The highly selective catalytic hydrogenation of halogenated nitroaromatics was achieved by employing Pd‑based catalysts that were co‑modified with organic and inorganic ligands.It was demonstrated that the catalysts c...The highly selective catalytic hydrogenation of halogenated nitroaromatics was achieved by employing Pd‑based catalysts that were co‑modified with organic and inorganic ligands.It was demonstrated that the catalysts contained Pd species in mixed valence states,with high valence Pd at the metal‑support interface and zero valence Pd at the metal surface.While the strong coordination of triphenylphosphine(PPh3)to Pd0 on the Pd surface prevents the adsorption of halogenated nitroaromatics and thus dehalogenation,the coordination of sodium metavanadate(NaVO3)to high‑valence Pd sites at the interface helps to activate H2 in a heterolytic pathway for the selective hydrogenation of nitro‑groups.The excellent catalytic performance of the interfacial active sites enables the selective hydrogenation of a wide range of halogenated nitroaromatics.展开更多
Halogenated aromatic disinfection byproducts(DBPs)are gradually receiving attention due to their high detection frequency and usually higher toxicity than regulated DBPs.In this study,we established a solid phase extr...Halogenated aromatic disinfection byproducts(DBPs)are gradually receiving attention due to their high detection frequency and usually higher toxicity than regulated DBPs.In this study,we established a solid phase extraction(SPE)-LC-MS/MS method to simultaneously trace analyze 59 halogenated aromatic DBPs.The limits of detection and limits of quantification of halogenated aromatic DBPs ranged from 0.03 to 135.23 ng/L and from 0.1 to 450.76 ng/L,respectively.The range of recoveries and relative standard deviation(RSD)in river water were between 72.41%to 119.54%and 1.86%to 16.03%,respectively.Therefore,this method can be used to accurately analyze trace levels of halogenated aromatic DBPs in drinking water.The occurrence and transformation of halogenated aromatic DBPs were explored based on this method.In the chlorinated simulated source water and chlorinated river water,20 and 45 halogenated aromatic DBPs were determined,respectively.The active halogen species(HOCl,HOBr,and HOI)first reacted with natural organic matter(NOM)to form halogenated aromatic DBPs.Then,chlorine further reacted with the halogenated aromatic DBPs to convert them into small-molecule halogenated aliphatic DBPs through oxidation,electrophilic substitution,and hydrolysis reaction,etc.In the chlorinated simulated source water,chlorinated river water,and tap water,the toxicity contribution of bromoacetic acids(Br-HAAs)accounted for themajority(>71.16%).Given that halogenated aromatic DBPs are intermediate products of halogenated aliphatic DBPs,controlling the formation of halogenated aromatic DBPs is beneficial in decreasing the formation of halogenated aliphatic DBPs,thereby diminishing the toxicity of drinking water.展开更多
Despite the extensive application of advanced oxidation processes(AOPs)in water treatment,the efficiency of AOPs in eliminating various emerging contaminants such as halogenated antibiotics is constrained by a number ...Despite the extensive application of advanced oxidation processes(AOPs)in water treatment,the efficiency of AOPs in eliminating various emerging contaminants such as halogenated antibiotics is constrained by a number of factors.Halogen moieties exhibit strong resistance to oxidative radicals,affecting the dehalogenation and detoxification efficiencies.To address these limitations of AOPs,advanced reduction processes(ARPs)have been proposed.Herein,a novel nucleophilic reductant—namely,the carbon dioxide radical anion(CO_(2)^(·-))—is introduced for the simultaneous degradation,dehalogenation,and detoxification of florfenicol(FF),a typical halogenated antibiotic.The results demonstrate that FF is completely eliminated by CO_(2)^(·-),with approximately 100%of Cland 46%of Freleased after 120 min of treatment.Simultaneous detoxification is observed,which exhibits a linear response to the release of free inorganic halogen ions(R^(2)=0.97,p<0.01).The formation of halogen-free products is the primary reason for the superior detoxification performance of this method,in comparison with conventional hydroxyl-radical-based AOPs.Products identification and density functional theory(DFT)calculations reveal the underlying dehalogenation mechanism,in which the chlorine moiety of FF is more susceptible than other moieties to nucleophilic attack by CO_(2)^(·-).Moreover,CO_(2)^(·-)-based ARPs exhibit superior dehalogenation efficiencies(>75%)in degrading a series of halogenated antibiotics,including chloramphenicol(CAP),thiamphenicol(THA),diclofenac(DLF),triclosan(TCS),and ciprofloxacin(CIP).The system shows high tolerance to the pH of the solution and the presence of natural water constituents,and demonstrates an excellent degradation performance in actual groundwater,indicating the strong application potential of CO_(2)^(·-)-based ARPs in real life.Overall,this study elucidates the feasibility of CO_(2)^(·-)for the simultaneous degradation,dehalogenation,and detoxification of halogenated antibiotics and provides a promising method for their regulation during water or wastewater treatment.展开更多
Ensuring the health and safety of drinking water is crucial for both nations and their citizens.Since the 20th century,the disinfection of drinking water,effectively controlling pathogens in water sources,has become o...Ensuring the health and safety of drinking water is crucial for both nations and their citizens.Since the 20th century,the disinfection of drinking water,effectively controlling pathogens in water sources,has become one of the significant advances in public health.However,the disinfectants used in the process,such as chlorine and chlorine dioxide,react with natural organic matter in the water to produce disinfection by-products(DBPs).Most of these DBPs contain chlorine,and if the source water contains bromine or iodine,brominated or iodinated DBPs,collectively referred to as Halogenated disinfection byproducts(X-DBPs),are formed.Numerous studies have found that X-DBPs pose potential risks to human health and the environment,leading to widespread concern.Mass spectrometry has become an important means of discovering new types of X-DBPs.This paper focuses on the study of methods for analyzing X-DBPs in drinking water using mass spectrometry.展开更多
