Surfactant modified waste ash for the removal of chloro and nitro group substituted benzene from wastewater.

A surfactant-modified coal fly ash was developed as a multifunctional adsorbent for the removal of organic pollutants from wastewater. Sodium dodecyl sulfate (SDS) was used to modify the surface of coal fly ash (CFA). The modified CFA was characterized using scanning electron microscopy (SEM), surface porosity analyzer, thermogravimetric analysis (TGA) and Fourier transform infrared (FTIR) spectroscopy. The results showed that loading CFA with SDS not only improved the functionality and surface morphology of the raw ash for the adsorption of organic pollutants, but also enhanced its thermal stability. The efficiency of the modified fly ash was tested in terms of removal of two non-polar organic pollutants namely chlorobenzene (CB) and nitrobenzene (NB) from aqueous phase. The maximum uptake capacity of chlorobenzene and nitrobenzene with SDS-modified coal fly ash (SCFA) was 225 mg/g and 90 mg/g, respectively. The kinetic analysis was done by controlled kinetic models, i.e., pseudo first and second order kinetic models. The results showed that adsorption of CB and NB onto SCFA followed a pseudo second order kinetic model. The adsorption of chlorobenzene was exothermic over the modified adsorbent while nitrobenzene showed an endothermic behavior. The isotherm analysis depicted the multilayer adsorption of both pollutants onto the surface of the surfactant modified adsorbent. This work has shown that surface modification using surfactants can be a viable option to enhance the adsorption capacity of fly ash for pollutants removal.

Concurrent adsorption of cationic and anionic dyes from environmental water on amine functionalized carbon.

Amine functionalized carbon (AFC) was synthesized from raw oil fly ash and later utilized it for simultaneous removal of methyl orange (MO) and rhodamine 6G (Rh6G) pollutant dyes from aqueous medium. AFC was analyzed through scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) surface area and Fourier transform infrared spectroscopy (FTIR) to examine its morphology, porosity and structural characteristics, respectively. The effect of various process parameters like mixing time, pollutant concentration, adsorbent dose, initial solution pH, and temperature of the medium were investigated for dye removal process. The experimental findings showed that the percentage removal of Rh6G was higher than MO and both dyes showed synergism during the adsorption from binary dye solution. Pseudo-second-order model was most appropriate model for both dyes and thermodynamic parameters showed that the dyes removal process was endothermic in nature. Among various isotherm models, Hill and Toth isotherms best explain the adsorption of Rh6G and MO from binary dye solution.

Enhancement of fuel characteristics of rice husk via torrefaction process.

Torrefaction, is a pretreatment process in the conversion of various biomass feedstocks into an efficient solid fuel. In the present research, rice husk was torrefied at 200°C, 250°C, and 300°C for 10, 30, 90, and 150 minutes under a non-oxidative environment. The energy yield and mass yield of torrefied solid residues ranged from 51.3% to 96.8%, and 49.1% to 95.1%, respectively, under torrefaction conditions. Increasing the residence time and temperature of thermal treatment causes a rise in carbon content from 32.45% to 48.5%, and raises the calorific value from 16.48 MJ/kg to 19.82 MJ/kg. The torrefaction process also reduced the swelling tendency of the biomass in water from its initial value of 308% to 92% only. Various other characterizations including Fourier transform infrared radiation, thermogravimetric analysis (TGA) and scanning electron microscopy were performed to analyze the structural and textural aspects of torrefied biomass. The TGA and derivative thermogravimetric analysis curves indicated that torrefaction affected the hemicellulose fraction of biomass significantly. The surface morphology of thermolyzed samples revealed the rupture of the surface induced by the torrefaction process. Overall, the torrefaction process has not only improved the fuel characteristics of the rice husk but also enhanced its hydrophobicity.

Hemoptysis of Uncertain Cause Leading to Delayed Diagnosis in an Elderly Lady With Anti-glomerular Basement Membrane Disease.

Anti-glomerular basement membrane (GBM) disease or Goodpasture syndrome is a rare disorder characterized by anti-GBM autoantibodies targeting the type 4 collagen of the basement membrane, resulting in rapidly progressive glomerulonephritis with or without alveolar hemorrhage. Pulmonary manifestations are less common in the elderly. Isolated pulmonary manifestations are rare in all age groups, and even more so in the elderly. We present the case of a lady in her late 70s, who presented initially with massive hemoptysis in the absence of renal dysfunction, which was presumed to be secondary to underlying bronchiectasis and infection. However, she later developed rapidly progressive acute kidney injury despite improvement in pulmonary symptoms and was diagnosed with anti-GBM disease. The delay in diagnosis and subsequent treatment due to the atypical presentation resulted in irreversible renal injury and the need for lifelong dialysis. This case demonstrates the need to consider atypical presentations of rare disorders, to ensure early diagnosis and optimal prognosis, especially when the clinical history cannot be explained by findings on examination and investigation.

