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Algal extracellular organic matter (EOM) will cause grievous membrane fouling during the filtration of algae-laden water; hence, boron-doped diamond (BDD) anodizing was selected as the pretreatment process before the ultrafiltration, and the EOM fouling mitigation mechanism and the purification efficiency were systematically investigated. The results showed that BDD oxidation could significantly alleviate the decline of membrane flux and reduce membrane fouling, and the effect was more notable with an increase in oxidation time. Less than 10% flux loss happened when oxidation duration was 100 min. The dominant fouling model was gradually replaced by standard blocking. BDD anodizing preferentially oxidizes hydrophobic organic matter and significantly reduces the DOC concentration in EOM. The effluent DOC was reduced to less than 1 mg/L when 100 min of BDD anodizing was applied. After the pre-oxidation of BDD, the zeta potential and interfacial free energy, including the cohesive and adhesive free energy, were all constantly increasing, which implied that the pollutants would agglomerate and deposit, and the repulsion between foulants and the ultrafiltration membrane was augmented with the extensive oxidation time. This further confirms the control of BDD on membrane fouling. In addition, the BDD anodizing coupled ultrafiltration process also showed excellent performance in removing disinfection by-product precursors.

The expansion of thermally expandable microspheres forces the conductive fillers to segregate and form a 3D network in situ without any external assistance.

A UV-LED at a fixed wavelength is increasingly employed in the UV/chlorine process to degrade contaminants of emerging concern. However, degradation of contaminants and formation of disinfection by-products (DBPs) in post-chlorination would be significantly altered in the presence of nitrite because of the generation of reactive nitrogen species (RNS). As nitrite has a maximum absorption at ∼350 nm, its impact on the performance of the UV-LED365/chlorine process and subsequent formation of DBPs was investigated. The presence of nitrite in the UV365 irradiation process accelerated the degradation of bisphenol A (BPA), while slightly inhibiting the degradation of BPA in the UV365/chlorine process; nitrite in UV365 and UV365/chlorine processes resulted in the non-negligible formation of trichloronitromethane (TCNM). The concentration of generated DBPs and the corresponding cytotoxicity and genotoxicity all changed because of the presence of nitrite; the concentrations of nitrite, pH, and UV fluence were important factors for the formation of TCNM during the UV365/chlorine/nitrite process. Therefore, the impact of nitrite on the TCNM formation in the UV-LED365/chlorine process is worth noting.

Organic chloramines formed in chlorination of algae-containing water are typical precursors of nitrogenous disinfection byproducts (N-DPBs). The objective to simultaneously enhance the removal efficiency of organic chloramines and control DBP formation remains a challenge. In this study, we report a two-step chlorination strategy for transferring organic chloramines to monochloramine based on the decomposition mechanisms of mono- and di-organic chloramines, which could limit organic chloramines formation and inhibit N-DBPs formation. We demonstrated that two-step chlorination could decrease the organic chloramines formation by nearly 50% than conventional one-step chlorination. Furthermore, two-step chlorination not only blocked the pathway that organic chloramines decomposed to nitriles, but also led to the conversion of organic chloramines to monochloramine. During two-step chlorination of algal organic matter, the organic chloramine transfer proportion decreased by 6.5% and the monochloramine transfer proportion increased by 17.0%. The N-DBP formation, especially haloacetonitriles (HANs), decreased significantly as organic nitrogen became inorganic nitrogen (monochloramine) in two-step chlorination. This work further clarified the process from algal organic matter to N-DBPs, which could expand our understanding of algae-derived organic chloramines removal and DBPs control.

