Indian Journal of Chemical Technology (IJCT)

Author Index & Keyword Index

CSIR NIScPR — 2025-03-06

IJCT

CSIR NIScPR — 2025-03-06

IJCT

Current practices for the management of sludge generated from common effluent treatment plants - A review

Krishna Kumar — 2025-03-06

Sludge management in common effluent treatment plants (CETPs) is a highly complex, difficult and expensive task that, if done incorrectly, might jeopardies the environment and sanitary advantages expected in the treatment systems. The sludge generated from the CETPs may contain hazardous waste that poses substantial or potential threats to public health and the environment. Hazardous wastes are frequently dumped directly into the environment in many developing and underdeveloped nations, which puts human health and the ecosystem at risk. The processing, managing and disposal of hazardous sludge is a major challenge in this technological era and it is very crucial to pick a sludge treatment and disposal system that is both practical and affordable from a technological & environmental standpoint. This review article discusses the current practices of hazardous sludge management, collection & transportation, recycling and reuse and various treatment techniques.

Novel molasses-grafted poly(sodium acrylate) hydrogel: A sustainable solution for water retention and controlled dinotefuran release

Manu Nandal — 2025-03-06

Sugarcane molasses, a byproduct derived from sucrose manufacturing, is a polyphenolic compound with high sugar content. In this study, a novel molasses-grafted poly(sodium acrylate) hydrogel (M-g-SAH) is synthesized via free radical co-polymerization, using potassium persulfate (KPS) as the initiator and N,N’-Methylenebisacrylamide (MBA) as the crosslinker. M-g-SAH is characterized using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and rheometer. Results demonstrated significant structural, thermal, and morphological changes in M-g-SAH compared to the non-grafted control hydrogel (ctrl). Swelling studies in Milli-Q water revealed that M-g-SAH achieved a maximum swelling index of 225.9 g g^-1, with swelling behavior influenced by molasses, KPS, and MBA concentrations. The controlled release of molasses from the M-g-SAH is modelled using Korsmeyer-Peppas, Higuchi, and first-order kinetics. M-g-SAH demonstrated a prolonged release of molasses over 39 h, outperforming the ctrl. According to ANOVA results, the addition of molasses proved to be an effective factor in agricultural trials, as the M-g-SAH hydrogel significantly showed improved water retention and reduced evaporation rate compared to ctrl. Additionally, dinotefuran loading and release studies confirmed M-g-SAH's potential as a pesticide carrier, supporting sustained release applications. These properties make M-g-SAH an eco-friendly and versatile material suitable for agricultural applications.

MHD radiative Williamson nanofluid through Darcy Forchheimer medium due to stretching sheet in the presence of heat source, activation energy and motile microorganisms

M. Vinodkumar Reddy — 2025-03-06

The study investigates the magneto radiative flow of Williamson nanofluid with entropy generation in Darcy Forchheimer porous medium over a stretching sheet with motile microorganisms and activation energy. The Brownian motion, thermophoresis, chemical reaction, heat source and suction/injection are also taken into this flow model. The set of partial differential equations (PDEs) in the mathematical framework is simplified to ordinary differential equations (ODEs) by employing the similarity transformation. Computational outcomes are obtained using a Runge-Kutta based shooting technique implemented via the BVP5C MATLAB package. The research illustrates graphical representations elucidating the influence of various dimensionless parameters on flow regime. The main findings indicate that the escalating velocity profile is observed with magnetic field and Darcy-Forchheimer number. Also, an escalation in the Brinkman number and magnetic field increases the entropy generation. The motile microorganism profile is reduced for enlarging values of the bio-convection Lewis number and Peclet number. Furthermore, the thermal efficacy rate in the proximity of the surface is significantly touched up by the enhancing Brownian motion, radiation and suction factor and the proximity solutal transfer rate exhibits elevation with escalating Schmidt and chemical reaction. Implications entail the refinement of thermal exchange and cooling mechanisms employing nanofluids to bolster efficacy and environmental viability.

Pretreatment strategy for enhanced lipid extraction from algal biomass in bio-oil production

Ajay Kumar Kataria — 2025-03-06

Efficient lipid extraction from algal biomass is a critical step in bio-oil production. Optimizing extraction parameters has led to the development of various methodologies; however, the primary challenge remains in effectively disrupting algal cells to facilitate lipid release. This study evaluates the impact of different pretreatment techniques on traditional lipid extraction methods, focusing on lipid extraction efficiency. Pretreatment methods examined include physical disruption (blending), irradiation (microwaving), and a novel combination of both. Traditional lipid extraction methods, such as Bligh-Dyer, Folch, and Soxhlet are employed. Results demonstrated that lipid extraction efficiency increased from 2.22–22.12% of dry weight (untreated biomass) to 10.09–52.08% of dry weight (pretreated biomass), varying across different algal species. The combined pretreatment (blender and microwave) followed by the Bligh-Dyer method yielded the highest lipid recovery. Chlamydomonas reinhardtii showed the maximum lipid content (52.08±2.22%). These findings highlight the significant enhancement in lipid recovery using the novel pretreatment and suggest its potential for improving bio-oil production.

