International Journal of Chemistry

International Journal of Chemistry | Vol. 11, No. 1, January 2020 | pp. 1–8

DOI: 10.46882/2020/IJC/000135

Article Type: Original Research Paper

Title: Spatial Variation, Speciation, and Carcinogenic Hazards of Cadmium Formulations in Groundwater Networks Near Batteries

Names of Authors: T. H. Awotunde¹, R. A. Silva²*

Authors’ Affiliations:
¹Department of Chemistry, Federal University of Agriculture, Abeokuta, Nigeria.
²Department of Environmental Chemistry, University of São Paulo, São Paulo, Brazil.

Abstract: Industrial battery processing operations discharge massive amounts of cadmium-rich effluents into surrounding topsoils, causing heavy metal leaching into shallow drinking water wells. This study monitors the spatial variations, chemical speciation, and carcinogenic health risk profiles of cadmium compounds across twenty household wells positioned around an active electronic industrial estate. Water monitoring was carried out over consecutive wet and dry cycles. Total cadmium levels and carcinogenic cadmium fractions were quantified utilizing ion chromatography coupled with inductively coupled plasma mass spectrometry (IC-ICP-MS). Total cadmium concentrations ranged from 12.5 to 145.8 μg/L, with 45% of monitored groundwater sites surpassing the strict WHO drinkable contaminant threshold of 3.0 μg/L. Speciation analysis showed that toxic free Cd²⁺ was the dominant species, accounting for up to 68.4% of the total metal burden profiles at down-gradient coordinates. Seasonal mapping confirmed elevated cadmium mobilization during the rainy period, indicating rain-induced plume leaching. Chronic Daily Intake (CDI) projections and Lifetime Cancer Risk (LCR) indices for child consumption cohorts surpassed 2.4 in 10,000 near industrial boundaries, emphasizing an immediate public healthcare concern and a need for local membrane filtration arrays.

Keywords: Groundwater pollution; Cadmium speciation; Free metal ions; Ion chromatography; Battery effluents; Cancer risk assessment

Manuscript Timeline: Received: June 02, 2019; Revised: July 14, 2019; Accepted: August 10, 2019; Published: January 03, 2020.

Citation: Awotunde, T. H., & Silva, R. A. (2020). Spatial Variation, Speciation, and Carcinogenic Hazards of Cadmium Formulations in Groundwater Networks Near Batteries. International Journal of Chemistry, 11(1), 1–8.

International Journal of Chemistry | Vol. 10, No. 9, September 2019 | pp. 65–72

DOI: 10.46882/2019/IJC/000131

Article Type: Original Research Paper

Title: Green Synthesis of Palladium Nanoparticles Using Aqueous Bark Extract of Khaya senegalensis and Their Catalytic Efficiencies

Names of Authors: S. I. Musa¹, K. A. Al-Jubouri²*

Authors’ Affiliations:
¹Department of Chemistry, University of Jos, Jos, Nigeria.
²Department of Chemistry, University of Baghdad, Baghdad, Iraq.

Abstract: The biological synthesis of noble metal nanoparticles using medicinal plant extracts offers an eco-friendly and economically sustainable alternative to traditional chemical reduction protocols. This study details the green synthesis of stable palladium nanoparticles (PdNPs) utilizing the aqueous bark extract of Khaya senegalensis as both a reducing and stabilizing agent. The bioreduction process was monitored via UV-Vis spectrophotometry, which revealed the gradual decay and disappearance of the palladium chloride precursor band over 60 minutes. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) analyses showed highly spherical nanoparticles with an average particle diameter of 14 nm. X-ray diffraction (XRD) patterns confirmed the face-centered cubic crystalline structure of the biosynthesized metallic palladium. Fourier-transform infrared (FT-IR) spectroscopy indicated that water-soluble biomolecules, primarily limonoids and sterols within the bark matrix, were responsible for capping and protecting the PdNPs against structural agglomeration. The catalytic efficiency of the synthesized PdNPs was evaluated by tracking the reduction of eosin Y dye by sodium borohydride (NaBH₄) in an aqueous system. In the absence of a catalyst, the reaction proceeded slowly, but the introduction of PdNPs accelerated the degradation process, achieving 97.4% decolorization within 10 minutes. The dye degradation kinetics conformed strictly to the pseudo-first-order kinetic model with a rate constant of 0.284 min⁻¹, indicating excellent catalytic potential for chemical waste neutralization.

Keywords: Palladium nanoparticles; Green synthesis; Khaya senegalensis; Biosynthesis; Heterogeneous catalysis; Eosin Y degradation

Manuscript Timeline: Received: January 12, 2019; Revised: February 20, 2019; Accepted: March 15, 2019; Published: September 09, 2019.

