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• Preparation of boronate-modified electro-spun Fe dopped carbon nanofibrous membrane. • Selective adsorption and mechanism analysis by kinetics model, isotherm model, and thermodynamics on dye pollutant. • Catalytic degradation, mechanism, degradation pathway analysis on dye pollutant. • Enhanced cycling reuseability for the membrane on dye removal. • High bactericidal rate against E. coli and S. aureus. Recently, dye and microorganism have become the main sources of water pollution due to the rapid development of modern industries and wantonly draining of living sewage. Therefore, the efficient removal of dye and microorganism from the wastewater have attracted considerable attentions of the scientists and engineers around the world. In this regard, a novel phenyl boronic acid (PBA) modified electro-spun Fe doped carbon nanofibrous membrane, C/Fe@PBA, was fabricated in this study for simultaneously selective removal of dye and efficient inhibition of bacteria in water. Firstly, the C/Fe@PBA displayed selective adsorption towards Congo Red (CR) among other dyes by the adsorption order of CR>Methyl Orange (MO) > Neutral Red (NR) > Methylene Blue (MB) > Malachite Green (MG) > Rhodamine B (RhB) with adsorption ability at 25.75, 8.41, 7.11, 7.02, 5.41, and 3.13 mg·g−1. The pseudo first order kinetics and Langmuir isotherm model is calculated to better match the adsorption process of the as prepared membrane towards CR. After 7 rounds of adsorption desorption or 5 degradation cycles, the carbon membrane showed a removal efficiency of 62.2 % or 57.4 %, respectively. Furthermore, the C/Fe@PBA can be employed as effective catalyst to degrade CR in presence of H 2 O 2 under 808 nm near-infrared (NIR) irradiation by the photothermal effect, and the possible catalytic mechanisms and degradation pathway were proposed. Moreover, the as prepared membrane exhibited high bactericidal rate of 99.94 % and 97.44 % against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), respectively. In conclusion, the as prepared carbon membrane with ability of selective adsorption, catalytic degradation, and bacterial inhiation is a promising candidate of filtration membrane in practical sewage management. [ABSTRACT FROM AUTHOR]

[Display omitted] • A green soil remediation method via nZVI@BC 800 /PS system was developed. • The removal rate of BaP in soil over nZVI@BC 800 /PS system was ultrafast. • 1O 2 and electron transfer pathway were the underlying degradation mechanisms. • Possible degradation pathway of BaP was proposed by GC–MS and DFT calculations. • The system could modulate microbial community to improve plant stress resistance. Efficient decomposition of organic pollutants in complex soil environments through non-radical pathways is vital but challenging. Herein, biochar supported nZVI (nZVI@BC 800) fabricated by carbothermal reduction method was prepared for persulfate activation, exhibiting ultrafast degradation efficiency of benzo[a]pyrene of 71.80 % within 5 min with excellent adaptability to wide pH range of 3.0–9.0 and high anti-interference capacity to coexisting substances in soil. In nZVI@BC 800 /persulfate system, non-radical pathways including singlet oxygen ( 1 O 2) and electron transfer made dominant contributions to benzo[a]pyrene degradation. 1 O 2 could be produced not only by the reaction between C = O on BC 800 and persulfate, but also via the transformation of O 2 ∙ - and ∙ O H. On the other hand, biochar as an electron shuttle could accelerate electron transfer from benzo[a]pyrene to persulfate adsorbed on the catalyst. Additionally, possible degradation pathways of benzo[a]pyrene in nZVI@BC 800 /persulfate system were inferred through GC–MS and DFT calculations. Furthermore, the system could modulate the soil microbial community to further improve plant stress resistance. Therefore, this study provided a promising strategy via developing carbon-supported iron catalyst for carrying out persulfate-based non-radical pathways to remediate organic-polluted soil. [ABSTRACT FROM AUTHOR]

• A novel technology for simultaneous soil SMZ degradation and N supply was developed. • The technology involves FB-catalyzed oxidation combined with UHP application. • Pot test confirmed FB-UHP is a promising technology for agricultural soil remediation. This study developed a novel remediation technology based on urea-hydrogen peroxide (UHP) activated by a synthesized Fe-impregnated biochar (FB). The technology can simultaneously degrade sulfamethoxazole (SMZ) and supply nitrogen nutrition in cropland soil. Experimental results showed that 97.56% of SMZ was removed in the FB-UHP system within 24 h, whereas 7.12% and 14.65% were removed in the individual application of FB and UHP. Chemical probe and scavenger test results demonstrated that SMZ degradation mainly occurred through oxidation of hydroxyl radicals generated from the activation of UHP by FB. The effects of FB pyrolysis temperature, initial pH, and reaction temperature were investigated. The combination of UHP and FB led to efficient SMZ degradation at a wide pH range of 2–10. Catalytic durability test results showed that FB exhibited good stability even after four uses. A soil column leaching experiment showed that the addition of FB-UHP reduced the SMZ leaching from the soil by 95.06%, increased the nitrogen content on surface soil by approximately 2.5 times, and decreased the nitrogen leaching by 97.57%. Early-stage seedling growth bioassay confirmed that FB-UHP significantly enhanced the SMZ degradation, increased the soil nitrogen content, and improved the lettuce plant growth. Therefore, application of FB-activated UHP is a promising technology for agricultural soil remediation. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Magnetic Ni-Co alloy encapsulated N-doped carbon nanotubes were prepared. • The materials were used in peroxymonosulfate activation for organic degradation. • Catalytic membrane configuration was employed for the operation. • The membrane catalysis exhibits high performance and stability. Abstract Nitrogen-doped carbon nanotubes encapsulated with Ni-Co alloy nanoparticles (NiCo@NCNTs) were readily synthesized by annealing Ni/Co salts with dicyandiamide. The magnetic nanocarbons were assembled as a flat membrane for heterogeneous degradation of organic toxins. The synergistic effect of nitrogen doping and metal alloy encapsulation significantly enhanced the catalytic activity and stability of NCNTs in catalytic activation of peroxymonosulfate (PMS) for purification of an emerging pollutant, ibuprofen. The hybrid catalyst yielded a fast reaction rate of 0.31 min−1, which was 23.4 and 5.8 times higher than that of pristine CNTs and monometallic (Ni or Co) encased CNTs, respectively. The robust membrane catalysis was further confirmed by degrading other organic aqueous pollutants, such as naproxen, sulfachloropyridazine, phenol, methylene blue, and methyl orange. Mechanistic investigation was performed using electron paramagnetic resonance and competitive radical screening tests, which indicated that radical (OH and SO 4 −) oxidation and nonradical pathway co-existed and played critical roles for catalytic degradation. The study provides a novel advanced oxidation system with catalytic membrane for wastewater remediation. [ABSTRACT FROM AUTHOR]