Chinalco’s Toromocho mine, located in the Morococha district of Peru, treated 117,200 mtpd ores during last 10 years. It is currently undergoing expansion, treating approximately 52,740 mtpd of chalcopyrite ore since 2021. As with the commissioning of most large plants, the metallurgical performance levels produced after stability was achieved were below the design criteria; more specifically, the Cu overall recoveries were 80–82% compared with the design value of 85%, and the final concentrate Cu grades were 20–23% compared with the design value of 24% over the past 2 years. It is clear that the copper losses in the fine size fraction (

As a feed additive, p-arsanilic acid (p-ASA) is hardly metabolized in animal bodies and is excreted chemically unchanged via feces and urine, which can be transformed into more toxic inorganic arsenic species and other organic by-products upon degradation in the aquatic environment. In this study, UV-LED/persulfate (PS)/Fe(Ⅲ) and UV-LED/peroxymonosulfate (PMS)/Fe(Ⅲ) processes were developed to remove p-ASA and immobilize the formed inorganic arsenic via tuning solution pH. UV-LED/PMS/Fe(Ⅲ) (90.8%) presented the best performance for p-ASA degradation at pH 3.0, and the p-ASA degradation in these processes both followed the pseudo-first-order kinetics. The ∙OH played the major role in UV-LED/PS/Fe(Ⅲ) and UV-LED/PMS/Fe(Ⅲ) systems. Solution pH greatly affected the p-ASA degradation and the maximum removal can be achieved at pH 3.0 due to the presence of more Fe(OH)(H

Formation of unknown chlorinated disinfection byproducts (Cl-DBPs) during chlorination gradually raised great concern, and pre-oxidation was considered as an efficient method to minimize Cl-DBP formation. In this study, pre-ozonation of algal organic matter was investigated, to explore its impacts on Cl-DBP formation and acute toxicity during subsequent chlorination. With fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) analysis, the conversion of algal organic matter in chlorination with/without pre-ozonation was tracked. The results show that pre-ozonation reduced the formation of trichloromethane (TCM), yet the species and intensity of unknown Cl-DBPs were significantly increased in subsequent chlorination. Meanwhile, the solution acute toxicity was higher in chlorination with pre-ozonation than in chlorination only. Besides, molecular properties of these unknown Cl-DBPs were further explored and featured. One-chlorine-containing DBPs were unsaturated high molecular-weight compounds with more CH

This study was aimed to evaluate the effects of a pre-treatment involving sulfite (S(IV)) synergistically activated by ultraviolet (UV)/Fe(II) on natural organic matter (NOM)-enhanced Ca

Organic chloramines posed significant risks to drinking water safety. However, the formation mechanism of algae-derived organic chloramines remained unclear. In this study, it was observed that pre-oxidation of algal suspensions increased organic chloramine formation during chlorination. Compared to KMnO

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. The radical chain reactions involved in the UV/free chlorine process are very complicated, and the reaction pathways for organic contaminants degradation are largely unknown. Therefore, we developed a computerized pathway generator that uses graph theory and experimentally determined reaction rules that were reported for the UV/free chlorine process. Our pathway generator predicts all possible intermediates, byproducts, and elementary reactions that are involved in the oxidation of organic contaminants. For example, the degradation of tricholoroethylene (TCE) produces 497 species (i.e., intermediates and byproducts) and 6608 elementary reactions. The predicted species from our pathway generator not only predict the major and stable byproducts that were observed in our experiments (e.g., CHCl2COOH, CHCl(OCl)COOH, etc.) but also include many other minor and toxic byproducts that were produced but not measured because they have a short lifetime. Overall, our pathway generator significantly improves our understanding of the reaction pathways that are involved in organic contaminant degradation in the UV/free chlorine process.

Bromide (Br

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 TiO2 nanotubes covered with SnO2-Sb2O3), a proton exchange membrane, and a stainless-steel wire mesh cathode, which were compressed firmly together. For the 3-D system, we placed the anode of a 3-D electrode toward the wastewater that flowed past the anode. Both the two-dimensional (2-D) and 3-D systems had the same anode and cathode. We found that the 3-D system could reduce the applied voltage by 75.7% and reduce the electrical efficiency per log order reduction (EE/O) by 73% for 0.001 M Na2SO4. For Na2SO4 concentrations greater than 0.05 M, the 2-D system had a slightly lower EE/O. We also compared the EE/O of electrochemical advanced oxidation processes (EAOPs) with that of other advanced oxidation processes (UV/H2O2, UV/persulfate, O3/H2O2, UV/ TiO2, and UV/chlorine). We found that EAOPs have a much higher EE/O for low BA concentrations (20 mg/L) and a much lower EE/O for high BA concentrations (2000 mg/L).