In this paper we take photobacterium phosphoreum （T3） as the experimental bacteria, and determine the half-inhibitory concentration （-1gEC50） against the photobacterium phosphoreum of 16 halogenated benzenes. Usin...In this paper we take photobacterium phosphoreum （T3） as the experimental bacteria, and determine the half-inhibitory concentration （-1gEC50） against the photobacterium phosphoreum of 16 halogenated benzenes. Using B3LYP method of DFT in the Gaussian 03 program, we obtain the structural and thermodynamic descriptors of 16 halogenated benzenes by fully-optimized calculation at the 6-311G＊＊ level. Taking the structural and thermodynamic descriptors as theoretical descriptors, the 2D QSAR model （R2 = 0.983） was established, which can be utilized to predict -lgEC50 of halogenated benzene according to the corrected linear solvation energy theory based on the experimental data of-lgECs0. In addition, the relationship between the toxicity and 3D spatial structure of the compound is studied by comparing the molecular similarity index analysis （CoMSIA） of 3D-QSAR method. By cross validation, the correlation coefficient q2 of CoMSIA model is 0.687, and the conventional correlation coefficient R2 = 0.958. The model is stable and reliable with great predictive ability. The 3D-QSAR model shows that the toxicity of halogenated benzene compound is mainly affected by the characteristics of hydrophobie field of the substituted halogens.展开更多
Halogenated methyl-phenyl ethers （anisoles） are ubiquitous organic compounds in the environment. In the present study, geometrical optimization and electrostatic potential calculations have been performed for 42 hal...Halogenated methyl-phenyl ethers （anisoles） are ubiquitous organic compounds in the environment. In the present study, geometrical optimization and electrostatic potential calculations have been performed for 42 halogenated anisoles at the HF/6-31 G^＊ level. A number of statistically based parameters have been obtained. By multiple regression method, linear relationships between the gas-chromatographic relative retention time （RRT） and structural descriptors have been established for the training set of 32 halogenated anisoles. The result showed that the parameters derived from electrostatic potentials （ESPs） together with the molecular volume （Vmc） could be well used to express the quantitative structure-RRT relationships of halogenated anisoles. The best two-variable regression model gives a correlation coefficient of 0.980 and a standard deviation of 0.07, and the leave-one-out cross-validated correlation coefficient is 0.975. The goodness of the model has been further validated through exploring the predictive power for the testing set of 10 halogenated anisoles.展开更多
This study shows that minor amount of water plays a very important role in solvent-free hydrogenation of halogenated nitrobenzenes. For dried sponge Pd, the reaction cannot occur in the absence of water. For Pd/C cata...This study shows that minor amount of water plays a very important role in solvent-free hydrogenation of halogenated nitrobenzenes. For dried sponge Pd, the reaction cannot occur in the absence of water. For Pd/C catalyst, minor amount of water reduces the induction time, increases the reaction rate and reaction TOFs. Water might enhance the diffusion, adsorption and dissociation of H2 on Pd catalysts.展开更多
The selective hydrogenation of halogenated nitrobenzene over noble metal catalysts(Pd, Pt, and Ir) has attracted much attention owing to its high efficiency and environmental friendliness. However, the effect of size ...The selective hydrogenation of halogenated nitrobenzene over noble metal catalysts(Pd, Pt, and Ir) has attracted much attention owing to its high efficiency and environmental friendliness. However, the effect of size on the catalytic performance varies among different metal catalysts. In this study, sub-nano(<3 nm) Ir and Pd particles were prepared, and their catalytic properties for hydrogenation of halogenated nitrobenzene were evaluated.Results show that high selectivity(N 99%) was achieved over small Ir nanoparticles, in which the selectivity over the Pd with same size was much lower than that on Ir nanoparticles. Meanwhile, Ir and Pd have different hydrogen consumption rates and reaction rates. Density functional theory calculations showed that p-chloronitrobenzene(CNB) has different adsorption properties on Ir and Pd. The distance between oxygen(cholorine) and Ir is much shorter(longer) than that between oxygen and Pd. The reaction barriers of dechlorination of p-CNB and p-chloroaniline over different Ir models are much larger than those on Pd. Especially,lower coordination of Ir leads to larger barriers of dechlorination reaction. These theoretical results explain the difference between Ir and Pd on hydrogenation of halogenated nitrobenzene.展开更多
Geometrical optimization and electrostatic potential calculations have been performed for a series of halogenated hydrocarbons at the HF/Gen-6d level. A number of electrostatic potentials and the statistically based s...Geometrical optimization and electrostatic potential calculations have been performed for a series of halogenated hydrocarbons at the HF/Gen-6d level. A number of electrostatic potentials and the statistically based structural descriptors derived from these electrostatic potentials have been obtained. Multiple linear regression analysis and artificial neural network are employed simultaneously in this paper. The result shows that the parameters derived from electrostatic 2 potentials σtot^2, V s and ∑ Vs^＋, together with the molecular volume （Vine） can be used to express the quantitative structure-infinite dilution activity coefficients （γ^∞） relationship of halogenated hydrocarbons in water. The result also demonstrates that the model obtained by using BFGS quasiNewton neural network method has much better predictive capability than that from multiple linear regression. The goodness of the model has been validated through exploring the predictive power for the external test set. The model obtained via neural network may be applied to predict γ^∞ of other halogenated hydrocarbons not present in the data set.展开更多
