Efficient extraction of metals (Fe, Zn, Pb) from hazardous jarosite using ionic liquid and waste-derived solvents.

The present study evaluated a solvo-metallurgical technique for metal extraction from industrial solid waste (jarosite) using ionic liquids (ILs) and waste-derived solvents. The jarosite contains a considerable amount of metal ions, namely iron, zinc, and lead. The jarosite was characterized by XRF, XRD, SEM, and FTIR techniques. The parameters affecting metal extraction, such as stirring time, acid molarity, and temperature, have been examined. Aliquat 336 was used to extract metals from fresh and roasted jarosite after equilibration with HCl. The response surface methodology (RSM) was used to optimize the parameters for the maximum metal extraction using [A336] [Cl]. Maximum extraction of iron (86.75%), zinc (51.96%), and lead (94.38%) from roasted jarosite was achieved at optimum conditions (125-min stirring time, 5 M acid molarity, and 20 ml/g liquid-to-solid ratio). Furthermore, the metal extraction was investigated using waste-derived solvents. The results show that waste-derived solvents, such as biomass and plastic pyrolysis oil, can effectively extract metals from fresh and roasted jarosite. Biomass pyrolysis oil achieved the highest extraction at 50 °C for 90 min, while plastic pyrolysis oil achieved the highest extraction at 50 °C for 60 min from roasted jarosite. These solvents are also cost-effective because they are made from waste plastic and biomass.

Circular economical approach of extracting nanocarbons from waste pea peel for sensing of p-nitrophenol and its conversion into paracetamol.

An important paradigm shift towards the circular economy is to prioritize waste prevention, reuse, recycling, and recovery before disposal is necessary. In this context, a sustainable protocol of converting waste pea peel (wPP) into low-cost carbon nanomaterials for sensing and conversion of p-nitrophenol (p-NP) into value-added paracetamol is being reported. Two fractions of the carbonaceous nanomaterials were obtained after the hydrothermal treatment (HT) of wPP, firstly an aqueous portion containing water-soluble carbon dots (wPP-CDs) and a solid residue, which was converted into carbonized biochar (wPP-BC). Blue-colored fluorescent wPP-CDs displayed excitation-dependent and pH-independent properties with a quantum yield (QY) of 8.82 %, which were exploited for the fluorescence sensing of p-NP with 4.20 µM limit of detection. Pyrolyzed biochar acting as an efficient catalyst effectively reduces p-NP to p-aminophenol (p-AP) in just 16 min with a 0.237 min-1 rate of conversion. Furthermore, the produced p-AP was converted into paracetamol, an analgesic and antipyretic drug, to achieve zero waste theory. Thus, this study provides the execution of sustainable approaches based on the integral valorization of biowaste that can be further recycled and reused, offering an effective way to attain a profitable circular economy.

Waste to value transformation: Converting Carica papaya seeds into green fluorescent carbon dots for simultaneous selective detection and degradation of tetracycline hydrochloride in water.

Rampant use of antibiotics has resulted in their seepage into groundwater and ultimately ending up in the food chain, causing antimicrobial resistance. To address this issue, it is imperative to not only quantitatively detect but eliminate them from water. An eco-friendly, one-step microwave-induced pyrolysis of waste papaya seeds (PS) with ethylenediamine (EDA) for just 5min gave green fluorescent nitrogen-doped carbon dots (PS-CDs), which are capable of detecting and photocatalytically degrading TC. The fluorescence properties of PS-CDs displayed that it has high sensitivity and selectivity towards sensing of TC with a detection limit as low as 120 nM. Also, the method gave satisfactory recovery results when extrapolated to determine TC in spiked milk, orange juice, tap water, and honey samples. On the other hand, PS-CDs alone potentially function as an efficient photocatalyst for the degradation of TC. PS-CDs' dual functionality provides an effectual method for the simultaneous detection and degradation of TC by a single nanoprobe.

Non-toxic and biodegradable κ-carrageenan/ZnO hydrogel for adsorptive removal of norfloxacin: Optimization using response surface methodology.