Chronic Eosinophilic Pneumonia: Unraveling Recurrent Chest Infections in a Female Patient With a Family History of Atopy.

Eosinophilic pneumonia is a rare condition characterized by the infiltration of eosinophils in the lungs. We present a case of eosinophilic pneumonia in a 51-year-old British Caucasian female with a history of lichen sclerosus, deranged liver function tests, and a family history of atopy. The patient presented with fever, shortness of breath, lethargy, dry cough, and weight loss over a three-month period. Initial treatment with antibiotics did not yield improvement, and further investigations revealed marked eosinophilia on blood count. Bronchoscopy and biopsies confirmed the diagnosis of eosinophilic pneumonia, and the patient responded well to a tapering dose of prednisolone. This study highlights the importance of considering eosinophilic pneumonia in patients with unexplained respiratory symptoms and eosinophilia and emphasizes the role of bronchoscopy in establishing a definitive diagnosis.

Decolorization of multicomponent dye-laden wastewater by modified waste fly ash: a parametric analysis for an anionic and cationic combination of dyes.

In this research study, waste fly ash (WFA) underwent acid activation and subsequent amine functionalization using ammonia solution. This treatment improves the porosity, thermal tendency and crystallinity of WFA. Modified WFA was tested under different experimental conditions to treat the wastewater consisting of different concentrations of cationic (methylene blue and rhodamine 6G) and anionic (methyl orange) dyes. As an individual, methylene blue (MB) and rhodamine 6G (Rh) showed ~ 100% and ~ 82% removal efficiencies respectively in an alkaline medium while methyl orange (MO) exhibited only ~ 20% adsorption in the same medium. An antagonistic effect was observed in adsorption when wastewater contains both cationic dyes whereas the combination of cationic and anionic dyes in solution manifested a synergistic effect. For all individual and binary dye combinations, there is a close agreement in observed and calculated uptakes when the data was fitted to the fractional order kinetic rate equation. The adsorption of all dyes is spontaneous and endothermic in nature except for MB/MO combination where the process is exothermic in nature. 24.93 mg/g, 24.83 mg/g, and 14.95 mg/g monolayer uptake capacities of MB, Rh, and MO were found respectively from isothermal analysis of single dye adsorption data. Further, extended sips model gave higher correlation coefficient (R2 = 0.99) and addressed the failed assumptions of both the Langmuir and Freundlich models. Overall, in the experimental results, the modified waste fly ash could act as successful adsorbent to treat dye bearing wastewater.

Adsorptive performance of MWCNTs for simultaneous cationic and anionic dyes removal; kinetics, thermodynamics, and isotherm study.

Disposal of contaminated wastewater causes many serious problems especially when it gets mixed with the ground and seawater. It is, therefore, important to apply any remedial action to eradicate dangerous pollutants from the aqueous effluents and to avoid exposure of this wastewater to aquatic life. The research results discussed herein deal with the removal of Rhodamine B (RhB) and Congo Red (CR) dye from wastewater by using multi-walled carbon nanotubes (MWCNTs) as an adsorbent. Different factors like solid dosage, initial pH and concentration, time, and temperature were studied to understand the behavior and mechanism of adsorption. The maximum adsorption capacity in case of a single component system was found to be 302 mg/g and 300 mg/g for Congo Red and Rhodamine B, respectively. Moreover, the mechanism of adsorption was best described by a pseudo-second-order kinetic model. Thermodynamic parameters showed that adsorption of CR and RhB was exothermic when these were removed from a single dye system. However, the overall process became endothermic for concurrent removal of both dyes from the solution. The research results showed that the MWCNTs could successfully be utilized to remove the dye from the industrial wastewater.

BET, FTIR, and RAMAN characterizations of activated carbon from waste oil fly ash.