Citation: Musa, S. I., & Al-Jubouri, K. A. (2019). Green Synthesis of Palladium Nanoparticles Using Aqueous Bark Extract of Khaya senegalensis and Their Catalytic Efficiencies. International Journal of Chemistry, 10(9), 65–72.

International Journal of Chemistry | Vol. 10, No. 10, October 2019 | pp. 73–80

DOI: 10.46882/2019/IJC/000132

Article Type: Original Research Paper

Title: Biochemical Assessment, Functional Properties, and Mineral Fingerprinting of Underutilized Root Crops from West Africa

Names of Authors: A. E. Ogunkoya¹, A. M. O. R. de Sousa²*

Authors’ Affiliations:
¹Department of Chemistry, Ekiti State University, Ado-Ekiti, Nigeria.
²Department of Food Science, National Institute of Health Dr. Ricardo Jorge, Lisbon, Portugal.

Abstract: Underutilized indigenous root crops serve as resilient agricultural reservoirs in arid zones, yet detailed mapping of their dietary matrices is required to expand their commercial adoption. This research evaluates the proximate nutritional composition, functional properties, and mineral mineral profile of three underutilized West African roots (Plectranthus esculentus, Sphenostylis stenocarpa, and Dioscorea dumetorum) gathered during the dry season harvest. Proximate analysis established high total carbohydrate contents ranging from 68.4% to 74.2% on a dry weight basis, alongside significant crude protein profiles (9.2% to 12.8%) and very low crude lipid levels (1.5% to 2.4%). Mineral profiling using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) revealed that iron and zinc were highly concentrated within P. esculentus fractions (5.4 mg/100g and 3.8 mg/100g respectively), while toxic heavy metals remained well below international safety benchmarks. Quantified antinutritional matrices showed exceptionally low baseline concentrations of tannins (0.12 to 0.24 mg/g) and phytic acid (1.15 to 1.84 mg/g). Functional parameter tracking confirmed high water absorption capacities and stable gel formation limits, proving that these roots are excellent dietary matrices for developing gluten-free infant weaning formulations.

Keywords: Underutilized roots; Proximate composition; Mineral profile; Antinutrients; Plectranthus esculentus; Gluten-free matrices

Manuscript Timeline: Received: February 18, 2019; Revised: March 28, 2019; Accepted: April 20, 2019; Published: October 05, 2019.

Citation: Ogunkoya, A. E., & de Sousa, A. M. O. R. (2019). Biochemical Assessment, Functional Properties, and Mineral Fingerprinting of Underutilized Root Crops from West Africa. International Journal of Chemistry, 10(10), 73–80.

International Journal of Chemistry | Vol. 10, No. 11, November 2019 | pp. 81–88

DOI: 10.46882/2019/IJC/000133

Article Type: Original Research Paper

Title: Isolation, Structural Profiling, and Optimizing Kinetics of Cellulolytic Complexes Sourced from Thermophilic Aspergillus Strains

Names of Authors: C. N. Nwosu¹, H. M. Sato²*

Authors’ Affiliations:
¹Department of Biochemistry, Nnamdi Azikiwe University, Awka, Nigeria.
²Department of Biotechnology, Tokyo Institute of Technology, Tokyo, Japan.

Abstract: The industrial saccharification of lignocellulose into simple glucose syrups requires robust cellulolytic enzymes that can resist thermal denaturation during high-temperature steam hydrolysis loops. This study details the isolation, microstructural profiling, and kinetic optimization of high-yielding endoglucanase complexes produced by a thermophilic fungal strain sourced from processing soil surrounding artisanal rice hulling mills. Enrichment culturing was executed in cellulose-infused Mandels' media at 50°C, isolating a dominant strain identified via internal transcribed spacer (ITS) rRNA gene sequencing as Aspergillus terreus strain Rice-C1. Response surface methodology optimized solid-state fermentation yields using wheat bran matrices. Maximum cellulase activity (54.5 U/mL) was achieved at an incubation temperature of 50°C, an initial substrate pH of 6.0, and a fermentation period of 96 hours. Biochemical characterization showed that the crude enzyme complex retained over 85% of its initial catalytic activity across a temperature range of 45 to 65°C and a pH stability window of 5.5 to 7.0 for 24 hours. The high thermal stability of this enzyme system, along with its independence from calcium ions, makes it a viable candidate for bio-refinery industrial operations.

Keywords: Endoglucanase; Aspergillus terreus; Solid-state fermentation; Thermal stability; Kinetic optimization; Cellulose saccharification

Manuscript Timeline: Received: March 10, 2019; Revised: April 18, 2019; Accepted: May 14, 2019; Published: November 02, 2019.

