Monitoring river systems is crucial for understanding and managing water resources, predicting natural disasters, and maintaining ecological balance. Assessment of heavy metal pollution derived valuable data which are critical for the environmental management and regulatory compliance of the Jukskei River. Heavy elements were evaluated in the Jukskei River for seasonal impact, potential health risks, and contamination level with concentration levels ranging from 6900 mg/kg iron (Fe) to 0.85 mg/kg cadmium (Cd) in the dry sampling season and 6900 mg/kg Fe to 0.26 mg/kg Cd in the wet season. Enrichment factor analysis indicated high contamination levels of Fe and Pb in both dry and wet seasons. Moreover, pollution indicators revealed extremely high contamination of geo-accumulation and enrichment factors in the downstream to upstream in both seasons with a mild contamination factor for mercury (Hg). Principal Component Analysis revealed anthropogenic sources of arsenic (As), Cd, and Pb due to wastewater and agricultural pesticide application while Thorium (Th), uranium (U) and Hg were attributed as a results of gold mining activities. ANOVA and Pearson correlation analysis showed a high and moderate link between As–Pb, Cd–Pd, and As–Hg, which are significantly correlated. The potential ecological risk index assessment revealed a significant impact of heavy metals on the freshwater ecosystem.

The increasing population has subjected rivers and streams to high levels of both industrial and domestic pollution. Significant environmental challenges have been brought about by their effects, particularly with regard to biota, ecosystem processes, soil quality, and groundwater pollution. This study examined the effects of human activity by applying pollution index models to evaluate the input of toxic elements in river sediments. Prior to sediment quality analysis, the total amount of arsenic (As), lead (Pb), cadmium (Cd), mercury (Hg), thorium (Th), and uranium (U) was determined in the concentration range of 1.09–10.0 mg/kg, 8.53–475 mg/kg, 0.12–0.16 mg/kg, 4.85–77.5 mg/kg, 3.14–5.9 mg/kg and 0.93–2.86 mg/kg, respectively. The enrichment factor, contamination factor, pollution load index, and geo-accumulation index revealed alarmingly high levels of Pb and Hg contamination at some sampling points, which are related to possible human input, ranging from severe enrichment to considerable contamination. The low ranges of pollution indices of some toxic elements suggest enrichment through the natural weathering process and atmospheric deposition. The Pearson correlation coefficient revealed a significant correlation between Pb-Fe and As-Fe, suggesting the possibility of acid mine contamination. Continual monitoring of river sediment is essential to minimize the impact of toxic elements to sustain sediment health and quality.

Direct monitoring of volatile organic compounds emitted from industrial sources as well as the monitoring of ambient levels thereof in the atmosphere play an important role in providing data for various legislative requirements. There are many volatile organic compounds emitted to the atmosphere, from biomass burning, power stations, and many other sources. Primary reference gas mixtures of volatile organic compounds containing six components, namely benzene, toluene, ethylbenzene, o-xylene, m-xylene, and p-xylene (BTEX) were prepared by gravimetric methods at nominal amount of substance fractions of 10 µmol/mol. The preparation was performed using the stainless steel (loop) method and direct liquid injection method using gas tight syringe connected to a dedicated syringe heater for comparison purposes. The results of the gravimetric values for both methods were within 1 % of the nominal amount of substance fraction. After the preparation, comparison was achieved by analysis of the BTEX gas mixtures using gas chromatography with flame ionisation detection (GC-FID) and showed comparability to within 2 % of the gravimetric values. The contributions to the uncertainty of measurement were from weighing stainless steel tubes, syringes, and gas cylinders, as well as purity data. The contribution to the uncertainty of measurement from the analysis by GC-FID were repeatability and reproducibility. The combined expanded uncertainty of measurement was between 1.09 % and 3.51 %. The larger deviation from the gravimetric values and associated uncertainty was observed for benzene due to its higher volatility compared to the other components. The BTEX reference gas mixtures prepared in this study are currently being used as a source of traceability in South Africa for air pollution monitoring purposes.

The global issue of water quality degradation that exacerbates water scarcity prompted establishment of strategic water management systems. The majority of anthropogenic activities that affect water quality are indispensable and economical. Despite its importance for achieving economic expansion, prosperity, and advancement on a national and international scale, industrialization is a primary cause of adverse environmental effects. There is significant strain on rivers and dams from chemical spills, fertilizers and pesticides, personal hygiene products, wastewater discharge, and land drainage due to lack of proper water treatment infrastructures or wilful activities of illegal disposal. The developing era of scientific research is focused on effective technologies for water-pollution monitoring. This study is interested in exploration of environmental forensics using forensic-analytical techniques such as aerial photography, satellite analytics, and chemometric and spectroscopic techniques to identify sources of water pollutants. This approach is of great importance in connecting the identified pollutants to their emission sources in order to provide efficient long-term strategies for a holistic water management system. The environmental forensics approach in this study can improve comprehension of pollution that will assist national departments and policy makers in charge of pollution control in the geographical locations to ensure that water polluters abide by applicable laws.

Heavy metal mining and industrial waste contamination are significant environmental issues that modern civilization has been grappling with for some time. In geological ores, nickel (Ni) fire assay fusion (Ni-FA) and lead (Pb) fire assay fusion (Pb-FA) are the most crucial classical analytical chemistry methodologies used for the collection and determination of platinum group elements (PGEs) and gold (Au) from PGE ore. These classical experiments involve the pre-concentration of PGEs and Au and separation into metallic and silicate phases, which offer high accuracy and high precision with a low limit of detection. Industrial metallurgical and FA processes produce lead-contaminated cupels with high Pb concentrations, posing health risks and environmental pollution if not retrieved. In this study, we discuss waste generated during the PGE separation method, particularly from FA processes. The study explores classical methods and analytical techniques for removing and quantifying Pb, Ni, and other critical minerals from lead and nickel waste streams, considering their potential levels in different environments. The chapter provides an overview of fire assay methods for PGM preparation, current quantification trends, potential environmental impacts, energy storage options, production effort, and hazards. In comparison with the pyrometallurgy approach, studies indicate that hydrometallurgical processing is a more effective way of recovering value-added metals. Lastly, the current status and future perspective on the application of critical minerals, and repurposing for a circular economy have been outlined, indicating the economic viability of recycling.