Pre-oxidation has been reported to be an effective way to remove algal cells in water, but the released algal organic matter (AOM) could be oxidized and lead to the increment in disinfection by-product (DBP) formation. The relationship between pre-oxidation and AOM-derived DBP formation needs to be approached more precisely. This study compared the impact of four pre-oxidants, ozone (O

Eutrophication is a globally concerned issue, which brings algal cells and algal organic matter (AOM) into drinking water treatment plants. AOM is an important branch of nitrogenous disinfection byproduct (N-DBP) precursors. The variation of AOM composition in UV-LEDs/chlorine process, and its relationship with N-DBP formation still remain much uncertainty. Herein, we used fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) to investigate AOM transformation in UV-LEDs/chlorine process, with UV

This study explored the risk of trichloronitromethane (TCNM) formation during chlorination of the nitrite-containing water after pre-chlorination and subsequent UV irradiation (i.e., the chlorine-UV process). The competitive reaction between amino acid (AA) and NO

β-N-methylamino-l-alanine (BMAA) is a cyanobacterial neurotoxin associated with human neurodegenerative diseases, and its removal in drinking water is receiving increasing attention. In this study, the degradation of BMAA in UV/peracetic acid (UV/PAA) system was investigated. BMAA degradation followed the pseudo-first-order kinetic model. The synergistic effect of UV and PAA exhibited a great potential for BMAA degradation, which was attributed to the generation of a large number of reactive radicals, of which R-C

The classic Chinese herbal medicine formula Xiao-qing-long-tang (XQLT) is commonly recommended to manage allergic rhinitis (AR), but the treatment efficacy and safety of XQLT are uncertain.This study aimed to evaluate the effectiveness and safety of XQLT in treating AR.Nine databases were searched from their inception to April 2021. Randomized controlled trials (RCTs) evaluating XQLT for AR were included. The methodological quality of the studies was assessed using the Cochrane risk-of-bias tool. A meta-analysis and a subgroup meta-analysis were conducted to evaluate the effectiveness of XQLT.Twenty-four RCTs were included in this meta-analysis. XQLT was compared to both placebo and Western medicine (WM), and XQLT combined with WM was compared with WM alone. Meta-analyses were conducted for total nasal symptom scores (TNSS), four individual nasal symptom scores, quality of life (QoL), effective rate, and recurrence rate. The TNSS decreased after XQLT treatment and combination treatment (mean difference (MD): -0.79; 95% confidence interval (CI) [-1.20, -0.38], standardized mean difference (SMD): -1.42; 95% CI [-1.59, -1.24], and SMD: -1.84; 95% CI [-2.08, -1.60]). The two individual nasal symptom scores decreased after XQLT treatment and combination treatment; these nasal symptoms comprised rhinorrhea (SMD: -0.30; 95% CI [-0.58, -0.02] and SMD: -0.48; 95% CI [-0.70, -0.26]), and nasal obstruction (SMD: -0.54; 95% CI [-0.78, -0.30] and SMD: -0.54; 95% CI [-0.76, -0.32). XQLT and XQLT combined with WM achieved a better effective rate than WM (risk ratio (RR): 1.18; 95% CI [1.11, 1.25] and RR: 1.16; 95% CI [1.10, 1.23]) and a lower recurrence rate than WM (RR: 0.24; 95% CI [0.13, 0.43] and RR: 0.47; 95% CI [0.31, 0.72]). XQLT was well tolerated in patients being treated for AR.Our results indicated that oral XQLT may alleviate the TNSS, rhinorrhea scores, and nasal obstruction scores of AR and is safe to use in clinical practice. However, more RCTs that follow rigorous methodologies and evaluate well-accepted outcome measures are required to evaluate the effectiveness of XQLT.