Efficient degradation and mineralization of 4-nitrophenol achieved through innovative saponite-based Al-Ti pillared clay catalyst

Sudha Minz — 2025-03-06

Pillared clay catalysts are emerging as heterogeneous catalysts for degrading refractory organic pollutants. The present study modified saponite clay using aluminium and saponite metal cations to synthesize Al-Ti pillared clay catalyst (Al-Ti PICC). It is subsequently used to study the degradation and mineralization of 4-nitrophenol. The synthesized Al-Ti saponite clay catalyst is characterized using XRD, BET isotherm, SEM, XRF, and thermo-gravimetric analysis. XRD, BET, XRD, and SEM characterization of Al-Ti PICC results indicate higher surface area (74 m²/g), d-spacing (17 Å), porous and fluffy surface compared to saponite clay. The thermo-gravimetric study reveals a lower decomposition of Al-Ti PICC (5.7%) than saponite clay (38.7%). The parameters affecting the degradation and mineralization of 4-nitrophenol, such as H₂O₂ dosage, catalyst dose, and temperature, were optimized. At optimized conditions: 20 mM H₂O₂, 3 g/L of synthesized Al-Ti PICC, and 70℃ at 5.7 pH 83.5% mineralization (Total organic carbon removal) with 95.6% degradation of 4-nitrophenol, was achieved after 240 min of reaction time. The TOC removal data was further used to study the reaction kinetics using the lumped kinetic model (LKM). It was observed that the data described well the LKM model for the mineralization of 4-nitrophenol.

Improving the suitability of triple blend biodiesel in a low heat rejection diesel engine with the addition of nanoparticle through performance and emission characteristics analysis

M. Elango — 2025-03-06

The primary aim of this research is to efficiently utilize biodiesel and nanoparticles in thermal barrier-coated (TBC) engines. In view of this, a novel neem seed oil (NSO) and linseed oil (LSO) have been chosen for this work, and they are changed into neem seed oil methyl ester (NME) and linseed oil methyl ester (LME) through transesterification process. The blend B20 (10% NME + 10% LME + 80% diesel) and B20 with 50 ppm CeO₂ (B20C50) is prepared and used for that analysis in both conventional and coated engines. For the coated engine, the combustion chamber parts are coated with partially stabilized zirconia (PSZ) using the atmospheric plasma spray coating method. Initially, neat diesel, B20, and B20C50 are tested in a conventional engine, and later, B20C50 is tested in a TBC engine. Load tests are conducted on a direct injection (DI) diesel engine by changing the load from 0 to 100% to assess performance and emission characteristics. From the experimental work, it was noted that B20C50 in the TBC engine showed 3.3% higher brake thermal efficiency (BTE) and 26.92% lower brake specific fuel consumption (BSFC) than diesel fuel operated in a conventional engine. When associated with diesel, the emissions of carbon monoxide (CO) and hydrocarbons (HC) are lower by 30.77% and 24.32%, respectively. The emission of oxides of nitrogen (NOx) in the TBC engine is recorded as similar to diesel fuel.

Corrosion resistance of plasma nitrided tool steel at variable temperature and time

P. Janardhana Kiran — 2025-03-06

Wood machining steel has been nitrided with the view to enhance the corrosion resistance properties. Nitriding is performed by varying the time and temperature in the nitrogen and hydrogen plasma. Steel samples after polishing are kept inside the nitriding reactor and biased at -250 V to attract the nitrogen and hydrogen ions. Nitrided and bare steels were then subjected to X-ray diffraction (XRD) for the phase analysis. The presence of FexN (where x = 2-3, 4) is observed after XRD analysis.Corrosion resistance of the bare and nitrided steels is assessed by following potentiodynamic polarization tests at room temperature in 3.5 wt.% NaCl solution. Field emission electron microscopic analysis (HRFE-SEM) of the corroded surface revealed pittings more on the surface of the bare steel than that on the nitrided steels. Finally, it has been concluded that corrosion resistance of nitrided steels was significantly improved when compared to that of the bare steel due to the formation of Fe-nitrides after nitriding.

