In this study, polymer-based modified electrodes (PGE/PPy and PGE/PPy/Cyanex 921) based on pencil graphite electrodes (PGE) have been prepared for the determination of copper(II) ions. Parameters such as the number of cycles, scan rate, and solution pH have been optimized to prepare the electrodes. As a result of the analyses, the optimum number of cycles is determined to be 8 for the PGE/PPy and PGE/PPy/Cyanex 921 electrodes. The scan rate is 40 mV/s for PGE and 80 mV/s for PGE/PPy and PGE/PPy/Cyanex 921 electrodes. The pH value of the analysis medium is set to 2 for both the PGE and PGE/PPy electrodes and 3 for the PGE/PPy/Cyanex 921 electrode. The electrodes are prepared using the cyclic voltammetry (CV) technique. The performance of the electrodes in the determination of copper(II) ions was investigated using the differential pulse voltammetry (DPV) method. As a result of experiments with the electrodes, linearity is obtained in the ranges of 20-200 ppm (R-2=0.9991) for the PGE electrode, 20-150 ppm (R-2=0.9983) for the PGE/PPy electrode, and 20-140 ppm (R-2=0.9991) for the PGE/PPy/Cyanex 921 electrode. The limits of detection (LOD) for the PGE, PGE/PPy, and PGE/PPy/Cyanex 921 electrodes are found to be 3.60, 3.51, and 2.15 ppm, respectively (S/N=3). Interference effect experiments showed that the selectivity and sensitivity of the PGE/PPy/Cyanex 921 electrode for copper(II) are not significantly affected by the presence of interfering species. The developed electrodes are used to determine copper(II) ions added to water samples by the standard addition method, and the recovery values of the method were close to 100%.
This research aims to protect freshwater resources from industrial effluents and reduce greenhouse gas emissions, addressing the issue of global warming. The study focuses on synthesizing smart non-metal functionalized graphene materials by converting saccharide units into graphene layers doped with oxygen, sulphur, and nitrogen (GO, S-GO, N-GO) for the primary treatment of various organic-based industrial effluents. The significant factors such as saccharides as precursor, heteroatom doping (O, N, S), pH, time, temperature, microstructure, surface functional groups, and morphology have been explored to enhance adsorption and photocatalytic efficiency. The study targeted less-explored pollutants like textile based azo, xanthenes, thiazine dyes and chlorophenols. Catalytic efficiency has been assessed via fluorescence properties, showing that S-GO exhibited superior photocatalytic performance compared to GO and N-GO. A linear correlation between fluorescence intensity, lifetime, and photocatalytic activity for degrading 2,6-dichlorophenol and organic dyes is observed using sample S-GO as the catalyst. The role play of Sulphur in the efficient catalytic activity of graphene structure is well analyzed. The research findings offer valuable insights for designing functionalized 2D Carbon materials, which could serve as effective catalysts for treating pollutants from textile, pharmaceutical, and petrochemical industries.
A small alkaline water electrolyzer with a six-cell capacity, using 316L stainless steel as electrodes, has been designed and described to produce distributed hydrogen. Both electrodes have widths of 130 mm, heights of 170 mm, a thickness of 1 mm, and an active surface area of 221 cm2. Potassium hydroxide electrolyte at four concentrations (10%, 20%, 30%, and 40% w/w) at atmospheric pressure and temperatures of 25-70 degrees C is used to test the system. Using the ADC-3303D regulated power supply (12.5V/10A, 125W), we obtained a constant average current of 7.75 A at all concentrations. An SD-6000 flowmeter is used to measure hydrogen production with maximum output recorded at 30% KOH concentration and 70 degrees C, 3.8 L/h. The purity of hydrogen is determined by gas chromatography analysis to be more than 99.5% in the absence of moisture. The results of the prolonged testing of greater than 1000 h showed the rate of corrosion of the electrode as low as 0.008 mm/year. It was shown that the system could perform optimally at 30% KOH with a thermoneutral potential efficiency of 72% and a Faraday efficiency of 96%. Its small size (15x20x25 cm) allows industrial applications to be deployed portably. Economic estimates show that the production of hydrogen will cost $28/kg at 2000 h per year of operation.