The production and dissemination of literary works have a huge influence and promotion on the inheritance and development of human civilization. The dissemination of literary works is inseparable from the dissemination carrier. New media provides a more novel and convenient way for the dissemination of literary works. The dissemination of literary works based on new media, especially mobile clients, has not only increased the speed of dissemination, but also expanded the dissemination population, allowing people to access reading samples more quickly and effectively. The purpose of this article is to study the dissemination of new computer media and the folk culture of Shaanxi literary works under the background of big data. This article first summarizes the basic theory of big data, and then extends the core technology of big data. Combined with the current status of the spread of Shaanxi literary works and folk culture, the problems and deficiencies in it are analyzed. And combined with the new computer media under the background of big data to conduct research and analysis on the spread of Shaanxi literary works and folk culture. This article systematically expounds the mechanism of new media influencing cultural communication and the inevitability of leading cultural communication. This article uses research methods such as questionnaire surveys, field surveys, observations and experimental research on the communication of new computer media and the folk culture of Shaanxi literary works under the background of big data. The research shows that compared with the traditional ways of dissemination of Shaanxi literary works and folk culture, the dissemination of new computer media and Shaanxi literary works and folk culture under the background of big data is more convenient and diverse.

Vacuum ultraviolet (VUV) photolysis is recognized as an environmental-friendly treatment process. Nitrate (NO

As a new cyanobacterial neurotoxin generated by cyanobacteria, BMAA was closely related to amyotrophic lateral sclerosis-parkinsonism dementia complex (ALS/PDC). In this study, the degradation of BMAA by UV/chlorine process was investigated under the impacts of chlorine dosage, NOM dosage, pH and alkalinity. Results showed that only 10% of BMAA was removed by UV irradiation and 46.8% by chlorination in 5 min, however, 98.6% of BMAA was removed by UV/chlorine process in 5 min. The reaction rates were increased under alkaline conditions, but all achieved complete degradation in 5 min. Besides, HCO3− had slight inhibition, while NOM had significant inhibition on the degradation of BMAA. Furthermore, based on the detected degradation products of BMAA during UV/chlorine process, the possible degradation pathways were concluded. Overall, outcomes of this study exhibited that the use of the UV/chlorine process for BMAA degradation was appropriate in practical applications.

The electro-activation of persulfate (PS) by graphite felt (GF) electrode is a novel advanced oxidation process applied for the degradation of contaminants of emerging concern (CECs). Both GF anode and cathode can electro-activate PS to degrade CECs, including atrazine (ATZ), bisphenol S, ethinylestradiol, and ibuprofen. The study examines the removal performance of ATZ in sulfate, nitrate, and perchlorate electrolyte. The degradation of ATZ followed the order of sulfate (36.3 L (Ah)−1) > perchlorate (22.2 L (Ah)−1) > nitrate (5.8 L (Ah)−1) in GF anode/PS system, while electrolytes had little influence on the degradation of ATZ (15.8–21.3 L (Ah)−1) in GF cathode/PS system. The mechanisms of PS electro-activation by GF anode and GF cathode were compared and investigated for the first time, through kinetic experiments, radical identification, and products analysis. Quenching experiments demonstrated that O2 − and 1O2 were generated in GF cathode/PS and GF anode/PS systems respectively, besides HO and SO4 −. Degradation pathways of ATZ in these two systems showed slight difference, and a total of eight transformation products of ATZ were identified. Acute toxicity of the treated ATZ solution decreased at the beginning and then increased in both systems at electric charge of 0.11 Ah L−1. Furthermore, both GF electrodes/PS systems exhibited satisfactory performance for actual effluent from wastewater treatment plants in the presence of 30 mM perchlorate (with ATZ removal of 78% at electric charge of 0.11 Ah L−1), leaving a potential possibility for its practical application.