Highly efficient adsorption of natural organic matter from aqueous solutions by macroporous weakly basic anion exchange resin: performance, mechanism, and fixed - bed column.

In this study, humic acid was used as a model pollutant to investigate the removal effect of a macroporous weakly alkaline anion exchange resin D301 on natural organic matter (NOM) in water. 3D fluorescence spectroscopy, UV - visible spectrophotometry and Fourier transform infrared (FTIR) spectroscopy were employed to analyze changes in the physical and chemical properties of humic acid solution and natural water samples before and after resin adsorption. The results showed that using humic acid as a model pollutant to simulate NOM in water is feasible.

Transcription factors CsWRKY53 and CsWRKY40 synergistically regulate l-theanine hydrolysis via the abscisic acid signaling pathway during tea withering.

l-Theanine hydrolysis in tea (Camellia sinensis) leaves not only reduces the quality of tea products but also decreases their health benefits. Postharvest dehydration-induced abscisic acid (ABA) contributes to l-theanine hydrolysis, but the specific underlying mechanism has not been explored. Based on transcriptome analysis and gene silencing experiments, CsNCED3a was shown to be a key gene for ABA synthesis in harvested tea leaves, and CsABF7 up-regulated the expression of CsWRKY40, which encodes a transcription factor that directly regulates a l-theanine hydrolysis gene, resulting in the loss of l-theanine.

Enhancement of 15% calcium oxide doped nano zero-valent iron on arsenic removal from high-arsenic acid wastewater.

Nano zero-valent iron (nZVI) has a great potential for arsenic removal, but it would form aggregates easily and consume largely by H in the strongly acidic solution. In this work, 15%CaO doped with nZVI (15%CaO-nZVI) was successfully synthesized from a simplified ball milling mixture combined with a hydrogen reduction method, which had a high adsorption capacity for As(V) removal from high-arsenic acid wastewater. More than 97% As(V) was removed by 15%CaO-nZVI under the optimum reaction conditions of pH 1.

Occurrence, distribution, and risk assessment of quinolone antibiotics in municipal sewage sludges throughout China.

A nationwide study of the occurrence, distribution, potential drivers, and ecological risks of 24 quinolone antibiotics (QNs) in 74 Chinese sludge samples from 48 wastewater treatment plants (WWTPs) was conducted. In domestic sludge, the ∑QNs concentrations were View Article and Find Full Text PDF

Whose Oxygen Atom Is Transferred to the Products? A Case Study of Peracetic Acid Activation via Complexed Mn for Organic Contaminant Degradation.

Identifying reactive species in advanced oxidation process (AOP) is an essential and intriguing topic that is also challenging and requires continuous efforts. In this study, we exploited a novel AOP technology involving peracetic acid (PAA) activation mediated by a Mn-nitrilotriacetic acid (NTA) complex, which outperformed iron- and cobalt-based PAA activation processes for rapidly degrading phenolic and aniline contaminants from water. The proposed Mn/NTA/PAA system exhibited non-radical oxidation features and could stoichiometrically oxidize sulfoxide probes to the corresponding sulfone products.

Identification of Heavy Metals and Organic Micropollutants in Drinking Water Sources in Typical Villages and Towns in Northeast China.

This study identified and detected the existence of major pollutants in northeast China. As an alpine region and an agricultural base, this region has representative significance in pollution research. We selected 56 samples from drinking water sources of typical villages and towns, focusing on the analysis of heavy metals and organic micropollutants in northeast China.

Characteristics and mechanisms of As(III) removal by potassium ferrate coupled with Al-based coagulants: Analysis of aluminum speciation distribution and transformation.

This study was carried out to investigate the enhanced removal of arsenite (As(III)) by potassium ferrate (KFeO) coupled with three Al-based coagulants, which focused innovatively on the distribution and transformation of hydrolyzed aluminum species as well as the mechanism of KFeO interacted with different aluminum hydrolyzed polymers during As(III) removal. Results demonstrated that As(III) removal efficiency could be substantially elevated by KFeO coupled with three Al-based coagulants treatment and the optimum As(III) removal effect was occurred at pH 6 with more than 97%. KFeO showed a great effect on the distribution and transformation of aluminum hydrolyzed polymers and then coupled with a variety of aluminum species produced by the hydrolysis of aluminum coagulants for arsenic removal.

Correlation Analysis of the Carboxyl and Carbonyl Groups of Natural Organic Matter and the Formation Potential of Trihalomethanes and Chloral Hydrate.