The enhancement of thermal performance with minimal thermodynamic irreversibility is a key requirement in the design of modern energy and thermal management systems, particularly those involving magnetized porous enclosures. The present study aims to numerically investigate entropy generation and thermodynamic optimization in a forced convection flow of a Cu-GO/water hybrid nanofluid confined within a square porous cavity subjected to a transverse magnetic field. The hybrid nanofluid behaviour is modeled using the Tiwari-Das formulation, while the porous medium is characterized by the Darcy-Brinkman-Forchheimer model. The cavity consists of stationary horizontal walls with centrally heated sections maintained at a constant high temperature, whereas the vertical walls are kept cold. The governing equations are solved numerically to analyze the effects of the Hartmann number, Darcy number, and nanoparticle volume fraction on heat transfer characteristics and entropy generation. The results reveal that the inclusion of graphene oxide nanoparticles significantly enhances heat transfer performance while suppressing entropy generation under appropriate magnetic field strengths and porous resistance conditions. The study concludes that Cu-GO hybrid nanofluids provide an effective thermodynamic optimization strategy for magnetohydrodynamic convection in porous cavity-based thermal systems.
The present study reports the utilization of municipal sewage sludge mixed with bagasse undergoes thermal decomposition for pyrolysis experiments and thermogravimetric analysis (TGA). The characterization tests established that bagasse contained higher levels of carbon and volatile matter than sewage sludge. Coats and Redfern method has been applied to TGA and differential thermogravimetric (DTG) data to extract kinetic parameters. The research showed that adding bagasse to sewage sludge during pyrolysis produced a shorter temperature window which scientists linked to quicker volatile component release. Bagasse's high volatile matter content enabled a combustion-like decomposition reaction of sludge to occur at reduced temperatures. A 50-50% sludge and bagasse mixture has lower activation energy than pure sewage sludge, suggesting that the presence of bagasse reduces the amount of reaction energy needed. This research uses Coats and Redfern method to calculate activation energy based on TG-DTG analysis of sewage sludge with bagasse in pyrolysis experiments.
In this study, the Box-Behnken design (BBD) of the response surface methodology (RSM) has been used to optimize the coprecipitation variables (coprecipitation pH, Al:Ni mole ratio, injection speed of base) for preconcentation of Ni using aluminum hydroxide to obtain accurate quantitation of Ni in biodiesel samples produced from waste cooking oil (WCO) by homemade flame atomic absorption spectrometer. The performance of homemade flame atomic absorption spectrometer has been evaluated through comparison with Perkin-Elmer 5100 PC flame atomic absorption spectrometer using aqueous standard solution of Cu, Ni. The predicted optimal conditions of statistical are pH=10.5 and Al:Ni mole ratio of 1.96 x 10(4), while the injection speed for NaOH is 0.85 mL/min at the concentration of 1.0 mol/L. The concentration of Ni is mu g/L level and preconcentration factors is between 50 similar to 200. To assess the accuracy of purposed method, a recovery test has been performed and compared to analytical values of Perkin-Elmer 5100 PC GFAAS.
Sustainability, which addresses the challenges of agricultural issues, requires the development of hydrogel-based systems. For this purpose, new hydrogels have been synthesized via free radical copolymerization using Iraqi Prunus domestica gums (IPDG) and lignosulfonic acid sodium salt (LS), and were analyzed by FTIR, 13C NMR, FESEM, XRD, and TGA techniques. The swelling capacities are 165.357 g.g(-1) of LS-IPDG-g-SAH, 159.267 g.g(-1) of LS-g-SAH, and 156.469 g.g(-1) of IPDG-g-SAH hydrogel formulations. The pH 7.2 exhibited the maximum swelling in distilled water compared to alkali and acidic media. The release behaviour of thiamethoxam in distilled water has been modeled using the Korsmeyer-Peppas, Weibull, and Higuchi models. Up to 92 h, 27.793%, 25.447%, and 23.538% of the pesticide are released from LS-IPDG-g-SAH, LS-g-SAH, and IPDG-g-SAH, respectively. For soil application, the trend of water evaporation is in the decreasing sequence: blank soil > IPDG-g-SAH >LS-g-SAH >LS-IPDG-g-SAH after 12 days. These results generally present the prospects of hydrogels as environmentally friendly materials for agrochemical applications, providing opportunities for the controlled delivery of pesticides and increased resource efficiency. Additionally, the novel approach by incorporating IPDG and lignin-based hydrogels makes it of fantastic value in the field of potential agricultural development.
