Auramine Research Articles

Advanced electrochemical degradation of basic yellow 28 textile dye using IrO2/Ti meshed electrode in different supporting electrolytes

One of the most concerning recent environmental threats is textile wastewater effluents. Although versatile methods exist for the treatment of textile effluents, electrochemical degradation is considered an efficient and promising approach. In the present study, the effect of an IrO 2 /Ti meshed electrode in the presence of Na 2 SO 4 or NaCl as a supporting electrolyte on the decolorization and mineralization of Basic Yellow 28 (BY28) textile dye is demonstrated. The results showed that the optimum conditions were a current density of 0.03A cm −2 , initial dye concentration of 2 × 10 −5 M, pH of 2.5 or 6.5 for Na 2 SO 4 or NaCl, and a supporting electrolyte concentration of 0.08 or 0.03 M for Na 2 SO 4 or NaCl, respectively. The degradation efficiency was followed using Ultraviolet-visible (UV–Vis) spectrophotometry, cyclic voltammetry, and chemical oxygen demand (COD). Cyclic voltammetry was carried out in the potential window from +1.0 V to −1.0 V. After 15 min, the color removal of the BY28 dye was 92.9% and 93.3% and the COD removal was 26.8% and 46.2% in the presence of Na 2 SO 4 and NaCl, respectively. Besides, the corresponding current efficiency and energy consumption were estimated to validate the proposed electrochemical method. The results revealed that NaCl was more powerful than Na 2 SO 4 as a supporting electrolyte. • Electrochemical decolourization of textile dye, Basic Yellow 28, was investigated. • Based on its performance, IrO 2 /Ti meshed electrode was selected and used in the presence of Na 2 SO 4 or NaCl as a supporting electrolyte. • Most effective parameters such as current density, pH, initial dye, and supporting electrolyte concentrations were tested and optimized. • The degradation efficiency was followed up using UV–Vis, CV and COD measurements. The results demonstrated that the oxidation process in NaCl electrolyte is more powerful than Na 2 SO 4 .

Application of Chemometrics into Removal of Dyes by NaX Nanozeolites: Simultaneous Model

In the present study, the simultaneous removal of malachite green (MG) and auramine-O (AO) dyes from the aqueous solution by NaX nanozeolites in a batch system is investigated. Taguchi method and response surface methodology (RSM) were used to optimize and model dye removal conditions. In order to do so, the effect of various factors (dyes concentration, sonication time, ionic strength, adsorbent dosage, temperature, and pH of the solution) on the amount of dye removal was evaluated by the Taguchi method. Then, the most important factors were chosen and modeled by the RSM method so as to reach the highest percentage of dye removal. The proposed quadratic models to remove both dyes were in good accordance with the actual experimental data. The maximum removal efficiencies of MG and AO dyes in optimal operating conditions were 99.07% and 99.61%, respectively. Also, coefficients of determination (R2) for test data were 0.9983 and 0.9988 for MG and AO dyes, respectively. The reusability of NaX nanozeolites was evaluated during the adsorption process of MG and AO. The results showed that the adsorption efficiency decreases very little up to 5 cycles. Moreover, NaX nanozeolites were also applied as adsorbents to remove MG and AO from environmental water samples and more than 98.1% of both dyes were removed from the solution in optimal conditions.

Comparative Evaluation of Clinical, Cytological and Microbiological Profile in Abdominal vs. Cervical Lymph Nodal Tuberculosis with Special Emphasis on Utility of Auramine-O Staining.