The development of innovative treatment technology for HCN at low temperatures is vital for the control of HCN pollution. Here, a copper manganese oxide (Cu-Mn-O) catalyst was prepared for the decomposition of HCN at temperatures from 80 to 200 °C. The results showed that the Cu-Mn-O catalyst exhibited excellent catalytic performance for HCN conversion. X-ray photoelectron spectroscopy analysis revealed that Mn 3+ manifested highly catalytic activity and was largely responsible for HCN decomposition. The N-contained products of HCN contained NH 3 , NO/NO 2 , N 2 O, and N 2 , thereby suggesting the concurrent catalytic oxidation and hydrolysis during HCN decomposition on the catalyst. The catalytic oxidation mechanism characterized by in situ diffuse reflectance infrared Fourier transform manifested that four N-contained intermediates (i.e., -CN, -NH 2 , =NH and -NCO) were produced; subsequent the oxidation of these intermediates resulted in the formation of final product and/or oxidative species NO + . The reaction of NO + with the N-contained intermediates also generated the final conversion products. Catalytic intermediate formamide plays a critical role in the hydrolysis of HCN, and its hydrolysis leads to the formation of NH 3 . Multiple cycle experiments demonstrate the long-term stability of the Cu-Mn-O catalyst. These results indicate that catalytic decomposition of HCN based on the Cu-Mn-O catalyst at low temperatures may be an efficient approach for the treatment of tail gases containing HCN. [ABSTRACT FROM AUTHOR]

The occurrence of benzophenone-3 (BP-3) in aquatic environments constitutes a potential risk to the environment and human health due to its phytotoxicity, carcinogenicity and endocrine disrupting effects. In this work, cobalt ferrite (CoFe 2 O 4 ) prepared by chemical co-precipitation method was used as a catalyst for the degradation of BP-3. The catalyst was characterized by SEM, TEM, XRD, XPS, BET and FT-IR spectroscopy, and its catalytic activity on BP-3 removal by persulfate (PS) was then evaluated at different operating parameters (catalyst loading, reaction temperature, solution pH and PS dose). The removal of BP-3 (1.31 μM) in 6 h reached 91% under the condition of [BP-3] 0 : [PS] 0 = 1: 1000, initial pH = 7.0, T = 25 °C and catalyst load = 500 mg L −1 . In addition to the satisfactory catalytic performance, the CoFe 2 O 4 also showed high stability and excellent recyclability. Electron paramagnetic resonance and radical quenching tests showed that sulfate radicals predominated in the decomposition of BP-3 by PS/CoFe 2 O 4 , while hydroxyl radicals also contributed to the catalytic oxidation process. Fifteen degradation products were identified by liquid chromatography-mass spectrometry (LC-MS), and two reaction pathways involving hydroxylation, demethylation, direct oxidation and benzene ring opening were proposed. This study could provide useful information for the potential application of CoFe 2 O 4 activated PS technology to treat water and wastewaters containing BP-3. [ABSTRACT FROM AUTHOR]

HZSM-5 zeolite was used to conquer the challenge of liquid adsorption of tobacco specific N -nitrosamines (TSNA), either in aqueous solution or tobacco extract solution, offering a candidate with an optimal Si/Al ratio and channel structure to capture the carcinogens. It could trap 84% of N ′-nitrosonornicotine (NNN) and 99% of 4-methylnitrosamino-1-3-pyridyl-1-butanone (NNK) in aqueous solution, much better than that by NaZSM-5 zeolite. Both FTIR and TG/MS technologies were employed to study the adsorption and catalytic degradation of NNN and NNK by HZSM-5 zeolite. The N–N bond of NNK was broken in the range of 423–573 K and the pyridine fragments appeared at 630 K due to the breakage of C–C bond between pyridine and carbonyl groups. Besides, HZSM-5 zeolite was sprayed on the rod of cigarette and smoked with different manners for the first time, in order to assess its function of reducing TSNA content in mainstream smoke and compared with that of liquid adsorption. [ABSTRACT FROM AUTHOR]

In this study, the polypyrrole/CNTs-CoFe 2 O 4 magnetic nanohybrid (CNTs-CoFe 2 O 4 @PPy) was prepared and then used as adsorbent and catalyst to remove anionic and cationic dyes. The hybrid material was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), elemental analysis, BET surface area, Fourier transform infrared (FTIR) spectroscopy and vibrating sample magnetometer (VSM). Adsorption behaviors of the as-prepared composites for anionic dyes such as Methyl Blue (MB), Methyl Orange (MO) and Acid Fuchsin (AF) were conducted where the effects of solution pH, initial dye concentration, contact time and ionic strength were systematically studied. The equilibrium adsorption data of MB, MO and AF were well fitted to the Langmuir isotherm model, yielding the maximum monolayer adsorption capacity of 137.00, 116.06 and 132.15 mg/g, respectively. Adsorption kinetics was best described by the pseudo-second order model. The introduction of CoFe 2 O 4 into CNTs-CoFe 2 O 4 @PPy hybrid could not only provide an effective magnetic separation performance, but also act as catalyst to activate peroxymonosulfate (PMS) for the degradation of cationic dye, Methylene Blue (MEB), from aqueous solution. The results showed that CNTs-CoFe 2 O 4 @PPy presented higher catalytic activity, better stability and reusability for the decolorization of MEB, resulting in an almost complete removal of 50 mg/L MEB after 30 min with 1.0 g/L catalyst and 4 mmol/L PMS. The characteristics of high adsorption capacity, effective separation, excellent catalytic activity and good reusability would make CNTs-CoFe 2 O 4 @PPy a promising candidate for wastewater treatment. [ABSTRACT FROM AUTHOR]

