Αναζήτηση αυτού του ιστολογίου

Παρασκευή 29 Ιουνίου 2018

Frontalis–Orbicularis Muscle Advancement for Correction of Upper Eyelid Ptosis: A Systematic Literature Review

Purpose: To review the level of standardization of frontalis–orbicularis muscle advancement to correct severe blepharoptosis and the degree of scientific evidence supporting the procedure as a useful modality of blepharoptosis repair. Methods: The authors searched the Medline, Lilacs, and Scopus databases for all articles in English, Spanish, and French that used as keywords the terms "frontalis muscle flap," "orbicularis muscle flap," and "ptosis." Data retrieved included authorship specialty, geographic region where the surgeries were performed, characteristics of the samples reported, type and dimensions of the flaps used, time of follow-up, rate of undercorrection, and complications. Results: Thirty-eight articles were retrieved and analyzed. Most studies originated from Asian countries, especially China, Taiwan, and Korea. Many variations of the procedure were encountered, including location of incisions and frontalis flap design. There were 23 case series with more than 10 patients. None compared the procedure to conventional frontalis suspension surgery. The samples were not homogeneous, including patients with different type of ptosis, variable degrees of levator function, and using distinct methods of evaluating eyelid position. Undercorrection rates ranged from 1.8% to 38% with a median value of 12.2%. The rate of complications (eyelid crease abnormalities, entropion, hematoma, and supraorbital nerve injury) was low. Conclusions: The direct frontalis–orbicularis muscle advancement has been judged positively in all reports analyzed. However, the level of standardization of the surgery is low, and the reported series are not homogeneous. Further studies are needed to better evaluate this operation. Accepted for publication April 4, 2018. The authors have no financial or conflicts of interest to disclose. Address correspondence and reprint requests to Patricia Mitiko S. Akaishi, M. D., Department of Ophthalmology, School of Medicine of Ribeirão Preto, University of São Paulo, Brazil. E-mail: patriciamitiko@gmail.com © 2018 by The American Society of Ophthalmic Plastic and Reconstructive Surgery, Inc., All rights reserved.

Stop eating plastic, molecular signaling of bisphenol A in breast cancer

Abstract

Breast cancer is the second most common fatal cancer in women. Developing a breast cancer is a multi-factorial and hormonal-dependent process, which may be triggered by many risk factors. An endocrine disrupting substance known as bisphenol A (BPA), that is used greatly in the manufacture of plastic products, was suggested as a possible risk factor for developing breast cancer. BPA has a strong binding affinity to non-classical membrane estrogen receptors like estrogen-related and G protein-coupled (GPER) receptors. Based on animal and in vitro studies, results showed a link between BPA exposure and increased incidence of breast cancer. BPA has the ability to alter multiple molecular pathways in cells namely, G protein-coupled receptor (GPER) pathway, estrogen-related receptor gamma (ERRγ) pathway, HOXB9 (homeobox-containing gene) pathway, bone morphogenetic protein 2 (BMP2) and (BMP4), immunoregulatory cytokine disturbance in the mammary gland, EGFR-STAT3 pathway, FOXA1 in ER-breast cancer cells, enhancer of zeste homolog 2 (EZH2), and epigenetic changes. Thus, the aforementioned alterations cause undesired gene stimulation or repression that increase risk of developing breast cancer. So, restricting exposure to BPA should be considered to aid in lowering the risk of developing breast cancer.



Removal of aromatic and hydrophobic fractions of natural organic matter (NOM) using surfactant modified magnetic nanoadsorbents (MNPs)

Abstract

The present study investigated the potential of surfactant modified magnetic nanoadsorbents (MNPs) for the removal of aromatic and hydrophobic fractions of natural organic matter (NOM), leading to the formation of trihalomethanes (THMs) in chlorinated drinking water. Co-precipitation method was used for the synthesis of MNPs. However, MNPs have a tendency to form an agglomeration. Therefore, polyethylene glycol (PEG) was used as a surface modifier to reduce the agglomeration. The PEG-coated MNPs were characterized by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy-dispersive X-ray analysis (EDX), BET surface area, X-ray diffraction (XRD), Fourier transform spectrometer (FTIR), and zeta (ζ) potential. FESEM observation indicates that PEG-coated MNPs were spherical in shape and 25 nm in size. Zeta potential values (− 58.35 to − 74.9 mV) indicated excellent stability of PEG-MNPs. FTIR spectra indicated the presence of a −CH2 group, responsible for the chemical interaction between aromatic and humic content. Batch experiments were conducted by studying the effect of pH, contact time, and adsorbent dosage on NOM removal. Excellent removal of DOC (94.49%) and UV254 (89.32%) was observed at the optimum dose of adsorbent (0.75 g/L) and at pH 7.0. Adsorption kinetics followed pseudo-second-order reaction (R2, 0.973) and occurs by multilayer chemisorption which is due to the chemical interaction between aromatic and humic compounds of NOM with MNPs. Thus, MNPs showed great potential as a novel adsorbent for the removal of aromatic and hydrophobic compounds of NOM and can significantly be used to curtail the problem of THMs in drinking water supplies.