These days, the automotive sector and manufacturing industries have begun adopting renewable materials due to public awareness of the usage of polymers and severe legal pressures surrounding their use. This research is focused on using casuarina leaf fibre as reinforcement in an epoxy matrix together with natural moringa gum filler since natural fibre reinforced composites are essential for the development of lightweight structural materials. It is observed that the synergistic impact of fibre and natural filler improved adhesion and stress is transferred more evenly across the reinforcements. The mechanical, viscoelastic, thermal and biodegradability properties have been investigated on incorporation of 4,8,12,16 and 20v/v % of moringa gum in casuarina epoxy composite and the results indicated that the addition of moringa gum filler increased the tensile, flexural and impact strength of the composites indicating that moringa gum is a promising filler. Using thermogravimetric analysis, Differential Scanning Calorimetric analysis, it is found that the development of hybrid composites increased thermal stability, with distinct degradation patterns.
The biosorption behaviour of metanil yellow from aqueous solution has been investigated in a batch system using a lowcost biochar-based nanobiomaterial prepared from Jatropha oil cake (JOC). The optimum pH was 4.0, which provided a maximum biosorption capacity of 21.71 mg/g and the equilibrium was established in 90 min. Kinetic analysis indicated that the contribution of intraparticle diffusion increased with dye concentration, whereas the apparent influence of film and pore diffusion decreased. Equilibrium data was well represented by the Sips isotherm followed by the Langmuir model, which confirmed monolayer coverage with maximum sorption capacity of 24.3 mg/g. Transmission Electron Microscopy (TEM) revealed primary particles in the nanoscale range (approximate to 60-80 nm), which exhibited partial aggregation. Fourier Transform Infrared Spectrometer (FTIR) analysis suggested the involvement of ion-exchange and surface complexation during the biosorption process. Desorption studies showed that up to 96.3% of metanil yellow could be recovered from the biochar using acetone. The results demonstrated that the nanobiomaterial derived from Jatropha biodiesel cake could be leveraged as a low-cost adsorbent for the removal of dye from the water environment.
This study presents the sulfite pretreatment in order to improve sludge biodegradability and methane production during anaerobic digestion. Different SO3 concentrations (0-500 mg/L SO3) have been used to investigate the sulfite pretreatment considering sludge disintegration. First, a 24 h period has been applied to determine the pre-treatment effects. At the end the period, 500 mg/L SO3 achieved the highest performance in terms of volatile solid reduction and increase in soluble chemical oxygen demand concentration. 13.84 % of organic matter reduction, 18.9 % of increase in soluble chemical oxygen demand and 1.18 % of disintegration degree are obtained. After that, effects of sulfite pre-treatment on methane production have been investigated during anaerobic digestion. Similarly, the anaerobic digester which fed with pretreated sludge using 500 mg/L SO3 showed the highest methane production with 96.5 mL CH4/g VS. Besides, in first time for the sulfite pre-treatment of sludge, Monte Carlo simulation has been used to estimate the volatile solid reduction and methane production considering removed chemical oxygen concentration and changes of volatile solid concentrations As a result of simulation, maximum organic matter reduction is found as 33 % and while methane production was 26,83 % LEL.
