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Due to the rapid development of industrial society, air pollution is becoming a serious problem which has being a huge threat to human health. Ultrafine particles (UFPs), one of the major air pollutants, are often the culprits of human diseases. At present, most of the toxicological studies of UFPs focus on their biological effects on lung cells and tissues, but there are less researches taking aim at the negative effects on functional proteins within the body. Therefore, we experimentally explored the effects of ultrafine carbon black (UFCB) on the structure and function of trypsin. After a short‐term exposure to UFCB, the trypsin aromatic amino acid microenvironment, protein backbone and secondary structure were changed significantly, and the enzyme activity showed a trend that rose at first, then dropped. In addition, UFCB interacts with trypsin in the form of a complex. These studies demonstrated the negative effects of UFCB on trypsin, evidencing potential effects on animals and humans. [ABSTRACT FROM AUTHOR]

The spread of antibiotic resistance genes (ARGs) has become a global environmental issue; it has been found that nanoparticles (NPs) can promote the transfer of ARGs between bacteria. However, it remains unclear whether NPs can affect this kind of conjugation in Streptomyces, which mainly conjugate with other bacteria via spores. In the present study, we demonstrated that Al2O3 NPs significantly promote the conjugative transfer of ARGs from Escherichia coli (E. coli) ET12567 to Streptomyces coelicolor (S. coelicolor) M145 without the use of heat shock method. The number of transconjugants induced by Al2O3 particles was associated with the size and concentration of Al2O3 particles, exposure time, and the ratio of E. coli and spores. When nanoparticle size was 30 nm at a concentration of 10 mg/L, the conjugation efficiency reached a peak value of 182 cfu/108 spores, which was more than 60-fold higher than that of the control. Compared with nanomaterials, bulk particles exhibited no significant effect on conjugation efficiency. We also explored the mechanisms by which NPs promote conjugative transfer. After the addition of NPs, the intracellular ROS content increased and the expression of the classical porin gene ompC was stimulated. In addition, ROS enhanced the mRNA expression levels of conjugative genes by inhibiting global regulation genes. Meanwhile, expression of the conjugation-related gene intA was also stimulated, ultimately increasing the number of transconjugants. Our results indicated that Al2O3 NPs significantly promoted the conjugative transfer of ARGs from bacteria to spores and aggravated the diffusion of resistance genes in the environment. [ABSTRACT FROM AUTHOR]

In this study, the preparation of pyrolyzed bone chars for the removal of nitrobenzene (NB) from the water was examined. Adsorption properties of bone chars prepared at diverse pyrolysis temperatures (300–900 ℃) were investigated for removing NB from aqueous solutions. At higher temperatures (700 and 900 ℃), bone chars showed superior adsorption properties for NB removal, and physicochemical characterizations showed that the pyrolyzed bone chars possessed improved properties and amended porous structure after pyrolysis treatment. Pyrolysis temperatures of > 700 ℃ contributed to the dehydroxylation of hydroxyapatite of bone chars, increasing their NB adsorption performance. Maximum NB adsorption capacity of higher temperature pyrolyzed bone chars calculated from the Langmuir isotherm model was 142.41 and 204.34 mg/g for bone char-700 and bone char-900, respectively, indicating that the bone chars had the potential for enhanced NB adsorption. For adsorption isotherm parameters, two-parameter (Langmuir and Freundlich) models showed satisfactory results of NB adsorption on bone char from aqueous solution. Adsorption kinetic parameters of NB adsorption on bone chars showed pleasing results for the pseudo 2nd order model. This study shows that the pyrolyzed bone char is an efficient adsorbent for removing NB from water. • Bone chars were prepared at 300–900 ℃ temperatures for NB removal from water. • Physicochemical properties of bone powder were improved after pyrolysis treatment. • >700 ℃ sponsored hydroxyapatite dehydroxylation of bone char for better NB adsorption. • 700 and 900 ℃ bone chars had superior NB adsorption capacity (142.41 and 204.34 mg/g). • This study shows that pyrolyzed bone chars can be used for environmental remediation. [ABSTRACT FROM AUTHOR]