The halogenated boron-doped diamond （BDD） surfaces were reacted with sodium azide through a nucle- ophilic substitution reaction. The resulting azide-terminated BDD surfaces were used to trigger the ＂click＂ reacti...The halogenated boron-doped diamond （BDD） surfaces were reacted with sodium azide through a nucle- ophilic substitution reaction. The resulting azide-terminated BDD surfaces were used to trigger the ＂click＂ reaction. Because of the attractive electrochemical properties of ferrocene-containing molecules, such as fast electron transfer rates, reversible redox activities, and favorable redox potentials, we show that ferrocene derivatives can be grafted onto non-oxidized diamond surfaces by ＂click chemistry＂. These redox-active ferrocene-containing layers on a BDD surface, because of their ability to store and release charges reversibly, have the potential to be used as hybrid molecular/semiconductor memory devices.展开更多
"One-step"method for the synthesis of secondary aliphatic amine substituted nitrobenzaldehyde was developed.In the presence of Pd catalyst,halogenated nitrobenzaldehyde could be smoothly coupled with seconda..."One-step"method for the synthesis of secondary aliphatic amine substituted nitrobenzaldehyde was developed.In the presence of Pd catalyst,halogenated nitrobenzaldehyde could be smoothly coupled with secondary aliphatic amine to give the target product in hexamethylphosphamide(HMPT) media without the protection of aldehyde groups.展开更多
A quantitative structure-property relationship （QSPR） study was suggested for the prediction of infinite dilution activity coefficients of halogenated hydrocarbons, γ∞ , in water at 298.15 K. After optimization of...A quantitative structure-property relationship （QSPR） study was suggested for the prediction of infinite dilution activity coefficients of halogenated hydrocarbons, γ∞ , in water at 298.15 K. After optimization of 3D geometry of the halogenated hydrocarbons with semi-empirical quantum chemical calculations at the AM1 level, different descriptors （1514 descriptors） were calculated by the HyperChem and Dragon softwares. A major problem of QSPR is the high dimensionality of the descriptor space; therefore, descriptor selection is the most important step. In this paper, an ant colony optimization （ACO） algorithm was proposed to select the best descriptors. Then the selected descriptors were applied for model development using multiple linear regression. The average absolute relative deviation and correlation coefficient for the training set were obtained as 4.36% and 0.951, respectively, while the corresponding values for the test set were 5.96% and 0.929, respectively. The results showed that the applied procedure is suitable for the prediction of γ∞ of halogenated hydrocarbons in water.展开更多
The capacity factors （k＇） of fourteen types ofhalogenated thiophenols in different phases of methanol-water eluent were determined by reversed phased high-performance liquid chromatography （RP-HPLC） and the relat...The capacity factors （k＇） of fourteen types ofhalogenated thiophenols in different phases of methanol-water eluent were determined by reversed phased high-performance liquid chromatography （RP-HPLC） and the relationships between the logarithm of capacity factor lgK＇ and methanol ratio ψ were analyzed. A fair linear relationship is found between lgK＇ and ψ, and the correlation coefficients R2 of the constructed linear equations are all greater than 0.990. Relationship between the chromatographic data lgKw＇ when extrapolated to pure water and n-octanol/water partition coefficient lgKow obtained by the group contribution method has shown a good linear correlation with R2= 0.956. The structure parameters of fourteen halogenated thiophenols were calculated by using DFT, and the correlation equation of lgKw＇ and structure parameters was obtained by using SPSS, lgKw＇ = -0.409 ＋ 0.039a and R2 = 0.981, meaning that lgKw＇ is mainly determined by the polarizability α.展开更多
We have shown recently that halogenated quinones could enhance the decomposition of hydroperoxides and formation of alkoxyl/hydroxyl radicals independent of transition
Disinfection by-products(DBPs), formed from the reactions of disinfectants with natural organic matter and halides in drinking water, were considered to be cytotoxic and genotoxic, and might trigger various cancers. T...Disinfection by-products(DBPs), formed from the reactions of disinfectants with natural organic matter and halides in drinking water, were considered to be cytotoxic and genotoxic, and might trigger various cancers. The relatively low concentration of DBPs in finished water(low μg/L or even ng/L levels) and the interference from water matrix inhibited in situ determination of DBPs. Moreover, the further formation and degradation of DBPs by disinfectants during the holding time(several hours to several days) from sample collection to analysis could adversely affect the determination of DBPs. To obtain accurate, precise and reliable data of DBP occurrence and formation, robust and reliable sample preservation is indispensable. However, the commonly used quenching agents(e.g., sodium sulfite, sodium thiosulfate, and ascorbic acid) for sample preservation can decompose reactive DBPs by reductive dehalogenation. This study evaluated the performance of N-acetylcysteine(NAC) and glutathione(GSH) as quenching agents for the analysis of halogenated DBPs by investigating the stoichiometry of the disinfectant-quenching agent reaction, the formation of DBPs during chlor(am)ination of NAC or GSH, and the effects of NAC or GSH on the stability of 18 individual DBPs and total organic halogen(TOX). Based on the results of this study, NAC and GSH were considered to be ideal quenching agents for the analysis of most DBPs and TOX, except halonitromethanes.展开更多
Rice,a primary food staple for over half of the global population,is susceptible to environmental pollution.The presence of lipophilic halogenated contaminants,including halogenated polycyclic aromatic hydrocarbons(XP...Rice,a primary food staple for over half of the global population,is susceptible to environmental pollution.The presence of lipophilic halogenated contaminants,including halogenated polycyclic aromatic hydrocarbons(XPAHs),polychlorinated biphenyls(PCBs),organochlorine pesticides(OCPs),brominated flame retardants(BFRs),and polyfluoroalkyl substances(PFAS),has become a growing concern due to their potential health risks and environmental impact.This review focused on the research of lipophilic halogenated contaminants in rice.We summarized the physicochemical properties,toxicity profiles,and contamination levels in rice.Moreover,the strategies for reducing lipophilic halogenated contaminant levels in rice were summarized and proposed,such as phytoremediation and improved processing methods.These findings can provide a reference for the understanding and control of lipophilic halogenated contaminants during rice growing and processing,and therefore reduce the associated risks.展开更多