Effect of controlled-release fertilizer on N 2 O emissions and tea yield from a tea field in subtropical central China

Abstract

Tea (Camellia sinensis L.), a perennial leaf-harvested crop, favors warm/humid climate and acidic/well-drained soils, and demands high nitrogen (N) fertilizer inputs which lead to significant emissions of N2O. Potential mitigation options should be adopted to improve N use efficiency (NUE) and reduce environmental pollution in tea field system. A 3-year field experiment was carried out in a tea field in southern China from January 2014 to December 2016 to investigate the effect of controlled-release fertilizer (CRF) application on N2O emissions in tea field system. Three practices, namely conventional treatment (CON, 105 kg N-oilcake ha−1 year−1 + 345 kg N-urea ha−1 year−1), treatment with a half amount of the N fertilizer (CRF50%, 105 kg N-oilcake ha−1 year−1 + 120 kg N CRF ha−1 year−1) and full amount of N fertilizer (CRF100%, 105 kg N-oilcake ha−1 year−1 + 345 kg N CRF ha−1 year−1) were used. Compared with the CON, our results showed that CRF50% reduced the N2O emissions by 26.2% (p > 0.05) and increased the tea yield by 31.3% (p > 0.05), while CRF100% significantly increased the N2O emissions by 96.7% (p < 0.05) and decreased the tea yield by 6.77% (p > 0.05). Overall, yield-scaled N2O emissions of tea were reduced by 44.5% (p > 0.05) under CRF50% and significantly increased by 100% (p < 0.05) under CRF100%, compared with CON. Based on the gross margin analysis, CRF50% obtained the highest net economic profit. Our findings suggest that reducing N input of CRF (CRF50%) is necessary and feasible for adoption in the current tea plantation system.



Prognostic significance of high serum p53 antibody titers in patients with esophageal squamous cell carcinoma

Abstract

Background

The p53 protein overexpression that usually results from genetic alterations reportedly induces serum antibodies against p53. However, little information is available about the prognostic significance of perioperative serum p53 antibody (s-p53-Abs) titers in patients with esophageal squamous cell carcinoma.

Methods

In this study, we retrospectively evaluated the clinical significance of perioperative s-p53-Abs in 135 patients with esophageal squamous cell carcinoma. Of these, 58 patients received neoadjuvant chemotherapy comprising 5-FU and CDDP. While the cutoff level at 1.3 U/ml indicated seropositive patients, level of 13.4 U/ml was used to identify high-titer patients. We monitored serum titers seropositive patients after surgery and evaluated the prognostic significance by the univariate and multivariate analyses.

Results

In this study, 29 patients (21.5%) were positive for s-p53-Abs before treatment. The frequency of both seropositive patients and high-titer patients (> 13.4 U/ml) was not significantly associated with tumor progression. While seropositive patients did not demonstrate significant poor overall survival, high-titer patients demonstrated significant poor overall survival based on the multivariate analysis (P < 0.001). Moreover, the s-p53-Abs titer did not correlate with the response to neoadjuvant chemotherapy. Among seropositive patients, the negative conversion of s-p53-Abs more likely led to be long-term survival.

Conclusions

This study determined that the high-titer of s-p53-Abs was an independent risk factor to reduce the overall survival of patients with esophageal cancer patients. The negative conversion of s-p53-Abs could be a good indicator of favorable prognosis.