Byline: Jingchun Tang, Yutang Xiao, Akinobu Oshima, Hiroshi Kawai, Shinichi Nagata A novel marine bacterium, identified as Halomonas sp. AW4 by partial 16S rDNA analysis, was isolated from the seaweeds in Awaji Island, Japan. Strain AW4 grew well even in the wide NaCl concentration ranges of 03 mol/L, where it showed an optimal growth in the presence of 0.5 mol/L NaCl. The organic components were reduced to 73.6% of initial dry weight after 168 h of composting by inoculation of AW4. The microbial community structure became complex after 72 h of composting. The initial content of alginate was 35.6%, which decreased to 15.6% after 168 h of composting. The decomposition of alginate mainly occurred at the late stage of composting, suggesting that the microbial community consisting of various types of microorganisms is effective in degrading alginate. The germination of plant Brassica campestris L. indicated the promotion effect of composted wakame.

To investigate the hydrocarbon-degrading ability, biosurfactant-producing capacity, and alkane monooxygenase system of Leclercia spp. A bacterial strain classified as Leclercia sp. B45 was isolated, and its biosurfactant-producing capacity, hydrocarbon-degrading ability, and alkane hydroxylase (alkB) gene transcriptional patterns were evaluated by TLC, FTIR, GC-MS, and RT-qPCR, respectively. Strain B45 showed active biosurfactant-producing ability, which was preferentially induced by C16. The extracted biosurfactant tolerated a wide range of salinity, pH, and temperature. The degradation rate of n-decane (C10), n-hexadecane (C16), and octacosane (C28) by strain B45 could reach 92.6%, 94.1%, and 67.8%, respectively. Furthermore, the alkB transcription levels in the strain B45 with C10, C16, or C28 as a carbon source were distinctly higher than those of the control group during the late exponential and stationary phases. The relative alkB transcript copy number decreased with the increase in alkane chain length, which is consistent with B45 strain biodegradation kinetics. Leclercia sp. B45 showed excellent n-alkane degradation performance and biosurfactant-producing capacity. Meanwhile, the alkB gene in Leclercia sp. B45 is likely to represent a novel gene, whose transcription level was significantly upregulated when induced by n-alkane. These results provide new insights into alkane metabolism mechanism in Leclercia sp. B45. [ABSTRACT FROM AUTHOR]

In this study, taking advantage of the amphiphilic properties of alkali lignin, carbon shell-encapsulated nano-zero-valent iron particles (AL@nZVI) anchored in a porous carbon framework were firstly synthesized by a combination of antisolvent reaction and carbothermal reduction method. AL@nZVI exhibited efficient catalytic performance for the activation of persulfate for the complete removal of 2,4-dichlorophenol at 30 min. The formation of a porous carbon skeleton and carbon shell enhanced the dispersibility and antioxidation of Fe0 nanoparticles and enabled long-term storage of AL@nZVI in air for more than 60 days. Furthermore, oxidation was mainly responsible for the removal of 2,4-dichlorophenol. The adsorption was determined to be 26.9% by analyzing the 2,4-dichlorophenol content in the used material. The generation of O 2 · − , SO 4 · − , 1O 2 and·OH, was confirmed by EPR and scavenging experiments, and O 2 · − and 1O 2 played dominant roles in the AL@nZVI+ persulfate system. The O 2 · − -guided free radical pathway was induced by activation of persulfate by Fe0 nanoparticles, while O 2 · − acted as a precursor to induce the 1O 2 -guided non-radical pathway. It is worth noting that C O may be favourable for the generation of 1O 2. Moreover, the graphitized carbon, micropores, and structural defects contained in AL@nZVI created an electron-rich environment to facilitate the interaction between 2,4-dichlorophenol and reactive oxygen species. Therefore, the free radical and non-radical pathways were coupled to work together to degrade 2,4-dichlorophenol. This work not only develops a new synthesis method for core-shell structured carbon-coated nZVI composites, but also open the way for the high-value utilization of industrial by-products and the advanced oxidation degradation of organic pollutants in environmental remediation. [Display omitted] • AL@nZVI was synthesized by a combination of the antisolvent method and the carbothermal reduction method. • The formation of carbon coated-iron core structure greatly improved the stability of nZVI in the air environment. • The AL@nZVI exhibited excellent degradation performance towards 2,4-DCP through activating PS. • Combination of free radical and non-radical pathways contributed to the degradation of 2,4-DCP. [ABSTRACT FROM AUTHOR]

