WATER RESEARCH
·
2019
·
IF 7.913
Xinran Zhang,Pengfei Ren,Weiguang Li,Yu Lei,Xin Yang,Ernest R. Blatchley
The presence of ammonium (NH 4 + ) in drinking water treatment results in inhibition of disinfection efficiency and formation of nitrogenous disinfection by-products. Our previous study found monochloramine (NH 2 Cl) photolysis under 254 nm UV irradiation can be effective for removal of NH 4 + ; however, the mechanisms of NH 4 + degradation in this process were unknown. The kinetics and fundamental radical chemistry responsible for NH 4 + removal in the UV/NH 2 Cl process were investigated in this study. The results showed that the pseudo first-order rate constant for NH 4 + degradation in the UV/NH 2 Cl process ranged between 3.6 × 10 −4 to 1.8 × 10 −3 s −1 . Solution pH affected radical conversion and a higher NH 4 + degradation efficiency was achieved under acidic conditions. The effects of chloride were limited; however, the presence of either bicarbonate or natural organic matter scavenged radicals and inhibited NH 4 + removal. NH 2 Cl photolysis generated an aminyl radical (NH 2 • ) and a chlorine radical (Cl • ) that further transformed to a chlorine dimer (Cl 2 •- ) and a hydroxyl radical (HO • ). The second-order rate constants for Cl • and Cl 2 •- reacting with NH 4 + were estimated as 2.59 × 10 8 M −1 s −1 and 3.45 × 10 5 M −1 s −1 at pH 3.9, respectively. Cl • , Cl 2 •- , and HO • contributed 95.2%, 3.5%, and 1.3% to NH 4 + removal, respectively, at the condition of 3 mM NH 2 Cl and pH 7.5. Major products included nitrite and nitrate, possibly accompanied by nitrogen-containing gases. This investigation provides insight into the photochemistry of NH 4 + degradation in the UV/NH 2 Cl process and offers an alternative method for drinking water production.
研究领域:
环境科学
·
饮用水处理
✓ 已验证
产品关联
DOI
PubMed
高影响因子
LANGMUIR
·
2024
·
IF 3.7
Zeqi Wu,Feng Niu,Wenhao Yao,Siyuan Gao,Da Chen,Yuexiang Huang
The activation of an inert C(sp3)–H bond in selective oxidation of hydrocarbons under mild conditions is a critical and challenging process. Herein, we report a stable chlorine-coordinated metal–organic framework (MOF) photocatalyst, MIL-101(Fe), for efficient visible-light-driven photocatalytic selective oxidation of toluene to benzaldehyde in air under ambient conditions. Encouragingly, a benzaldehyde formation yield of 3.11 mmol·g–1·h–1 with a selectivity of 92.1% is achieved in 5 h, which is superior to most of the reported works. Based on the experimental results and characterizations, the high catalytic performance is mainly due to the promoted rate-limiting step of C(sp3)–H bond activation by a chlorine radical (Cl·) from the coordinated −Cl in the MIL-101(Fe) structure. In addition, the present photocatalyst possesses good substrate tolerance for photocatalytic selective oxidation of various toluene derivatives under optimized conditions.
研究领域:
化学
·
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHINESE JOURNAL OF STRUCTURAL CHEMISTRY
·
2024
·
IF 5.9
Limin Wang,Feiyi Huang,Xinyi Liang,Rajkumar Devasenathipathy,Xiaotian Liu,Qiulan Huang,Zhongyun Yang,Dujuan Huang,Xinglan Peng,Du-Hong Chen,Youjun Fan,Wei Chen
Chemical functionalization of graphene is a topic of paramount importance to broaden its applications in chemistry, physics, and biological science but remains a great challenge due to its low chemical activity and poor dispersion. Here, we report a strategy for the photosynergetic electrochemical functionalization of graphene (EFG). By using chloride ion (Cl − ) as the intercalation anions and co-reactants, the electrogenerated radicals confined in the expanded graphite layers enable efficient radical addition reaction, thus grasping crystalline-perfect EFG. We found that the ultraviolet irradiation and applied voltage have increased the surface/interface concentration of Cl • , thus boosting the functionalization of graphene. Theoretical calculation and experimental results verified the oxygen evolution reaction (OER) on EFG has been improved by regulating the doping of chlorine atoms. In addition, the reduced interlayer distance and the enhanced electrostatic repulsion near the basal plane endow the fabricated EFG-based membrane with high salt retention. This work highlights a method for the in situ functionalization of graphene and the subsequent applications in OER and water desalination.