Studies on the UV filtering and radical scavenging capacity of the bitter masking flavanone Eriodictyol

Publication date: Available online 28 June 2018
Source:Journal of Photochemistry and Photobiology B: Biology
Author(s): Vijisha K. Rajan, T.K. Shameera Ahamed, K. Muraleedharan
A computational analysis of UV filtering and radical scavenging capacity of a flavanone, Eriodictyol has been performed under DFT-B3LYP/6–31+ G (d, p). Eriodictyol is nontoxic and nonirritant bitter masker commonly used in the wine industry. It has been reported that the flavanones were widely acceptable for photoprotection due to its potential UV filtering and radical scavenging capacity. This study provides theoretical evidence that the eriodictyol has an absorbance in the UV-A and UV-B region of the electromagnetic spectrum and therefore can be used as a potential UV filter in sunscreen lotions and other cosmetic products. The major transitions in the UV–Visible spectrum of Eriodictyol are between HOMO and HOMO-1 with LUMO level and are well explained by NBO-NLMO tool in G09 software. In addition to this, Eriodictyol is a potent antioxidant than that of the most commonly studied Quercetin. The most active site in the compound is 3′ position and is confirmed by NPA, NBO and pKa value analysis. The lowest energy conformer of Eriodictyol contains a Hydrogen bond between carbonyl oxygen (O2) and H30. This is confirmed by the highest value of interaction energy between lone pairs of O2 and σ* of O3– H30. Both the two lone pairs of O2 interacts with the σ* of O3-H30. This decreases the bond order of 5 OH and at the same time it restricts the hydrogen transfer from this position to form a radical. Similarly, the lone pair of O5 (3′ position) interacts with H33 resulting in the low bond order value and consequently less favorable for radical formation. These results indicate that the BDE values follow the order 3′ < 4′ < 7 < 5. Thus the title compound can be used for photo protection due to its potential UV filtering and radical scavenging capacity.

Graphical abstract

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Wetlands for wastewater treatment and subsequent recycling of treated effluent: a review

Abstract

Due to water scarcity challenges around the world, it is essential to think about non-conventional water resources to address the increased demand in clean freshwater. Environmental and public health problems may result from insufficient provision of sanitation and wastewater disposal facilities. Because of this, wastewater treatment and recycling methods will be vital to provide sufficient freshwater in the coming decades, since water resources are limited and more than 70% of water are consumed for irrigation purposes. Therefore, the application of treated wastewater for agricultural irrigation has much potential, especially when incorporating the reuse of nutrients like nitrogen and phosphorous, which are essential for plant production. Among the current treatment technologies applied in urban wastewater reuse for irrigation, wetlands were concluded to be the one of the most suitable ones in terms of pollutant removal and have advantages due to both low maintenance costs and required energy. Wetland behavior and efficiency concerning wastewater treatment is mainly linked to macrophyte composition, substrate, hydrology, surface loading rate, influent feeding mode, microorganism availability, and temperature. Constructed wetlands are very effective in removing organics and suspended solids, whereas the removal of nitrogen is relatively low, but could be improved by using a combination of various types of constructed wetlands meeting the irrigation reuse standards. The removal of phosphorus is usually low, unless special media with high sorption capacity are used. Pathogen removal from wetland effluent to meet irrigation reuse standards is a challenge unless supplementary lagoons or hybrid wetland systems are used.



Analysis of the adsorption and retention models for Cd, Cr, Cu, Ni, Pb, and Zn through neural networks: selection of variables and competitive model

Abstract

In this study, the neural networks are used to predict and explain the behavior of different edaphological variables in the adsorption and retention of heavy metals, both isolated and competing. A comparison with the results obtained using multiple regression, stepwise analysis, and regression trees is performed. In the neural network technique, CEC amorphous and crystallized oxides and kaolinite in the clay fraction are the most selected variables for making the optimal models, while mica and, to a lesser extent, plagioclase, are the next variables selected. Additionally, a competitive model has been considered, using simultaneously different metals. In the competitive model, the model predicts a more intense competence between Pb and Ni for the adsorption process and between Cr and Ni for the retention process.



Reply to the Editor: The pedicled internal pudendal artery perforator (PIPAP) flap for ischial pressure sore reconstruction: Technique and long-term outcome of a cohort study

Publication date: Available online 28 June 2018
Source:Journal of Plastic, Reconstructive & Aesthetic Surgery
Author(s): K.W. Karl Waked, A.Z. Assaf A. Zeltzer




Patients with Abdominal-based Free Flap Breast Reconstruction a Decade after Surgery - A Comprehensive Long-term Follow-up Study