This study proposes a sine wave tube reactor for efficient hydrogen production. Numerical research was conducted on the structural parameters (wavelength and amplitude) of the sine wave tube reactor as well as operating parameters (including temperature, flow rate, and steam-to-carbon (S/C) mole ratio) to investigate their effects on methanol conversion rate and CO selectivity. The results indicate that as the wavelength decreases, the methanol conversion rate gradually increases and then stabilizes. The increase in wave amplitude has a more pronounced effect on the performance of the methanol steam reforming (MSR) device. Increasing the temperature of the heating gas has a greater impact on the methanol conversion rate than increasing the gas flow rate. When the temperature of the heating gas is increased from 473K to 533K, while keeping other parameters constant, the methanol conversion rate increases by 105%. Additionally, increasing the steam to carbon mole ratio (S/C) can reduce the rate of CO generation. [Display omitted] • An MSR reactor with sine wave tube was proposed. • The triple rate kinetic model of MSR was is embedded through user-defined functions. • The effect of structural parameters and operating parameters on reforming performance was analyzed. • The increase in steam to carbon molar ratio can promote the decrease in CO selectivity. [ABSTRACT FROM AUTHOR]

In this study, simple and environmentally friendly magnetic biochars were successfully prepared by ball-milling biochar with Fe 3 O 4 nanoparticles to remove NPs from water. The magnetic biochars synthesized at various pyrolysis temperatures of 300 °C (MBC300), 500 °C (MBC500), and 700 °C (MBC700) were used to eliminate the unmodified (PS), aged under UV radiation (UVPS), amine-modified (PS–NH 2) and carboxylate-modified (PS–COOH) polystyrene NPs of 100 nm in size. Results showed that the removal efficiency of MBC300, MBC500, and MBC700 for PS were 43.67, 82.73 and 57.02%, which were 3.01, 5.76, and 3.10 times greater than that of corresponding pristine biochars at the same temperatures, respectively, and the strongest removal efficiency of MBC500 was 95.2% since it has the largest specific surface area and abundant oxygen-containing functional groups. The surface properties of the NPs affected their removal, and the PS-NH 2 had the highest removal rate using magnetic biochars. Compared to pristine biochars, the magnetic biochars displayed faster adsorption kinetics. The Langmuir maximum adsorption capacity of magnetic biochars for NPs were 107.7181–229.5772 mg/g, much greater than those of the pristine biochars (55.4602–80.3096 mg/g). Mechanism analysis revealed that the hydrophobicity, electrostatic attraction, H-bonding formation and π-π conjunction between the NPs and MBCs contributed to the adsorption process. This work highlights the promising potential of ball milling to be used as a simple technique for the preparation of magnetic biochar to remove NPs, especially NPs with various surface groups. [Display omitted] • Magnetic biochars presented stronger potential than pristine biochars for NPs adsorption. • The functionality of nanoplastics significantly influenced their adsorption performance. • Hydrophobicity, electrostatics, H-bonding and π-π conjunction all involved in NPs adsorption. [ABSTRACT FROM AUTHOR]