Context:Extrapulmonary tuberculosis (EPTB) especially abdominal lymph nodal tuberculosis (LNTB) poses a unique diagnostic challenge. The clinical, cytological, and microbiological profiles, especially with respect to the use and role of Auramine –O (AO) stain, are not as well characterized in abdominal LNTB as cervical LNTB and were evaluated in the present comparative study.Subjects and Methods:This study was conducted in the Department of Pathology of a tertiary care hospital in Shillong, Meghalaya in 540 clinical suspected cases of tuberculosis who underwent FNAC. The smears were submitted for Leishman's stain for cytological analysis, along with ZN and Auramine O stain for demonstration of the organism, analyzed, and scored and the results were compared with culture wherever available. The results from abdominal and cervical lymph nodal tuberculosis were compared using Microsoft Excel and SPSS software.Results:Out of 540 cases, most were tuberculosis (266) followed by reactive lymphadenitis (162), malignancy, and acute necrotizing lesion. On comparing, abdominal lymph nodes (n = 163) were more likely to reveal cheesy/purulent material macroscopically, necrotizing lymphadenitis along with ZN stain and Auramine positivity (P < 0.05) while cervical lymph nodes (n = 66) revealed a higher proportion of granulomatous lymphadenitis and culture positivity (P < 0.05). The sensitivity, NPV, and diagnostic accuracy of AO stain (85.9%, 48.0%, and 62.3%) were higher as compared to ZN stain (47.4%, 39.3%, and 51.9%) with culture as the gold standard. The combined sensitivity of Ziehl Neelsen stain and Auramine stain was 92.05%.Conclusion:Cytological and microbiologic features of abdominal LNTB differ from cervical LNTB. Moreover, AO stain increases the smear positivity, is almost twice as sensitive as ZN stain and should be used as an adjunct in cytological material wherever available.

Investigation of antibacterial and photocatalytic efficiency of green ZnO nanoparticles that synthesized with Celosia Cristata flower extract.

Increasing interest in green chemistry has led scientists to an environmentally friendly nanoparticle synthesis approach that has many advantages, such as simple, affordable and versatility for a wide range of commercial production. In this study, green synthesis of zinc oxide nanoparticles (ZnO NPs), which is widely researched in the field of nanotechnology, was performed under different conditions (volume ratio of CC flower extract to Zn(CH3COO)2 solution, time, pH and temperature) using the aqueous extract of Amarant (Celosia cristata L., CC, cockscome) plant flowers. Produced ZnO NPs were characterized by UV-Vis absorption spectroscopy, Fourier transform infrared spectroscopy (FTIR), high-resolution transmission electron microscopy (HR-TEM) and scanning electron microscopy (SEM) analysis. The characteristic absorption peak seen at λmax: 364 nm in the UV-Vis absorption spectrum and the band seen at 381 cm-1 in the FTIR spectrum indicate that ZnO NPs were synthesized. TEM image also confirmed the formation of nanoparticles. The average size of nanoparticles is approximately 22-27 nm and the shape of the ZnO NPs as nearly spherical. The effect of different calcination temperatures (100, 200, 300, 400, and 500 °C) on the size of ZnO NPs was investigated and it was observed that the particle size decreased as the calcination temperature increased. ZnO NPs were also used as photo catalyst for removal of basic yellow28 (BY28) and basic violet39 (BV39) dyestuffs which are used in textile industry and ecologically toxic. The decolorization efficiency was found 95%-100% and 62% respectively when the BV39 and BY28 dyestuffs were exposed to UV light for 160 min. Antibacterial activity of ZnO NPs produced with different amounts of CC flower extract and calcined at different temperatures (100, 200, 300, 400, and 500 °C) was investigated using modified disc diffusion method. Produced ZnO NPs displayed antibacterial activity against Staphylococcus aureus and Escherichia coli bacterial strains and were more effective against gram-positive pathogens. The findings displayed that the antibacterial activity of ZnO NPs is related to the particle size. This new environmentally friendly synthesis approach is a suitable technique for large-scale commercial production and can be considered as an alternative to chemical methods.