The rovibrational spectra of thioanisole(TA)and its halogenated derivatives,3-fluorothioanisole(3FTA)and 3-chlorothioanisole(3ClTA),were measured using synchrotron-based Fourier transform infrared spectroscopy(FTIR)at...The rovibrational spectra of thioanisole(TA)and its halogenated derivatives,3-fluorothioanisole(3FTA)and 3-chlorothioanisole(3ClTA),were measured using synchrotron-based Fourier transform infrared spectroscopy(FTIR)at the Canadian Light Source.Combined with density functional theory calculations,the stable structures and vibrational modes of TA,3FTA,and 3ClTA in their vibrational states were analyzed.The theoretical vibrational mode frequencies were corrected by simulating the rotational structure of a vibrational band.The contributions of the cis-and trans-isomers of 3FTA and 3ClTA to the FTIR spectra at 298 K were estimated using the Boltzmann distribution,revealing their coexistence in the experimental spectra.The results indicate that both fluorine and chlorine substitution significantly affect the vibrational modes,particularly in the benzene ring.Compared to TA,the FTIR spectra of 3FTA and 3ClTA show changes in the frequencies and intensities of some vibrational modes,with halogen substitution causing specific modes to shift to higher wavenumbers.A comparison of the FTIR spectra of TA,3FTA,and 3ClTA highlights the influence of halogen substitution on vibrational properties,emphasizing how the type and position of the substituent affect frequency shifts and spectral intensities.These findings provide deeper insights into how halogenation alters vibrational spectra,which is crucial for further spectral analysis and molecular structure determination.展开更多
Halogenated natural products(HNPs)are considered to be emerging contaminants whose environmental distribution and fate are only incompletely known.Therefore,several persistent and bioaccumulative HNP groups,together w...Halogenated natural products(HNPs)are considered to be emerging contaminants whose environmental distribution and fate are only incompletely known.Therefore,several persistent and bioaccumulative HNP groups,together with manmade polychlorinated biphenyls(PCBs)and polybrominated diphenyl ethers(PBDEs),were quantified in the blubber of nine sperm whales(Physeter macrocephalus)stranded on the coast of the Mediterranean Sea in Italy.The naturally occurring polybrominated hexahydroxanthene derivatives(PBHDs;sum of TetraBHD and TriBHD)were the most prominent substance class with up to 77,000 ng/g blubber.The mean PBHD content(35,800 ng/g blubber)even exceeded the one of PCBs(28,400 ng/g blubber),although the region is known to be highly contaminated with manmade contaminants.Based on mean values,Q1∼PBDEs>MeO-BDEs∼2,2′-diMeO-BB 80 and several other HNPs followed with decreasing amounts.All blubber samples contained an abundant compound whose molecular formula(C_(16)H_(19)Br_(3)O_(2))was verified using high-resolution mass spectrometry.The only plausible matching isomer was(2S,4′S,9R,9′S)-2,7-dibromo-4′-bromomethyl-1,1-dimethyl-2,3,4,4′,9,9′-9,9′-hexahydro-1H-xanthen-9-ol(OH-TriBHD),a hydroxylated secondary metabolite previously detected together with TriBHD and TetraBHD in a sponge known to be a natural producer of PBHDs.The estimated mean amount of the presumed OH-TriBHD was 3000 ng/g blubber,which is unexpectedly high for hydroxylated compounds in the lipids of marine mammals.展开更多
Zero-valent iron(ZVI),an ideal reductant treating persistent pollutants,is hampered by issues like corrosion,passivation,and suboptimal utilization.Recent advancements in nonmetallic modified ZVI(NM-ZVI)show promising...Zero-valent iron(ZVI),an ideal reductant treating persistent pollutants,is hampered by issues like corrosion,passivation,and suboptimal utilization.Recent advancements in nonmetallic modified ZVI(NM-ZVI)show promising potential in circumventing these challenges by modifying ZVI's surface and internal physicochemical properties.Despite its promise,a thorough synthesis of research advancements in this domain remains elusive.Here we review the innovative methodologies,regulatory principles,and reduction-centric mechanisms underpinning NM-ZVI's effectiveness against two prevalent persistent pollutants:halogenated organic compounds and heavy metals.We start by evaluating different nonmetallic modification techniques,such as liquid-phase reduction,mechanical ball milling,and pyrolysis,and their respective advantages.The discussion progresses towards a critical analysis of current strategies and mechanisms used for NM-ZVI to enhance its reactivity,electron selectivity,and electron utilization efficiency.This is achieved by optimizing the elemental compositions,content ratios,lattice constants,hydrophobicity,and conductivity.Furthermore,we propose novel approaches for augmenting NM-ZVI's capability to address complex pollution challenges.This review highlights NM-ZVI's potential as an alternative to remediate water environments contaminated with halogenated organic compounds or heavy metals,contributing to the broader discourse on green remediation technologies.展开更多
文摘The highly selective catalytic hydrogenation of halogenated nitroaromatics was achieved by employing Pd‑based catalysts that were co‑modified with organic and inorganic ligands.It was demonstrated that the catalysts contained Pd species in mixed valence states,with high valence Pd at the metal‑support interface and zero valence Pd at the metal surface.While the strong coordination of triphenylphosphine(PPh3)to Pd0 on the Pd surface prevents the adsorption of halogenated nitroaromatics and thus dehalogenation,the coordination of sodium metavanadate(NaVO3)to high‑valence Pd sites at the interface helps to activate H2 in a heterolytic pathway for the selective hydrogenation of nitro‑groups.The excellent catalytic performance of the interfacial active sites enables the selective hydrogenation of a wide range of halogenated nitroaromatics.