研究领域:
材料科学
·
化学工程
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Lu-Yan Zhang,Chen-Hao Cui,Shan-Shan Yang,Yan Li,Han-Jun Sun,Nan-Qi Ren,Jie Ding
The development of sustainable and efficient wastewater treatment technologies is vital for tackling the challenges posed by high salinity and antibiotic-contaminated industrial wastewater. In this study, a highly active, metal-free photocatalyst (AQ@CN) was successfully synthesized via a simple and environmentally friendly method. Under conditions of high chloride ion (Cl - ) concentration, AQ@CN exhibited a for significantly enhanced degradation rate constant for sulfadiazine (SDZ), achieving a rate five times higher than that of g-C 3 N 4 . Mechanistic investigations identified superoxide radicals ( • O 2 – ), dichloride radicals ( • Cl 2 - ), and photogenerated holes (h + ) as the primary reactive species. Photoelectrochemical experiments and density functional theory (DFT) calculations revealed that the incorporation of anthraquinones (AQs) optimized local electron density, facilitating the separation of photogenerated carriers and enhancing the electron transfer rate. Furthermore, the degradation pathway of SDZ was proposed, and the toxicity of the degradation products was substantially reduced. This study offers an effective strategy to enhance the performance of metal-free photocatalysts, providing a robust theoretical and technical foundation for pollutant degradation in complex high-salinity industrial wastewater.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Fishes
·
2025
·Vol. 10
·期 3
·116
·
IF 2.4
Qikai Liu,Yang Liu,Yaqi Mao,Ru Li,Yujie Jiao,Jiali Lei,Fenzhen Zhang
The degradation of organic matter using TiO2nanotube photocatalytic technology is limited by the short lifetime and diffusion radius of the generated hydroxyl radicals, decreasing the removal efficiency. This study developed a chlorine radical-coupled photoelectrocatalytic system, significantly enhancing the performance of TiO2nanotube arrays in removing sulfonamide antibiotics (SAs) from cold-water aquaculture systems. The highest degradation rates were observed at 5 mM NaCl and 15 mM NaNO3. When SA concentrations were 0.1–10 mg/L, degradation efficiency decreased with higher initial concentrations. The best degradation was achieved at an initial pH of 3 for SA. Humic acid and sodium acetate, natural organic matter in the water column, served as low-concentration promoters and high-concentration inhibitors. In our study, three degradation intermediates were identified, and hydrolysis and nitration reactions are proposed as the primary pathways for SA degradation. We confirmed that oxygen radicals play a major role in this system. Furthermore, toxicology experiments revealed the weakening of the toxicity of the degraded products. This study provides an efficient method for treating organic matter in cold-water fish culture water in chloride-containing saline and alkaline waters.
研究领域:
环境科学
·
水产养殖学
·
毒理学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2025
·
IF 21.1
Xiaoai Guo,Zhiyan Feng,Miao Li,Chencheng Qin,He Zhang,Qian Peng,Jiaxin Wu,Aoqiang Shu,Abing Duan,Xingzhong Yuan,Hou Wang
A circulating microdroplet-driven self-Fenton system (MDSFS) was developed for efficient wastewater treatment utilizing the synergism of microdroplet chemistry and metal-to-ligand charge transfer (LMCT) without requiring external light, catalysts, or sacrificial agents. This innovative system was pioneered by nebulizing a ferric chloride–sulfamethoxazole complex solution into microdroplets via ultrasonic technology. The MDSFS achieved a superior performance with a H₂O₂ yield of 258.5 μM, achieving an 11-fold faster iron cycling rate and a 5-fold higher reaction rate constant (0.139 min⁻¹ vs. 0.029 min⁻¹) for sulfamethoxazole removal compared to traditional bulk Fenton system. The microdroplets acted as an active medium, facilitating electron generation, •OH radical formation, H₂O₂ production, and enhancing ligand-to-metal charge transfer via the air-water interfacial electric field. This enables a dual redox cycle of Fe(III)/Fe(II) and Cl⁻/•Cl, generating abundant •OH and •Cl for efficient SMX removal. The study proposes a sustainable, self-driven redox strategy for environmental remediation and health.
研究领域:
环境科学
·
化学工程
·
废水处理
✓ 已验证
产品关联
DOI
高影响因子
Engineering
·
2025
·
IF 11.6
Bin Zhao,Jialin Yang,Ruiping Liu,Jiuhui Qu,Meng Sun
The contamination of wastewater with organic pollutants and nitrogen compounds poses significant environmental challenges. The primary objective of wastewater treatment is the simultaneous denitrification and decarbonization of ammonia nitrogen into harmless by-products. This study presents a novel method for the directional generation of chlorine radical species like ·ClO and ·Cl using electro-reactive membranes (EMs), which were fabricated using an electro-deposition coupled template approach known as RuO 2 @PbO 2 -M. This method facilitates the rapid and efficient conversion of ammonia to nitrogen and concurrently reduces the chemical oxygen demand in the effluent. Our system achieved ultra-efficient simultaneous denitrification and decarbonization with minimal energy consumption in single-filtration mode, thereby eliminating the need for chemical precursors. We elucidate the formation pathway of ·ClO and ·Cl during the electrochemical oxidation process involving RuO 2 @PbO 2 -M, where ·Cl generated from RuO 2 reacts with ·OH from PbO 2 under hypochlorous acid conditions, thereby enhancing nitrogen and carbon removal. These findings highlight a novel filtration model that utilizes single-channel electro-filtration and an innovative reactive membrane design for ·ClO synthesis, which provides a new research framework for the concurrent removal of nitrogen and carbon, and offers a promising solution to enhance wastewater treatment efficiency.