Citation: Nwosu, C. N., & Sato, H. M. (2019). Isolation, Structural Profiling, and Optimizing Kinetics of Cellulolytic Complexes Sourced from Thermophilic Aspergillus Strains. International Journal of Chemistry, 10(11), 81–88.

International Journal of Chemistry | Vol. 10, No. 12, December 2019 | pp. 89–96

DOI: 10.46882/2019/IJC/000134

Article Type: Original Research Paper

Title: Synthesis, Microcharacterization, and Viscosity Profiling of Alginate-Graft-Polyacrylamide Superabsorbent Hydrogels

Names of Authors: J. K. Mensah¹, S. K. Roy²*

Authors’ Affiliations:
¹Department of Chemistry, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
²Department of Chemical Engineering, Indian Institute of Technology, Kharagpur, India.

Abstract: The development of durable biopolymeric hydrogel networks is essential for agricultural soil water retention and controlled agrochemical delivery due to the requirement for specific structural coordination sites. This study describes the chemical synthesis and rheological optimization of a hybrid hydrogel fabricated via the free-radical graft copolymerization of acrylamide onto a high-viscosity sodium alginate backbone. The grafting reaction was initiated using potassium persulfate (KPS) and crosslinked via N,N'-methylenebisacrylamide (MBA) under optimized atmospheric conditions. Structural networks and morphology features were characterized using FT-IR spectroscopy, thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). Swelling kinetics were evaluated as a function of time, pH, and saline concentration. The hydrogel showed highly responsive pH-dependent swelling profiles, achieving a maximum water absorption capacity of 410 g/g at pH 7.4 due to structural carboxylate ionizations causing intermolecular chain repulsions. Rheological analysis confirmed strong non-Newtonian shear-thinning characteristics with a storage modulus (G') that remained constant up to 80°C. Batch adsorption tests showed high affinity for divalent lead and copper ions, matching the Langmuir isotherm with monolayer capacities of 72.4 mg/g and 85.6 mg/g at 298 K, confirming high remediation potential.

Keywords: Sodium alginate; Acrylamide; Graft copolymerization; Hydrogel; Viscosity profiling; Heavy metal adsorption

Manuscript Timeline: Received: March 15, 2019; Revised: April 22, 2019; Accepted: May 20, 2019; Published: December 08, 2019.

Citation: Mensah, J. K., & Roy, S. K. (2019). Synthesis, Microcharacterization, and Viscosity Profiling of Alginate-Graft-Polyacrylamide Superabsorbent Hydrogels. International Journal of Chemistry, 10(12), 89–96.

International Journal of Chemistry | Vol. 10, No. 5, May 2019 | pp. 33–40

DOI: 10.46882/2019/IJC/000127

Article Type: Original Research Paper

Title: Green Corrosion Inhibition of Carbon Steel in Hydrochloric Acid Medium Using Extract of Musa paradisiaca Peels

Names of Authors: M. A. Haruna¹, S. Swaminathan²*

Authors’ Affiliations:
¹Department of Chemistry, Federal University of Technology, Minna, Nigeria.
²Department of Chemistry, Indian Institute of Technology, Madras, India.

Abstract: The utilization of toxic synthetic chemical inhibitors in industrial acid descaling operations creates substantial environmental and safety hazards, driving research into sustainable green alternatives. The corrosion mitigation performance of the methanolic peel extract of Musa paradisiaca (Plantain) on carbon steel in 1.0 M HCl was investigated via gravimetric weight loss and electrochemical test protocols. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) measurements were recorded across varying inhibitor dosages (0.2 to 2.0 g/L) and system temperatures (303 to 333 K). Weight loss metrics revealed that protection efficiency increased with extract concentration, peaking at 92.5% at a dose of 2.0 g/L. Polarization diagrams established that the plant extract functions as a mixed-type inhibitor, suppressing both anodic iron dissolution and cathodic hydrogen gas evolution pathways. EIS scans confirmed that charge-transfer resistance (Rct) increased with higher extract amounts, indicating the formation of a robust organic protective film on the steel face. The adsorption behavior of the bioactive compounds conformed to the Langmuir isotherm model, yielding a negative standard free energy of adsorption (delta G°ads = -21.4 kJ/mol), denoting a spontaneous physical adsorption mechanism driven by the presence of rich plant polyphenols.

Keywords: Carbon steel; Corrosion inhibition; Musa paradisiaca; Electrochemical impedance spectroscopy; Polarization; Adsorption isotherm

Manuscript Timeline: Received: June 05, 2018; Revised: July 18, 2018; Accepted: August 20, 2018; Published: May 04, 2019.

Citation: Haruna, M. A., & Swaminathan, S. (2019). Green Corrosion Inhibition of Carbon Steel in Hydrochloric Acid Medium Using Extract of Musa paradisiaca Peels. International Journal of Chemistry, 10(5), 33–40.