Electrocatalytic persulfate (PS) generation of sulfate radicals has been extensively studied for the removal of organic pollutants, while continuous electricity output causes high energy consumption. Microbial fuel cell (MFC) is an environmentally friendly approach that can catalyze PS for degradation of pollutants through bioelectricity and achieve electricity recovery and utilization at the same time. In this study, a MFC based on electrocatalytic PS activation in cathode (PS-MFC) was constructed to remove 2,4-dichlorophenol (2,4-DCP) with simultaneous electricity recovery. Results showed that 2,4-DCP was successfully removed by PS-MFC with a maximum removal rate of 68.7% after 220 mins of reaction, and the removal process followed pseudo-second-order kinetic. In addition to the wide pH reaction range (pH 3–11), PS-MFC exhibited excellent electrical performance with a higher maximum power density (300.28 mW/m2) than reported studies of the similar type of MFC. Active species for the degradation of 2,4-DCP by PS-MFC system are O 2 • − , • O H , S O 4 • − and O 2 1 , with O 2 • − and • O H accounting for major part. The degradation pathway of 2,4-DCP in PS-MFC was proposed by free radical quenching experiments and intermediate product analysis. This work provided a green and sustainable solution for the removal of refractory organic pollutants and promoted research for the further practical application of MFCs. • PS-based MFC achieved effective degradation of 2,4-DCP. • Valuable electricity was recovered in PS-based MFC during 2,4-DCP degradation. • Two active species (O 2 • and •OH) dominated degradation of 2,4-DCP in neutrality. [ABSTRACT FROM AUTHOR]

The easy passivation defect of nano zero-valent iron (nZVI) greatly limits its application in site pollution remediation. Carbon coating can effectively inhibit the passivation of nZVI, but its effectiveness in the soil is still unknown. This study investigated the feasibility of carbon-coated nZVI (Fe0@C) as a persulfate (PS) activator to degrade anthracene (ANT) in soil. The results show that the Fe0@C/PS system can remove 51.6% of ANT in the soil after 0.5 h of reaction, and reach 76.4% after 12 h of reaction. Not only that, the Fe0@C/PS system shows a good removal effect on ANT within the initial pH range of 3–9. Free radical scavenging experiments show that superoxide radicals (O 2 •−) and singlet oxygen (1O 2) are mainly responsible for the removal of ANT, while O 2 •− may be mainly used as a precursor for the generation of 1O 2. The activation of PS by Fe0@C can generate a large number of free radicals, and soil components (such as β -MnO 2) can promote the conversion of O 2 •− to 1O 2. Furthermore, the possible degradation pathway of ANT was also proposed. The findings are of great significance to fill up the knowledge gaps in the application of nZVI in soil remediation. [Display omitted] • Carbon-coated nZVI can effectively activate PS to remove soil pollution. • Different reactive oxygen species participate in the degradation of anthracene. • The presence of β -MnO 2 promotes the generation of singlet oxygen. • The catalytic system has a wide operating pH range. [ABSTRACT FROM AUTHOR]

Low molecular weight organic acids with low cost and environmentally friendly characteristics can enhance the electron transfer between materials and contaminants. In this study, oxalic acid (OA), citric acid (CA), and ethylenediaminetetraacetic acid (EDTA) were selected to strengthen ball milled natural FeS 2 /biochar composite (FeS 2 /biochar) for aqueous Cr(VI) removal. 100% of Cr(VI) was removed when 5 mM of OA and 0.25 g·L−1 FeS 2 /biochar were used together. In contrast, the removal rate of Cr(VI) by the individual FeS 2 /biochar and OA was 57.9% and 6.3%, respectively. The experimental and characterization results suggested that OA was adsorbed on the surface of FeS 2 /biochar through the conjugated structure of pine biochar, thereby enhancing the dissolution rate of Fe(II) and S(-II) in the FeS 2 /biochar composite, and facilitating the conversion of Fe(II), S(-II), and Cr(VI) to Fe(III), SO 4 2-, and Cr(III), respectively. In addition, the complexation of OA with Fe(III) and Cr(III) reduced the formation of Fe(OH) 3 and Cr(OH) 3 , exposing more surface active site of FeS 2 /biochar for the reduction of Cr(VI). As an electron donor, the addition of OA enhanced the electron transfer process of FeS 2 /biochar to Cr(VI) on the one hand, and on the other hand promoted the redox cycle of Fe(II) through the electron transfer between OA and Fe ions. FeS 2 /biochar showed better stability even after 5 cycles (in 5 mM OA system). The present study demonstrated the promise of low molecular weight organic acids in strengthening materials for environmental remediation. [Display omitted] • Oxalic acid enhanced the dissolution rate of Fe(II) and S(-II) in the FeS 2 /biochar. • Oxalic acid promoted the transfer of electrons from FeS 2 /biochar to Cr(VI). • Oxalic acid reduced the formation of Fe(OH) 3 and Cr(OH) 3. • Oxalic acid promoted the redox cycle of iron and sulfur, enhancing Cr(VI) removal by the FeS 2 /biochar. • The graphite structure and conjugate structure in biochar transferred electrons to Cr(VI). [ABSTRACT FROM AUTHOR]

