This study investigates the potential of non-edible waste-derived Karanja seed (Pongamia pinnata) biochar (KSB) as a biosorbent for Cr(VI) removal from synthetic effluents. Characterization of KSB before and after Cr(VI) biosorption using thermogravimetric analysis, scanning electron microscopy/energy dispersive X-ray spectroscopy, X-ray diffraction, and Fourier-transform infrared spectroscopy confirmed that the adsorption process primarily occurs through chemisorption, ion exchange, and/or complexation mechanisms. The effects of several process parameters, including pH, contact time, initial Cr(VI) concentration, KSB dosage, and temperature, on Cr(VI) biosorption efficiencywere systematically examined through batch experiments. The results indicated an optimum biosorption efficiency of 91% under the following conditions: initial Cr(VI) concentration of 20 mg L-1, contact time of 60 min, pH 2, KSB loading of 0.01 g, and a temperature of 303 K. Adsorption equilibrium data were analyzed using the Freundlich and Langmuir isotherm models, with the Langmuir model yielding a maximum biosorption capacity of 164 mg g-1, suggesting monolayer biosorption. Kinetic analysis demonstrated that the pseudo-second-order model provided the best fit, indicating that chemisorption governed Cr(VI) uptake on KSB, involving three distinct intra-particle diffusion stages. Thermodynamic parameters (Delta H0, Delta G0, and Delta S0) were evaluated, confirming that the biosorption process was spontaneous, exothermic, and thermodynamically feasible. Additionally, the biosorption-desorption performance of KSB for Cr(VI) was assessed through cyclic experiments, highlighting its regeneration potential for practical applications. Finally, the results revealed that KSB is an efficient and cheap biosorbent for the sequestration of Cr (VI) from a synthetic medium.

Magnesium titanate is a metal oxide powder mainly used as an additive in ceramic dielectric components. Due to its fundamental dielectric properties, it finds applications in the field of precision electronic ceramics, such as capacitor ceramic substrates. It can also be used as electrets in alternator and radiographic detector devices. Despite its various applications, increasing the tunability of magnesium titanate remains a challenge for its progressive use. In the present work, a co-precipitation synthesis of magnesium titanate was developed using magnesium chloride flakes, titanium tetrachloride, and oxalic acid. The characteristics of this material were investigated through EDS, XRD, FTIR, TGA, and SEM analyses. The composition of magnesium titanate is 19.69

There is a high demand for nickel hydroxide as an engineering material used in the positive electrode of nickel metal hydride (Ni-MH) rechargeable batteries. These batteries are extensively used in various small instruments, disposable batteries, and electric vehicles. The structure of nickel hydroxide significantly influences the discharge capacity and energy density, key properties of Ni-MH batteries, and this structure is primarily determined by the synthesis method used. In this study, nickel hydroxide was synthesized using an electrochemical precipitation method, with current density acting as a parameter to control the desired phase of the product, whether α-nickel hydroxide, β-nickel hydroxide, or a combination of both. At a current density of 50 A/m2, the synthesized nickel hydroxide demonstrated a smaller particle size and a superior discharge electrochemical property in comparison to that generated at 500 A/m2. The effect of agitation in catholyte was also investigated to examine the change in discharge property of the precipitated material. The product synthesized at 500 A/m2 from an agitated catholyte exhibited a tap density of 1.24 g/cc and an improved discharge capacity of 254 mAh per gram of Ni(OH)2.