Adsorptive removal of malachite green using fox nutshell activated carbon: Adsorption isotherms and kinetic study

Abhishek Srivastava — 2025-03-06

Over the past few years, environmental concerns regarding dye contamination have grown. Removing dye from wastewater from industry is crucial for environmental sustainability. Fox nutshell, an agricultural byproduct, is widely available in India. Its fibrous texture and high cellulose, hemicellulose, and lignin content make it ideal for dye adsorption. By zinc chloride activation followed by carbonization at 600 ℃, fox nutshell has been converted into low-cost fox nutshell activated carbon (FNAC). Its ability to adsorb malachite green (MG) from aquatic solutions is investigated. A porous framework with 2408.9 m²/g surface area and 2.51 nm average pore diameter is discovered in the FNAC using SEM, and BET investigations. FTIR analysis shows the presence of the –COOH, C=C, C=O, and –OH, functional groups on the surface of FNAC. The adsorption system adhered to a pseudo-second-order kinetic model, with the equilibrium time being determined at 90 min. The Langmuir model accurately simulated the adsorption isotherms. The optimum pH for MG (500 mg/L) adsorption onto FNAC (0.08 gm/100 mL) was 6.5, with an adsorption capacity of 523.3 mg/g at 298 K. Negative ΔG° and ΔH° indicate spontaneous MG adsorption onto FNAC, decreasing with temperature. π–π interactions, electrostatic attractions, and hydrogen bonding amongst the FNAC functional groups and the MG lead to the potential adsorption of MG.

Development & validation of level A: In-vitro and in-vivo correlation for ofloxacin using a systematic approach

Nidhi Makadiya — 2025-03-06

The key objective of the current research is to establish an IVIVC (in vitro and in vivo correlation) model for ofloxacin tablet formulations. The USP apparatus II is used to determine the in vitro drug release characteristics of drug, rpm ranging from 50-150, in a pH-varying medium. The in vitro dissolution testing is found to be applicable for calculating the in vivo drug concentration. Three different formulations are used for the study. The in vivo data is referred from the study aimed to assess bioequivalence of ofloxacin tablets. Plasma concentration is converted to cumulative percentages of drug absorbed using the Wagner-Nelson equation. The percentage in vitro cumulative drug dissolved, intercept, and slope are used to calculate the in vivo drug release. The cumulative drug release is plotted against the percent cumulative drug absorbed and the level A IVIVC model is developed using regression technique.

Effect of system parameters on phase holdups for an inverse fluidized bed

ANUP KUMAR SWAIN — 2025-03-06

Phase holdups for an inverse fluidized bed (IFB) have been studied using low density polypropylene (PP) particles for different system parameters viz. superficial gas velocities (U_g), ratio of bed volume to liquid (reactor) volume (V_b/V_r), and liquid recirculation velocities (U_lr). Gas phase holdup (e_g) is found to increase with increase in U_g for all V_b/V_r ratios with and without liquid recirculation. Without liquid recirculation, e_g decreased with increase in V_b/V_r ratio upto a certain V_b/V_r ratio for all U_g values and then increases with further increase in V_b/V_r ratios. While with liquid recirculation, e_gis found to be higher than the case of without liquid recirculation. Liquid phase holdup (e_l) and solid phase holdup (e_s) are both found to decrease with increase in U_g for all V_b/V_r ratios with and without liquid recirculation. Regression analysis based mathematical correlations are developed to predict e_g for different U_g, V_b/V_r, and U_lr values. Average absolute percent deviations of the developed correlations are found to be 7.90 and 7.39 which are less compared to the data available in the literature. Thus this study on phase holdups gives a clear insight providing a basis for the design of a three phase
IFB reactor.

Removal of lead ions from aqueous solution using potassium hydroxide modified natural adsorbents

Nivya Mary Abraham — 2025-03-06

As time progresses, a combination of human activities and natural occurrences releases contaminants, specifically heavy metals. These contaminants enter into water bodies, posing a threat to aquatic ecosystems and emphasizing the importance of implementing effective measures for pollution control and water quality preservation. This makes it necessary to treat water to reduce the negative impacts of toxic heavy metals in water and supply pure water for domestic and environmental use. Thus, the increased release of heavy metals like lead into the environment due to rapid industrialization has raised severe global concerns. This study aims to remove lead ions from water using a low-cost bio adsorbent. The present study examined the utilization of groundnut shells, tamarind pod shells, rubber seed shells, and pistachio shells as lead adsorbents. The adsorption efficiency is examined in relation to adsorbent dose, pH, contact time, and initial concentration, and the most efficient adsorption parameters are identified. In addition, adsorption mechanism, thermodynamics parameters and kinetic modeling are carried out to clarify the mechanism of adsorption. Isometric models, namely, Langmuir and Freundlich, are used to characterize the adsorption process, with better correlation to the Langmuir model. Kinetic observations indicated that adsorption in similar manner with transition of pseudo-second-order model and thermodynamic analysis confirmed the nature of spontaneous exothermic and spontaneous endothermic adsorption reaction. The pistachio shell emerged as the most effective of the four examined adsorbents, displaying the highest adsorption capacity of 88.9% at an adsorbent dosage of 1.2 g/L. This result underscores the superior performance of pistachio shells, positioning it as the optimal choice among the tested adsorbents.