In this study, mackinawite (FeS) was prepared and used as the heterogeneous catalyst to activate persulfate (PS) for 2,4-dichlorophenoxyacetic acid (2,4-D) degradation, and impact factors including initial pH, PS concentration, FeS dosage, reaction temperature and inorganic anions (Cl − , NO 3 − , and HCO 3 − ), were investigated. The results showed that 2,4-D could be efficiently degraded and mineralized by FeS/PS system. Acidic pH would accelerate 2,4-D degradation, whereas neutral and alkaline conditions showed negative effects. The degradation efficiency of 2,4-D was improved with increasing FeS dosage, PS concentration and reaction temperature. Furthermore, inorganic anions exerted different effects on 2,4-D degradation. The quenching experiments indicated that though both sulfate radicals (SO 4 − ) and hydroxyl radicals (HO ) were responsible for 2,4-D degradation, HO played a more important role. Based on the quenching tests and electron paramagnetic resonance (EPR) analysis, the possible mechanism of 2,4-D oxidation in FeS/PS system was proposed. Additionally, the reusability tests revealed that, although FeS had a short time of deactivation after first use, it still maintained satisfactory catalytic activity in five consecutive 2,4-D degradation experiments. The transformation intermediates were identified by a gas chromatography mass spectrometry (GC–MS), and the possible reaction pathways were proposed based on the measured results. The method of activating PS with FeS may offer great benefits for the application of iron-containing mineral in remediation of herbicide-contaminated water. [ABSTRACT FROM AUTHOR]

[Display omitted] • Formation, identification, detection and reaction kinetics of RS were discussed. • Water quality parameters show crucial influence on RS quenching. • Present studies on RS identification in AOPs may confuse the truth. • Challenges and perspectives of RS quenching experiment were proposed. Advanced oxidation processes (AOPs) are promising, efficient and eco-friendly technologies for treatment of various organic wastewater. However, it has found that the identification of reactive species (RS) (e.g., •OH, SO 4 -•, 1O 2 , O 2 –•, h+, Cl•) during investigating catalytic and degradation mechanism is confused, maybe misunderstand the truth of RS contribution for degradation. Therefore, do we really understand the RS production, transformation process and the corresponding influencing factors? This is the key to correctly perform quenching experiment of RS and reveal precise catalytic degradation mechanism. This review comprehensively presents on the state-of-the-art research progress of the formation of RS in various AOPs, quenching experiment, reaction kinetics of RS and typical influencing factors on RS formation. Further, the main problems in the whole process of RS formation, transformation, identification, and related methods are discussed in detail. Finally, based on overall understanding, challenges for deeply revealing catalytic degradation mechanism via correctly obtaining the quenching results of RS are proposed. This review may help researchers to deeply understand the quenching process of RS in AOPs and make clear the real catalytic degradation mechanism of different organic pollutants. [ABSTRACT FROM AUTHOR]

[Display omitted] • Preparation of new active photocatalyst by modifying algal CHs with ZIF-8. • ZIF-8 protects CHs while also adsorb TCH to achieve accelerated degradation. • ZIF-8@CHs has strong ability of photosynthetic active oxygen species release. • ZIF-8@CHs can effectively photocatalytic degrade TCH and recycle. A novel ZIF-8@CHs photocatalyst, which was generated using the metal organic framework ZIF-8 and intact chloroplasts (CHs) from Chlorella sp. in a one-pot synthesis, was used in this study for the first time to degrade tetracycline hydrochloride (TCH) through photocatalysis. The results of systematic characterization demonstrated that ZIF-8@CHs was successfully p0repared. Meanwhile, ZIF-8@CHs exhibited excellent photocatalytic performance and good adaptability. Under the condition of simulated sunlight, the high porosity ZIF-8 shell enabled CHs to maintain typical photosynthetic oxygen evolution behavior in vitro, and using CHs as the core produced significant ROS, significantly improving the efficiency of TCH photocatalytic degradation. In addition, the radical trapping test and EPR spectra proved that O 2 –, 1O 2 , and •OH were the key active species for TCH degradation. Eventually, the ZIF-8@CHs system can not only expand the new concept of organic pollutant degradation in water bodies, but also offer recommendations for live organ envelope modification.. [ABSTRACT FROM AUTHOR]

[Display omitted] • Summary of the classification and preparation strategies of MOFs-derived CMs. • Summary of mechanisms of PDS/PMS activation by MOFs-derived CMs. • Combination and transformation of the radical and non-radical pathways. • Future challenges and research directions related to MOFs-derived CMs. With the increasing challenges of environmental pollution, the sulfate radical-based advanced oxidation processes (SR-AOPs) have received increasing attention owing to their high efficiency and environment-friendliness. The future development of SR-AOPs depends on the development of new catalysts with high activity and stability. Various Metal – organic frameworks (MOFs) derived carbon-based materials (CMs) with unique physical and chemical properties have been prepared by pyrolyzing MOFs, which have been provn to show excellent performance in SR-AOPs and become a rapidly expanding research field. Herein, to clarify the application advances of MOFs-derived CMs in SR-AOPs, we have summarized the classification, synthesis strategies, and corresponding characteristics of MOFs-derived CMs. In addition, the mechanisms related to the activation of PDS/PMS for organic degradation by MOFs-derived CMs are outlined. Moreover, the bottlenecks, application prospects of MOFs-derived CMs are briefly summarized. This review aims to elucidate the recent trends and critical mechanisms of MOFs-derived CMs applied in SR-AOPs, offering new insights for the further design of MOFs-derived CMs and organic pollution remediation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Construction strategies for acidic sites of catalyst are classified and summarized. • The functions of different types of acidic sites in the catalyst are summarized. • The effects of acidic sites in the catalytic degradation of VOCs are outlined. • The future research directions of the acidic site in the VOCs degradation are prospected. Volatile organic compounds (VOCs) emissions seriously endanger human health and the environment, making it the focus of global air pollution control. Catalytic degradation technology possesses the advantage of low energy consumption, a high purification rate, and no secondary pollution. However, catalysts that fully meet industrial requirements have not been developed. Acidity, as a property of catalysts, has played a decisive role in the catalytic oxidation of VOCs, together with the redox property of catalysts. However, a comprehensive and systematic review of the effect of acidity on the catalytic degradation of VOCs is still lacking. In this paper, the construction strategy of acid sites and their roles in the catalytic oxidation of different VOCs are described in detail. In addition, the effect of acidic sites on VOCs adsorption, bond breaking, harmful substances desorption, and promotion of oxidation was summarized. This review provided a reference value for future catalyst design, mechanism analysis, and practical operation. [ABSTRACT FROM AUTHOR]

This work provides an immediate fabrication approach for a manganese dioxide/graphite (MnO 2 /C) composite, as a photocatalyst for the degradation of glyphosate, via high energy electron beam irradiation. Such irradiation can effectively and facilely reduce MnO 4 − to MnO 2 nanospheres through the reduction effects of e − , e aq − , and H, as well as make graphite possess rough surface through thermal and sputtering effects of electron beam. In addition, the fabrication process introduces numerous hydroxyl groups on the surface of MnO 2 nanospheres, which can promote the adhesion of MnO 2 nanospheres onto the rough surface of graphite via hydrogen bonds. The resulting MnO 2 /C composite exhibits a large specific surface area, high dispersion, and thus an excellent adsorption and catalytic degradation performance on glyphosate. Importantly, the MnO 2 /C composite is rather sensitive to sunlight, and can effectively degrade glyphosate under sunlight. [ABSTRACT FROM AUTHOR]