Publication date: Available online 28 June 2018
Source:Journal of Plastic, Reconstructive & Aesthetic Surgery
Author(s): Tianyi Liu, Christoffer Freijs, Holger J Klein, Anna Feinbaum, Andreas Svee, Andres Rodrigues Lorenzo, Anders Liss, Rafael Acosta, Maria Mani
BackgroundAbdominal-based free flap breast reconstruction has increasingly become the gold standard, however long-term evidence of aesthetic outcome and quality of life is lacking. Our study aims to gain an overview of patients with abdominal-based free flap breast reconstructions in a long-term perspective.MethodsSeventy-five patients who received abdominal-based free flap breast reconstructions between 2000-2007 in Uppsala, Sweden were invited back for photographs, 3D imaging and questionnaires. A retrospective chart review was conducted. Patient satisfaction with appearance and quality of life were assessed using the Breast-Q questionnaire. A layman panel and a professional panel rated the aesthetic appearance of the reconstructed breast from photographs and 3D images.ResultsFifty-five patients participated with a mean age of 52±8 years at the time of reconstruction and a mean follow-up time of 11.4±1.8 years completed the study. The majority of the patients had received unilateral (83%), delayed reconstructions (73%) with prior radiation (55%). There were 53 patients with DIEP flaps, one with free TRAM flap and one with SIEA flap. Overall patient satisfaction and quality of life were comparable to normative values of women without breast cancer (p<0.001). There was a high level of agreement for the aesthetic results of the reconstructions between patient, professionals and layman panels (0.89 ICC, 95% CI: 0.83 - 0.93).ConclusionAbdominal-based free flap reconstructions were effective in achieving a lasting positive aesthetic result and a high quality of life in patients a decade after surgery.



Examining the Role of Neighborhood-Level Foreclosure in Smoking and Alcohol Use Among Older Adults in the Multi-Ethnic Study of Atherosclerosis

Abstract
The US Great Recession resulted in an alarming number of home foreclosures that weakened the social and physical environment of thousands of neighborhoods. Few studies have evaluated whether these neighborhood changes were related to changes in individual behaviors. We examined the relationship between changes in neighborhood-level home foreclosure within a quarter-mile (0.4-km) buffer of the residence and changes in cigarette smoking and alcohol use among 3,807 adults enrolled in the Multi-Ethnic Study of Atherosclerosis during 2005–2012, using econometric individual-level fixed-effects models. Increases in neighborhood-level foreclosure were associated with small decreases in the number of cigarettes smoked per day (mean difference = −0.08, 95% confidence interval: −0.11, −0.04) and small increases in the number of alcoholic beverages consumed per week (mean difference = 0.11, 95% confidence interval: 0.05, 0.17). Neighborhood-level foreclosure may not uniformly influence high-risk behaviors. The impact of home foreclosure on adult drinking should be further explored, given its potentially negative implications for health.

Leukocyte Telomere Length and All-Cause Mortality: A Between-Within Twin Study With Time Dependent Effects Using Generalized Survival Models

Abstract
Although previous studies examining leukocyte telomere length (LTL) and all-cause mortality controlled for several confounders, the observed association could be biased due to unmeasured confounders, including familial factors. We aimed to examine the association of LTL with all-cause mortality in a Swedish twin sample adjusting for familial factors and allowing for time dependent effects. Three hundred and sixty-six participants were recruited from the Swedish Twin Registry. LTL was assessed using the Southern blot method. All-cause mortality data were obtained through linkage to the Swedish Population Registry updated through to November 2017. To control for familial factors within twin pairs, we applied a between-within shared frailty model based on generalized survival models. Overall, 115 (31.4%) participants were men and 251 (68.6%) were women. The average age of the study participants when blood was drawn was 79.1 years, and follow-up duration spanned from ten days to 25.7 years (mean = 10.2 years). During the follow-up period, 341 (93.2%) participants died. Shorter LTL was associated with higher mortality rates when controlling for familial factors in the between-within shared frailty model. We found significant time dependent effects of LTL on all-cause mortality, where the mortality rate ratios were attenuated with increasing age.

As Long as the Breath Lasts. In Utero Exposure to Ramadan and the Occurrence of Wheezing in Adulthood

Abstract
While prenatal exposure to Ramadan has been shown to be negatively associated with general physical and mental health, studies on specific organs remain scarce. This study explores whether Ramadan during pregnancy has impacts on the occurrence of wheezing, a main symptom for obstructive airways diseases. Using data from the Indonesian Family Life Survey collected between 1993 and 2008 (waves 1 to 4), we compare wheezing occurrence among adult Muslims who had been in utero during Ramadan with adult Muslims who had not been in utero during Ramadan. Wheezing prevalence is higher among adult Muslims who had been in utero during Ramadan, independent of the pregnancy phase in which the exposure to Ramadan occurred. Moreover, this association tends to increase with age, being strongest in the age groups 45+. This is in line with fetal programming theory suggesting that impacts of in utero exposures often only show after the reproductive age. Particularly strong associations were detected for smokers. The respiratory system of prenatally exposed Muslims thus seems to perform worse in mitigating later ex utero harmful influences such as smoking. This study suggests that exposure to Ramadan during pregnancy may have lasting consequences for adult lung functionality.