Preparation of chitosan modified montmorillonite biocomposite for sonocatalysis of dyes: Parameters and degradation mechanism

In this study, the natural chitosan biopolymer was immobilized onto montmorillonite (MMT) surface for efficient ultrasound-assisted removal of dyes in aqueous solution. The MMT, chitosan, and prepared chitosan/MMT samples were characterized using XRD, HR-SEM/EDX, FT-IR, and BET analyses. The sonocatalytic activity of the chitosan/MMT biocomposite was compared in degradation Acid Orange 7 (AO7), Basic Red 46 (BR4), Basic Yellow 2 (BY2) and Basic Yellow 28 (BY28). To define the optimized reaction conditions, the removal efficiency of BY2 was examined by various operational variables, such as biocomposite dosage, initial BY2 concentration, degree of high power, and pH. Besides, the effects of various treatment processes and scavengers were tested. The experimental results revealed that the highest removal efficiency, 82.74%, was obtained at natural pH of 6.95 for the processing conditions of 1.0 g/L catalyst dosage, 200 mg/L dye concentration, 350 W high power, and 60 min reaction time. Moreover, the obtained results pointed out that the sonocatalytic process was the most effective process due to the increased mass transfer and the degradation of BY2 by •OH radicals generation. The kinetic of sonocatalytic process can be represented by the combination of both pseudo-second order and intra-particle diffusion models. Among the Langmuir, Freundlich, BET, Temkin, and Dubinin-Radushkevich isotherm models, the Langmuir model was found to be the best conformity. The trapping experiments suggested that the hydroxyl radicals (•OH) for BY2 oxidation have a predominant role, whereas hydroperoxyl (HO2•) radicals have less effect. GC-MS analysis was also used for the determination of by-products that occurred throughout the removal process.

Removal of organic dyes from wastewater using Eichhornia crassipes: a potential phytoremediation option.

Wastewater from textile industries is a potential source of organic dyes in natural water bodies. Environmental concerns of chemical methods for removal of dyes from wastewater are no more a viable solution, and there is growing concern to develop alternative approaches such as green chemistry and phytoremediation. This study reports the removal of organic dyes from wastewater using Eichhornia crassipes (Mart.) Solms (water hyacinth), as an easily available and fast-growing plant species. Growth of water hyacinth among individual cationic (rose bengal (RB), methylene blue (MB), crystal violet (CV), auramine O (AO), rhodamine B (RhB) and anionic (xylenol orange (XO), phenol red (PR), cresol red (CR), methyl orange (MO)) dye solutions and degradation of dyes were monitored. Results indicated that water hyacinth has good absorption and degradation potential for both types of dyes (cationic or anionic) and effectively removes dyes from solution. Water hyacinth can be used as a suitable and effective phytoremediate for removal of organic dyes from the wastewater.Graphical abstract.

Removal of Basic Yellow 28 by biosorption onto watermelon seeds, Part I: The principal factors influencing by Plackett-Burman screening design

The study by experimental designs of the adsorption process of the Basic Yellow 28 textile dye on Watermelon Seeds Treated powder was carried out by the application of a Plackett and Burman screening design type to distinguish among six factors temperature (20–30°C), pH (3–11), adsorbent weight (0.1–3 g), contact time (0–180 min), ionic strength (0–1 mol/L) and initial dye concentration (10–60 mg/L) those which actually considered to be potentially influential.A detailed analysis of the results was conducted using multilinear regression methods, based on the analysis of variance using a Fisher test, validation of the model was confirmed by the coefficient of determination R2. The results have shown that only the temperature, the weight of adsorbent and the initial concentration of dye remain active and must be well controlled during the implementation of the process.

A simple one-step transferred sample preparation for effective purification and extraction of auramine O in bean product by combining air-assisted ionic liquid-based dispersive liquid-liquid microextraction

A one-step transferred sample preparation was developed for the direct purification and extraction of auramine O (AO) in solid bean products by combining air-assisted ionic liquid-based dispersive liquid-liquid microextraction (AA-IL-DLLME). The amount of AO was then determined using high-performance liquid chromatography-ultraviolet/visible detection. Herein, acidified extractant was employed to extract AO from solid samples and served as dispersant of AA-IL-DLLME simultaneously, which simplified the procedure and achieved the one-step transferred operation. The air assistance in IL-DLLME facilitated the rapid and sufficient dispersion of IL in low volume of dispersant, decreasing the consumption of organic solvent and enhancing the extraction efficiency. The high extraction recovery of nearly 90% was ascribed to the possible hydrophobic and π-π interactions between IL and AO. Parameters affecting extraction efficiency, including type and volume of extractant and IL, vortex and centrifugation time etc., were investigated in detail. The limit of detection (LOD, S/N = 3) and limit of quantification (LOQ, S/N = 10) were 0.01 μg g−1 and 0.04 μg g−1, respectively. The relative standard deviations (RSDs, n = 5) for intra-day and inter-day were 2.7%–7.4% and 4.3%–8.1%, respectively. The applicability of the proposed technique was demonstrated by analyzing various bean products with satisfactory relative recoveries of 83.5%–104.8% and RSDs (n = 3) of 1.8%–6.2%.