基金supported by the National Natural Science Foundation of China(No.52300005)China Postdoctoral Science Foundation(No.2023TQ0098)+5 种基金Heilongjiang Postdoctoral Fund(No.LBH-Z23175)Heilongjiang Touyan Innovation Team Program(No.HIT-SE-01)the Crossover Fund of Medical Engineering Science of Harbin Institute of Technology(No.IR2021107)the National Natural Science Foundation of International(Regional)Cooperation and Exchange Project(No.51961125104)the State Key Laboratory of Urban Water Resource and Environment(Harbin Institute of Technology)(No.2022TS15)the Ecological and Environmental Protection Research Project of Heilongjiang Province(No.HST2022ST006).
文摘Halogenated aromatic disinfection byproducts(DBPs)are gradually receiving attention due to their high detection frequency and usually higher toxicity than regulated DBPs.In this study,we established a solid phase extraction(SPE)-LC-MS/MS method to simultaneously trace analyze 59 halogenated aromatic DBPs.The limits of detection and limits of quantification of halogenated aromatic DBPs ranged from 0.03 to 135.23 ng/L and from 0.1 to 450.76 ng/L,respectively.The range of recoveries and relative standard deviation(RSD)in river water were between 72.41%to 119.54%and 1.86%to 16.03%,respectively.Therefore,this method can be used to accurately analyze trace levels of halogenated aromatic DBPs in drinking water.The occurrence and transformation of halogenated aromatic DBPs were explored based on this method.In the chlorinated simulated source water and chlorinated river water,20 and 45 halogenated aromatic DBPs were determined,respectively.The active halogen species(HOCl,HOBr,and HOI)first reacted with natural organic matter(NOM)to form halogenated aromatic DBPs.Then,chlorine further reacted with the halogenated aromatic DBPs to convert them into small-molecule halogenated aliphatic DBPs through oxidation,electrophilic substitution,and hydrolysis reaction,etc.In the chlorinated simulated source water,chlorinated river water,and tap water,the toxicity contribution of bromoacetic acids(Br-HAAs)accounted for themajority(>71.16%).Given that halogenated aromatic DBPs are intermediate products of halogenated aliphatic DBPs,controlling the formation of halogenated aromatic DBPs is beneficial in decreasing the formation of halogenated aliphatic DBPs,thereby diminishing the toxicity of drinking water.
基金financially supported by the National Natural Science Foundation of China(22176059,21777042,and 22076045)the authors would also like to acknowledge support from the Science and Technology Commission of Shanghai Municipality’s Yangfan Special Project(23YF1408400)the Fundamental Research Funds for the Central Universities.
文摘Despite the extensive application of advanced oxidation processes(AOPs)in water treatment,the efficiency of AOPs in eliminating various emerging contaminants such as halogenated antibiotics is constrained by a number of factors.Halogen moieties exhibit strong resistance to oxidative radicals,affecting the dehalogenation and detoxification efficiencies.To address these limitations of AOPs,advanced reduction processes(ARPs)have been proposed.Herein,a novel nucleophilic reductant—namely,the carbon dioxide radical anion(CO_(2)^(·-))—is introduced for the simultaneous degradation,dehalogenation,and detoxification of florfenicol(FF),a typical halogenated antibiotic.The results demonstrate that FF is completely eliminated by CO_(2)^(·-),with approximately 100%of Cland 46%of Freleased after 120 min of treatment.Simultaneous detoxification is observed,which exhibits a linear response to the release of free inorganic halogen ions(R^(2)=0.97,p<0.01).The formation of halogen-free products is the primary reason for the superior detoxification performance of this method,in comparison with conventional hydroxyl-radical-based AOPs.Products identification and density functional theory(DFT)calculations reveal the underlying dehalogenation mechanism,in which the chlorine moiety of FF is more susceptible than other moieties to nucleophilic attack by CO_(2)^(·-).Moreover,CO_(2)^(·-)-based ARPs exhibit superior dehalogenation efficiencies(>75%)in degrading a series of halogenated antibiotics,including chloramphenicol(CAP),thiamphenicol(THA),diclofenac(DLF),triclosan(TCS),and ciprofloxacin(CIP).The system shows high tolerance to the pH of the solution and the presence of natural water constituents,and demonstrates an excellent degradation performance in actual groundwater,indicating the strong application potential of CO_(2)^(·-)-based ARPs in real life.Overall,this study elucidates the feasibility of CO_(2)^(·-)for the simultaneous degradation,dehalogenation,and detoxification of halogenated antibiotics and provides a promising method for their regulation during water or wastewater treatment.