Associations of dietary protein intake with fat free mass and grip strength: cross-sectional study in 146,816 UK Biobank participants

Abstract
Adequate dietary protein intake is important for the maintenance of fat-free mass (FFM) and muscle strength: optimal requirements remain unknown. The aim of the current study was to explore the associations of protein intake with FFM and grip strength. We used baseline data from the UK Biobank (146,816 participants aged 40-69 years with data collected 2007-2010 across the UK) to examine the associations of protein intake with FFM and grip strength. Protein intake was positively associated with FFM (men 5.1% [95% CI: 5.0; 5.2] and women 7.7% [95% CI: 7.7; 7.8]) and grip strength (men 0.076 kg/kg [95% CI: 0.074; 0.078] and women 0.074 kg/kg [95% CI: 0.073; 0.076]) per 0.5 grams per kg body mass per day (g/kg/day) increment in protein intake. FFM and grip strength were higher with higher intakes across the full range of intakes, i.e. highest in those reporting consuming > 2.0 g/grams per kg/day independently of socio-demographics, other dietary measures, physical activity and comorbidities. FFM and grip strength were lower with age, but this association did not differ by protein intake categories (P > 0.05). Current recommendation for all adults (40-69 years) for protein intake (0.8 grams per kg body mass per day) may need to be increased to optimise FFM and grip strength.

Adsorptive removal of endocrine-disrupting compounds and a pharmaceutical using activated charcoal from aqueous solution: kinetics, equilibrium, and mechanism studies

Abstract

Bisphenol A (BPA), diethyl phthalate (DEP), and carbamazepine (CBZ) have been widely used in chemical and pharmaceutical fields, and their residues are detected in various environments. Therefore, to find a suitable method for removing the compounds from an aqueous solution, an adsorption method by granular activated charcoal (AC) was studied. To investigate the adsorption properties of AC, its kinetics, equilibrium, pH effects, and regeneration of AC were examined. Moreover, its surface properties (i.e., surface area, pore volume, functional groups, and surface charge) were characterized by N2 adsorption and desorption isotherm, Fourier transform infrared (FTIR), and zeta potential analyses. Experimental results show that AC has high removal efficiencies for the target compounds at the low initial concentration as well as high estimated adsorption capacities (qm) for DEP, BPA, and CBZ, whose values were 293.4 ± 18.8, 254.9 ± 16.2, and 153.3 ± 1.61 mg/g, respectively. In comparison with other adsorbents based on previously reported results, AC was shown to have generally higher removability for the three compounds than others. Moreover, it was observed that AC's ability to adsorb DEP and BPA was dependent on pH because of hydrolysis and ionization, respectively. Meanwhile, there is no pH effect for CBZ adsorption by AC. After 3 cycles of adsorption/desorption, AC still maintained 92, 100, and 82% of initial adsorption capacities for DEP, BPA, and CBZ, respectively. Therefore, the AC is an effective adsorbent for the removal of endocrine-disrupting chemicals and pharmaceuticals from aqueous solution.



Organophosphorus poisoning in animals and enzymatic antidotes

Abstract

Organophosphorus compounds (OPs) are neurotoxic molecules developed as pesticides and chemical warfare nerve agents (CWNAs). Most of them are covalent inhibitors of acetylcholinesterase (AChE), a key enzyme in nervous systems, and are therefore responsible for numerous poisonings around the world. Many animal models have been studied over the years in order to decipher the toxicity of OPs and to provide insights for therapeutic and decontamination purposes. Environmental impact on wild animal species has been analyzed to understand the consequences of OP uses in agriculture. In complement, various laboratory models, from invertebrates to aquatic organisms, rodents and primates, have been chosen to study chronic and acute toxicity as well as neurobehavioral impact, immune response, developmental disruption, and other pathological signs. Several decontamination approaches were developed to counteract the poisoning effects of OPs. Among these, enzyme-based strategies are particularly attractive as they allow efficient external decontamination without toxicity or environmental impact and may be of interest for treatment. Approaches using bioscavengers for prophylaxis, treatment, and external decontamination are emphasized and their potential is discussed in the light of toxicological observations from various animal models. The relevance of animal models, regarding their cholinergic system and the abundance of naturally protecting enzymes, is also discussed for better extrapolation of results to human.