Removal of Basic Dyes from Aqueous Solution Onto H2SO4-modified Rice Husk

Rice husk, as local agricultural waste, was modified by treating it with H2SO4 to obtain a low-cost and an effective adsorbent. This adsorbent was investigated for the removal of basic violet 10 (BV) and basic yellow 28 (BY) dyes from aqueous solutions via batch adsorption procedure. The experiments included the initial concentration of dye, contact time and temperature. Langmuir, Freundlich, and Dubinin–Radushkevich models were studied to follow the adsorption process. The results reveal that the Langmuir model showed a better fit to the equilibrium adsorption data and the adsorption kinetics fit the pseudo-second-order model. Scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR) were used in the course of characterization. The intraparticle diffusion model via the mass transfer was applied to examine the mechanisms of the rate-controlling step. It was found that intraparticle diffusion was mostly the rate controlling step in the adsorption of BV dye only, while the thermodynamic parameters (ΔH˚, ΔS˚, and ΔG˚) showed that the adsorption process is a typical chemical, spontaneous, and exothermic in nature.

Synthesis and characterization of Ethiopian kaolin for the removal of basic yellow (BY 28) dye from aqueous solution as a potential adsorbent

In the present research, the kaolin adsorbents (beneficiated, raw powder, and calcined) were prepared from Ethiopian natural kaolin through mechanical, wet, and thermal processes. The geochemical and surface properties of kaolin adsorbent were characterized using FTIR, SEM/EDS, XRD, and XRF. In the batch experiment, basic operation parameters (initial dye concentrations, pH, temperature, contact time, and adsorbent dosage) were examined. Percentage removal efficiency basic yellow 28 (BY28) dye were recorded as 94.79%, 92.08%, and 87.08% onto beneficiated, raw, and calcined kaolin absorbents, respectively at an initial dye concentration of 20 mg/L, solution pH of 9, the temperature of 30 °C°C, and contact time of 60 min and adsorbent dosage of 1g/100L. The molar ratio of SiO2/Al2O3 was recorded as 2.911 Percent mass composition of Ethiopian kaolin which is higher than the expected pure kaolinite standard which allows us to classify the kaolin clay as a siliceous one. The calculated values of ΔG0 for beneficiated adsorbent are -1.243, 1.576, and 4.396 kJ/mol at 303.15, 323.15, and 343.15 K, respectively for 20 mg/L of dye concentration and solution pH of 9, suggests that the thermodynamic behavior at lowest temperature is more feasible and spontaneous as compared with the higher temperature one. A similar fashion was calculated for raw and calcined adsorbents. The negative values of ΔHo and ΔS° suggest that the adsorption phenomenon is exothermic and the adsorbate molecules are organized on the solid phase in a more disordered fashion than the liquid phase. The pseudo-first-order and pseudo-second-order models have been used to describe the kinetics in the adsorption processes. The Pseudo-second-order model has been fitted for the BY 28 dye adsorption in the studied concentration range. The adsorption of BY 28 dye for raw and calcined adsorbents follows the Langmuir isotherm and the Freundlich isotherm fitted for the beneficiated adsorbent. The amount of BY28 dye taken up by beneficiated, raw, and calcined kaolin adsorbents was found as 1.896, 1.842, and 1.742 mg/g, respectively at a contact time of 1.0 h, the adsorbent dosage of 1.0 g, initial dye concentration = 20 mg/L and solution pH = 9 at 30 °C. The results found that these raw and prepared local kaolin adsorbents have a capacity as low-cost alternatives for the removal of dyes in industrial wastewater.