研究领域:
环境科学
·
水处理技术
·
电化学
·
膜科学
·
化学工程
·
可持续废水管理
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2024
·
IF 10.8
Wenxiao Zheng,Xin Luo,Hengyi Fu,Weijian Duan,Shishu Zhu,Xin Yang,Chunhua Feng
The electrochemical technology provides a practical and viable solution to the global water scarcity issue, but it has an inherent challenge of generating toxic halogenated byproducts in treatment of saline wastewater. Our study reveals an unexpected discovery: the presence of a trace amount of Br– not only enhanced the electrochemical oxidation of organic compounds with electron-rich groups but also significantly reduced the formation of halogenated byproducts. For example, in the presence of 20 μM Br–, the oxidation rate of phenol increased from 0.156 to 0.563 min–1, and the concentration of total organic halogen decreased from 59.2 to 8.6 μM. Through probe experiments, direct electron transfer and HO• were ruled out as major contributors; transient absorption spectroscopy (TAS) and computational kinetic models revealed that trace Br– triggers a shift in the dominant reactive species from Cl2•– to Br2•–, which plays a key role in pollutant removal. Both TAS and electron paramagnetic resonance identified signals unique to the phenoxyl and carbon-centered radicals in the Br2•–-dominated system, indicating distinct reaction mechanisms compared to those involving Cl2•–. Kinetic isotope experiments and density functional theory calculations confirmed that the interaction between Br2•– and phenolic pollutants follows a hydrogen atom abstraction pathway, whereas Cl2•– predominantly engages pollutants through radical adduct formation. These insights significantly enhance our understanding of bromine radical-involved oxidation processes and have crucial implications for optimizing electrochemical treatment systems for saline wastewater.
研究领域:
环境科学
·
电化学
·
水处理技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Shizong Wang,Jianlong Wang
Coking wastewater concentrate (CWC) generated during the membrane filtration process is difficult to treat mainly due to its higher chloridion concentration. Advanced oxidation process is ineffective in treating CWC because of the quenching effect of chloridion on hydroxyl radicals. In this study, peroxymonosulfate (PMS)/chloridion process was developed to treat CWC, and 2,4-dimethyphenol (DMP) was selected as targeted pollutant to investigate the reaction mechanism of PMS/chloridion process. Unlike the traditional view that hypochloride acids are the main active species during the PMS/chloridion process, it was found that singlet oxygen, hypochloric acids and chlorine radicals contributed to the degradation of DMP, which was evidenced by the quenching experiments, electron paramagnetic resonance spectroscopy and identified degradation products. Based on the degradation products, the possible degradation pathway of DMP was tentatively proposed. The PMS/chloridion process can be applied in a wide pH range from 3 to 8. The optimal ratio of PMS to chloridion was 1:1 for mineralizing DMP in which the maximum mineralization of DMP reached 33.3%. The PMS/chloridion process can effectively remove COD and colourity of actual CWC. However, the ratio of PMS to chloridion varied with the initial COD concentration of CWC. This study provides a novel treatment process for CWC, and an insight into the removal mechanism of the PMS/chloridion process.
研究领域:
环境工程
·
化学工程
·
废水处理
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Xiaoya Huang,Yan Zhang,Jing Bai,Jinhua Li,Linsen Li,Tingsheng Zhou,Shuai Chen,Jiachen Wang,Mohammadi Rahim,Xiaohong Guan,Baoxue Zhou
N-containing organic wastewater is harmful to human health and ecosystem while its degradation remains a huge challenge for decarburization and denitrification simultaneously. In this paper, we proposed a new photoelectrochemical method of chlorine oxide radicals production to oxidize mixture wastewater of phenol and N-ammonia into N 2 and CO 2 . The chlorine oxide radicals were generated via a rapid reaction of HClO with hydroxyl radicals or chlorine free radicals on a synergistic dual anode, in which hydroxyl radicals and chlorine free radicals generated on WO 3 side, and HClO generated on Sb-SnO 2 side, respectively. Phenol degradation rate on WO 3 -Sb/SnO 2 was 2.54 and 4.79 times than that on WO 3 and Sb/SnO 2 . Meanwhile, N-ammonia removal rate on WO 3 -Sb/SnO 2 was 5.69 and 20 times greater than that on WO 3 and Sb/SnO 2 , respectively. The effects of potential, Cl − concentration and initial pH were examined and the optimal conditions were potential 2.0 V vs Ag/AgCl, 0.05 M NaCl, pH = 5. The free radical quenching experiments and electron-spin resonance (ESR) confirmed that chlorine oxide radicals played an important role in the degradation of N-ammonia and phenol. Reasonable pathways of phenol in the WO 3 -Sb/SnO 2 system were also proposed. This work provides an exhaustive, novel, environmental-friendly photoelectrochemical system for N-containing organic wastewater treatment.