Bamboo, a perennial and monocarpic plant, holds immense potential beyond its commonly recognized applications. In this study, fiber was extracted from bamboo leaves. Pyrolytic kinetic studies were done on leaves and the extracted fibers, utilizing thermogravimetry and derivative thermogravimetry (TG/DTG) data obtained at heating rates 10, 20, and 30 K/min within the temperature range of 298-1093 K. Model-free methods such as Ozawa-Flynn-Wall (OFW), Kissinger-Akahira-Sunose (KAS), and Friedman were employed to calculate the activation energy (Ea) and the pre-exponential factor (A). For leaves, the calculated Ea values were found to be 283 kJ/mol (KAS), 279 kJ/mol (OFW), and 318 kJ/mol (Friedman), while the A values were determined as 7.2 x 1043 s-1 (KAS), 1.07 x 1043 s-1 (OFW), and 5.7 x 1045 s-1 (Friedman). In the case of fiber, the Ea values were found to be 162 kJ/mol (KAS), 164 kJ/mol (OFW), and 165 kJ/mol (Friedman), with corresponding A of 4.6 x 1015 s-1 (KAS), 5.6 x 1013 s-1 (OFW), and 348 x 1013 s-1 (Friedman). Additionally, scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX), and Fourier transform infrared spectroscopy (FTIR) analyses were conducted on both leaves and fiber.

This study explores the preparation of magnesium titanate using magnesium chloride, a byproduct of the titanium production plantas a precursor. The synthesis involves the reaction of MgCl 2 with titanium tetrachloride under controlled thermal conditions. Initially, MgCl 2 and TiCl 4 are thoroughly mixed in stoichiometric proportions with an excess of oxalic acid solution to produce magnesium titanyl oxalate. The mixture is then subjected to a calcination process at temperatures ranging from 300 degrees C to 1000 degrees C in an oxygen-rich environment. The physicochemical properties of the synthesized MgTiO 3 were analyzed using EDS, XRD, TG/DTA, SEM, and particle size analysis. This comprehensive set of analytical techniques provides a thorough understanding of the elemental, structural, thermal, morphological and physical characteristics of magnesium titanate. The formation of pure magnesium titanate is confirmed at temperatures above 800 degrees C, with lower temperatures leading to the presence of intermediate phases such as MgTi 2 O 5 . The synthesized MgTiO 3 exhibits a homogeneous microstructure with well-defined grain boundaries, indicating successful preparation of the desired ceramic material.

Abstract Biochar-aided Advanced Oxidation Processes (BC-AOPs) have emerged as a novel and promising method for degrading wide organic contaminants in water and wastewater treatment. In this investigation, the principles, processes, and possible applications of BC-AOPs are highlighted. AOPs produce highly reactive oxygen species (ROS), such as hydroxyl radicals (•OH), to oxidize and mineralize organic contaminants. Biochar, a carbonaceous material derived from biomass pyrolysis, serves as a catalyst or support in AOPs, enhancing their efficiency and stability. Biochar distinctive physicochemical features, such as large pore volumes, functional groups, and high surface area, contribute to its catalytic role in enhancing OH production. The combination of biochar and AOPs creates synergistic effects, enabling the degradation of a wide range of recalcitrant dyeing contaminants, inclusive of many industries. BC-AOPs offer several advantages, including low-cost materials, versatility, and the potential for sustainable synthesis through the utilization of various biomass residues. However, challenges remain in optimizing biochar characteristics, understanding reaction kinetics, and evaluating the long-term stability and reusability of biochar in AOPs. BC-AOPs hold significant promise as an effective and environmentally friendly technology for water and wastewater treatment, contributing to the mitigation of water pollution and ensuring water resource sustainability.

The present research aims to investigate the degradation of Rhodamine B (RHB) in water by utilizing UV radiation in a specially designed photoreactor equipped with two 16-W Philips UV lamps. The study explores the influence of experimental parameters, which includes pH, photocatalyst dosage, and dye concentration on the degradation process. Silver (Ag) nanoparticles were utilized as the photocatalyst, and their synthesis associated a green approach, ensuring an eco-friendly nanoparticle production process. The characterization of the produced Ag nanoparticles was executed by various analytical methods, including Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) coupled energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD). The degradation of RHB was analyzed using a UV–VIS spectrophotometer. The optimum conditions for RHB degradation were determined through systematic batch experiments. The results obtained from the analytical methods suggested valuable insights into the size, shape, and composition of the Ag nanoparticles. Notably, the maximum degradation of RHB was observed at a pH of 3 and a catalyst dosage of 3 g/L. The overall maximum degradation efficiency achieved was 93.56