[Display omitted] • nZVI@gBC were synthesized by one-step carbothermal reduction method aided by Tetrahydrofuran. • The formation of graphene nano-shells greatly enhanced the stability of nZVI in the air environment. • The nZVI@gBC exhibited superior degradation performance to 2,4-DCP by activating PS. • Four active free radicals (SO 4 •−, •OH, O 2 •− and 1O 2) were produced and participated in the degradation of 2,4-DCP. The defects of easy agglomeration and oxidation of nano zero valent iron (nZVI) limit its large-scale application in industry, especially in the field of environmental remediation. In this study, the iron nanoparticles encapsulated by graphene nano-shells which anchored on the surface of carbon substrate (nZVI@gBC) were synthesized by a one-step carbothermal reduction method aided by Tetrahydrofuran. When the mass ratio of carbon source to iron source is 2:3 and the carbothermic reduction temperature is 700 °C, stabilized nZVI @gBC can be successfully synthesized with a high iron loading rate of 32.5%. The multilayer graphene shell can effectively prevent the rapid passivation and agglomeration of the nZVI core, and the electronic interaction between the iron nanoparticles core and the graphene carbon shell further enhances the catalytic activity and stability of nZVI@gBC. Therefore, due to the unique structure of graphene nano-shells, nZVI@gBC can be stably stored in the air for more than 80 days. In addition, nZVI@gBC exhibited superior catalytic activity in the experiment of removing 2,4-dichlorophenol (2,4-DCP) in groundwater as a persulfate activator. Notably, both the electron paramagnetic resonance (EPR) and quenching tests showed that SO 4 •−, •OH, O 2 •− and 1O 2 were both involved in the degradation process of 2,4-DCP, and SO 4 •− were the major active species. Simultaneously, three possible degradation pathways of 2,4-DCP were deduced by GC/MS, which were caused by dechlorination, dehydrogenation or carbon–carbon bond cleavage under the attack of SO 4 •−, •OH, O 2 •− and 1O 2. Besides, nZVI@gBC can use the dissolved oxygen in the liquid to generate hydroxyl radicals to effectively remove 2,4-DCP without persulfate. This kind of multifunctional nZVI@gBC may become a promising iron-carbon catalyst for large-scale applications in the field of environmental remediation. [ABSTRACT FROM AUTHOR]

As a natural reduction mineral, pyrite (FeS 2), was combined with biochar by simply ball milling technology to synthesize FeS 2 @biochar composite (BM-FeS 2 @BC) and applied for the removal of hexavalent chromium (Cr(VI)) in aqueous solution. SEM, XRD, FTIR, and XPS characterization results showed that the FeS 2 and biochar were successfully combined and biochar suppressed the agglomeration of FeS 2. Batch sorption experiments showed that the BM-FeS 2 @BC700 composite (mass ratio of FeS 2 -to-biochar = 3:1) had enhanced Cr(VI) removal capacity of 134 mg·g−1, which were 3–25 times higher than those of the corresponding pristine and ball-milled biochar and FeS 2. The removal of Cr(VI) by BM-FeS 2 @BC700 was dosage and pH dependent. The addition of oxalic acid (OA) exhibited a promotion effect on the removal of Cr(VI) by increasing the removal rate of Cr(VI) from 56% to 100%. Reduction, adsorption, and surface complexation were the dominate mechanisms for Cr(VI) removal by BM-FeS 2 @BC700. At the equilibrium Cr(VI) concentration of 15.7 mg·L−1, 92.25% of Cr(VI) was removed through reduction/precipitation and 8.75% was removed by adsorption/surface complexation. The fitting results of the Langmuir model proved that the removal of Cr(VI) by BM-FeS 2 @BC700 composite was chemical surface monolayer adsorption. This work demonstrates the potential of ball milling for the preparation of FeS 2 @BC composite to remove Cr(VI) from water and wastewater. [Display omitted] • Preparation of BM-FeS 2 @BC700 achieved the reuse of waste. • Ball milling inhibited the oxidation of the pyrite surface. • BM-FeS 2 @BC dramatically increased the uptake of Cr(VI). • Adsorption and reduction were the main mechanisms to remove Cr(VI). • Acidic pH was more beneficial to the reduction of Cr(VI). [ABSTRACT FROM AUTHOR]