Analytical method validation of reversed phase HPLC for quantitative analysis of tartrazine and auramine o in powder drinks

This study was aimed to perform analytical method validation of high-performance liquid chromatography (HPLC) technique using photo-diode array detector for the simultaneous determination of Tartrazine (TAR) and Auramine O (AUO) in powder drink products. TAR and AUO were analysed using Waters Shield C18 column (250 mm x 4.6 mm i.d., 5 µm) using PDA detector at 300-650 nm. The mobile phase used was acetonitrileammonium acetate 19 mM (86:14 v/v) delivered isocratically at a flow rate of 1.2 mL/ min. The optimized HPLC condition was subjected to analytical method validation by assessing some performance characteristics as guided by International Conference on Harmonization (ICH). The method was linear over the studied concentration ranges with the coefficient of determination (R2 ) of 0.999 and 0.997 for TAR and AUR with % intercept less than 2%, respectively. The developed method was sensitive with a limit of detection value of 0.0325 μg/mL and 0.1052 μg/mL for TAR and AUO, respectively. The method is also accurate and precise as indicated with acceptable recovery values of 99.0- 100.7% for TAR and 102.1-106.5% for AUO with relative standard deviation (RSD) values lower than those required by Association of Official Analytical Chemists’ (AOAC). The developed method is simple and can be used for routine analysis of TAR and AUO for quality assurance purposes of powder drinks.

Chiral poly(amide-imide)/ZnS nanocomposite as a new adsorbent for simultaneous removal of cationic dyes from aqueous solution

A new adsorbent, poly(amide-imide)/zinc sulfide nanocomposite (PAI/ZnS NC), was fabricated and identified by Fourier-transform infrared spectroscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy, field emission-scanning electron microscopy, and transmission electron microscopy. Then, the obtained NC was applied for the simultaneous removal of auramine O (AO) and rhodamine B (RB) dyes from aqueous solution via the interactions of hydrogen bonding, π– π stacking, and Lewis acid–base interaction. The effects of operational variables including pH, PAI/ZnS NC mass, AO and RB concentration, and sonication time on removal efficiency were examined and optimized values were found to be 8.0, 16 mg, 11 mg L−1, and 6 min, respectively. The adsorption capacities of PAI/ZnS NC for the removal of AO and RB dyes were found to be 70.92 and 91.74 mg g−1, respectively. Ultraviolet–visible spectrophotometer was used to determine the amount of residual dye in solution. Fitting the experimental equilibrium data to isotherm models such as Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich reveals the suitability of the Langmuir model with high correlation coefficients ( R2 = 0.998 for AO and R2 = 0.999 for RB). Pseudo-first-order, pseudo-second-order, intraparticle diffusion, and Elovich kinetic models applicability was tested and the pseudo-second-order equation controls the kinetics of the adsorption process. Furthermore, this study establishes that PAI/ZnS NC can be successfully applied as a low-cost adsorbent and conserve its high efficiency after nine cycles for the removal of AO and RB dyes.

A dual surface inorganic molecularly imprinted Bi2WO6-CuO/Ag2O heterostructure with enhanced activity-selectivity towards the photocatalytic degradation of target contaminantst.