This study presents a novel and efficient co-precipitation method for synthesising high-purity magnesium titanate (MgTiO3) using oxalate precipitation of purified sea water bitterns and titanium tetrachloride (TiCl4). Sea water bitterns, a byproduct of salt production, serve as a sustainable and cost-effective source of magnesium. The process involves the controlled reaction of magnesium ions from sea water bitterns and titanium ions from TiCl4 with oxalic acid, followed by thermal treatment to achieve the desired MgTiO3 (Geikielite) phase. Comprehensive characterisation techniques, including EDS, XRD, TG/DTA, FT-IR, and SEM confirms the successful synthesis of pure MgTiO3 with excellent crystallinity and uniform particle morphology. The average crystallite size of synthesised MgTiO3 was obtained as 47.06 nm with prominent X-ray diffraction peaks and minimal weight loss of around 4% in TG analysis confirms its thermal stability. This method not only provides a green and economical route for MgTiO3 production but also valorises an industrial waste product, aligning with sustainable development goals. The synthesised MgTiO3 exhibits as a promising asset for applications in microelectronics and energy storage devices. [GRAPHICS] .

Polymers, such as plastics, are composed of polymeric compounds that may be formed into solid objects of different shapes formed by applying pressure and heat. Plastics are utilized in a range of sectors, including the medical area, automotive, electrical, and packaging. Most modern plastics are made of substances derived from fossil fuels, like natural gas or petroleum. Plastics used in containers and packaging include polyethylene (PE), polypropylene (PP), polystyrene (PS), and polycarbonate (PC). Plastic wastes are thermally pyrolyzed to yield a wide range of hydrocarbons, from waxy compounds to methane. High temperatures are involved in this procedure. Although it is possible to burn the gaseous compounds produced to provide the process heat requirements, the pyrolysis process is rarely used as a feedstock recycling method for the plastic waste stream because of the low overall output of useful gasoline range hydrocarbons. This study presents FT-IR and GC–MS investigations of a zeolite-catalyzed pyrolysis method for fuel extraction through plastic recycling.

Tellurium is used in cadmium tellurium-based solar cells. Mercury cadmium telluride is used as a sensing material for thermal imaging devices. High-purity tellurium is used in alloys for electronic applications. It is one of the important raw materials for solar energy applications. It is used as an alloying element in the production of low-carbon steel and copper alloys. Tellurium catalysts are used chiefly for the oxidation of organic compounds and as vulcanizing/accelerating agents in the processing of rubber compounds. Even though several researchers tried to recover tellurium from different raw materials, there is no attempt to develop a process flow sheet to recover tellurium from waste anode slime having a high tellurium concentration. In this study, optimum conditions were developed to recover Te and Cu from anode slime with the composition Cu: 31.8%, Te: 24.7%, and As: 0.96%. The unit operations involved are leaching, purification, and electro winning. The optimum conditions for producing Te at a recovery of 90% are found to be roasting of anode slime at 450 °C without the addition of soda ash followed by leaching in 1 M NaOH at 10% pulp density for 2 h. The purity of Te metal achieved was up to 99.99%, which could provide a sustainable energy future. The major impurities of the tellurium are observed to be in the order: Se > Sb > As > Cu.

