SOUTHERN JOURNAL OF SCIENCES

Background: Industrial wastewater contains pollutants that are detrimental to human health in varied proportions. Among the pollutants are heavy metals, including Zn2+, Pb2+, and Cu2+ found in a characterized pharmaceutical wastewater. Several techniques have been proposed for the heavy metal sequester. However, they are with attendant challenges. The adsorption techniques using clay-metal oxide modified adsorbent/composite such as silver-clay adsorbent is considered suitable for an effective sequestering process. Aims: To develop and characterize Ag/clay adsorbent for pharmaceutical wastewater treatment. Methods: The Ag nanoparticles were synthesized using Parkia biglobossa aqueous leaves extract in an optimization study. The raw clay was beneficiated and doped with silver nanoparticles via the wet impregnation method. The silver-clay adsorbent was characterized using FTIR, XRD, SEM, and EDS characterization tools. The developed adsorbent was used for the batch adsorption process of the heavy metal ion removal from the wastewater. Results and Discussion: The phytochemical analysis and FTIR results of the P. biglobosa showed that the leaf contains phenol, tannin, and flavonoids which acts as reducing, capping, and stabilizing agent required for synthesizing the silver nanoparticles. The prepared silver nanoparticles modified clay adsorbent Ag/clay, have evenly distributed stacks of pseudo-hexagonal plates, are rich in silica, possess silver nanoparticles in the frameworks, and contain functional groups suitable for binding heavy metals. The adsorptions of Zn2+, Pb2+, and Cu2+ from pharmaceutical wastewater onto the silver-modified clay were studied as a function of adsorbent dosage and contact time. The percentage removal results obtained showed that the adsorbent had up to 99.96%, 99.5%, and 99.44% removal efficiency for Zn2+, Pb2+, and Cu2+, respectively, which are better compared with previous studies. The adsorption process was feasible, spontaneous, and exothermic, with Langmuir and Pseudo-second-order models as best fits for the process. Conclusions: The adsorption of selected heavy metal ions onto the green synthesized silver-modified clay adsorbent (Ag/clay) was feasible, spontaneous, and exothermic in the order Zn2+>Pb2+>Cu2+ with Langmuir and Pseudo-second-order model best fitted for the process. These show that the synthesized silver oxide nanoparticles supported on local clay can be used as a potentially low-cost adsorbent to remove heavy metal ions from industrial wastewater.

Background: Scientific conferences play a vital role in knowledge exchange and collaboration across disciplines. Building on the success of its 2022 inaugural event, the Second Southern Science Conference (SSCON 2024) aimed to expand international scientific collaboration while addressing contemporary challenges in sustainability and research methodology. Aims: To evaluate the effectiveness of a hybrid conference format in facilitating global scientific collaboration and to showcase cutting-edge research across multiple disciplines, with particular emphasis on sustainability and technological innovation in Latin America. Methods: The conference implemented a hybrid format combining in-person and virtual attendance. Over three days, 38 lectures were presented by renowned researchers, covering key topics including materials science, environmental sustainability, chemical processes, and regional development. Participation metrics and collaboration patterns were analyzed to assess the conference's impact. Results: The conference achieved significant participation with 242 contributing authors from 13 countries across four continents. Notable research presentations included advances in laser surface modification techniques, geotechnology applications in biofuel production, sustainable silica synthesis from biomass, and green valorization of tropical seeds. The conference produced 66 approved papers, with most involving 2-5 collaborators. Discussion: The hybrid format proved effective in removing geographical barriers and promoting global engagement. The strong representation from Latin American institutions highlighted the region's growing influence in international scientific discourse. Key research presentations demonstrated innovative approaches to sustainability challenges, particularly in waste utilization and environmental technology. Conclusion: SSCON 2024 successfully evolved from its predecessor, demonstrating the effectiveness of hybrid conferencing in fostering international scientific collaboration. The conference established itself as a vital platform for knowledge exchange, particularly in sustainability and technological innovation, while identifying areas for future improvement such as extended submission timelines and permanent management structures.

Background: Despite innovations in orthopedic dentistry, the manufacture of removable dentures belongs to the most popular orthopedic care category. Removable dentures are combined stimuli that affect the mucous membrane and neuro-receptor apparatus. Acrylic plastic prostheses, widely used in prosthetic dentistry, have a negative side mechanical, chemical-toxic, sensitizing, and thermal insulating effect on oral tissue and prosthetic impression area. This is often complicated by a violation of the biocenosis of the oral cavity, the growth of pathogenic microflora that releases toxins, especially an increase in the number of yeast colonies that irritate the oral mucosa and prosthetic stomatitis. According to the WHO, one-fifth of the world s population suffers or has suffered various candidiasis forms at least once. The worldwide increase in the incidence of the disease is primarily related to the fact that this infection is opportunistic, more than half of the world s population is a carrier of fungi of this kind, i.e., in most cases, it is an endogenous infection, which makes candidiasis different from other opportunistic mycoses. Aims: The purpose of this study was to study the prevalence of candidiasis in patients using removable dentures and to evaluate the effectiveness and prevention of candidiasis treatment. Methods: 100 patients with oral candidiasis of various age groups from 45 to 65 years were observed. Of these, 60 patients with removable plate prostheses; 40 patients with partially removable prostheses. Results and Discussion: Chronic forms of candidiasis were diagnosed in 40 patients and with exacerbation of chronic forms of candidiasis-60 people. The number of untreated carious cavities and poor hygienic condition of the oral cavity directly affects the severity of candidiasis. Acute forms of candidiasis were observed mainly in patients with high DMF and PMA indices. The severity of candidiasis depends on the degree and duration of wearing dentures and hygienic conditions - the most severe forms of invasive candidiasis were observed in the presence of removable plate prostheses, the complete absence of teeth, and the use of a prosthesis for more than 10-15 years. A combined lesion of the oral mucosa and the red border of the lips was observed mainly in patients older than 60 years. Conclusions: The presence of candidiasis in the oral cavity in patients with removable plate prostheses leads to a statistically significant change in the indicators of local immunity of the oral cavity: an increase in the concentration of serum IgG and IgA and the values of the coefficient of the balance of local immunity factors.