• Ball-milled magnetic FeS@BC was synthesized successfully and it was applied in persulfate activation for the first time. • TC could be degraded in FeS@BC/PS system effectively after 30 min. • Surface-bond Fe(Ⅱ) and S(Ⅱ) participated in generation of SO 4 − and OH radicals. • BC acted as linker-transfer media to accelerate the degradation process in FeS@BC system. • Both of radical and non-radical degradation processes were involved in the FeS@BC/PS/TC system. In this study, composite of iron sulfide and biochar (FeS@BC) was synthesized successfully via physical ball milling and applied to the oxidative removal of tetracycline (TC) in the presence of persulfate (PS). Characterization results showed that FeS@BC, which has a small particle size, can be synthesized at a preset FeS-BC mass ratio. In addition, the ball-milled FeS@BC showed sufficient ferromagnetism. The effects of pH, dosages of FeS@BC and PS, and co-existing anions on TC degradation were investigated. Our results showed that TC degradation efficiency was enhanced at low pH and high dosages of PS and FeS@BC. Under optimal conditions (pH = 3.6, [FeS@BC] = 0.3 g/L and [PS] = 10 mM), a TC removal efficiency of 87.4% could be achieved after 30 min. Nevertheless, the TC removal rate was slightly inhibited by inorganic anions in the order of CO 3 2− > Cl− > NO 3 −. Surface-bound Fe(Ⅱ) and S(Ⅱ) acted as electron donors in the activation process and generated SO 4 − and OH at the surface of FeS@BC. In addition, S(Ⅱ) also participated in Fe(III) reduction. BC not only reduced the agglomeration of FeS, serving as a continuous source of effective Fe, but also acted as an electron shuttle and a suitable carbon-based adsorption material, facilitating fast electron transfer among PS, electron donors, and pollutants. Moreover, non-radical degradation processes might also exist in the FeS@BC/PS/TC system. The FeS@BC could be a promising effective activator for the remediation of other emerging organic contaminants. [ABSTRACT FROM AUTHOR]

Antibiotic resistance genes (ARGs) are emerging pollutants that are widely present in the environment, and are affected by microplastics (MPs). The coexistence of MPs and ARGs enhances their abundance and transmission ability, thereby increasing their environmental hazard. This study summarized the effects of MPs on the abundance and transmission of ARGs. First, the effects of MPs on ARGs in aquatic, terrestrial, atmospheric, and animal intestinal environments were analyzed. Furthermore, factors that affect the enrichment and transfer ability of MPs, including MPs properties, human activities, environmental factors, and other pollutants, were discussed. Previous studies mainly focused on the abundance changes, propagation and diffusion of ARGs on MPs, however, the possible mechanism of these changes on ARGs caused by MPs has not been fully studied, which also leads to many explanations that are not appropriate. Therefore, in the fourth section, the detailed mechanism of MPs on abundance and transfer of ARGs is systematically discussed. As the core innovation in this article, it fills the gap that has been to be supplemented in recent years. Finally, the research challenges and prospects of the effects of MPs on the abundance and spread of ARGs are proposed in the hope that this review will be helpful to better understand the environmental risks and mechanisms of MPs on ARGs. [ABSTRACT FROM AUTHOR]