Activated carbon (AC), a porous material with high pore volume, attracts increasing attention owing to its potential applications in several fields. The development of a porous structure in AC marginally relies on both the treatment methods and the type of precursor. Thus far, both renewable and nonrenewable precursor sources have been used to synthesize AC with high surface area and pore volume. This study presents the synthesis of AC via physicochemical treatment of waste oil fly ash (OFA), a waste material produced from power plants. The aim was to produce AC by adding surface pores and surface functional groups to the basal plane of OFA. Toward this objective, OFA was first chemically leached/activated with various combinations of H2SO4 and H3PO4, and then physically activated with CO2 at 900 °C. The chemical activation step, synergistically combined with CO2 activation, resulted in an increase of 24 times the specific surface area of the OFA. The maximum increase in surface area was obtained for the sample physicochemically treated with 100% H2SO4 . Moreover, the spectroscopic analysis confirmed the presence of acid functional groups after the chemical treatment step. To explore the surface heterogeneity, adsorptive potential distribution in terms of surface energy was also discussed as a function of the surface coverage. Following chemical activation, the OFA surface became heterogeneous. A major portion of the AC showed surface energy in the range of 40-50 erg/K, which was further increased as a result of physical activation at a higher temperature. Thus, the synergism created by physicochemical activation resulted in a material with high surface area and pore volume, and excellent adsorption characteristics. From the findings of this study, it was concluded that OFA is a cost-effective and environmentally benign precursor for the synthesis of AC.

Synthesis of Femur extracted hydroxyapatite reinforced nanocomposite and its application for Pb(II) ions abatement from aqueous phase.

This research study shows the adsorptive potential of biopolymer based nanocomposite for the removal of Pb(II) ions from aqueous phase. The nanocomposite was synthesized by Femur calcined hydroxyapatite and glutaraldehyde cross-linked chitosan. Characterizations like Fourier Transform Infrared (FTIR) Spectroscopy, X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) were performed to investigate the structural modifications, mineral composition and the surface texture of prepared nanocomposite. The adsorption of Pb(II) ions over nanocomposite reveals that the synthesized solid sorbent has promising abatement tendency for heavy metal ions. The adsorption process followed the pseudo-second-order kinetics and the equilibrium data of lead ions adsorption was best fitted to Sips isotherm model. The uptake capacity of synthesized nanocomposite increased from 209 mg/g to 354 mg/g with rise in temperature from 18 °C to 48 °C. The thermodynamic analysis suggested that the Pb(II) ions adsorption was spontaneous and endothermic in nature. Additionally, enthalpy of adsorption (~22.07 KJ/mol) indicated that the heavy metal ions were chemisorbed over nanocomposite surface. Adsorption of Pb2+ increased about ~1.6 times in the observed pH range and highest uptake was obtained at pH 5.

Adsorption kinetics and modeling of H2S by treated waste oil fly ash.

Waste oil fly ash (OFA) collected from disposal of power generation plants was treated by physicochemical activation technique to improve the surface properties of OFA. This synthesized material was further used for potential hydrogen sulfide (H2S) adsorption from synthetic natural gas. The raw OFA was basically modified with a mixture of acids (20% nitric acid [HNO3] and 80% phosphoric acid [H3PO4]), and it was further treated with 2 M potassium hydroxide (KOH) to enhance the surface affinity as well as surface area of synthesized activated carbon. Correspondingly, it enhanced the adsorption of H2S. Crystallinity, surface morphology, and pore volume distribution of prepared activated carbon were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET) analyses. Fourier transform infrared (FTIR) study was also performed to identify the functional groups during different synthesis stages of modified activated carbon. The Langmuir, Freundlich, Sips, and dual-site Langmuir (DSL) models were used to study the kinetic and breakthrough behavior of H2S adsorption over alkali-modified activated carbon. Modeling results of isotherms indicated that OFA has dual sites with high and low affinity for H2S adsorption. The Clark model, Thomas model, and Yoon-Nelson model were used to examine the effects of flow rate and inlet concentration on the adsorption of H2S. Maximum uptake capacity of 8.5 mg/g was achieved at 100 ppm inlet concentration and flow rate of 0.2 L/min. Implications: Utilization of worthless oil fly ash from power plant is important not only for cleaning the environment but also for solid waste minimization. This research scope is to eradicate one pollutant by using another pollutant (waste ash) as a raw material. Chemical functionalization of synthesized activated carbon from oil fly ash would lead to attachment of functional groups of basic nature to attract the acidic H2S. Such type of treatment can enhance the uptake capacity of sorbent several times.

Adsorptive removal of acidic dye onto grafted chitosan: A plausible grafting and adsorption mechanism.