In this work, a high-surface-area dual inorganic molecularly imprinted (DIMI) Bi2WO6/CuO/Ag2O photo-catalyst was developed for the selective photocatalytic degradation of methyl green (MG) and auramine O (AO) dyes as target pollutants. The DIMI-Bi2WO6/CuO/Ag2O heterojunction was synthesized by a sono-chemically assisted sol-gel method by coating a layer of molecularly imprinted Ag2O/CuO on the surface of Bi2WO6 nanocubes with MG and AO as the templates. This was followed by calcination for the removal of target molecules and annealing for Ag/Cu oxide preparation. This novel photocatalyst was prepared to overcome the challenge of the co-existing non-target molecules, which has limited the photocatalytic degradation performance. The surface DIMI sites could act as surface defects for accelerating the separation of photogenerated holes and electrons, which led to the increased generation of OH radicals. Moreover, the DIMI sites had increased binding affinity toward MG and AO via the formation of multiple H bonds and electrostatic bonds, which were confirmed by FTIR spectroscopy, PL and EIS studies. The surface DIMI sites led to the increased adsorption and improved local concentration of MG and AO on Bi2WO6/CuO/Ag2O. Consequently, the heterojunction properties of the final DIMI product accelerated the transfer and separation of photogenerated carriers. The high binding affinity of the DIMI sites to MG and AO confirmed the selective recognition, which was tested in the presence of coexisting pollutant dyes. The other characterizations confirmed the successful fabrication and high photocatalytic activity of the high-surface-area DIMI-Bi2WO6/CuO/Ag2O heterostructured composite. In general, the superior interfacial electronic interactions, high migration efficiency of photoinduced charge carriers, and strong visible light absorption of the prepared photocatalyst resulted in good photocatalytic performance.

Selective adsorption and separation of toxic cationic dyes using hierarchically porous SDBS modified vaterite microspheres (Hr-SMV)

The application of hierarchically porous sodium dodecylbenzene sulfonate (SDBS) modified vaterite microspheres (Hr-SMV) for the selective adsorption of toxic cationic dyes has been explored in this work. Hr-SMV has been synthesized using a facile and low-cost precipitation method. X-Ray diffraction (XRD), Fourier transform infrared (FTIR), Scanning electron microscopy (SEM), Thermogravimetric analysis (TGA) and N2 adsorption-desorption isotherms have been used to understand the crystal structure, surface area, morphology and surface functionalities of Hr-SMV. As prepared Hr-SMV possesses a surface area of 31.15 m2 g−1 and a hierarchical porous structure. Influence of adsorption parameters on the adsorption of two cationic dyes, Crystal violet (CV) and Methylene blue (MB) has been studied in detail using batch adsorption studies. Maximum adsorption capacities of 68.8 and 316.8 mg g−1 were exhibited by Hr-SMV for MB and CV, respectively. Further, Hr-SMV shows efficient adsorptive removal of other cationic dyes, including Basic fuchsine (BF) and Auramine O (AO). In binary mixtures of cationic dyes, Hr-SMV efficiently removes both cationic dyes, thus highlighting its prospect for practical applications. In binary mixtures of cationic and anionic dyes, Hr-SMV is found to selectively adsorb cationic dyes with high separation factors. Thus, Hr-SMV has been found to be a promising low-cost adsorbent for the efficient adsorption and separation of cationic dyes from effluents.

Wood-based cellulose nanocrystals as adsorbent of cationic toxic dye, Auramine O, for water treatment

Abstract Removal of toxic organic cationic dye, Auramine O (AO), is critical prior to its discharge to the environment. In this work, wood-based colloidal cellulose nanocrystals (CNCs) in their anionic forms (sulfated and carboxylated) were examined as nanoadsorbents for the effective removal of cationic toxic AO. Both sulfated and carboxylated CNCs were characterized by FTIR, DLS, zeta potential, AFM and XRD techniques. The impact of both surface functionalities (half-ester sulfate and carboxylate) of CNCs were studied in relation to the adsorption of AO. The batch adsorption experiments were performed at 0 and 25 °C at different contact time and the highest removal percentage (82 %) and adsorption capacity (20 mg g−1) were obtained for the sulfated CNCs for an equilibrium contact time of 30 min. The kinetic data was fitted to the pseudo-second-order adsorption model, with the highest rate constant (0.55 g mg-1. min−1) related to the sulfated CNCs for the adsorption at 0 °C. The calculated thermodynamics parameters indicated that AO adsorption on both CNC samples was a spontaneous exothermic process with a decrease in the entropy of the system for the sulfated CNCs and an increase in entropy for the carboxylated CNCs. Fitting equilibrium data to four different types of isotherms (Henry, Freundlich, Langmuir and Temkin) showed that Freundlich isotherm was the most suitable to describe the adsorption behavior of AO at either 0 or 25 °C. Overall, this study demonstrated the potential application of sustainable and biodegradable wood-based CNCs as green bioadsorbents for the adsorption of toxic cationic AO dye.