[Display omitted] • Insights into catalytic degradation of plastic wastes in terms of 3D pore structure evolution. • Visualize the microstructure evolution and 3D distribution within FCC by X-ray nano-CT. • FCC promoted the degradation of C 16 -C 30 to C 9 -centered monocyclic aromatics. • The porosity decreased remarkably at the depth of ∼16.5 μm from the outmost of particle. • The heavier molecules preferably accumulated on large-size pore of the external surface. Insightfully understanding the process of volatiles from plastic depolymerization entering from the exterior into internal structure of catalyst favors to rationalize the catalyst design in scale-up principles. Herein, catalytic degradation of plastic wastes with fluid catalytic cracking catalyst (FCC) was investigated in-depth. The yield and composition of liquid and gas products over various FCCs were studied quantitatively. The structural evolution of catalyst on overall scope, including the topology of heterogeneous pore systems and spatial distribution of zeolite was probed by X-ray nano-CT. The results showed that FCC enhanced the transformation of C 16 -C 30 chains to C 9 -centered monocyclic aromatics. The nano-CT analysis of FCCs illustrated remarkable loss of exterior porosity after reaction, particularly at the depth of ∼16.5 μ m from the outmost layer. While the interior pores were marginally affected, indicating large hydrocarbons incapable of engaging with active sites to full advantage, which preferably occupied large-size pores (>385 nm) of external surface. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel magnetic mesoporous carbon (Fe 3 O 4 /MC) was prepared to activate PS. • The synergistic effect between Fe 3 O 4 and MC facilitated the PS activation. • SO 4 •−, •O 2 – and 1O 2 in Fe 3 O 4 /MC + PS system mainly contributed to TC degradation. • The main degradation pathways of TC were demethylation and deamidation. • The toxicity of TC in Fe 3 O 4 /MC + PS system was greatly reduced. In this study, a novel magnetic mesoporous carbon composite (Fe 3 O 4 /MC) was prepared by manganese carbonate (MnCO 3) as the template to activate persulfate (PS) for tetracycline hydrochloride (TC) degradation. The characterization results showed that Fe 3 O 4 nanoparticles were evenly distributed on the surface of MC, and Fe 3 O 4 /MC had the large surface area of 433.88 m2∙g−1. When the initial TC concentration was 50 mg·L−1, Fe 3 O 4 /MC dosage was 0.0336 g, PS dosage was 0.0476 g and the reaction temperature was 30 °C, Fe 3 O 4 /MC + PS system could degrade 92.9% of TC within 90 min. TC degradation efficiency increased with the increase of Fe 3 O 4 /MC dosage and temperature, but decreased with the increase of TC initial concentration and pH value. The increase of PS concentration first improved TC degradation efficiency, and then was not conducive to its degradation. The quenching experiments indicated that the sulfate radical (SO 4 •−), superoxide radical (•O 2 –) and singlet oxygen (1O 2) in Fe 3 O 4 /MC + PS system contributed to TC degradation. Meanwhile, the toxicity evaluation of the degradation products confirmed that the toxicity of TC in Fe 3 O 4 /MC + PS system was greatly reduced. Totally, this study systematically investigated the performance of the Fe 3 O 4 /MC + PS system for TC removal, laying a theoretical and practical foundation for treatment of potential antibiotic wastewater (ppm range) in the future. [ABSTRACT FROM AUTHOR]

[Display omitted] • AgBr/ZnAl-MMO heterojunction was prepared by hydrothermal precipitation method. • ABMO0.2 composite with S-scheme heterojunction was constructed. • AgBr/ZnAl-MMO with special shape reduces the recombination of electrons and holes. • The catalytic mechanism and the degradation pathways of TC were proposed. A novel hexagonal AgBr/Zn-Al MMO S-scheme photocatalyst was prepared by adopting a simplified hydrothermal and co-precipitation method. The prepared photocatalytic system exhibited excellent photocatalytic performance in degradation of tetracycline hydrochloride (TC). In particular, the ABMO0.2/Vis system generated the best TC removal rate (95%) within 60 min of visible light irradiation. Moreover, no significant decrease of the photocatalytic performance had been observed after four cycles, while the leaching of silver ions was effectively controlled. The excellent photocatalytic performance can be attributed to the synergistic effect occurring between the unique morphological structure and the S-scheme heterojunction charge transfer mechanism, since that that synergistic effect enhanced light absorption capacity and separation efficiency of the photogenerated carriers and the redox ability. In addition, liquid chromatography-mass spectrometry (LC-MS) analysis clarified the mineralization behavior and detailed decomposition pathways of TC. This work opens a new pathway for the design of efficient S-scheme heterojunctions and provides new insights into the photocatalytic degradation mechanism of antibiotics. [ABSTRACT FROM AUTHOR]