Natural organic matter (NOM) has always been considered the main precursor of disinfection by-products (DBPs) during the chlorine disinfection of drinking water. This research focuses on investigating the correlation between the functional group (carboxyl and carbonyl groups) content of NOM and the formation of trichloromethane (TCM) and chloral hydrate (CH). The quantitative determination of carboxyl groups, carbonyl groups, TCM, and CH were conducted during the drinking water treatment processes with different coagulant dosages and with/without pre-oxidation by KMnO or NaClO.

Highly efficient removal of arsenate and arsenite with potassium ferrate: role of in situ formed ferric nanoparticle.

It is well known the capacity of potassium ferrate (Fe(VI)) for the oxidation of pollutants or co-precipitation and adsorption of hazardous species. However, little information has been paid on the adsorption and co-precipitation contribution of the Fe(VI) resultant nanoparticles, the in situ hydrolytic ferric iron oxides. Here, the removal of arsenate (As(V)) and arsenite (As(III)) by Fe(VI) was investigated, which focused on the interaction mechanisms of Fe(VI) with arsenic, especially in the contribution of the co-precipitation and adsorption of its hydrolytic ferric iron oxides.

Activation of peroxymonosulfate by palygorskite-mediated cobalt-copper-ferrite nanoparticles for bisphenol S degradation: Influencing factors, pathways and toxicity evaluation.

Peroxymonosulfate (PMS)-based advanced oxidation process is considered a potential technology for water treatment. Here, palygorskite (PAL)-mediated cobalt-copper-ferrite nanoparticles (16%-CoCuFeO@PAL, donated as 16%-CCFO@PAL) were employed for PMS activation to remove bisphenol S (BPS). BPS degradation was greater than 99% under the optimal conditions within 25 min, on which the effects of various influencing factors were explored.

Variations of disinfection byproduct precursors through conventional drinking water treatment processes and a real-time monitoring method.

In this investigation, raw water (RW), settled water (SW), and filtered water (FW) collected from a drinking water treatment plant were fractionated into 24 natural organic matter (NOM) fractions with varying molecular weights and hydrophobicity. The yields of disinfection byproducts (DBPs) obtained during the chlorination of the NOM fractions were explored. Results revealed that the 0-1 kDa, 5-10 kDa, and hydrophobic DBP precursors dominated RW.

Characteristics and disinfection by-product formation potential of dissolved organic matter in reservoir water in cold area.

The severe cold in winter with harsh natural conditions in Northeastern China seriously affect the water quality of the reservoir, showing the increased content and more complex types of organic matter, which brings severe challenges to the control of disinfection by-products (DBPs) in drinking water treatment with reservoir water as the water source. In this study, the fractions of dissolved organic matter (DOM) in source water at before ice formation period (P1), ice-age period (P2), and ice begin to melt period (P3) were separated by membrane separation technology. Subsequently, the contributions of DOM fractions with different molecular weights (MW) to DOC, UV, and SUVA, and their disinfection by-product formation potential (DBPFP) were evaluated.

Non-radical dominated degradation of bisphenol S by peroxymonosulfate activation under high salinity condition: Overlooked HOCl, formation of intermediates, and toxicity assessment.

Extensive studies revealed that Cl could inhibit the removal of targeted pollutants under low Cl conditions in the peroxymonosulfate (PMS) system. However, the enhanced effect of Cl has always been overlooked under high Cl conditions. Here, we find that high concentration of Cl played a critical role in bisphenol S (BPS) degradation by activating PMS using 16%-CoFeO@PAL (16%-CFO@PAL).

Preparation of novel N-doped biochar and its high adsorption capacity for atrazine based on π-π electron donor-acceptor interaction.

Novel nitrogen (N)-doped cellulose biochar (NC1000-10) with large adsorption capacity (103.59 mg g) for atrazine (ATZ) was synthesized through the one-pot method. It has the best adsorption efficiency than N-doped biochars prepared from hemicellulose and lignin.

Formation pathway of disinfection by-products of lignin monomers in raw water during disinfection.

In this study, the dissolved organic matter (DOM) profiles of water samples from a water source in northeastern China were analyzed by high-resolution mass spectrometry (HRMS), and its changes after chlorination were investigated. The results showed that lignin substances accounted for a significant proportion in DOM and chlorinated products and were the main precursors of disinfection by-products (DBPs). During disinfection, macromolecular DOM was transformed into small molecules, and lignin substances have the most obvious and complex changes in reaction.