Equilibrium adsorption study of the adsorptive removal of Cd 2+ and Cr 6+ using activated carbon

Abstract

The performance of activated carbon (AC) with respect to characterization, adsorption kinetics, thermodynamics, and isotherms was addressed in this study. The effects of initial concentration, pH, contact time, ion strength, and temperature on removal efficiency were also studied. The adsorption isotherms of Cd2+ and Cr6+ on activated carbon can fit the Langmuir model well, and correlation coefficients were above 0.99, all higher than the Freundlich and Temkin models. The maximum adsorption quantities of Cd2+ and Cr6+ were 19.380 and 19.305 mg g−1 at 25 °C, respectively. The adsorption capacities of Cd2+ and Cr6+ are clearly pH dependent. The kinetics of the removal of Cd2+ and Cr6+ was in agreement with a pseudo-second-order model, and the adsorption efficiency of Cd2+ is higher than that of Cr6+. The thermodynamic results showed that increased temperature is favorable to adsorption. The speciation on activated carbon was mainly residual Cd2+ and Cr6+, and the potential ecological risk of Cd2+ is higher than that of Cr6+. The adsorptions of Cd2+ and Cr6+ on activated carbon were dominated by chelation and ion exchange, respectively.



The effects of recombinant human epidermal growth factor containing ointment on wound healing and post inflammatory hyperpigmentation prevention after fractional ablative skin resurfacing: A split‐face randomized controlled study

Journal of Cosmetic Dermatology, EarlyView.


Πέμπτη 28 Ιουνίου 2018

Screening of microalgae for treating Garcinia cambogia wash water with potential lipid production

Abstract

The microalgae-based water treatment is gaining importance in recent years as it serves multiple purposes of which includes water treatment and biofuel production. Garcinia cambogia, a Malabar tamarind is a tropical fruit and the active ingredient hydroxycitric acid is popularly used as a weight-loss supplement. After extraction of the hydroxycitric acid, the wash water of G. cambogia is considered as an effluent. The potential microalgal species that can grow and treat G. cambogia wash water were isolated and identified as Dicloster acuatus BVR1 and Kalenjenia gelanitosa BVR2. Both the microalgal species adapted to G. cambogia wash water and entered exponential phase after sixth day with maximum specific growth rate of 0.310 day−1 for D. acuatus and 0.296 day−1 for K. gelanitosa during tenth day. The biomass productivity of D. acuatus was 0.03 g L−1 day−1 which is 58% higher than K. gelanitosa with 0.019 g L−1 day−1. The microalgal strains besides water treatment were subsequently subjected for lipid extraction and lipid productivity determination. The lipid productivity of D. acuatus was 2.68 mg L−1 day−1 which is lesser compared to 3.38 mg L−1 day−1 for K. gelatinosa. Both the microalgal isolates were promising for G. cambogia wash water treatment and lipid production. Hence, an environment friendly approach of water treatment with simultaneous lipid production for biofuel conversion is conducted.



Simultaneous removal of NO and SO 2 from flue gas using vaporized H 2 O 2 catalyzed by nanoscale zero-valent iron

Abstract

To remove NO and SO2 from flue gas simultaneously, a heterogeneous catalytic oxidation system was developed with the nanoscale zero-valent iron (nZVI), vaporized H2O2, and sodium humate (HA-Na) acting as the catalyst, oxidant, and absorbent, respectively. The experimental results indicated that the desulfurization was mainly influenced by the absorption, and the denitrification was significantly affected by the catalytic oxidation parameters. Under the optimal conditions, the simultaneous removal efficiencies of SO2 and NO were 100 and 88.4%, respectively. The presence of ·OH during the removal process was proved by the scavenger tests, and the production of ·OH with and without nZVI was indirectly evaluated by the electron paramagnetic resonance (EPR) and methylene blue experiments. Moreover, the fresh and aged nZVI were characterized by a series of techniques and the results suggested that the redox pair Fe2+/Fe3+ released by nZVI could react with H2O2 to provide the sustainable ·OH, which was important for the oxidation from NO and SO2 to NO3− and SO42−. The removal mechanism was proposed preliminarily based on the correlative experiments, characterizations, and references.