Utility of smear microscopy and GeneXpert for the detection of Mycobacterium tuberculosis in clinical samples

Rapid identification of Mycobacterium tuberculosis (MTB), its resistance to rifampicin and differentiation of MTB from nontuberculous mycobacteria (NTM) is necessary in the management of mycobacterial diseases. Culture, the "gold standard" for the detection of MTB, is time consuming. In spite of its rapidity and low cost, smear microscopy has poor sensitivity for the detection of acid-fast bacilli (AFB). A real-time PCR based rapid diagnostic method like GeneXpert MTB/RIF assay can simultaneously detect M. tuberculosis and rifampicin (RIF) resistance. Hence, we aim to compare the performance of GeneXpert MTB/RIF assay with smear microscopy and culture. In this descriptive cross-sectional study, we compared the performance of GeneXpert in pulmonary (N=127) and extrapulmonary (N=48) clinical specimens with other diagnostic methods like culture, Auramine O (AO), and Ziehl Neelsen (ZN) staining. Rifampicin resistance was detected only by GeneXpert. Demographic data and clinical history of the subjects were collected from the patient's hospital records. AO and ZN staining when compared with mycobacterial growth indicator (MGIT) culture showed the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of 68.6, 95.7, 80, 92.4, 90.3% and 65.7, 95.7, 79.3, 91.8, 89.7%, respectively. The sensitivity, specificity, PPV, NPV and accuracy of GeneXpert was 88.6, 93.6, 77.5, 97.0 and 92.6%, respectively. GeneXpert is the best available rapid diagnostic method as it can detect MTB and rifampicin resistance gene simultaneously. Accuracy and negative predictive value of GeneXpert was found to be better than AFB staining. Thus, a negative GeneXpert test can rule out TB. Further, a negative GeneXpert and a positive smear microscopy results indicate the presence of NTM. However, GeneXpert is expensive and needs sophisticated instrument when compared to smear microscopy.

Selective and competitive removal of three basic dyes from single, binary and ternary systems in aqueous solutions: A combined experimental and theoretical study

The present study evaluates the selective and competitive adsorption of three basic dyes, namely, Basic blue 9 (BB9), Basic blue 41 (BB41) and Basic yellow 28 (BY28) from single, binary and ternary solutions onto natural safiot clay (NSC). For this, the effect of various parameters such as initial pH, initial dye concentration, adsorbent dose and temperature of the solution was studied and examined in a batch mode. The tested adsorbent was characterized by X-ray fluorescence (XRF), Scanning Electron Microscopy (SEM), Dispersive X-ray spectroscopy (EDX), Fourier Transform Infrared (FT-IR) and X-Ray Diffraction (XRD). XRF results indicate high percentages of SiO2 (47.44%) and Al2O3 (31.24%). X-ray diffraction diffractogram identified kaolinite as the main mineral phase in the presence of quartz, illite, calcite, and dolomite. The adsorption data were examined by Langmuir, Freundlich and Dubinin-Radushkevich isotherms. It was found that for single, binary and ternary systems the results indicated that Langmuir model provided the better correlation of experimental data. The experimental results obtained demonstrate high adsorption efficiency of dyes in the mono and multi systems by NSC. DFT calculations show that BB9 (ω = 6.18) is more electrophilic than BB41 (ω = 4.10) and BY28 (ω = 2.60) which indicates that BB9 is adsorbed first and favored compared to BB41 and BY28. Moreover, Molecular dynamics (MD) and Monte Carlo (MC) simulations are used as a powerful tool to provide a better theoretical scenario for understanding the mode of adsorption on the natural safiot clay (NSC).

