Insight into the mechanisms of trichloronitromethane formation by vacuum ultraviolet: QSAR model and FTICR-MS analysis.

Vacuum ultraviolet (VUV) photolysis is recognized as an environmental-friendly treatment process. Nitrate (NO) and natural organic matter (NOM) are widely present in water source. We investigated trichloronitromethane (TCNM) formation during chlorination after VUV photolysis, because TCNM is an unregulated highly toxic disinfection byproduct.

UV-induced activation of organic chloramine: Radicals generation, transformation pathway and DBP formation.

Organic chloramines of little disinfection efficacy commonly exist in disinfection process (chlor(am)ination) due to the wide presence of organic amines in water, of which N-chlorodimethylamine (CDMA) is a typical one. For the first time, UV photolysis for the activation of CDMA was investigated. UV photolysis caused the cleavage of N-Cl bond in CDMA to form Cl and subsequently HO, both of which are dominant contributors to the destruction of model contaminant bisphenol A (BPA).

The role of carbonate radicals on the kinetics, radical chemistry, and energy requirement of UV/chlorine and UV/HO processes.

Quantitative insight into the HCO-dependent degradation kinetics is critical to improve understanding of the UV processes for the most-cost effective application. In this study, we developed a kinetic model to precisely predict the kinetics in UV/HO and UV/chlorine processes. The second-order rate constants of HO, Cl, ClO, Cl, and CO with carbamazepine (CBZ) were fitted as 1.

Computerized Pathway Generator for the UV/Free Chlorine Process: Prediction of Byproducts and Reactions.

The ultraviolet (UV)/free chlorine process is a very promising treatment technology to remove persistent organic contaminants (POCs, e.g., pharmaceutical and personal care products) from water.

Simultaneous removal of chlorite and contaminants of emerging concern under UV photolysis: Hydroxyl radicals vs. chlorate formation.

It is well known that using chlorine dioxide (ClO) as a disinfectant inevitably produces a common disinfection byproducts chlorite (ClO). In this study, we found that UV photolysis after ClO disinfection can effectively eliminate both ClO and contaminants of emerging concern (CECs). However, the kinetic mechanisms of UV/ClO process destructing CECs, as well as transformation of ClO in UV/ClO system are not clear yet.

Development of a highly efficient electrochemical flow-through anode based on inner in-site enhanced TiO-nanotubes array.

This paper reports on the development of macroporous flow-through anodes. The anodes comprised an enhanced TiO nanotube array (ENTA) that was grown on three macroporous titanium substrates (MP-Ti) with nominal pore sizes of 10, 20, and 50 µm. The ENTA was then covered with SnO-SbO.

Development of a Three-Dimensional Electrochemical System Using a Blue TiO/SnO-SbO Anode for Treating Low-Ionic-Strength Wastewater.

Reducing energy use is crucial to commercialize electrochemical oxidation technologies. We developed a three-dimensional (3-D) electrochemical system that can significantly reduce the applied voltage and effectively degrade organic contaminants in low-ionic-strength wastewaters. The 3-D system consisted of a composite wire mesh anode (composed of blue TiO nanotubes covered with SnO-SbO), a proton exchange membrane, and a stainless-steel wire mesh cathode, which were compressed firmly together.

Non-negligible risk of chloropicrin formation during chlorination with the UV/persulfate pretreatment process in the presence of low concentrations of nitrite.

The UV/persulfate (PS) process is a promising water treatment technology, and it can not only effectively degrade contaminants of emerging concern, but also control formation of disinfection byproducts (DBPs). In this study, we investigated the potential and mechanisms of chloropicrin (i.e.

Deactivation Mechanism of Multipoisons in Cement Furnace Flue Gas on Selective Catalytic Reduction Catalysts.

Increasing numbers of cement furnaces have applied selective catalytic reduction (SCR) units for advanced treatment of NO in the flue gas. However, the SCR catalysts may face various poisons, such as acidic, alkaline, and heavy metal species, in the fly ash. In this work, we studied the deactivation mechanisms of multipoisons (Ca, Pb, and S) on the CeO-WO/TiO catalyst, using the in situ diffuse reflectance infrared Fourier transform spectroscopy method.

The individual and Co-exposure degradation of benzophenone derivatives by UV/HO and UV/PDS in different water matrices.

Benzophenone derivatives, including benzophenone-1 (CHO, BP1), benzophenone-3 (CHO, BP3) and benzophenone-8 (CHO, BP8), that used as UV filters are currently viewed as emerging contaminants. Degradation behaviors on co-exposure benzophenone derivatives using UV-driven advanced oxidation processes under different aqueous environments are still unknown. In this study, the degradation behavior of mixed benzophenone derivatives via UV/HO and UV/peroxydisulfate (PDS), in different water matrices (surface water, hydrolyzed urine and seawater) were systematically examined.