研究领域:
环境科学
·
化工工程
·
废水处理
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2021
·
IF 19.503
Cheng-Xin Chen,Shan-Shan Yang,Jie Ding,Guang-Yuan Wang,Le Zhong,Shuang-Yang Zhao,Ya-Ni Zang,Jun-Qiu Jiang,Lan Ding,Yan Zhao,Lu-Ming Liu,Nan-Qi Ren
In this study, the effect of chloride ion (Cl − ) on the degradation of sulfadiazine (SDZ) was evaluated using reduced graphene oxide (rGO) modified with sodium anthraquinone-2-sulfonate (AQ2S) photocatalyst ( [email protected] ), which was prepared in a one-pot hydrothermal synthesis. AQ2S molecules are small organic photoactive components, that are intercalated and immobilized on the rGO surface through noncovalent π-π stacking. Under solar light, SDZ effectively underwent 99 % photodegradation within 150 min in a Cl − -rich solution (0.5 mol/L). The [email protected] system exhibited an excellent photocatalytic removal ability for some typical contaminants. SDZ degradation was driven by 3 AQ2S*. Superoxide radicals ( O 2 − ) and dichlorine radicals (Cl 2 − ) were found to be the dominant reactive species, whereas OH and 1 O 2 have minor roles. Density functional theory (DFT) calculations confirmed the interactions between AQ2S and rGO, and the electronic structural characteristics between Cl − and [email protected] The [email protected] composite has great potential for use in treating micropollutants under saline water conditions under solar irradiation.
研究领域:
环境科学
·
纳米技术
·
光化学
·
材料科学
✓ 已验证
DOI
高影响因子
Environmental Chemistry
·
2018
·Vol. 15
·期 7
·411-423
·
IF 2.923
Shuyan Wang,Lin Du,Narcisse T. Tsona,Wenxing Wang
Environmental context Acetate esters, emitted into the atmosphere from both natural and anthropogenic sources, can participate in photochemical processes leading to the formation of secondary organic aerosols. We report a study on the kinetics and mechanisms of the reaction of two acetate esters with O3, OH, NO3, and Cl radicals. The results help our understanding of the chemical behaviour of this important class of compounds in the atmosphere. The photodegradation reactions of isopropenyl acetate (IPA) and 2-methyl-2-propenyl acetate (MPA) initiated by O3, OH, Cl and NO3 radicals have been investigated in a 100 L Teflon reactor at 293 ± 3 K, by using gas chromatography with flame-ionisation detection as well as thermal desorption–gas chromatography–mass spectrometry to monitor the reactants and the products. The rate constants for the reactions of IPA and MPA with the four atmospheric oxidants were determined by using either absolute or relative rate methods. The following rate constants (in units of cm3 molecule−1 s−1) were obtained: k(O3 + IPA) = (0.37 ± 0.06) × 10−18, k(OH + IPA) = (6.44 ± 0.74) × 10−11, k(Cl+ IPA) = (4.33 ± 0.52) × 10−10, k(NO3 + IPA) = (1.62 ± 0.22) × 10−14, k(O3 + MPA) = (2.76 ± 0.40) × 10−18, k(OH + MPA) = (7.41 ± 0.92) × 10−11, k(Cl + MPA) = (3.33 ± 0.39) × 10−10, k(NO3 + MPA) = (1.34 ± 0.23) × 10−14. With the exception of the kinetic study of the reactions of O3 and OH with IPA and the mechanistic study of the reaction of IPA with O3, the current research reports the first kinetic and mechanistic investigation for these reactions at atmospheric pressure. Acetic anhydride and 1-acetoxyacetone are the main products of the reactions of IPA and MPA, respectively. On the basis of the products and estimated tropospheric lifetimes of the two esters, reaction mechanisms are proposed and the atmospheric implications are discussed.
研究领域:
大气化学
·
环境科学
·
物理化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）