Antibiotic resistance is increasing globally due to increased prescription and easy dispensing of antibiotic drugs universally. Hence, to mitigate this effect, efficient, biodegradable, and non-toxic adsorbents are required to be developed. Carrageenan (CG), a natural polymer, having multiple functional groups, provides a backbone for crosslinking with borax and incorporation of ZnO nanoparticles that formed borax-cross-linked κ-carrageenan (CG/Bx/ZnO) hydrogel which is used for efficient adsorption of norfloxacin from water. Surface morphology of as-synthesized hydrogel revealed the rough surface, which was determined by FESEM. Surface area of CG/Bx/ZnO hydrogel was found to be 22.90 m2/g with 3.41 nm pore radius. Systematic batch adsorption studies revealed that 99.4 % removal efficiency could be achieved at a dosage level of 20 mg/L of norfloxacin with 10 mg of hydrogel at pH of 4 in 8 h at room temperature. Experimentally optimized key parameters affecting the overall efficiency of adsorption matched well with the results assessed from ANOVA using Box-Behnken composite design model. The adsorption process was well fitted with the pseudo-second-order model and Langmuir isotherm with 1282.05 mg/g adsorption capacity. Thermodynamic study results show that adsorption is spontaneous and endothermic. The CG/Bx/ZnO hydrogel demonstrated excellent repeatability with minimal loss in norfloxacin adsorption for seven cycles.

Utilization of metal industry solid waste as an adsorbent for adsorption of anionic and cationic dyes from aqueous solution through the batch and continuous study.

Industrial waste, for instance, textile effluents when released into the ecological system without first being treated or with inappropriate levels of treatment, can lead to serious issues deteriorating the environment and human health. Moreover, solid waste from various industries has also become a major issue due to massive urbanization. For instance, the waste from the metal industry has been rapidly increasing such as Jarosite which has various metals, metal oxides, and silica in its composition. Therefore, Jarosite was utilized as an adsorbent for the adsorption of anionic Congo red (CR) and cationic Methylene blue (MB) dyes from aqueous solutions. The processed adsorbent sample was characterized by BET, XRD, SEM, EDS, FTIR, and XPS techniques. The effects of initial dye concentration, pH, adsorbent dose, temperature, and contact time were examined. The metal industry waste is used as a low-cost abundant adsorbent with great potential for adsorption ability to remove the CR (97.5%) and MB (68.5%) at pH 7, contact time 90 min, adsorbent dose 0.1 g, and initial dye concentration 50 mg/L. The adsorption data followed the adsorption isotherm and Kinetics for both dyes. The removal of both dyes was a physical adsorption process, endothermic and spontaneous reaction. Column adsorption investigation was described by AB (Adams-Bohart) and YN (Yoon-Nelson) models. According to the economic view, the utilization of jarosite for dye removal is a cost-effective approach, because it is collected free of cost from industries. Henceforth, for the first time, toxic metal industry waste was successfully utilized as an adsorbent for wastewater treatment.

MIL-88B(Fe) MOF modified screen-printed electrodes for non-enzymatic electrochemical sensing of malathion.

An enzyme-free electrochemical approach for ultra-trace quantification of the organophosphate insecticide malathion is proposed in this study. It is premised on screen-printed carbon electrodes modified by the MIL-88B(Fe) metal-organic framework (MOF). A one-pot solvothermal method was used to synthesise MIL-88B(Fe). The surface modification of electrodes allowed for increased electroactive surface area and accelerated electron transport on the electrode. Inhibition in the redox signal of MIL-88B(Fe) was observed due to the affinity between metal centres of the MOF and the functional groups of malathion, leading to an accurate determination of malathion. The proposed sensor effectively quantified malathion in the wide concentration range of 1 × 10-12 M to 1 × 10-6 M. The limit of detection for malathion was 0.79 pM. The proposed sensor also possessed excellent stability, repeatability, and anti-interference characteristics. Furthermore, the proposed sensor demonstrated satisfactory malathion recovery in spiked vegetable samples.

Simultaneous removal of heavy metals and dye from wastewater: modelling and experimental study.

In this work, heavy metals were removed simultaneously using wheat bran as an adsorbent. For batch experiments, the Box-Behnken design of response surface methodology was used and the effect of dye on metal removal was analysed. It has been observed that the presence of dye has reduced the removal of each metal in the range of 100-20% with no appreciable reduction in dye adsorption. The optimum pH, temperature, and adsorbent dose were found to be 7.59, 33.23 °C, and 2.90 g/L, respectively, for 79.70% chromium, 99.9% cadmium and 87.27% copper removal. It was found that Langmuir isotherm fits well with the experimental data (RMSE value up to 0.033). The maximum adsorption capacity obtained for copper, chromium, cadmium and dye were 2.17 mg/g, 1.76 mg/g, 1.52 mg/g and 3.215 mg/g, respectively. The continuous study was performed for parameters, i.e. bed height (0.15-0.45 m), flow rate (5-15 mL/min) and initial metal concentration (100-500 mg/L). In continuous study, dye acted as an interfering species and as a result breakthrough and exhaustion time decreased. The modelling and simulation of continuous adsorption process were performed. A dynamic mathematical model was developed for continuous fixed bed adsorption column to compare the breakthrough curve with experimental results.