文摘Ensuring the health and safety of drinking water is crucial for both nations and their citizens.Since the 20th century,the disinfection of drinking water,effectively controlling pathogens in water sources,has become one of the significant advances in public health.However,the disinfectants used in the process,such as chlorine and chlorine dioxide,react with natural organic matter in the water to produce disinfection by-products(DBPs).Most of these DBPs contain chlorine,and if the source water contains bromine or iodine,brominated or iodinated DBPs,collectively referred to as Halogenated disinfection byproducts(X-DBPs),are formed.Numerous studies have found that X-DBPs pose potential risks to human health and the environment,leading to widespread concern.Mass spectrometry has become an important means of discovering new types of X-DBPs.This paper focuses on the study of methods for analyzing X-DBPs in drinking water using mass spectrometry.
基金supported by the National Natural Science Foundation of China(20977046, 20737001) the Natural Science Foundation of Zhejiang Province(2007Y507280)
文摘In this paper we take photobacterium phosphoreum （T3） as the experimental bacteria, and determine the half-inhibitory concentration （-1gEC50） against the photobacterium phosphoreum of 16 halogenated benzenes. Using B3LYP method of DFT in the Gaussian 03 program, we obtain the structural and thermodynamic descriptors of 16 halogenated benzenes by fully-optimized calculation at the 6-311G＊＊ level. Taking the structural and thermodynamic descriptors as theoretical descriptors, the 2D QSAR model （R2 = 0.983） was established, which can be utilized to predict -lgEC50 of halogenated benzene according to the corrected linear solvation energy theory based on the experimental data of-lgECs0. In addition, the relationship between the toxicity and 3D spatial structure of the compound is studied by comparing the molecular similarity index analysis （CoMSIA） of 3D-QSAR method. By cross validation, the correlation coefficient q2 of CoMSIA model is 0.687, and the conventional correlation coefficient R2 = 0.958. The model is stable and reliable with great predictive ability. The 3D-QSAR model shows that the toxicity of halogenated benzene compound is mainly affected by the characteristics of hydrophobie field of the substituted halogens.
基金This work was supported by the National Natural Science Foundation of China (No. 20502022) and the Ph.D. Fund of Ningbo ( No. 2004A610010)
文摘Halogenated methyl-phenyl ethers （anisoles） are ubiquitous organic compounds in the environment. In the present study, geometrical optimization and electrostatic potential calculations have been performed for 42 halogenated anisoles at the HF/6-31 G^＊ level. A number of statistically based parameters have been obtained. By multiple regression method, linear relationships between the gas-chromatographic relative retention time （RRT） and structural descriptors have been established for the training set of 32 halogenated anisoles. The result showed that the parameters derived from electrostatic potentials （ESPs） together with the molecular volume （Vmc） could be well used to express the quantitative structure-RRT relationships of halogenated anisoles. The best two-variable regression model gives a correlation coefficient of 0.980 and a standard deviation of 0.07, and the leave-one-out cross-validated correlation coefficient is 0.975. The goodness of the model has been further validated through exploring the predictive power for the testing set of 10 halogenated anisoles.
基金supported by the National Natural Science Foundation of China(Nos.20976164,21176221 and 21136001)National Basic Research Program of China(973 Program)(Nos. 2011CB710803,2013CB733500)Zhejiang Provincial Natural Science Foundation of China(No.LY12B03005)
文摘This study shows that minor amount of water plays a very important role in solvent-free hydrogenation of halogenated nitrobenzenes. For dried sponge Pd, the reaction cannot occur in the absence of water. For Pd/C catalyst, minor amount of water reduces the induction time, increases the reaction rate and reaction TOFs. Water might enhance the diffusion, adsorption and dissociation of H2 on Pd catalysts.
基金Supported by the National Natural Science Foundation of China(Nos.21473159 and91334013)
文摘The selective hydrogenation of halogenated nitrobenzene over noble metal catalysts(Pd, Pt, and Ir) has attracted much attention owing to its high efficiency and environmental friendliness. However, the effect of size on the catalytic performance varies among different metal catalysts. In this study, sub-nano(<3 nm) Ir and Pd particles were prepared, and their catalytic properties for hydrogenation of halogenated nitrobenzene were evaluated.Results show that high selectivity(N 99%) was achieved over small Ir nanoparticles, in which the selectivity over the Pd with same size was much lower than that on Ir nanoparticles. Meanwhile, Ir and Pd have different hydrogen consumption rates and reaction rates. Density functional theory calculations showed that p-chloronitrobenzene(CNB) has different adsorption properties on Ir and Pd. The distance between oxygen(cholorine) and Ir is much shorter(longer) than that between oxygen and Pd. The reaction barriers of dechlorination of p-CNB and p-chloroaniline over different Ir models are much larger than those on Pd. Especially,lower coordination of Ir leads to larger barriers of dechlorination reaction. These theoretical results explain the difference between Ir and Pd on hydrogenation of halogenated nitrobenzene.
文摘Geometrical optimization and electrostatic potential calculations have been performed for a series of halogenated hydrocarbons at the HF/Gen-6d level. A number of electrostatic potentials and the statistically based structural descriptors derived from these electrostatic potentials have been obtained. Multiple linear regression analysis and artificial neural network are employed simultaneously in this paper. The result shows that the parameters derived from electrostatic 2 potentials σtot^2, V s and ∑ Vs^＋, together with the molecular volume （Vine） can be used to express the quantitative structure-infinite dilution activity coefficients （γ^∞） relationship of halogenated hydrocarbons in water. The result also demonstrates that the model obtained by using BFGS quasiNewton neural network method has much better predictive capability than that from multiple linear regression. The goodness of the model has been validated through exploring the predictive power for the external test set. The model obtained via neural network may be applied to predict γ^∞ of other halogenated hydrocarbons not present in the data set.