Mechanochemical assisted acetylation of aromatic amines, phenols and thiol catalysed by RHA-SiO2 (NPs)@BO3H3

Raju Shekhanavar — 2025-03-06

In this work, rice husk-derived silica nanoparticles (RHA-SiO₂-NPs) are synthesized and further surface functionalized with boric acid to avoid tedious recycling of the silica NPs and also increasing Lewis acid strength of the silica. The prepared heterogeneous catalysts (RHA-SiO₂NPs@BO₃H₃) demonstrated application in the formation of acetyl derivatives of aryl amine, thiol and phenol in the presence of acetic anhydride under grindstone method gave excellent product isolation (98% yield in 5-8 min). The benefit of this method found simple, efficient, solvent-free and reusable. The catalyst prepared in this work derived from the agro-waste and functionalized for the efficient catalytic activity.

A comparative study on removal of As(III) from industrial wastewater using newly synthesized polysaccharide-based chelating resins

Abhishek Solanki — 2025-03-06

Water contamination by a wide range of hazardous substances including heavy metals, metalloids, and dyes is a major environmental concern due to their potential human toxicity. Therefore, technologies for the removal of harmful contaminants in wastewater have been developed substantially. Among all the methods that have been proposed, ion exchange and adsorption processes are the most efficient techniques for removal of contaminants from industrial wastewater and very important tools for environmental protection also. In this study, we focus on removing As(III) by applying an ion exchange mechanism using TKP (Tamarind kernel powder) and CCSP (Citrullus Colocynthis seed powder) based chelating resin. FTIR spectra & SEM analysis confirm the functional groups and structure of newly synthesized resins subsequently. With the use of the Langmuir and Freundlich isotherm models, the interaction of metalloid ion with chelating resin has been evaluated. Effects of various parameters like contact time, chelating resin dosage, metalloid ion concentration, and pH on removal efficiency are also discussed. The maximum removal efficiencies of TTABA (Tamarind Triazine Amino Butanedioic Acid) resin and CTABA (Citrullus Triazine Amino Butanedioic Acid) resin have been observed as 82.3% and 75.6%, respectively, for As(III).

Synthesis of new bacterial cellulose-oriented micropore membrane filter

Chung-Song Hong — 2025-03-06

This study investigates a novel synthesis method of bacterial cellulose (BC)-oriented micropore membrane filter and its characteristics. BC-oriented micropore membrane filter has been synthesized by preparation of BC-benzol suspension and evaporation of benzol to render dried BC membrane micro-sized porosity. The structures of BC fibrils before and after hydrolysis are studied by X-ray diffraction (XRD). XRD intensity at 23° (2θ) in HCl-treated BC is higher (73%) than the control (60%), however, the diffraction intensity at 23° (2θ) in BC treated with mixture of H₂SO₄ and HNO₃ is lower(53%) than the control. The SEM analysis reveals that the synthesized BC membrane has many micropores in comparison to the native BC film. The FTIR spectra of cotton cellulose, native BC film and the synthesized BC microfilter showed a band at 3345 and 1643 cm⁻¹ which is assigned to OH stretching vibration and OH deformation vibration and a band attributed to CO asymmetric and symmetric stretching vibration in a range from 1032 to 1166 cm⁻¹, respectively. Maximum pore size, pure water flux, the breakage pressure, ζ-potential and bacteria-retentive efficiency of the filter are characterized. The synthesized microfilter has maximum pore size of 0.2 µm and high water flux of 220 L/m² h under 0.1 MPa. It demonstrates 99.9% filterability against Escherichia coli and Brevundimonas diminuta. The biodegradability test shows that the newly developed BC microfilter is totally decomposed in a month. This suggests that the novel BC microfilter can be a promising candidate for membrane filer used in pharmaceutical, food, cosmetic and water industry.

A quantum chemical and experimental study on the protective performance of N-(4-(piperidin-1-ylsulfonyl)phenyl)acetamide for mild steel corrosion

Vijayalakshmi K — 2025-03-06

In this study, the anticorrosive potential of N-(4-(piperidin-1-ylsulfonyl)phenyl)acetamide (PSPA) in the 1M HCl solution has been investigated. An inhibitory efficiency of 96% at 30 ppm is achieved using the polarization, mass reduction, and impedance approaches. To pinpoint the precise modes of the adsorption process, the kinetic, thermodynamic, and adsorption parameters are studied at various temperatures. The protective probability of the examined inhibitor is further evaluated by employing Density Functional Theory. Additional crucial information on the inhibitory mechanism is provided by the Fukui condensed function. Conclusively, various parameters are used to confirm the protective properties of the thin film, including SEM, EDS, and AFM.