An experimental approach to treat salt and dye contaminated water via capacitive deionization.

This article is intended to provide the versatility of the CDI process for an application covering various pollutants, namely, dye and salt contaminated stream treatment. It was observed that tailoring the base material enhances stated properties revealing proficiency in desalting and dye removal performance. Further, the experimental investigations were performed by modifying the surface of agro-waste developed electrodes to improve the sorption of contaminants over bio-based activated carbon (B-AC). The chemical activation was with potassium hydroxide (KOH-BAC) and phosphoric acid (H3PO4-BAC). The study indicates the best electrochemical and sorption properties with H3PO4-BAC incorporated electrode of the electrode 76.97 F/g specific capacitance. Moreover, these fabricated electrodes were implemented for dye effluent treatment and desalting the concentrated stream from RO reject. It was evaluated that a strong sorption capacity for 18.4 mg/g in the case of salt stream was observed for H3PO4-BAC electrode whereas 0.12 mg/g was reported for dye removal. The equilibrium data was fitted into the isotherm and kinetic model of adsorption. Lastly, the study reveals that the fabricated electrode has huge potential to treat contaminated water.

Green synthesis of guar gum/Ag nanoparticles and their role in peel-off gel for enhanced antibacterial efficiency and optimization using RSM.

Polysaccharide-based guar gum (GG) biopolymer is used via a hydrothermal process to synthesize silver nanoparticles. The GG biopolymer act as a reducing and stabilizing agent. Moreover, GG was used for preparing peel-off masks to provide the desired consistency of formulation and synthesis of nanoparticles as an antibacterial agent. This work presents the novel GG/Ag nanoparticles peel-off gel and evaluates the antibacterial efficiency. The synthesized Ag-nanoparticles analyzed by UV-spectroscopy reflect a prominent peak at 413 nm. The size and distribution of nanoparticles were examined by TEM images obtained from the 6 to 18 nm range. We demonstrate the efficiency of peel-off facial gel as an antibacterial and preservative-free cosmetic product at different temperature ranges. The RSM study was used for parameter optimization of peel-off gel for extrudability, spreadability, and drying time by employing a CCD. The results show that the optimized GG, PVA, and ethanol concentration were 3.47, 8.30, and 5.80 w/w%, respectively, with 0.02 w/w% Ag nanoparticles. The peel-off gel antibacterial activity against Escherichia coli (11 ± 0.1 mm), Staphylococcus aureus (10 ± 0.3 mm), and Propionibacterium acnes (11 ± 0.3 mm). The peel-off gel was prepared from natural ingredients; due to this, it is non-toxic for human skin.

Quick and hassle-free smartphone's RGB-based color to photocatalytic degradation rate assessment of malachite green dye in water by fluorescent Zr-N-S co-doped carbon dots.

Sunlight active blue emissive zirconium, nitrogen, and sulfur co-doped carbon dots (Zr-N-S-CDs) have been synthesized by microwave-induced pyrolysis for achieving efficient photocatalytic degradation of pollutant malachite green dye (MG) in water. Surface morphology studies using high-resolution transmission electron microscopy confirmed the formation of spherical-shaped CDs with an absorbance peak at 350 nm and emission peak at 437 nm in UV-vis and fluorescence spectroscopy, respectively. Surface functional groups, elemental composition, and metal/non-metal co-doping were confirmed by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. To understand the photocatalytic performance of Zr-N-S-CDs, various parameters, such as the source of energy, concentration of dye, catalyst dosage, and change in pH, were investigated. MG dye (20 ppm) at a pH 7 with 0.5 mg/mL of Zr-N-S-CDs could be photodegraded efficiently in 90 min under sunlight (99%) compared to dark and artificial light conditions. Moreover, real-time analysis of degradation rate could be conveniently calculated by integrating the colorimetric responses of MG dye with RGB values obtained by the "Color Picker" app of a smartphone. The degradation rate obtained using a smartphone (97.89%) was found to be in agreement with the UV-vis spectroscopy (99%), thus, providing a new, handy, and instrument-free route for speedy and quantitative estimation of the degradation of hazardous MG dye by Zr-N-S-CDs.

Development of an integrating coagulation and reverse osmosis system to treat highly turbid water using synthesized coagulants.