[Display omitted] • 3D-blocky catalyst (CoMnO x @sponge) was fabricated via separating Co-Mn bimetallic oxide on sponge. • CoMnO x @sponge exhibited excellent catalytic performance and superior reusability for PMS activation. • CoMnO x @sponge possessed elasticity and could be assembled with a column to remove pollutants continuously. • SO 4 •−, •OH and 1O 2 were the reactive oxygen species responsible for the SIZ degradation. • The possible pathways and declined bio-toxicity of the SIZ degradation were proposed. An elastic and 3D-blocky catalyst (CoMnO x @sponge) was successfully prepared via uniform growth and distribution of Co-Mn bimetallic oxide inside the sponge for the activation of peroxymonosulfate (PMS). The results showed that 30 mg/L sulfisoxazole (SIZ) could be completely degraded by PMS (1 mM) activated with CoMnO x @sponge (0.1 g/L) within 5 min. The pseudo-first-order rate constant was calculated to be 1.83 min−1, which was much larger than those from previous reports. The excellent stability and reusability of CoMnO x @sponge were confirmed through 20 recycle runs with more than 90% degradation of SIZ and less than 0.9 mg/L leached metal ions. Singlet oxygen (1O 2), hydroxyl radicals (•OH) and sulfate radicals (SO 4 •−) were determined to be the dominating reactive oxygen species (ROS) responsible for the degradation of SIZ. The possible pathways of SIZ degradation as well as underlying catalytic mechanism were deduced. The bio-toxicity declined obviously after the mineralization of SIZ and the removal of TOC at 5 mg/L SIZ was high up to 90.4%. Furthermore, the system of CoMnO x @sponge/PMS also exhibited the strong anti-interference ability in natural water and the universal degradation capacity towards other common organic pollutants. More remarkably, the 3D-catalyst possessing an elasticity and extremely high porosity could be easily assembled with a column to realize the consecutive degradation of pollutants. The labor- and time-saving removal of pollutants based on a combination of CoMnO x @sponge with PMS makes it great potential in practical application. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ag@AgCl/ZnAl-LDH was employed to activate peroxymonosulfate (PMS) under simulated sunlight. • A synergistic effect between photochemical and catalytic processes was achieved. • Several reaction pathways and the mechanism of NTP degradation were proposed. • The AACMO3.4/PMS/Vis system exhibits good reusability and high stability. In this study, the degradation of nitenpyram (NTP) using Ag@AgCl/ZnAl-LDH (AACMO) material photocatalytically activated peroxymonosulfate (PMS) system was analyzed. As photocatalysts, Ag@AgCl and calcined zinc-aluminum layered double hydroxide (MMO) had high efficiency to achieve the separation of charge. In addition, the electron injection from AACMO to PMS facilitated the production of active species. Through the AACMO/PMS/Vis system, 40 mg/L of nitenpyram (NTP, 50 mL) could be removed in 45 min with the use of 0.8 g/L of photocatalyst and 0.2 g/L of PMS on the basis of optimal reaction conditions and visible light (780 nm > λ > 420 nm). According to electron paramagnetic resonance technology and free radical quenching tests, the removal of contaminants was promoted by 1O 2 , h+, SO 4 -•, •O 2 –, and •OH. Moreover, the photodegradation of NTP occurring within the AACMO/PMS/Vis system was almost equally effective for the water from four different water bodies. In general, the AACMO/PMS/Vis system had high efficiency and could be employed for the water pollution control in agricultural production. [ABSTRACT FROM AUTHOR]

In this work, core-satellites nanostructural composites have been synthesized through self-assembly combined with in situ growth strategy for catalytic degradation of common organic contaminants. At first, a three-component microsphere catalyst support containing alkyl-functionalized Fe3O4 magnetite core and a layered chitosan (CTS) shell has been constructed for loading of gold nanoparticles (Au NPs). Wherein, the Fe3O4 microsphere core is in favor for recycling and the formation of a hexadecyltrimethoxysilance@CTS (C16@CTS) layer effectively increases its surface area and provides more docking sites for small Au satellite NPs to construct core-satellites nanostructure. Through electrostatic interaction and coordination, small Au NPs automatically assembled on the surface of support which served as seeds for further in situ growth of bigger stable Au NPs. The obtained catalyst was stable and had enhanced performance for fast catalytic reduction and fading of common organic contaminants, including 4-nitrophenol (4-NP), methylene blue (MB), Congo red (CR), rhodamine B (RhB), rhodamine 6G (R6G), acid orange (AO) and methyl orange (MO). No significant inactivation of the catalyst was observed even after recycling for eleven cycles or stored for more than 1 month. In addition, the catalyst was used for effective degradation of organic pollutant in Yellow River water sample, which indicated its potential for practical applications in water pollutant removal and environmental remediation. [ABSTRACT FROM AUTHOR]

Highlights: [•] In situ growth of Au NPs with magnetic graphene oxide as support was developed. [•] The nanocomposite shows enhanced catalytic efficiency for reduction of 4-NP. [•] The novel catalyst can be used for 10cycles and stored for at least one month. [•] GO Fe3O4 is an excellent support and in situ growth makes the catalyst more stable. [Copyright &y& Elsevier]

Abstract: Fenton process is an effective treatment for organic wastewater. In this study, we introduced a microwave enhanced Fenton process to remove dye from aqueous solution. The conversion rate of methylene blue (MB) was increased and accelerated due to the assistance of microwave irradiation, with value of 93.0% after heated for only 1min, even higher than that of treated by traditional Fenton process for 65min. The MB conversion increases with initial concentrations of H2O2 and Fe2+ because of the increased generation of hydroxyl radicals. The MB conversion changes slightly with pH at values of below 7 and declines dramatically when the pH is higher than 8, with optimum pH value of about 3. During the microwave treatment, the maximum UV–Vis absorption peak decreased much quicker than that of other two peaks, and blue shifted from wavelength of 664–629nm, indicating the decomposition of dimethylamino and methyl groups in MB molecules. The microwave enhanced Fenton process is a promising treatment for organic contaminants due to advantages of fast and effective processing. [Copyright &y& Elsevier]

Abstract: Dichloromethane (DCM) is a recalcitrant groundwater contaminant that shows nearly no reactivity with zero-valent iron (ZVI) nanoparticles. In this study, an effective dechlorination of DCM has been demonstrated using zero-valent copper (Cu0) nanoparticles as a catalyst under sodium borohydride reduction conditions. The average diameter of Cu0 nanoparticles was about 50nm and the specific surface area was about 19m2 g−1. Batch experiments revealed that 90% of DCM (26.4mgL−1) was rapidly degraded within 1h in the presence of Cu0 nanoparticles (2.5gL−1) and sodium borohydride (1gL−1). The observed pseudo-first-order rate constant (k obs) was 2.19h−1, corresponding to a surface area normalized rate constant of 0.052Lm−2 h−1, which is 2–3 orders of magnitude higher than for other zero-valent metals. The DCM degradation rate is a function of the Cu0 nanoparticle dose. Increasing the dose increased the observed reaction rate. Product analysis indicated that the degradation of DCM involved hydrodechlorination. Soluble copper ions generated by the dissolution of Cu0 nanoparticles are lower than the World Health Organization drinking water standard, which suggests that the use of Cu0 nanoparticles under reduction conditions may be potentially useful for the treatment of recalcitrant contaminants that are unable to be degraded by ZVI technology. [Copyright &y& Elsevier]

