was reduced to Fe(II) during the reaction and resulted in improved decomposition of PMS as well as the degradation of 4-chloriphenol (4-CP). The decomposition rate of PMS and degradation efficiency of 4-CP were 10% and 25% in the Fe(II)/PMS process, while the efficiencies respectively increased to 99% and 100% in the WS 2 assisted Fe(II)/PMS system. The degradation of 4-CP was completed via the free radical pathway and SO 4 •- played a more important role than other active species. Low concentration of inorganic ions such as Cl− and HCO 3 − exhibited irrelevant effect while humic acid showed significant suppression on the WS 2 /Fe(II)/PMS system. Additionally, characterization and recycle results implied that WS 2 maintained a good stability during the co-catalytic processes. Fe(II) was regenerated effectively with the assistance of WS 2 in the advanced oxidation processes involved PMS decomposition. Image 1 • Cyclic conversion of Fe(II)/Fe(III) was achieved by the addition of WS 2. • The decomposition of PMS was remarkably enhanced in the presence of WS 2. • WS 2 maintained a good stability after the co-catalytic processes. • Cl−, HCO 3 − and humic acid showed different suppress effects on the reaction. [ABSTRACT FROM AUTHOR]

The electrocatalytic activity, H 2 O 2 generation capacities and kinetics, and energy consumption of engineered carbonaceous cathodes including graphite plate, graphite felt, carbon felt, activated carbon felt and carbon fiber felt (CFF) was systematically evaluated in a double-chamber electrolysis system. The CFF cathode exhibited an excellent electrocatalytic activity in 2-electron oxygen reduction for H 2 O 2 generation in both acidic and alkaline solutions. Furthermore, Reactive Red X-3B oxidation efficacy of carbonaceous cathodes via electro-generated H 2 O 2 was compared in synthetic dyeing wastewater. The nature of carbonaceous materials dominated the degradation of Reactive Red X-3B in the cathodic chamber. Decolorization rate of more than 99% was achieved in all the cathodes tested, but there was a significant difference in the rate of mineralization. It was found that CFF was outclassed by 24.54% COD removal and high H 2 O 2 generation ability in long runs. The degradation rate constant of Reactive Red X-3B in the CFF cathode chamber was 3.3 times faster than that of the graphite felt with rate constants of 1.27 × 10−3 min−1 and 3.82 × 10−4 min-1, respectively. The desirable stability and electrocatalytic activity of CFF were attributed to the better graphitic structure, higher conductivity and electroactive surface area with N-containing functional groups. Our findings demonstrate the potential of CFF to be used as a high-efficiency cathode in the electrochemical treatment of recalcitrant pollutants in practical applications. Unlabelled Image • Electrocatalytic activity of carbonic cathodes in electrolysis systems was compared. • N-bearing CFF exhibited remarkable H 2 O 2 yield capacity in acidic and alkaline pHs. • CFF showed excellent long-term performance for electro-degradation of reactive dye. • Desirable electro-performance of CFF was mainly due to high electroactive surface. [ABSTRACT FROM AUTHOR]

We used five types of surfactants assisted with sodium salts, including sodium tartrate (ST), sodium chloride (SC), and humic acid sodium (HAS) as auxiliary agents for soil washing to remove diesel from contaminated soil. Decontamination enhancement of diesel polluted soil washing with biosurfactant and H 2 O 2 was examined, which showed higher effectiveness for newly contaminated soil. An increase in temperature and sodium salt addition exhibited a profound enhancement in diesel removal from aged contaminated soils. Compared to ST and SC, HAS exhibited a higher removal efficiency with saponin washing for aged diesel contaminated soil by lowering surface tension, shifting zeta potential, and increasing the number of micelles. Phytotoxicity experiments showed no significant inhibition of germination of lettuce, arugula, and cucumber with 0.2 g L−1 saponin incubation. Conversely, there was a promotion on the root extension of lettuce and cucumber except for arugula. Similarly, the addition of 2% HAS (wight of saponin) improved on root growth of lettuce, arugula, and cucumber, increasing by 25%, 5%, and 22% at the period of 14 d, respectively. Because of excellent removal efficiency and non-toxicity, enhanced wash with saponin and HAS might be considered in the future design of full-scale remediation processes of diesel contaminated soil. Image 1 • Surfactant washing enhancement of diesel contaminated soil with salts was studied. • Sodium salts exhibited a higher efficacy by changing surface tension and micelle. • Phytotoxicity of biosurfactant on lettuce, arugula, and cucumber were studied. • Addition of humic acid sodium in soil washing may improve root growth of plants. [ABSTRACT FROM AUTHOR]

Sulfamethazine can be photocatalytic degraded efficiently over S, Gd codoped graphitic carbon nitride (SCN/Gd) catalyst under visible light irritation. Abstract Bulk graphitic carbon nitride (CN), S doped carbon nitride (SCN) and S/Gd co-doped carbon nitride (SCN/Gd) with varied Gd amounts were prepared via a simple thermal polymerization method, and the visible light photocatalytic degradation of sulfamethazine (SMT) over these catalysts was investigated. The catalysts were characterized by X-ray diffraction, transmission electron microscope, Fourier transform infrared, X-ray photoelectron spectroscopy, UV–vis diffuse reflectance spectra and photoluminescence spectra. Characterization results showed that the nanosheets of CN were exfoliated by Gd doping, and SCN/Gd showed an obvious red shift of the absorption edge and narrower band gap. Additionally, SCN/Gd displayed much lower recombination rates of photogenerated electron-hole pairs than that of CN and SCN. The photocatalytic degradation efficiencies of SMT were 10%, 20% and 72% over CN, SCN and SCN/Gd-0.1, respectively. The O 2 − was found to be the most important active species for SMT degradation and the possible photocatalytic decomposition mechanism was proposed. The SCN/Gd-0.1 catalyst exhibited a high photostability during a recycling test, indicating that SMT can be efficiently photodegraded over S, Gd codoped graphitic carbon nitride (SCN/Gd) catalyst under visible-light irradiation. [ABSTRACT FROM AUTHOR]