This study details the synthesis and characterization of photochromic tungsten-molybdenum oxide (W-Mo) nanocomposites using a deep eutectic solvent (Ethaline) composed of choline chloride and ethylene glycol in a 1:2 molar ratio, providing a green and efficient fabrication route. FTIR analysis confirmed the successful incorporation of metal oxides into the DES matrix, evidenced by characteristic metal-oxygen (W-O and Mo-O) stretching vibrations observed within the 947-767 cm-1 and functional group interactions. Scanning electron microscopy imaging revealed agglomerated, irregularly shaped particles with porous morphologies, while energy dispersive X-ray spectroscopy confirmed the homogeneous distribution of W and Mo within the composite. X-Ray diffraction patterns indicated a predominantly amorphous structure with broad peaks corresponding to semicrystalline tungsten and molybdenum oxide phases. Ultraviolet-visible spectroscopy showed strong absorption in the 259-476 nm range, confirming efficient light-induced activation. The nanocomposites exhibited excellent photochromic performance, transitioning rapidly from cream-yellow to blue within three seconds under UV exposure, and reversibly fading in an oxygen-rich environment within 50 min. Electrochemical impedance spectroscopy (EIS) further revealed that the W-Mo (0.8:0.2) composite had the lowest charge transfer resistance, enhancing electron transport and accelerating photo-switching behaviour. The combined structural, optical, and electrochemical properties of these materials underscore their promise for use in smart windows, UV sensors, and dynamic display technologies.
The main objective of this work is devoted to the microencapsulation process by the complex coacervation using two types of natural polymer namely sodium alginate and gelatin to encapsulate a pharmaceutical active ingredient of the "Diclofenac" family of analgesics and to prolong its release in vivo. In a first step, the influence of physicochemical parameters on the existing interactions between both polymers has been studied. The effects of pH, Pr:Ps (Protein: polysaccharide) ratio and the addition of salt concentration through the particle size and Zetametry by the dynamic light scattering technique, make it possible to experimentally limit the optimal domain of coacervate formation; which is used to formulate the Diclofenac-based microparticles. The results revealed a great influence of pH on the formation of the Pr:Ps complex with an impact on the mean diameter (D42). The latter recorded a clear increase, with a decrease in the electro-kinetic potential reflecting the neutralization of the charges at pH 3.5-4. The results also showed a better coacervation (interaction between the polymers) for ratios of alginate / gelatin equal to 4/1 and 3/1. The formulation of microparticles based on Diclofenac by coacervation was subsequently characterized on the technical (size and texture) and biopharmaceutical levels, which revealed a prolonged type release of 8 h.
In this study, a novel approach is elucidated by utilizing a synergistic combination of photocatalytic oxidation and bioremediation for the degradation of Acid Blue 113 dye. TiO2/GO composite is employed as a photocatalyst in the photocatalytic reactor, while polyurethane foam is used as packing media to immobilize the microbes in a fixed bed bioreactor. TiO2/GO composite has been prepared using a one-step hydrothermal technique and characterized through FTIR, HR-XRD, SEM, and BET analyses, revealing its structural and morphological properties. The energy band gap of the composite is determined to be 2.73 eV. Preliminary photocatalytic oxidation of the Acid Blue 113 dye demonstrated a notable improvement in the biodegradability index (BOD/COD = 0.416 +/- 0.0128) and a significant reduction in the permanganate index (66.18%). Furthermore, the application of a fixed bed bioreactor proved highly effective in mitigating dye loading stress and exhibited excellent dye biodegradation efficiency. The bioreactor system demonstrated its remarkable capability of 85.03 +/- 2.76% biodegradation of the dye loading of 700 mg/L. Additionally, residual toxicity assessment ensured the safe disposal of the treated dye wastewater into the environment.
Many industries typically like chemical industry, petrochemical and oil refineries etc. are prone to fire. In such a case intumescent (IMT) paint will provide extra protection to substrate wherever it is applied. The aim of present work was to optimize the fire protection performance and thermal properties of water-based IMT fire protective coatings on steel structures through the use of flame-retardant paints. The IMT coating paint was prepared using water-based styrene acrylic emulsion (SAE), flame-retardant additives (Ammonium phosphate, Pentaerythritol, Melamine and Dicyanadamide and flame-retardant fillers (TiO2 and CaCO3). All these ingredients are mixed using mortal pestle. The coating paints with and without fire retardant have been characterized by studying chemical properties by using FTIR, mechanical properties (Flexibility test, Impact resistance test and Pull off test) and thermal properties (Bunsen burner test, furnace test, and Thermogravimetric analysis test). The results demonstrated that mild steel specimens coated with IMT paint exhibited effective fire protection performance; excellent adhesion strength, improved uniform char layer formation, and enhanced thermal stability. It revealed that fire retardant coating had better or same properties than without fire retardant coating. Hence, formulated IMT coating paint proved effective in protecting steel structures against fire.