Abstract: The performance of pure and aluminum containing SBA-type catalysts prepared using different aluminum sources and different Al/Si ratios were investigated in the polypropylene degradation reaction using a thermogravimetric analyzer. For the synthesis of catalysts, aluminum isopropoxide and aluminum sulphate were used as the aluminum sources. Synthesized materials had high surface areas and exhibited nitrogen adsorption isotherms of type IV. EDS results showed that the aluminum incorporation into the structure was very effective. 27Al MAS NMR spectra of the catalysts exhibited tetrahedrally and octahedrally coordinated aluminum species in the structure. TEM images of synthesized catalysts showed well-ordered hexagonal arrays of uniform mesopores with cylindrical channels. With the aluminum loading, DRIFTS analysis of the pyridine adsorbed materials revealed the existence of Brönsted acid sites in the synthesized catalysts in addition to Lewis acid sites. Thermogravimetric analysis results showed a marked reduction in the degradation temperature in the presence of aluminum containing SBA-type catalysts. The activation energy value of the degradation reaction decreased to about 51–70kJ/mole in the presence of catalysts synthesized using aluminum sulphate as the aluminum source and when aluminum isopropoxide was used as the aluminum source activation energy value of the reaction decreased to 82–89kJ/mol. [Copyright &y& Elsevier]

Abstract: Environmental nanotechnology is considered to play a key role in shaping current environmental engineering and science. Looking at the nanoscale has stimulated the development and use of novel and cost-effective technologies for catalytic degradation, adsorptive removal and detection of contaminants as well as other environmental concerns. Polymer-based nanocomposites (PNCs), which incorporate advantages of both nanoparticles and polymers, have received increasing attention in both academia and industry. They present outstanding mechanical properties and compatibility owing to their polymer matrix, the unique physical and chemical properties caused by the unusually large surface area to volume ratios and high interfacial reactivity of the nanofillers. In addition, the composites provide an effective approach to overcome the bottleneck problems of nanoparticles in practice such as separation and reuse. This article gives an overview of PNCs for environment application. A brief summary of the fabrication methods of PNCs is provided, and recent advances on the application of PNC materials for treatment of contaminants, pollutant sensing and detection and green chemistry are highlighted. In addition, the research trends and prospective in the coming future are briefly discussed. [Copyright &y& Elsevier]

Abstract: A nano-MoS2/kaolin composite was synthesized by calcining a MoS3/kaolin precursor in H2, which was obtained via a quick deposition of MoS3 on kaolin under a strong acidic condition. The obtained nano-MoS2/kaolin composite was characterized using X-ray diffraction spectroscopy, Brunauer–Emmett–Teller (BET) surface area, scanning electron microscopy, high-resolution transmission electron microscopy, thermal analysis, ultraviolet–visible spectroscopy, and Fourier transform infrared spectroscopy. The results show that the composite had a 16m2/g BET surface area. MoS2 in the composite was composed of layered structures with thickness of ∼5nm and length of ∼10nm. The composite contained an intensive absorption at 380–500nm, which is in the visible light region, and presented a positive catalytic effect on removing methyl orange from the aqueous solution. The catalytic activity of the composite was influenced by the initial concentration of methyl orange, the amount of the catalyst, the pH value, and the degradation temperature. In addition, the composite catalyst could be regenerated and repeatedly used via filtration. The deactivating catalyst could be reactivated after catalytic reaction by heating at 450°C for 30min in H2. The kaolin can decrease the sizes of nano-MoS2 and improve the photo absorption of the composite. Thus, the composite shows excellent catalytic properties. Moreover, the kaolin mineral is very cheap and the using of the composite is very low-cost and practical. [ABSTRACT FROM AUTHOR]

Abstract: This study demonstrated that coal ash, as widely distributed solid waste disposal, would function as a media for organic pollutants removal in the presence or absence of H2O2/O3 under ultrasonic radiation. Coal ash could act as a catalyst to generate ls with the presence of H2O2/O3 and consequently enhance the phenol degradation. Experimental results showed that when using coal ash as a catalyst under ultrasonic irradiation, 83.4% and 88.8% of phenol was degraded in the presence of H2O2 or O3, respectively. The degradation rate of phenol would increase with increasing amount of O3, while there was an optimal concentration of H2O2 (1.5mM) for phenol degradation. Higher dosage of coal ash could result in higher phenol degradation rates. H2O2/coal ash/ultrasonic system could achieve better performance for phenol degradation under more acidic conditions, while more alkaline condition in O3/coal ash/ultrasonic system favored phenol degradation. This study provides a new approach for wastewater treatment especially when contaminated with phenolic pollutants. [Copyright &y& Elsevier]

[Display omitted] • Electrospun CuS nanoparticles/chitosan nanofiber composites (ENFCs) were developed. • The removal mechanism of tetracycline includes adsorption and catalytic degradation. • Visible and near-infrared light-driven photo-Fenton degradation of tetracycline. • The degradation intermediates and possible transformation pathways were evaluated. In the present study, copper sulfide nanoparticles (CuS NPs)/chitosan nanofiber composites with photo-Fenton catalytic and photothermal activities were developed to enhance the removal of recalcitrant biomedical pollutants such as tetracycline (TC). CuS NPs were encapsulated in CS nanofibers by an electrospinning technique (CS ENFs) to obtain CuS@CS ENF composite (CuS@CS ENFC) membranes with high porosity and large surface areas. An investigation of the mechanism of TC removal revealed the complementary performances between adsorption of TC by CS ENFs and the Fenton-like reaction of TC with CuS NPs during the degradation of TC. The ENFCs were cross-linked with genipin (GP) to improve the stability of CuS NPs in long-term storage and the availability of the ENFCs over a wide pH range. CuS@CS ENFCs generated electron-hole pairs and local hyperthermia under near infrared (NIR) laser irradiation, which caused the H 2 O 2 -involved catalytic reaction on ENFCs to take place at a faster rate than in the dark. Compared to pristine CuS NPs, ENFCs were more easily separated from the reaction mixture, and the adsorption sites on ENFCs could be regenerated by the photo-Fenton catalytic degradation of TC. The ENFCs also exhibited antibacterial activity. ENFCs are eco-friendly and easily recyclable, so they have the potential for chemical engineering, biomedical, and environmental applications. [ABSTRACT FROM AUTHOR]

• The classification of MOF-derived carbon-based nanomaterials were introduced. • The morphology control of the nanomaterials were summarized. • Their application in adsorption and catalytic degradation of pollutants was reviewed. • The future development direction and challenge of these nanomaterials were put forward. Due to the rich structures and ingredients, diverse heteroatom doping, regular network hole structure, adjustable unique morphology and pore structure, large specific surface area, Metal-organic frameworks (MOFs) have attracted widespread attention. However, most MOFs have poor stability and are prone to self-decompose in the water phase, which limits their use to remove environmental pollutants. Some recent studies have shown that the porous carbon materials derived from MOFs not only maintain the original structure and morphology, but also get excellent stability in water. Considering these advantages, the carbon materials derived from MOFs represent great potential and high performance as adsorbents and catalysts. So far, MOF-derived carbon-based nanomaterials have been used in the field of environmental adsorption and degradation. In this review, we summarize the classification and morphology control of MOF-derived carbon-based nanomaterials, and then focusing on their application of adsorption, electrocatalytic, photocatalytic and advanced oxidative degradation in the environment field for the first time. Finally, we give our own views on the future development of carbon materials derived from MOFs in the environmental field. [ABSTRACT FROM AUTHOR]