基金The National Nature Science Foundation of China(Nos.51002090 and 50972078)the Outstanding Young Scientist Research Award Fund of Shandong Province(No.BS2010CL028)were gratefully acknowledged for financial support
文摘The halogenated boron-doped diamond （BDD） surfaces were reacted with sodium azide through a nucle- ophilic substitution reaction. The resulting azide-terminated BDD surfaces were used to trigger the ＂click＂ reaction. Because of the attractive electrochemical properties of ferrocene-containing molecules, such as fast electron transfer rates, reversible redox activities, and favorable redox potentials, we show that ferrocene derivatives can be grafted onto non-oxidized diamond surfaces by ＂click chemistry＂. These redox-active ferrocene-containing layers on a BDD surface, because of their ability to store and release charges reversibly, have the potential to be used as hybrid molecular/semiconductor memory devices.
基金financial support by the open project program of Key Laboratory of Environmentally Friendly Chemistry and Applications of Ministry of Education of China(No.09HJYH04)Hunan Science & Technology Department Project(No.2009FJ3166)
文摘"One-step"method for the synthesis of secondary aliphatic amine substituted nitrobenzaldehyde was developed.In the presence of Pd catalyst,halogenated nitrobenzaldehyde could be smoothly coupled with secondary aliphatic amine to give the target product in hexamethylphosphamide(HMPT) media without the protection of aldehyde groups.
文摘A quantitative structure-property relationship （QSPR） study was suggested for the prediction of infinite dilution activity coefficients of halogenated hydrocarbons, γ∞ , in water at 298.15 K. After optimization of 3D geometry of the halogenated hydrocarbons with semi-empirical quantum chemical calculations at the AM1 level, different descriptors （1514 descriptors） were calculated by the HyperChem and Dragon softwares. A major problem of QSPR is the high dimensionality of the descriptor space; therefore, descriptor selection is the most important step. In this paper, an ant colony optimization （ACO） algorithm was proposed to select the best descriptors. Then the selected descriptors were applied for model development using multiple linear regression. The average absolute relative deviation and correlation coefficient for the training set were obtained as 4.36% and 0.951, respectively, while the corresponding values for the test set were 5.96% and 0.929, respectively. The results showed that the applied procedure is suitable for the prediction of γ∞ of halogenated hydrocarbons in water.
文摘The capacity factors （k＇） of fourteen types ofhalogenated thiophenols in different phases of methanol-water eluent were determined by reversed phased high-performance liquid chromatography （RP-HPLC） and the relationships between the logarithm of capacity factor lgK＇ and methanol ratio ψ were analyzed. A fair linear relationship is found between lgK＇ and ψ, and the correlation coefficients R2 of the constructed linear equations are all greater than 0.990. Relationship between the chromatographic data lgKw＇ when extrapolated to pure water and n-octanol/water partition coefficient lgKow obtained by the group contribution method has shown a good linear correlation with R2= 0.956. The structure parameters of fourteen halogenated thiophenols were calculated by using DFT, and the correlation equation of lgKw＇ and structure parameters was obtained by using SPSS, lgKw＇ = -0.409 ＋ 0.039a and R2 = 0.981, meaning that lgKw＇ is mainly determined by the polarizability α.
文摘We have shown recently that halogenated quinones could enhance the decomposition of hydroperoxides and formation of alkoxyl/hydroxyl radicals independent of transition
基金supported by the National Natural Science Foundation of China (Nos. 5217000952091542)+6 种基金National Key Research and Development Program of China (2021YFC3200702)Science and Technology Innovation Action Plan of Shanghai Science and Technology Commission (No. 21DZ1202203)Program of Shanghai Academic Research Leader (No. 21XD1424000)International Cooperation Project of Shanghai Science and Technology Commission (No. 20230714100)Shanghai Soft Science Project (No. 20692113900)Tongji University Youth 100 Programsupported by Shanghai Post-doctoral Excellence Program (No. 2021327)。
文摘Disinfection by-products(DBPs), formed from the reactions of disinfectants with natural organic matter and halides in drinking water, were considered to be cytotoxic and genotoxic, and might trigger various cancers. The relatively low concentration of DBPs in finished water(low μg/L or even ng/L levels) and the interference from water matrix inhibited in situ determination of DBPs. Moreover, the further formation and degradation of DBPs by disinfectants during the holding time(several hours to several days) from sample collection to analysis could adversely affect the determination of DBPs. To obtain accurate, precise and reliable data of DBP occurrence and formation, robust and reliable sample preservation is indispensable. However, the commonly used quenching agents(e.g., sodium sulfite, sodium thiosulfate, and ascorbic acid) for sample preservation can decompose reactive DBPs by reductive dehalogenation. This study evaluated the performance of N-acetylcysteine(NAC) and glutathione(GSH) as quenching agents for the analysis of halogenated DBPs by investigating the stoichiometry of the disinfectant-quenching agent reaction, the formation of DBPs during chlor(am)ination of NAC or GSH, and the effects of NAC or GSH on the stability of 18 individual DBPs and total organic halogen(TOX). Based on the results of this study, NAC and GSH were considered to be ideal quenching agents for the analysis of most DBPs and TOX, except halonitromethanes.
基金supported by the National Natural Science Foundation of China(No.32061160476).