The mathematical modeling and simulation have been performed to an esterification of Acetic Acid (AA) with Ethyl Alcohol (EOH) for production of Ethyl Acetate (EA) and water in a Reactive Distillation Column (RDC). The equilibrium and non-equilibrium (rate based) models have been applied to perform simulations for an esterification system. The ethyl alcohol and acetic acid reacts with sulphuric acidin reactive zone for the production of ethyl acetate and water. The in-situ separations of components in reaction section improves conversion and purity. The feeds entered into the column are at a temperature of 25 degrees C and a pressure of 1 bar. The feed flow rates are adjusted from 0.02 L/min to 0.09 L/min. The acetic acid is fed on 8th stage and ethanol is fed on 14th stage. The composition and temperature profiles have compared for the equilibrium and rate based models from condenser stage to reboiler stage. Sensitivity analysis was performed under various operating conditions for the equilibrium and rate based models. From the simulations it is found that mole fraction of ethyl acetate is 71.41% from rate based model which is higher than equilibrium model.
The demand for renewable fuel sources has increased as a result of declining fossil fuel supplies and declining air quality. Plant-based biodiesel appears to be a desirable alternative to fossil diesel; however, the usage of biodiesel is restricted due to its low heating value, poor atomization, lower thermal efficiency, and higher nitrogen oxides (NOx) emissions. In particular, reducing NOx emissions from engines is crucial for environmental protection and public health. The addition of nanoparticles and antioxidant additives to biodiesel plays a crucial role in overcoming its limitations. Antioxidants help reduce NOx emissions by removing decomposing peroxides and free radicals, as well as by disrupting the chain reactions of free radicals. This study looks at the influence of incorporating butylated hydroxytoluene (BH) antioxidant and aluminium oxide (Al2O3) nanoparticles into a Ceiba pentandra biodiesel blend (CPB) on engine performance and emission characteristics. The experimental work has been carried out on a direct injection (DI) diesel engine by blending 250, 500, 750, and 1000 ppm of BH and 25, 50, and 75 ppm of Al2O3 with 20% CPB. A total of eight different test blends were prepared and utilized for engine operation, and the results were compared with baseline diesel fuel. The experimental results expose that adding BH and Al2O3 significantly reduced NOx emissions. Compared to diesel, the addition of 1000 ppm BH and 50 ppm Al2O3 reduced the emission of NOx by 16.1%, carbon monoxide (CO) by 52.38%, and unburned hydrocarbon (HC) by 25.93%. However, there was a slight increase of 2.27 % in brake thermal efficiency (BTE) and a decrease of 7.14% in brake specific fuel consumption (BSFC).
This study investigates the flocculation behaviour of feldspar suspension using a variety of anionic, cationic, and nonionic flocculants (A.336, A.338, A.1011, A.5250, A.110, A.120, A.1858, C.573, N.333 and N.351) in single and two-step flocculation systems. Experiments have been performed at various dosages ranging from 0.2 to 12.5 mg/L. Flocculation performance is evaluated based on turbidity, settling rate, and efficiency. Of the flocculants tested, non-ionic flocculant N.351 demonstrated the most effective flocculation performance in terms of both turbidity reduction and flocculation efficiency. N.351 achieved a flocculation efficiency of 98.5% at a dosage of 0.8 mg/L, achieving the lowest turbidity value of 6.4 NTU (Nephelometric Turbidity Unit). Although N.351 demonstrated turbidity reduction and flocculation efficiency, the highest settling rates are observed in the two-step system employing the cationic-anionic flocculation combinations of C.573-A.338 and C.573-A.1011. These combinations achieved the highest settling rate of 2700 mm/min at dosages of 8.5 mg/L and 12.5 mg/L, respectively. This experimental study demonstrates that optimum flocculant dosages can vary significantly depending on the type of flocculant, the combination used, and the performance parameters. These results provide valuable information to optimize feldspar flocculation in industrial applications, which could improve process efficiency and product quality in feldspar using industries.