[Display omitted] • A one-pot method realized BC acidification and PDI self-assembly simultaneously. • PS was effectively activated by PDI/BC for IOH removal under visible light. • Electrostatic and π-π stacking interaction were the immobilization method. • The PDI band gap can be adjusted by controlling the amount of BC. • Holes and hydroxyl radicals were the dominant active species for IOH elimination. Persulfate (PS) is extensively employed as an oxidant to develop the sulfate radical-based advanced oxidation processes for removing organic pollutants and various PS activation methods have been explored. Iohexol (IOH), as a typical iodinated X-ray contrast media, poses a threat to human health and ecological environment, which is difficult to be removed by conventional treatment methods. In our work, a photocatalytic coupling persulfate system was constructed for efficient IOH degradation. A novel binary photocatalyst of biochar loaded with perylene diimide (PDI/BC, PB) was successfully prepared via a one-pot water bath heating method, which achieved BC acidification and PDI self-assembly simultaneously. Different mass ratios of BC and PDI lead to variance in average particle size, electronegativity, bandgap width and electron/hole separation efficiency. The optimized efficiency of 10 mg/L IOH on PB-9 (PDI:BC = 1:9, w/w) reached 100% in 2 h with 1.5 mM sodium persulfate under visible light irradiation. Based on the results of trapping experiments and electron paramagnetic resonance, holes and hydroxyl radicals were the dominant active species and the free radical chain reaction and mutual conversion reaction of active species occurred. The amide hydrolysis, amine and C-OH oxidation, hydrogen extraction, deiodination and OH addition were observed during the degradation process. Density functional theory calculation was conducted to confirm the free radical attack sites. The findings of this work demonstrate that metal-free supramolecular loaded photocatalyst has the potential for application in the removal of organic pollutants for water remediation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Bifunctional nitrogen and sulfur co-doped mesoporous graphite-like carbon nanosheets (NS-MGCNS) were fabricated. • Tetracycline was removed by the synergistic effect of adsorption and catalytic degradation processes. • NS-MGCNS exhibited an outstanding removal capacity for tetracycline and an excellent reusability. • DFT calculations verified N and S doping created active sites. • Mechanisms of adsorption and persulfate activation over NS-MGCNS were revealed. In this study, nitrogen and sulfur co-doped mesoporous graphite-like carbon nanosheets (NS-MGCNS) were synthesized via a facile pyrolysis method. The as-prepared sample at a calcined temperature of 800 °C (NS-MGCNS-800) exhibited remarkably outstanding removal capacity for tetracycline (TC). About 94.5% of TC (20 mg/L) was removed within 60 min via the synergistic effect of adsorption and catalytic degradation processes. Pseudo-second-order adsorption plot and Langmuir models fitted well with the adsorption process. The maximum adsorption capacity of NS-MGCNS-800 was 91.57 mg/g through π-π interactions. Besides, NS-MGCNS-800 could activate persulfate (PS) for TC degradation with the pseudo-first-order degradation reaction rate constant of 0.144 min−1, which was 51.4, 24.0, and 1.3-fold as high as that over graphitic carbon nitride (CN), pure carbon (C), and nitrogen doped carbon nanosheets (N-CNS), respectively. Meanwhile, NS-MGCNS-800 possessed superior reusability for removing TC with the removal efficiency of over 87% after 5 cycles. Quenching tests, electron spin resonance spectroscopy (ESR), and electrochemical measurement revealed that radical and non-radical pathways were involved in the NS-MGCNS-800/PS/TC system. More importantly, by means of experimental methods and density functional theory (DFT) calculations, the introduction of sulfur could significantly adjust the electron density of the carbon lattice though the synergistic effect of nitrogen doped carbon nanosheests, promoting the TC adsorption and PS activation of NS-MGCNS-800. Finally, TC intermediates were detected and six possible degradation pathways of TC were proposed. Consequently, this study not only developed a high-performance bifunctional graphite-like carbon nanomaterial, but also provided a new direction for removing the trace antibiotics in environmental remediation. [ABSTRACT FROM AUTHOR]

• 2-D MXene functionalized with CoFe 2 O 4 was synthesized by liquid self-assembly method. • The prepared CoFe 2 O 4 @Mxene was employed for the activation of PS to degrade NPX. • Radical and nonradical reaction pathways were involved in the catalytic degradation of NPX. • CoFe 2 O 4 @Mxene/PS is a promising system for the effective removal of organic pollutants. Naproxen (NPX) is a nonsteroidal anti-inflammatory drug that, at concentrations of 20 ng/L to several µg/L in aqueous environments, can cause detrimental effects to human and ecosystem health. A heterogeneous nanocatalyst composed of two-dimensional MXene nanosheets functionalized with CoFe 2 O 4 nanoparticles was fabricated by liquid self-assembly for the activation of persulfate (PS) to degrade NPX. Approximately 99.1% of NPX was degraded within 90 min with the addition of 0.5 mM PS at 1 g/L of CoFe 2 O 4 @MXene dosage. To better understand the removal process, different influencing parameters, including the solution pH, catalyst dosage, and PS concentration, during NPX removal were studied. Radical scavenging and electron spin resonance experiments revealed that both radical (i.e. , O 2 −, OH, SO 4 −, and S 2 O 8 −) and nonradical (i.e. , 1O 2) pathways were involved in the catalytic degradation of NPX. The results suggest that CoFe 2 O 4 @MXene/PS is a promising catalytic system for the treatment of water polluted with NPX. [ABSTRACT FROM AUTHOR]