In the present study a coagulation process was used as a pretreatment for a reverse osmosis (RO) membrane with turbid raw water collected from Bisalpur dam, Rajasthan, India. To optimize the coagulation performance, three kinds of coagulant, namely, alum (commercially available), synthesized inorganic polymeric coagulant-medium basicity (IPC-M), and inorganic polymeric coagulant-ultrahigh basicity (IPC-UH) were examined for turbidity removal with varying operating parameters. It was observed that in the optimum pH range of 6-7, the IPC-UH was the best performing coagulant with a 0.99 mg/L equivalent Al2O3 dose, revealing 2 NTU residual turbidity and residual aluminium of 0.001 mg/L. Moreover, the Langelier saturation index and Ryznar stability index values were evaluated at optimum conditions for all the three coagulants providing negligible scaling potential. Furthermore, the coagulant-treated water (100 L) was fed to the RO membrane, and the performance was noted in terms of flux, pressure, and total dissolved solids. It was observed that IPC-UH had the lowest reduction in permeate flux of 0.78 L/min/m2 compared with the commercially available coagulant alum (0.90 L/min/m2). Also, an increased feed pressure was observed for all the coagulant-treated waters with the lowest value of 2.3 kg/cm2 for IPC-UH, which was 2.5 kg/cm2 for alum (commercially available coagulant). Therefore, integration of coagulation before the RO system resulted in effective pretreatment of turbid water with very minute scaling.

Fluoride occurrences, health problems, detection, and remediation methods for drinking water: A comprehensive review.

Fluoride contamination has become a considerable threat to our society worldwide. Fluoride in drinking water is primarily due to rich fluoride soil, volcanic activity, forage, grasses and grains, and anthropogenic reasons. World Health Organization has regulated the upper limit for fluoride in drinking water to be 1.5 mg/L while different countries have set their standards according to their circumstances. Excess amounts of fluoride ions in drinking water can cause dental fluorosis, skeletal fluorosis, arthritis, bone damage, osteoporosis, muscular damage, fatigue, joint-related problems, and chronicle issues. In extreme conditions, it could adversely damage the heart, arteries, kidney, liver, endocrine glands, neuron system, and several other delicate parts of a living organism, briefed in the present article. Moreover, a comprehensive scenario for the situations in countries like, China, Canada, Mexico, United States, Yemen, Pakistan, Saudi Arabia, South Korea, Sri Lanka, Indonesia, Iran, Turkey, Australia, and India affected with high fluoride levels in ground water has been described. To analyze the presence of fluoride molecule, out of different detections methods, ion selective and colorimetric method has been adopted for real situation in the field of water application. Also, different methods to remove fluoride from water like reverse osmosis, nano filtration, adsorption, ion-exchange, and precipitation/coagulation with their removal mechanism were highlighted in the review. Moreover, the applicability of the approach with the prospect of country's economic status has been discussed, due to high cost and maintenance the membrane technology is not popular in developing countries like India, Senegal, Tanzania, and Kenya which employ adsorption and coagulation-precipitation for fluoride removal. It is noticeable from literature study that different approaches show unique potential for defluoridation. Some key parameters and mechanistic adaptations which could pave the defluoridation methods to newer horizons have been put forward.

Removal of fluoride from water by using a coagulant (inorganic polymeric coagulant).

Excess fluoride (F) ion of drinking water is a major problem in many areas of India and causes harmful effects such as dental and skeletal fluorosis. The World Health Organization (WHO 2004) recommends an upper limit of 1.5 mg/L fluoride in drinking water, and the concentration of fluoride in groundwater has been found 10-20 times higher in many of the States in India. In this study, the performance of inorganic polymeric coagulant (IPC) named as IPC-23, IPC-13, IPC-17, and alum for fluoride removal from drinking water was investigated. The amount of IPC was decided according to the Al2O3 amount present in the alum dose recommended in the batch Nalgonda defluoridation technique. The effects of coagulant dosage (IPC) at different pH and initial concentrations of fluoride on fluoride removal have been studied. The synthetic sample having a fluoride concentration of 2 to 6 mg/L was treated at the optimized dosage and residual fluoride was reduced to 1.0 to 1.2 ppm with IPC-17. Residual aluminum in treated water was well within WHO norms (< 200 µg/L) for drinking water. Optimum pH for fluoride removal was 6.5, and there was deterioration in the performance of IPC at both lower and higher pH.

Antipyrine based Schiff's base as a reversible fluorescence turn "off-on-off" chemosensor for sequential recognition of Al3+ and F- ions: A theoretical and experimental perspective.

