Among the naturally occurring polysaccharides, chitosan is the second-most abundant polysaccharide. It is obtained from chitin through a process known as deacetylation. It is biodegradable, biocompatible, and non-toxic, which made it suitable for various environmental applications. In the present review, the structure, properties, and characteristics of chitosan were discussed. In addition, the modified forms of chitosan (including cross-linked, nanoparticles, functionalized, and grafted forms of chitosan) were enumerated. The applications of these modified forms of chitosan in the adsorption of organic pollutants (such as antibiotics, dyes, pesticides, microplastics, polyaromatic hydrocarbons, parabens, and polychlorobiphenyls) are comprehensively reviewed. Furthermore, the mechanism of adsorption, adsorption isotherm (Langmuir and Freundlich), and the kinetic models are highlighted. Finally, the economic viability assessment and environmental impact of processing tons of shrimp shells into chitosan annually were discussed.

The poor in Sub-Saharan Africa (SSA) are in a worse predicament than their counterparts in other regions. The goal of this study was to establish the key drivers of poverty in SSA by looking at how economic variables affect growth and poverty. Data from ten SSA nations—upper-middle-income countries (UMIC), lower-middle-income countries (LMIC), and low-income countries (LIC)—were analyzed based on historical values from 2015 to 2019. From the six economic variables studied, the best model reveals that 78% of the differences in poverty can be accounted for using a methodical, statistical approach. Poverty and unemployment rates have a substantial positive relationship (p = 0.001662). The gross domestic product (GDP) growth rate and poverty have a slight link, which is significant at the 10% level (p = 0.067) but is not a significant contributor to poverty alleviation. The secondary school enrolment rate has no bearing on poverty variation (p = 0.33). Increased GDP does not necessarily correspond to poverty reduction. Unemployment, on the other hand, is a major contributor to poverty in the region. Moreover, education (secondary school ennoblement) plays a less important role in reducing poverty, whereas per capita personal consumer spending and GDP growth rate have a bigger impact on poverty reduction. The proposed theoretical and numerical model works on general indicators and trends; it does not guarantee that people in the UMIC, LMIC, and LIC countries may not fall below the international poverty line ($1.90 per day). The poverty rates are predicted to climb by more than 2% by 2030, postponing poverty elimination in the SSA region by almost five years. This signifies that more than half of the SSA population will remain poor.

Surface water quality has major environmental and socioeconomic consequences, notably in terms of the country’s long-term fresh water supply. This study aimed at assessing the current state of water quality and status of the Boesmanspruit in a coal mining environment. The study used historical water quality data for a period of five years from 2017 to 2021. Aluminum, calcium, iron, manganese, magnesium, sodium, sulfate, electrical conductivity, pH, and total dissolved solids were the water quality variables selected for the study; the chosen variables were chosen based on the available secondary data. The water quality was evaluated against South African resource quality objectives, the South African water quality guidelines, and the Canadian Council of Ministers of the Environment water quality index (CCME-WQI). The data were analyzed using such as the CCME-WQI, the comprehensive pollution index (CPI), and multivariate statistics. The following parameters were above the prescribed thresholds: pH, total dissolved solids, electrical conductivity, sulfate, manganese, and iron. The CCME-WQI results showed that monitoring locations GR S26 and GR S21 near mining activities had poor water quality (40–44), whereas comprehensive pollution index (CPI) also had similar category results for the monitoring points, indicating that they were heavily polluted (2.4–4.8). The WQI showed that if certain variables, such as aluminum, iron, magnesium, sulfate, electrical conductivity, and total dissolved solids, exceed the permissible range, the water quality would deteriorate in accordance with the CPI classification. Therefore, the CPI was the best way to categorize the water quality. The principal component analysis and cluster analysis identified two primary sources of pollution which are anthropogenic and natural. The utilization of statistical analysis proved to be effective in determining the ideal quantity of significant variables within the study area. The study recommends low-cost options for reducing the effects of acid mine drainage, which includes passive mine water treatment methods using artificial wetlands.

The objective of this study was to assess the water quality status of the surface water and groundwater resources in the Middelburg area, South Africa. The assessment was addressed using combined water quality indices, investigating selected chemical parameters over four different seasons for a period of five years from 2017 to 2021. A combination of the Canadian Council of Ministers of the Environment water quality index and the comprehensive pollution index was used to analyze the water quality status of surface water and groundwater of the town of Middelburg, situated near coal mining activities in Mpumalanga, South Africa. The combination of the indices indicated that some surface water monitoring sites ranged between poor to fair water quality. Groundwater monitoring points also showed a poor to fair ranking. The comprehensive pollution index confirmed that some sites showed very poor water quality in the summer seasons, exceeding expected limits for the period 2017 to 2021. The principal component analysis further showed that both surface water and groundwater sites had high levels of contamination with increased chemical parameters. The results were compared against the different water quality guidelines. In an extensive monitoring program, water management systems must be properly implemented to mitigate impacts on water resources.

Novel cellulose-chitosan crosslinked polymers were synthesized using a Schiff base reaction by combining cellulose extracted from corn cobs via chemically treated methods (NaOH, H ₂ O ₂ /NaOH) and shrimp chitosan with aldehyde linkers (glutaraldehyde and formaldehyde). Structural, compositional, and chemical characterization of the fiber was performed using SEM, FTIR, UV-Vis, XRD, and EDX analyses. Treatment with H₂O₂ effectively removed waxy and fatty acid residues from the cellulose surface without altering its chemical composition. FTIR analysis confirmed the presence of aldehyde crosslinking, with variations in peak intensities (around 1400 cm⁻¹) indicating differential interactions between formaldehyde and glutaraldehyde linkers. SEM revealed an amorphous microstructure with compact, globular particles of varying sizes. Crosslinking enhanced antibacterial activity, as demonstrated by minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of 9.37 mg/mL and 18.75 mg/mL, respectively, against Staphylococcus aureus and Pseudomonas aeruginosa . These results highlight the potential of cellulose-chitosan crosslinked polymers as effective antimicrobial agents, with aldehyde crosslinking playing a pivotal role in improving their efficacy.