Engineering Proceedings

The escalating accumulation of pharmaceutical micropollutants in global water systems represents a significant challenge to current circular economy frameworks, highlighting a critical gap in the management of environmental persistence. Although advanced remediation technologies are often proposed to mitigate this crisis, their engineering optimization is frequently compromised by a reliance on empirical approximations rather than precise physicochemical constants. Addressing this fundamental deficit, this study executes a rigorous determination of mass transfer properties for two ubiquitous contaminants: Butylparaben and Triclosan. Utilizing a high-precision electrolytic conductance method under infinite dilution, we investigated transport dynamics across varying temperature gradients (305.15–319.15 K). Experimental data were subjected to advanced mathematical modeling, where the Modified Robinson–Stokes (MRS) quadratic model significantly outperformed classical linear approaches ($R^2>0.98$), accurately capturing non-ideal solute–solvent interactions. The derived limiting molar conductivities facilitated the calculation of infinite dilution diffusion coefficients via the Nernst–Haskell equation, yielding values of $0.99\times {10}^{-8}$ m²/s for Butylparaben and $0.98\times {10}^{-8}$ m²/s for Triclosan. Furthermore, Stokes–Einstein analysis quantified the hydrodynamic radii, elucidating the steric mechanisms governing the sluggish migration of bulky chlorinated ethers compared to single-ring esters. These precise transport parameters are not merely theoretical values; they are essential inputs for developing accurate computational fate models and designing regenerable separation processes, thereby providing the hard physics required to engineer solutions for the perpetual pollution era.

During the early years of interaction between humans and computer systems, user authentication and identification was carried out with the support of knowledge-based factors (something the user knows: passwords, PINs, etc.) and tokens (something the user possesses: credentials, RFID cards, etc.) or a combination of both. In other words, the user presents a token and a password to the system in order to gain access. These solutions pose major challenges: Knowledge-based systems, which rely on secrets like passwords, are vulnerable to those secrets being guessed, shared, or forgotten. On the other hand, tokens are also vulnerable; some, despite implementing encryption, attract cyber attackers who can forge them, and users can share or lose them. In the search for more robust methods, the use of biometrics has been considered.

Per- and polyfluoroalkyl substances (PFASs) are synthetic chemicals widely used in industrial applications and consumer products due to their thermal stability and resistance to degradation. These properties also contribute to their environmental persistence and potential adverse health effects. Despite increasing global concern regarding PFAS exposure, biomonitoring data from African populations remain limited. This study investigated the serum concentrations of perfluorooctanoic acid (PFOA), perfluorooctanesulfonate (PFOS), and perfluorobutane sulfonate (PFBS), and their association with diabetes mellitus (DM) in a mixed-ancestry population from Bellville South, Cape Town, South Africa. Serum samples (n = 179) were analysed using liquid chromatography–tandem mass spectrometry (LC–MS-8030), and statistical analyses were performed using STATISTICA 13.5 software. All three PFASs were detected in 100% of samples, with PFOA exhibiting the highest mean concentration (9.43 ± 13.16 ng/mL), followed by PFBS and PFOS. PFAS concentrations were generally higher in females than in males, with significantly elevated PFOA levels observed among women (p = 0.0116). No statistically significant associations were identified between PFAS concentrations and glycemic status, obesity, or related metabolic indicators (p > 0.05). However, PFOS showed a modest positive correlation with HbA1c in females, suggesting potential gender-specific interactions. These findings confirm measurable PFAS exposure in the South African population and highlight the need for larger longitudinal studies implications.