A Schiff's base probe (L) based on antipyrine has been intended, synthesized and assessed as a turn "off-on-off" probe for successive recognition of Al3+ and F-. The probe L act out as a turn "on" fluorescence probe towards Al3+ in methanol at pH 6 which turned "off" by F- at 433 nm. The 1:1 binding stoichiometry of L + Al3+ complex was revealed by Job's plot and approved by ESI-HRMS data. The binding constant and limit of detection of probe L for Al3+ were found to be 2.951 × 107 M-1 and 0.61 × 10-7 M respectively, which is lesser than the acceptable limit (0.74 × 10-7 M) in drinking water. The proposed binding sites and the mode of interaction of probe L was studied and validated by 1H NMR titration and 27Al NMR spectroscopic studies. To get detailed vision into binding mechanism and optimized structure of receptor L and L + Al3+, L + Al3+ + F- complex, theoretical calculations using DFT/DND and TDDFT method were performed. Furthermore, probe L can mimic INHIBIT logic function using Al3+ and F- being logic inputs and examining the fluorescence maxima at 433 nm as output.

Double scrotum? A rare ignored paraphimosis - Case report.

Paraphimosis is usually acute painful condition. Delay in medical attention might result in dreaded complications like gangrene and auto-amputation. Very rarely patient might present late with large painless paraphimosis as in our case just because it interrupts intromission despite satisfactory painless erection.

Robust synthesis of sugar-coumarin based fluorescent 1,4-disubstituted-1,2,3-triazoles using highly efficient recyclable citrate grafted ß-cyclodextrin@magnetite nano phase transfer catalyst in aqueous media.

Green synthesis of 1,4-disubstituted-1,2,3-triazoles via click reaction using nano magnetic Fe3O4 core decorated with cyclodextrin-citric acid (Fe3O4@CD-CIT) acting as a phase transfer nanoreactor with low copper loading under ultrasonication at 40 °C, in aqueous media is described. Anchoring the surface of magnetite with cyclodextrin (CD) prevents its agglomeration and at the same time, CD provides a hydrophobic niche for lipophilic reactants while its outer hydrophilic core makes the reaction feasible in water yielding almost quantitative yield of desired products. Magnetic separation using an external magnet, recyclability and reuse (7 times), without appreciably affecting the %yield of the products are its other attractive attributes. Gram scale synthesis was also achieved with 93% yield.

Study of reaction parameters and kinetics of esterification of lauric acid with butanol by immobilized Candida antarctica lipase.

Esterification of lauric acid with n-butanol, catalyzed by immobilized Candida antarctica lipase (CAL) in aqueous-organic biphasic solvent system was studied. Effects of various reaction parameters on esterification were investigated, such as type and amount of solvent, amount of buffer, pH, temperature, speed of agitation, amount of enzyme, butanol and lauric acid. The most suitable reaction conditions for esterification were observed at 50 degrees C and pH 7.0 using 5000 micromoles of lauric acid, 7000 pmoles of butanol, 0.25 ml phosphate buffer, 1 ml of isooctane as the solvent and 50 mg of immobilized enzyme in the reaction medium at agitation speed of 150 rpm. Maximum esterification of 96.36% was acheived in 600 min of reaction time at n-butanol to lauric acid molar ratio of 1: 0.7. Kinetic study for the esterification of lauric acid with n-butanol using immobilized CAL was carried out and the kinetic constants were estimated by using non-linear regression method. The estimated value of Michaelis kinetic constants for butanol (KmBt) and acid (KmAc) were 451.56 (M) and 4.7 x 10(-7)(M), respectively and the value of dissociation constant (KBt) of the butanol-lipase complex was 9.41 x 10(7)(M). The estimated constants agreed fairly well with literature data.

Adult-onset asthma and severe periocular xanthogranuloma: a case report.

A 55-year-old obese Mexican American male with a 3-year history of adult-onset asthma presented with a 10-year history of disfiguring eyelid edema. A biopsy revealed lymphoid aggregates consisting of reactive lymphoid follicles and Touton giant cells. He was diagnosed with adult-onset asthma associated with periocular xanthogranuloma and treated with systemic steroids. This case highlights an uncommon disease in its most severe presentation.

IgA orbital plasmacytoma in multiple myeloma.

The authors report a case of orbital plasmacytoma in a 48-year-old man with known multiple myeloma. He presented with proptosis, diplopia, and decreased vision of the left eye for several weeks. He had been previously treated for IgA lambda multiple myeloma with chemotherapy, radiation, and autologous stem cell transplant. After a left orbitotomy, flow cytometry revealed a tumor rich in plasma cells expressing CD138 with equivocal lambda light chain expression. The patient underwent orbital radiation, with improvement of vision and disc edema OS. The patient is currently undergoing salvage chemotherapy for relapse of multiple myeloma. This is the third reported case of IgA myeloma involving the orbit.