Oxidation Mechanisms of the UV/Free Chlorine Process: Kinetic Modeling and Quantitative Structure Activity Relationships.

Recently, the UV/free chlorine process has gained attention as a promising technology for destroying refractory organic contaminants in the aqueous phase. We have developed a kinetic model based on first-principles to describe the kinetics and mechanisms of the oxidation of organic contaminants in the UV/free chlorine process. Substituted benzoic acid compounds (SBACs) were chosen as the target parent contaminants.

Sulfadiazine destruction by chlorination in a pilot-scale water distribution system: Kinetics, pathway, and bacterial community structure.

Sulfadiazine (SDZ) has been frequently detected in surface waters in recent years. We evaluated the kinetics, mechanisms, intermediate products and bacterial community structure that result from the reaction of SDZ with free chlorine (HOCl/OCl). We examined this in a pilot-scale water distribution system.

The role of reactive oxygen species and carbonate radical in oxcarbazepine degradation via UV, UV/HO: Kinetics, mechanisms and toxicity evaluation.

Oxcarbazepine (OXC) is ubiquitous in the aqueous environment. And due to its ecotoxicological effects and potential risks to human, an effective way to eliminate OXC from aqueous environment has aroused public concerns in recent years. Radical-based reactions have been shown to be an efficient way for OXC destruction, but the reactions of OXC with reactive oxygen species (ROS) and carbonate radical (CO) are still unclear.

Impact of Chloride Ions on UV/HO and UV/Persulfate Advanced Oxidation Processes.

Chloride ion (Cl) is one of the most common anions in the aqueous environment. A mathematical model was developed to determine and quantify the impact of Cl on the oxidization rate of organic compounds at the beginning stage of the UV/persulfate (PS) and UV/HO processes. We examined two cases for the UV/PS process: (1) when the target organic compounds react only with sulfate radicals, the ratio of the destruction rate of the target organic compound when Cl is present to the rate when Cl is not present (designated as r/ r) is no larger than 1.

Oxidation of Microcystin-LR via Activation of Peroxymonosulfate Using Ascorbic Acid: Kinetic Modeling and Toxicity Assessment.

Advanced oxidation processes (AOPs) have been widely used for the destruction of organic contaminants in the aqueous phase. In this study, we introduce an AOP on activated peroxymonosulfate (PMS) by using ascorbic acid (HA) to generate sulfate radicals (SO). Sulfate radicals, hydroxyl radicals (HO), and ascorbyl radicals (A) were found using electron spin resonance (ESR).

Degradation of dyes by peroxymonosulfate activated by ternary CoFeNi-layered double hydroxide: Catalytic performance, mechanism and kinetic modeling.

Ternary CoFeNi-layered double hydroxide (CoFeNi-LDH) was synthesized and initially applied to activate peroxymonosulfate (PMS) for the degradation of Congo red (CR) and Rhodamine B (RhB). The results show that the CoFeNi-LDH/PMS system can efficiently degrade nearly 100% of 20 mg/L CR or 20 mg/L RhB within 6- and 10-min reaction times, respectively. And the catalyst exhibits higher degradation efficiency on CR than on RhB under identical conditions, which is confirmed by electron clouds of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) performed by DFT calculations.

Antagonist of thromboxane A2 receptor by SQ29548 lowers DOCA-induced hypertension in diabetic rats.

Diabetes is one of high risk factors for cardiovascular diseases, including atherosclerosis and hypertension. This study was conducted to elucidate whether and how thromboxane receptor (TPr) activation contributes to hypertension in diabetes. Human umbilical vein endothelial cells (HUVECs) were cultured.

Escherichia coli isolates from sick chickens in China: changes in antimicrobial resistance between 1993 and 2013.

The use of antimicrobials for the control of infectious disease has increased in recent decades. Understanding trends in antimicrobial resistance provides clues about the relationship between antimicrobial use and the emergence of resistance. We examined the resistance of 540 Escherichia coli isolates to 19 antimicrobials that represent 11 classes of antimicrobial agents.

[Prevalence and transmission of plasmid-mediated quinolone resistance qnrS gene among Escherichia coli isolates in a poultry farm].

Objective: To investigate the prevalence and transmission of plasmid-mediated quinolone resistance qnrS gene among Escherichia coli isolates in a poultry farm and its environment.

Methods: E. coli isolates from fecal samples in a poultry farm and its environment from February to June 2010 were screened for the prevalence and dynamic changes of qnrS gene.

Prevalence of qnr, aac(6')-Ib-cr, qepA, and oqxAB in Escherichia coli isolates from humans, animals, and the environment.

qnr, aac(6')-Ib-cr, qepA, and oqxAB genes were detected in 5.7%, 4.9%, 2.