• BC/GM was prepared by an in-situ synchronous carbonation and self-activation process. • Nearly 100% of TC was degraded by 0.15 g BC/GM and 1 mL H 2 O 2 (pH 5.0, 60 °C, 5 h). • BC/GM possessed excellent stability and reusability during 5 repeated cycling. • The oxygen-containing groups of BC/GM played a key role on catalytic removal of TC. A new biochar/geopolymer composite membrane (BC/GM) was prepared by an in-situ synchronous carbonation and self-activation process from two sustainable materials. The monolithic geopolymer membrane (GM) served not only as a porous support, achieving good dispersion and retrieve of biochar (BC), but also as a solid base for in-situ activating BC during carbonization of lignin precursor. The obtained BC/GM contained a hierarchically porous structure (exhibiting a bi-modal pore size distribution at 3.54 and 16.53 nm, respectively), having a large specific surface area (37.46 m2/g, 28 times of BC), containing rich functional groups (C OH, C O and O C O, etc.) and a high degree of graphitization (evidenced by a lower value of I D /I G = 0.81) which exhibited a high activity in decomposing H 2 O 2 to generate ·OH radicals for degradation of tetracycline (TC). Nearly 100% of TC (50 mg/L, 100 mL) was removed by 0.15 g BC/GM (1 mL H 2 O 2 , pH 5.0, 60 °C, 5 h). It also showed a good stability and reusability during 5 repeated cycling. EPR, XPS, FTIR and Raman analysis suggested the phenolic-OH, ketone, quinone moieties and defect structures in BC contributed to the generation of ·OH through transferring electrons to H 2 O 2 , while the graphitized carbon in BC with porous structure and large surface area provided intimate contact between catalyst and TC molecules that accordingly enhanced the electron conductivity and suppressed the decay of ·OH radicals during redox reaction, which eventually realized the efficient degradation of TC into CO 2 , H 2 O, and other inorganic compounds through ring-opening reaction, isomerization, demethylation, deamination, and dehydration reaction. [ABSTRACT FROM AUTHOR]

• CoTiO 3 overlayer was formed on nanosheets-assembled hierarchical TiO 2 nanospheres. • Cobalt sites of CoTiO 3 /TiO 2 showed a better activation ability than those of Co 3 O 4. • CoTiO 3 /TiO 2 was highly efficient in catalytic degradation of metronidazole. • Plausible degradation pathways and catalytic mechanism were elucidated. • Low cobalt leaching and excellent reusability were also achieved. Catalytic performance of a heterogeneous cobalt-based catalyst for advanced oxidative process (AOP) correlates tightly with its structure and composition. The main objective of this study is to maximize the utilization and accessibility of cobalt sites while enhancing their activity and stability through rational structural and composition designs, and thus to achieve an excellent performance for heterogeneous peroxymonosulfate (PMS) activation. To this end, a novel CoTiO 3 /TiO 2 composite (CTT), composed of CoTiO 3 overlayer on nanosheets-assembled hierarchical TiO 2 nanospheres, was elaborately designed and synthesized. The resulting CTT possessed certain features including CoTiO 3 -rich surface, large surface area (114.8 m2 g−1), and highly open porous channels, which afforded sufficient accessible active sites against undesirable particle agglomeration and shedding. Moreover, cobalt sites of CTT exhibited a higher activity toward PMS than those of Co 3 O 4 due to the composition-induced distinct adsorption nature, easy electron transfer, and strong bond-weakening ability. Benefitting from the unique combination of structural and compositional advantages, CTT manifested remarkable catalytic efficiency, low cobalt leaching (0.078 mg L−1), and excellent reusability in activation of PMS for degradation of the emerging antibiotic pollutant metronidazole (MNZ). The potential degradation pathway for MNZ and the catalytic mechanism were further elucidated. The design strategy proposed in this study may provide a new opportunity for future development of high-performance heterogeneous cobalt-based catalysts in remediation of aquatic environment. [ABSTRACT FROM AUTHOR]

• A cubic p-Mn/Fe 3 O 4 was synthesized with abundant micro- and meso-pores. • p-Mn/Fe 3 O 4 exhibited high catalytic efficiency and long-term stability. • Sulfate and hydroxyl radicals were reactive species for contaminants degradation. • Mn/Fe species exerted the synergistic effect during reactions. Metal oxides are potentially interesting catalysts for activating peroxymonosulfate (PMS) for the degradation of recalcitrant contaminants. This study presents a magnetic porous Mn-Fe binary oxide (p-Mn/Fe 3 O 4) in micron-size with abundant micro- and meso- pores. This novel catalyst exhibited high efficacy and long-term stability in activating PMS for degradation of bisphenol A (BPA). Sulfate radicals and hydroxyl radicals were identified from catalytic PMS activation according to electron paramagnetic resonance (EPR) characterization. The effects of Fe/Mn ratio, catalyst dose, initial pH and temperature were investigated. Compared to monometallic oxides, p-Mn/Fe 3 O 4 exhibited a better catalytic performance because of the significant synergy between Mn and Fe species. Several BPA intermediates were identified. On the basis of bio-toxicity assay and TOC measurements, BPA transformed to some toxic intermediates during the initial reaction stage, and then decomposed efficiently to low toxicity products and mineralized to carbon dioxide and water molecules. This study shows that p-Mn/Fe 3 O 4 is an efficient and environmentally benign catalyst for PMS oxidation of organic pollutants. [ABSTRACT FROM AUTHOR]

• Catalytic abilities of BC700 was comparable to AC, but less effective for BC400. • Stronger radicals in solution was responsible for SMX degradation in biochar system. • The radicals in solid phase contributed to the higher catalytic performance for AC. • The degradation of SMX was more complete by BC700 than that by AC. Biochar as a carbonaceous material alternative to activated carbon (AC) has received increasing application in the catalytic degradation of organic pollutants. However, the different underlying mechanism between biochar and AC for the catalytic degradation is still unclear. In this study, two biochar produced from the pyrolysis of peanut shell at 400 °C (BC400) and 700 °C (BC700) were used to assist persulfate (PS) catalytic degradation of sulfamethoxazole (SMX), a commercial AC was included as a comparison. Results showed that BC700 had a comparable high catalytic degradation performance to AC (88.7% vs 91.2%) but less effective degradation was observed for BC400 (30.4%). Strong sulfate radicals and hydroxyl radials contributed to the higher catalytic abilities of BC700 and AC, as evidenced by Electron Paramagnetic Resonance analysis. Degradation of SMX by BC700 + PS system mainly happened in solution (53.1%) with the relatively complete degradation. High sorption and dominance of radicals in solid phase of AC (84.3%) was responsible for the faster catalytic performance of AC, but incomplete degradation was observed. Density functional theory calculations confirmed that S-N bond adjacent to the S atom in SMX was the susceptible site for radical's attack. Our findings provide new insight into the different catalytic mechanisms for different carbon materials, which is helpful for the specific carbon materials designed for antibiotics wastewater treatment. [ABSTRACT FROM AUTHOR]