The present study investigates the potential application of activated biomass waste decorated with hydroxyapatite nanoparticles (HANP), i.e., HANP@AP, for decontamination of Cu and Fe metals from aqueous medium. We presumed that Cu and Fe ions can be removed from water contaminated with these ions efficiently owing to the electrostatic interaction provided by phosphate (PO4)3- and (-OH) groups of HANP. Thus, the adsorption experiments have been designed to explore the potential of this HANP modified activated biomass waste. The influence of various factors like time (5-180 min), adsorbent dose (0.01-0.1 g), metal concentration (20-300 mg L-1), and pH (2-8) on the adsorption process have also been investigated. The Langmuir adsorption isotherm is suited for the adsorption of both Cu and Fe showed that the maximum adsorption capacity of 76.3 mg g-1 for copper and 166.6 mg g-1 for iron when batch adsorption experiments are performed with initial metal ion concentration of 20-300 mg L-1 at pH 5 over the period of 180 min for Cu and 5 min for Fe using 0.1 and 0.04 g of adsorbent, respectively. It is observed that the pH plays quite an important role for the adsorption of Cu on to the surface of HANP@AP whereas the adsorption of iron on its surface remains unaffected by pH variations. Further, to understand the mechanism for the adsorption of copper and iron the surface of HANP@AP, kinetic studies are done in the time range of 20-180 min. The kinetics study data revealed that the Cu and Fe adsorption on activated waste following pseudo-second kinetics. Further, a comparison study with the previously reported biomass based biosorbents is also done which showed the superiority of HANP@AP for the decontamination of these heavy metal ions.
The ionic liquid-based emulsion liquid membrane (ELM) has been developed to extract phenol from aqueous solution. The effects of ionic liquid type, internal NaOH concentration, Aliquat 336 concentration, liquid paraffin concentration, carrier type and concentration, homogenizer speed, volume ratio of emulsion to external phase, stirring speed and initial phenol concentration on extraction efficiencies of phenol have been studied. The results show that Aliquat 336 is the most preferred ionic liquid during extraction of phenol by ELM. The optimal experimental conditions during extraction of phenol are Aliquat 336 concentration of 4%, internal NaOH concentration of 378 mg & centerdot;L-1, liquid paraffin concentration of 3%, 1-octanol concentration of 3%, homogenizer speed of 6500 r & centerdot;min(-1), volume ratio of emulsion to external phase of 1:1, stirring speed of 200 r & centerdot;min(-1), and initial phenol concentration of 1019 mg & centerdot;L-1. The extraction efficiency of phenol by ionic liquid-based ELM could be above 94%. Orthogonal experiments show that during extraction of phenol by ELM, the order of importance of the four factors is volume ratio of emulsion to external phase>homogenizer speed>volume fraction of Aliquat 336>internal NaOH concentration. The recycled ionic liquid-based ELM with Span-80 have been demulsified by centrifuge successfully. The demulsification efficiency of ELM reaches nearly 100% in 20 min.
Co-pyrolysis is an efficient way of reducing environmental pollution and turning poultry manure into biofuels and chemicals. This study examines a novel approach to turning poultry manure (PM) into biofuels by pyrolyzing it with agricultural biomass. The impact of combining sugarcane bagasse (SB) with PM under different proportions and their effect on the yield of pyrolysis oil, char, and gas were evaluated by mixing SB with PM in different mass ratios. The blended PM40SB60 (40% PM + 60% SB), and PM20SB80 (20% PM + 80% SB) have been prepared and co-pyrolyzed along with the individual pyrolysis of PM and SB. According to the findings, the yields from PM pyrolysis were 45.01 wt% for oil, 39.52 wt% for biochar, and 18.83 wt% for the gas product. The quality of the oil, char, and gaseous products is significantly enhanced by co-pyrolyzing PM with SB. The highest production of oil components (64.8 wt%) with positive synergy is obtained with the lowest yield of oxygenated elements under the ideal experimental conditions of 40% SB loading. It is also found that the co-pyrolysis oil has a higher calorific value than the PM pyrolysis oil. These findings demonstrate that, in contrast to PM pyrolysis products, PM could be recycled through co-pyrolysis with SB to produce oil, char, and gas with better properties.