文摘Rice,a primary food staple for over half of the global population,is susceptible to environmental pollution.The presence of lipophilic halogenated contaminants,including halogenated polycyclic aromatic hydrocarbons(XPAHs),polychlorinated biphenyls(PCBs),organochlorine pesticides(OCPs),brominated flame retardants(BFRs),and polyfluoroalkyl substances(PFAS),has become a growing concern due to their potential health risks and environmental impact.This review focused on the research of lipophilic halogenated contaminants in rice.We summarized the physicochemical properties,toxicity profiles,and contamination levels in rice.Moreover,the strategies for reducing lipophilic halogenated contaminant levels in rice were summarized and proposed,such as phytoremediation and improved processing methods.These findings can provide a reference for the understanding and control of lipophilic halogenated contaminants during rice growing and processing,and therefore reduce the associated risks.
基金supported by the National Natural Science Foundation of China(No.223B2306)the Innovation Capability Support Program of Shaanxi Province(2023-CX-TD-49)the Natural Science Basic Research Program of Shaanxi Province(2025JC-JCQN-043).
文摘The rovibrational spectra of thioanisole(TA)and its halogenated derivatives,3-fluorothioanisole(3FTA)and 3-chlorothioanisole(3ClTA),were measured using synchrotron-based Fourier transform infrared spectroscopy(FTIR)at the Canadian Light Source.Combined with density functional theory calculations,the stable structures and vibrational modes of TA,3FTA,and 3ClTA in their vibrational states were analyzed.The theoretical vibrational mode frequencies were corrected by simulating the rotational structure of a vibrational band.The contributions of the cis-and trans-isomers of 3FTA and 3ClTA to the FTIR spectra at 298 K were estimated using the Boltzmann distribution,revealing their coexistence in the experimental spectra.The results indicate that both fluorine and chlorine substitution significantly affect the vibrational modes,particularly in the benzene ring.Compared to TA,the FTIR spectra of 3FTA and 3ClTA show changes in the frequencies and intensities of some vibrational modes,with halogen substitution causing specific modes to shift to higher wavenumbers.A comparison of the FTIR spectra of TA,3FTA,and 3ClTA highlights the influence of halogen substitution on vibrational properties,emphasizing how the type and position of the substituent affect frequency shifts and spectral intensities.These findings provide deeper insights into how halogenation alters vibrational spectra,which is crucial for further spectral analysis and molecular structure determination.
文摘Halogenated natural products(HNPs)are considered to be emerging contaminants whose environmental distribution and fate are only incompletely known.Therefore,several persistent and bioaccumulative HNP groups,together with manmade polychlorinated biphenyls(PCBs)and polybrominated diphenyl ethers(PBDEs),were quantified in the blubber of nine sperm whales(Physeter macrocephalus)stranded on the coast of the Mediterranean Sea in Italy.The naturally occurring polybrominated hexahydroxanthene derivatives(PBHDs;sum of TetraBHD and TriBHD)were the most prominent substance class with up to 77,000 ng/g blubber.The mean PBHD content(35,800 ng/g blubber)even exceeded the one of PCBs(28,400 ng/g blubber),although the region is known to be highly contaminated with manmade contaminants.Based on mean values,Q1∼PBDEs>MeO-BDEs∼2,2′-diMeO-BB 80 and several other HNPs followed with decreasing amounts.All blubber samples contained an abundant compound whose molecular formula(C_(16)H_(19)Br_(3)O_(2))was verified using high-resolution mass spectrometry.The only plausible matching isomer was(2S,4′S,9R,9′S)-2,7-dibromo-4′-bromomethyl-1,1-dimethyl-2,3,4,4′,9,9′-9,9′-hexahydro-1H-xanthen-9-ol(OH-TriBHD),a hydroxylated secondary metabolite previously detected together with TriBHD and TetraBHD in a sponge known to be a natural producer of PBHDs.The estimated mean amount of the presumed OH-TriBHD was 3000 ng/g blubber,which is unexpectedly high for hydroxylated compounds in the lipids of marine mammals.
基金supported by the NSFC-JSPS joint research program(No.51961145202)the National Natural Science Foundation of China(No.52370163,52321005,and 52293443)the State Key Laboratory of Urban Water Resource and Environment(Harbin Institute of Technology)(No.2022TS42).
文摘Zero-valent iron(ZVI),an ideal reductant treating persistent pollutants,is hampered by issues like corrosion,passivation,and suboptimal utilization.Recent advancements in nonmetallic modified ZVI(NM-ZVI)show promising potential in circumventing these challenges by modifying ZVI's surface and internal physicochemical properties.Despite its promise,a thorough synthesis of research advancements in this domain remains elusive.Here we review the innovative methodologies,regulatory principles,and reduction-centric mechanisms underpinning NM-ZVI's effectiveness against two prevalent persistent pollutants:halogenated organic compounds and heavy metals.We start by evaluating different nonmetallic modification techniques,such as liquid-phase reduction,mechanical ball milling,and pyrolysis,and their respective advantages.The discussion progresses towards a critical analysis of current strategies and mechanisms used for NM-ZVI to enhance its reactivity,electron selectivity,and electron utilization efficiency.This is achieved by optimizing the elemental compositions,content ratios,lattice constants,hydrophobicity,and conductivity.Furthermore,we propose novel approaches for augmenting NM-ZVI's capability to address complex pollution challenges.This review highlights NM-ZVI's potential as an alternative to remediate water environments contaminated with halogenated organic compounds or heavy metals,contributing to the broader discourse on green remediation technologies.