Ipomoea aquatica roots as environmentally friendly and green adsorbent for efficient removal of Auramine O dye

This study presents Ipomoea aquatica root (“kangkong” root or KR) as a plausible environmentally friendly adsorbent. This readily available adsorbent, after oven drying, demonstrates strong adsorption characteristics toward Auramine O (AO) dye exhibiting 2.0 h equilibration time and stable efficiency within a sufficiently broad range in both pH and ionic strength. Adsorption kinetics was best described by the pseudo second order and Elovich models, indicating that chemisorption of two reactive moieties could be involved. Application of the experimentally obtained adsorption equilibrium data to investigate the conformity among many adsorption isotherm models, namely Langmuir, Freundlich, Temkin, Redlich-Peterson and Sips, together with corresponding error analyses, identified that the Sips model be the best-fit model, leading to attractive maximum adsorption capacity of 455.74 mg g−1. Further, regeneration and reuse of the spent adsorbent would be possible with ~ 75% AO dye being adsorbed even at the 5th cycle, when using base treatment. Hence, the utilization of Ipomoea aquatica root as a low-cost, effective adsorbent in wastewater treatment could be possible.

Comparative study on ultrasonic assisted adsorption of Basic Blue 3, Basic Yellow 28 and Acid Red 336 dyes onto hydromagnesite stromatolite: kinetic, isotherm and error analysis

In this study, we focused on the performance of an adsorbent such as a hydromagnesite stromatolite (HS) for rapid and efficient ultrasonic-assisted adsorption of Basic Blue 3, Basic Yellow 28 and Acid Red 336 dyes from aqueous solution. The initial dye concentration (0.05-0.10 g/L), adsorbent dose (0.1–0.5 g), pH (2–10), and temperature (20-40 °C) were evaluated. HS was characterized by means of BET, FTIR, SEM, and XRD. The surface area was observed to be 20.12 m2/g for HS. Different kinetic models, isotherm models (Langmuir, Freundlich, Temkin, Dubinin–Radushkevich, Redlich-Peterson, Frumkin, Harkins - Jura, Halsey and Henderson) and error analysis were calculated to explain the adsorption mechanism of dye on the surface of HS. The kinetic parameters of adsorption of all dyes were well-defined by the pseudo-second-order with R2 of 0.984-1.000 while the thermodynamic parameters demonstrated endothermic and feasible nature of the adsorption with ΔHo of 24.6-45.1 kJ/mol and ΔSo of 109.4-322.5 J/mol K. The uptake (%) values of HS for BB3, BY28 and AR336 were %31, %50, and %91, respectively. An eco-friendly and low-cost HS for removal of dyes from the aqueous solution within 100 s – 1200 s; HS was proposed in wastewater treatment.

New MOF/COF Hybrid as a Robust Adsorbent for Simultaneous Removal of Auramine O and Rhodamine B Dyes.

In this study, by hybridization of zinc-based metal–organic framework-5 (MOF-5) and melamine-terephthaldehyde-based intergrade two-dimensional π-conjugated covalent organic framework (COF), a novel MOF-5/COF (M5C) hybrid material was prepared and characterized by Fourier transform infrared, field emission scanning electron microscopy, X-ray diffraction, and thermogravimetric analysis. MOF-5 has a well-defined cubic structure, and the proposed COF has an orderly and spherical nanosize shape. The prepared MOF-5/COF was applied as an effective adsorbent for rapid and high-efficient simultaneous removal of auramine O (AO) and rhodamine B (RB) cationic dyes via electrostatic, H-bonding, Lewis acid–base interactions, and π–π stacking from aqueous solution. The effect of experimental parameters such as pH, M5C mass, contact time, and AO and RB dyes concentration was investigated for removal efficiency and optimized. The M5C adsorbent showed an adsorption capacity of 17.95 and 16.18 mg/g for AO and RB dyes, respectively, at pH 9.5. The adsorption study of AO and RB dyes by M5C comprises both isotherm and kinetic studies. The equilibrium adsorption data followed by Langmuir isotherm and the adsorption kinetic process were found to be a pseudo-second-order model. The robustness adsorption efficiency of MOF/COF hybrids can be attributed to the formation of amide bonds between COF and MOFs, which improve the stability of the adsorbent.