Natural impurities such iron, sulphates, chlorides, and heavy metals that cannot be removed by recrystallization are present in the magnesia that is formed. One method for making magnesium perchlorate includes combining per chloric acid and magnesite dust, a process that generates a lot of heat and hydrogen gas during the reaction. Magnesite is leached using an aqueous per chloric acid solution with a 500 rpm stirring speed. The following factors were taken into account in this study: fluctuation in leaching temperature (°K), per chloric acid volume percentage, and time of leaching. Magnesium perchlorate recovery is 97.3

Magnesium metal is used in automobile, sports and aircraft industries. It is also used in aluminum alloys and titanium production. The main raw material for magnesium production is anhydrous magnesium chloride which can be produced from sea water bitterns, magnesite and dolomite. Sea water bitterns from Bhavanagar, Gujarat, India has been used to produce magnesium chloride in the present study using low temperature spray drying. As bitterns solution contains lot of sodium and sulfate, efforts have been made to remove both these elements before spray drying. The purified solution is subjected for spray drying and the variables covered during spray drying are feed flow rate, inlet temperature and atomization pressure. With increase in flow rate from 2 to 5 mL/min, % of magnesium chloride content in the product is reduced from 57.58 to 52.73 %. Temperature and atomization pressure are not having significant effect on percentage of magnesium chloride in the product. The spray dried powder contains moisture content which is removed by thermal decomposition. Thermal drying studies such as temperature, duration of thermal drying have been carried out. The final product of MgCl21.31H2O is suitable for magnesium metal production using fused salt electrolysis.

Process industries deal with high energy inputs and often generate high temperature exit gases, which can potentially be considered as secondary energy sources. If such waste heat is recovered, considerable savings in the net energy demand is possible. This report, based on this objective, details the outcome of an experimental study conducted in a vertical transport duct (riser) where solid particles, through a co-current contact with hot gas, recover the energy content of the gas. Data relevant to heat transfer patterns are collected as not much information is available in the literature on these aspects. Empirical correlation for heat transfer coefficient (Nusselt Number) is proposed as Nu=0.04863 (ReP)(0.9567) (Pr)(0.7532). Fabricated experimental setup is a prototype of suspension preheater (riser - cyclone combination) used in a modern day cement industry but the correlation can be extended to diverse other industries, where waste heat recovery is possible.

The purpose of this research is to explore if Pterocladia pinnata (PP) (Red Algae), which is a biosorbent frequently used as an edible seaweed in India, can be used to remove Pb(II) from synthetic media. Scanning electron microscopy(SEM) and Fourier transform IR spectroscopy (FTIR) analyses were utilized to identify the functional groups and shape of PP before and after biosorption. A statistical optimization study was done using response surface methodology (RSM) and the central composite design (CCD) technique to generate response surfaces for the sample with the highest uptake capacity. The effects of agitation period, pH, PP size, dosage, initial Pb(II) concentrations, and temperature on % biosorption were studied. The maximum Pb(II) adsorption was obtained at agitation time 240 min, pH 4, initial Pb(II) concentration – 20 mg L−1, PP dosage 20 mg/L, and temperature 303 K. Batch scale testing was used to investigate the kinetic, equilibrium, and thermodynamic aspects of biosorption. The process of biosorption experimentation reveals that the pseudo-second-order rate kinetic and Langmuir isotherm models are in good accord. According to thermodynamic parameters, Pb(II) biosorption on PP was spontaneous and endothermic and findings confirmed that PP might be a viable biomaterial for eliminating Pb(II) from polluted streams.

Gum ghatti (anogeissus latifolia) is being widely used as an emulsifier, thickener, stabilizer in food, pharmaceutical, and allied industries due to its shelf life, tolerance of heat, and pH stability. Considering the oil & gas industry application, it is ideal for a hydraulic fracturing fluid additive as a direct replacement for guar gum. Basically, unlike guar gum, it contains less residual hull and it is suitable for low permeability unconventional reservoir; mainly shale gas reservoir, where permeability counts trivial in amount. The polymer of ghatti aid exceptional rheological properties and help to produce higher molecular weight polymer; which has excellent proppant carrying capacity and fracture propagation. In this paper, the experimental study has been carried out in two different phases. This was achieved through optimization and characterization of hydraulic fracturing fluid which was embedded with gum matrices. In Phase-I, the study was carried out by using response surface methodology (RSM). Wherein, the relation between several explanatory and response variables have been measured. In Phase-II, the characterization was done by using a scanning electron microscope (SEM), differential scanning calorimeter (DSC), thermo-gravimetric analysis (TGA) and also, Fourier-transform infrared spectroscopy (FT-IR). This experimental study will potentially benefit for development of a new hydraulic fracturing fluid. Where gum ghatti observed as a satisfactory alternative agent for guar gum.