In the present research, a biopolymer Chitosan (C) grafted with ethylenediamine (EDA) and methyl acrylate (MA) were compared for the adsorption of Congo red dye from aqueous phase. The grafted chitosan product was characterized by Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), Differential scanning calorimetry (DSC), X-ray diffraction (XRD) and point of zero charge to study the change in mechanical and thermal properties. The effects of process variables like adsorbent loading, initial dye concentration, initial solution pH, contact time and temperature on adsorption phenomena were investigated. The equilibrium isotherm data was analyzed using Langmuir and Freundlich isotherm models, and the adsorption followed the Langmuir isotherm model (R2 = 0.992 and 0.991 for EDAC and MAC, respectively). The maximum adsorption capacity of EDAC and MAC for Congo red uptake calculated from Langmuir isotherm model was 1607 mg/g and 1143 mg/g, respectively. The adsorption kinetics was studied using pseudo 1st and 2nd order models. Pseudo second order rate model provided the best fit for both grafted adsorbents with R2 ≥0.99. The values of Gibbs free energy (-9.628 and -8.878 kJ/mol), enthalpy (44.9 and 42.2 kJ/mol) and entropy (0.18 and 0.17 J/mol·K) revealed spontaneous and endothermic adsorption of Congo red onto EDAC and MAC surface. The pollutant adsorption test indicated that chitosan grafting with ethylenediamine is superior to Methyl acrylate grafting agent.

Synchronous neural interactions assessed by magnetoencephalography: a functional biomarker for brain disorders.

We report on a test to assess the dynamic brain function at high temporal resolution using magnetoencephalography (MEG). The essence of the test is the measurement of the dynamic synchronous neural interactions, an essential aspect of the brain function. MEG signals were recorded from 248 axial gradiometers while 142 human subjects fixated a spot of light for 45-60 s. After fitting an autoregressive integrative moving average (ARIMA) model and taking the stationary residuals, all pairwise, zero-lag, partial cross-correlations (PCC(ij)(0)) and their z-transforms (z(ij)(0)) between i and j sensors were calculated, providing estimates of the strength and sign (positive, negative) of direct synchronous coupling at 1 ms temporal resolution. We found that subsets of z(ij)(0) successfully classified individual subjects to their respective groups (multiple sclerosis, Alzheimer's disease, schizophrenia, Sjögren's syndrome, chronic alcoholism, facial pain, healthy controls) and gave excellent external cross-validation results.

Synthesis and characterization of Cu-Zn/TiO2 for the photocatalytic conversion of CO2 to methane.

Different Cu-Zn/TiO2 catalysts were synthesized by using the wet impregnation method. The prepared catalysts were used for the conversion of CO2 into methane by photocatalysis. Various characterization techniques were used to observe the surface morphology, crystalline phase, Brunauer-Emmett-Teller (BET) surface area, presence of impregnated Cu and Zn, and functional group. Scanning electron microscope analysis showed spherical morphology, and slight agglomeration of catalyst particles was observed. BET analysis revealed that the surface area of the catalyst was decreased from 10 to 8.5 m2/g after impregnation of Cu and Zn over TiO2 support. Synergetic effect of Cu and Zn over TiO2 support (Cu2.6/TiO2, Zn0.5/TiO2 and Cu2.6-Zn0.5/TiO2) and the effects of Cu loading (0, 1.8, 2.1, 2.6 and 2.9 wt%) were also investigated at different feed molar ratios of H2/CO2 (2:1 and 4:1). The Cu2.6-Zn0.5/TiO2 catalyst showed a maximum conversion of 14.3% at a feed molar ratio of 4. The addition of Zn over the catalyst surface increased the conversion of CO2 from 10% to 14.3% which might be due to synergy of Cu and Zn over TiO2 support.

Research on energy expenditure in individuals with eating disorders: a review.

OBJECTIVE: This study reviews the published research on energy expenditure in individuals with anorexia nervosa (AN), bulimia nervosa (BN), and binge eating disorder (BED). METHOD: Individual studies are reviewed and their results summarized. RESULTS: The most consistent finding is a reduction in resting energy expenditure (REE) in patients with AN, which increases with increased energy intake and body weight. Data regarding BN are inconsistent. Three available studies in subjects with BED have not found evidence of changes in energy expenditure corrected for lean body mass compared with obese non-binge eaters. DISCUSSION: The ability to measure REE reliably and cost-effectively may aid in the refeeding of patients with AN in whom REE is reduced. Changes in individuals with BN and BED have yet to be consistently identified.

Research on energy expenditure in individuals with eating disorders: a review.

OBJECTIVE: This study reviews the published research on energy expenditure in individuals with anorexia nervosa (AN), bulimia nervosa (BN), and binge eating disorder (BED). METHOD: Individual studies are reviewed and their results summarized. RESULTS: The most consistent finding is evidence of reduction in resting energy expenditure (REE) in patients with AN, which increases with increased energy intake and body weight. Data regarding BN are inconsistent. Three available studies in subjects with BED have not found evidence of changes in energy expenditure corrected for lean body mass compared with obese non-binge eaters. DISCUSSION: The ability to reliably and cost-effectively measure REE may aid in the refeeding of patients with AN where REE is reduced. Changes in BN and BED subjects have yet to be identified consistently.