Regrowth potential of chlorine-resistant bacteria in drinking water under chloramination.

The regrowth of chlorine-resistant bacteria in drinking water can deteriorate water quality. The study evaluated the relationship between organic carbon and the regrowth potential of chlorine-resistant bacteria remaining in chloraminated water samples. The results showed that the community structure of bacteria changed with the increase of chloramine dosage.

N-nitrosodimethylamine formation during oxidation of N,N-dimethylhydrazine compounds by peroxymonosulfate: Kinetics, reactive species, mechanism and influencing factors.

This study found that peroxymonosulfate (PMS) oxidation without activation has the potential to generate a suspected human carcinogen, N-nitrosodimethylamine (NDMA), in water containing N,N-dimethylhydrazine compounds. Considerable amounts of NDMA formed from three compounds by PMS oxidation were observed. 1,1,1',1'-Tetramethyl-4,4'-(methylene-di-p-phenylene) disemicarbazide (TMDS), which is an industrial antiyellowing agent and light stabilizer, was used as a representative to elucidate the kinetics, transformation products, mechanism and NDMA formation pathways of PMS oxidation.

Black Tea Alleviates Particulate Matter-Induced Lung Injury via the Gut-Lung Axis in Mice.

Black tea, as the most consumed kind of tea, is shown to have beneficial effects on human health. However, its impact on particulate matter (PM) induced lung injury and the mechanisms involved have been sparsely addressed. Here, we show that PM-exposed mice exhibited oxidative stress and inflammation in the lungs, which was significantly alleviated by a daily intake of black tea infusion (TI) in a concentration-dependent manner.

Enhanced degradation of iohexol in water by CuFeO activated peroxymonosulfate: Efficiency, mechanism and degradation pathway.

Iohexol as an iodinated X-ray contrast agent is widely used, and it is the potential precursor for toxic iodinated disinfection by-products in the disinfection process. In this study, a series of CuFeO catalysts were prepared by sol-gel method with different molar ratios of total metal cations to citric acid ([Me]/CA) and employed as heterogeneous catalysts to activate peroxymonosulfate (PMS) for the removal of iohexol. The catalysts were characterized by various technologies, and the effect of [Me]/CA molar ratio on the catalysts' properties was explored.

A new insight into the ARG association with antibiotics and non-antibiotic agents-antibiotic resistance and toxicity.

Although concerns have been raised about co-selection for antibiotic resistance and various antibiotics and non-antibiotic agents, the data on their association in urban sludge is still limited. In addition, antibiotic contamination can result in not only the toxicity but also the antibiotic resistance. In this study, the first large-scale identification of antibiotics and non-antibiotic agents concern for co-selection of resistance against antibiotics was conducted in urban sludge.

Powdered activated carbon doping improves the mechanical and adsorption properties of cementitious microfiltration membrane.

Cementitious membrane (CM) is a promising microfiltration membrane with low cost for raw materials and low energy consumption of non-sintering fabrication process. A novel carbon-cementitious microfiltration membrane (CCM) was fabricated with powdered activated carbon (PAC) as an additive based on CM, to solve the low mechanical strength of CM during multiple practical uses. While maintaining adequate pure water flux and porosity, the mechanical strength of the membrane was greatly improved to ensure the stability of the membrane in the filtration process.

Catalytic Efficiency of Carbon-Cementitious Microfiltration Membrane on the Ozonation-Based Oxidation of Small Molecule Organic Compounds and Its Alkaline Buffering Effect in Aqueous Solution.

In this study, powdered activated carbon (PAC) was added to replace the silica in a cementitious microfiltration membrane (CM) to solve the problems of the low mechanical strength and short lifetime of CMs. The carbon-cementitious microfiltration membrane (CCM) was fabricated by the dry pressing method and cured at room temperature. The bending strength of CCM was 12.

Fabrication of Cementitious Microfiltration Membrane and Its Catalytic Ozonation for the Removal of Small Molecule Organic Pollutants.

In this study, a low-cost cementitious microfiltration membrane (CM) with a catalytic ozone oxidation function for the removal of organic pollutants was fabricated by using cementitious and C-10 μm silica powders at a certain silica-cementitious particle ratio (s/c). The effect of the s/c on the pore size distribution and mechanical strength of the membrane was investigated. The membrane pore size showed a bimodal distribution, and the higher the s/c, the closer the second peak was to the accumulated average particle size of silica.