Pesticides in aqua bodies resulting from drainage of industrial pollutants are the most potential environmental concerns, and their elimination is critical. Atrazine is a broad-leaf herbicide that is widely used around the world. Atrizine, on the other hand, is frequently found in water sources as a result of its long-term use. Biochar has proven potential for sorption of atrazine from solution considering the number and type of functional groups found on it. Adsorption experiments to remove atrizine from water bodies using rice husk biochar as an adsorbent are discussed in this work. Elemental analyzer, scanning electron microscopy (SEM), and the Brunauer, Emmett, and Teller (BET) analyzer were used to determine the activation and surface properties of rice husk biochar. For different pesticide concentrations, the effect of contact time on adsorption ability and percentage removal was investigated.

Sodium iodide (NaI) doped polymer polyacrylonitrile (PAN) based gel polymer electrolytes were synthesized with different compositions by solution cast technique. Optical characterizations were performed by UV-visible absorption spectroscopy in the wavelength range of 200-800 nm. Optical transmission, optical absorption, energy bandgap, real and imaginary parts of dielectric constants were studied on the prepared samples. Optical absorption, absorption coefficient, refractive index and extinction coefficient achieved high values for 70% PAN:30% NaI whereas some properties like transmittance and dielectric constant for imaginary parts have achieved minimum values for the same concentration.

Leaching studies of magnesite obtained from Tamilnadu Magnesite Limited, Salem, have been carried out using hydrochloric acid leaching and percentage of magnesium chloride recovered was estimated. The variables considered in this study were the following: duration of leaching, volume percentage of hydrochloric acid, temperature, and pulp density. Percentage recovery of magnesium chloride increased with duration of the leaching, volume % of concentrated hydrochloric acid, and temperature. Percentage recovery of magnesium chloride decreased with increase of pulp density. The optimum conditions found to be pulp density (10%), hydrochloric acid concentration (30%), duration of leaching (2 h), and temperature (348.15 K). Iron was removed by treating the leach liquor with hydrogen peroxide and by raising the pH to 3.5–4. The purified leach liquor was subjected to spray drying for producing high pure magnesium chloride.

Current density plays a major role in deciding the plant size, current efficiency, and energy consumption in electrorefining cells. In general, operating current density will be 40% of the limiting current density. Forced circulation of the electrolyte in the presence of promoters improves the mass transfer coefficient. In the present study, rectangular turbulence promoters are fitted at the bottom side of the cell to improve the mass transfer coefficient at the cathode support plate. The limiting current density technique is used to measure the mass transfer coefficient. The variables covered in the present study are the effects of flow rate, promoter height, and spacing among the promoters. The electrolyte consists of copper sulfate and sulphuric acid. At a regulated flow rate, the electrolyte is pumped from the recirculation tank to the cell through an intermediate overhead tank. The limiting current density increased with an increasing flow rate in the presence of promoters, and thus the overall mass transfer coefficient on the cathode support plate also improved. With an increase in the flow rate of the electrolyte from 6.67 × 10−6 to 153.33 m3/s, limiting current density increased from 356.8 to 488.8 A/m2 for spacing of 0.30 m, with a promoter height of 0.01 m. However, it is noteworthy that when the promoter height is increased from 0.01 to 0.07 m, the overall mass transfer coefficient is found to increase up to 60%, but with the further increase in the promoter height to 0.30 m the mass transfer coefficient starts to decrease. Therefore, the optimized cell parameters are established in this work. The current sustainable concept of employing rectangular turbulence promoters will bring benefits to any precious metal refining or electrowinning tank house electrolytes.