• Linear cooling of continuous microfluidic was achieved based on a single TEC. • Multi-structure TEC was proposed to generate a linear temperature gradient. • Numerical model was established and verified by experiment. • Linearity, cooling rate and temperature of linear cooling were analyzed. • Cooling rate can be controlled by changing the current and microfluidic velocity. Linear cooling of continuous microfluidic is crucial to the microfluidic analysis of cell cryopreservation and homogenous ice nucleation. This study presents a method to establish a linear temperature gradient for linear cooling of continuous microfluidic based on a single thermoelectric cooler. A novel multi-structure thermoelectric cooler was proposed to generate a stable linear temperature gradient. Furthermore, a numerical model was established to explore the performance of linear cooling of continuous microfluidic. Meanwhile, experiments were carried out to validate the model. Based on the proposed multi-structure thermoelectric cooler, linear cooling of continuous microfluidic can be successfully achieved, even if the current of the thermoelectric cooler or microfluidic velocity changes. For the case of current equal to 3 A and microfluidic velocity equal to 50 mm/s, microfluidic can be linearly cooled from 297 K to 251 K with a cooling rate of 64.5 K/s and linearity of 0.9912. It was also found that the temperature gradient decreases slightly with increasing microfluidic velocity while the cooling rate increases and is approximately proportional to the microfluidic velocity. With the increase of microfluidic velocity , the linearity increases at first and then decreases. Maximum goodness of fit equal to 0.9942 appears at the microfluidic velocity of 20 mm/s. [ABSTRACT FROM AUTHOR]

[Display omitted] • Mn-NGO enhanced adsorption-photodegradation of SNM in lake, tap, and DI water. • Single-atom Mn anchored on N -GO with interactions of d electrons and π rings. • Removal mechanism was studied by electronic channels and active radios. • The degradation of SNM starts from two pathways of C6-S14 and C3-N11 cleavage. • SNM removal rate of Mn-NGO remained at 55.6% after six cycles of reaction. Synergy between adsorption and photocatalysis provides an ideal green technology to treat antibiotic pollution in water. In this study, single-atom Mn anchored on N-doped graphene oxide (Mn-NGO) was synthesized for enhanced adsorptive-photocatalytic removal of aqueous sulfanilamide (SNM) and the corresponding mechanisms were revealed. The Mn-NGO had better performance of SNM degradation and TOC removal than GO and NGO. Density functional theory (DFT) calculation showed that the electrons of d-orbital (Mn) and p-orbital (N) upgraded the electronic structures of GO of the Mn-NGO to interact with amino and aromatic rings of SNM, increasing the adsorption and polarizing of SNM. Furthermore, more hydroxyl and superoxide radicals were observed on Mn-NGO, leading to the generation of key reaction intermediates of 2-aminohydroquinone and benzenesulfonic and thus subsequently opening loops and mineralizing SNM. In addition, Mn-NGO effectively removed SNM in different types of water systems (e.g., lake water, tap water, and deionized water) through synergistic adsorption-photocatalytic degradation. [ABSTRACT FROM AUTHOR]

• The schematic mechanism for R1234yf combustion were revealed in unimolecular lysis reactions, colliding reactions with oxygen molecules, collision reaction with active radicals (H and OH radicals). • The new chemical reaction equations for the combustion of R1234yf were proposed. • This paper provided an effective method to establish the combustion mechanism of flammable hydrofluoroolefins. To describe the combustion process of hydrofluoroolefins (HFOs) 2,3,3,3-tetrafluroropropene (R1234yf), a kinetics mechanism was developed. On the M06–2X/6–311++ G (d,p) level, dynamic calculations have been performed using the density function theory (DFT) method. Proposed R1234yf kinetic reactions included unimolecular decomposition and intermolecular reactions, such as collisions with O 2 , OH, and H radicals. The results indicated that R1234yf combustion is a step-by-step chain reaction involving chain initiation (unimolecular lysis and collision reaction with oxygen), chain transmission (collision reactions with free radicals), and chain termination. In conjunction with the priority rule of kinetics reactions, a schematic diagram of the primary microscopic combustion pathways for R1234yf was created at 298.15 K and 1 atm. All the simulation results could provide a data basis to establish the kinetic model of hydrofluoroolefin pyrolysis and combustion. In addition, to verify the product direction of the reaction path, experiments were conducted to determine the properties of the R1234yf combustion products. [Display omitted] [ABSTRACT FROM AUTHOR]