Hamidreza Sharifan

Coconut-shell-derived activated carbon was functionalized with amine and surfactant groups to enhance the selective removal of short-chain PFAS from water.

Soil salinity is a major abiotic stress that limits agricultural productivity worldwide and is defined as the accumulation of soluble salts, mainly chlorides, sulfates, and carbonates of Na+, Ca2+,...

Forensic science and chemistry curricula often lack hands-on experimental designs that effectively simulate the impact of environmental tobacco smoke (ETS) or other common elements found at crime scenes, such as marijuana, on trace forensic evidence. Hair, a critical form of trace evidence, offers unique advantages for assessing long-term exposure to environmental pollutants, including ETS. This study presents a novel, noninvasive forensic laboratory module designed to evaluate ETS exposure on various human hair types (untreated, dyed, and bleached). The experimental procedure involved controlled cigarette smoke exposure, followed by analysis using UV–visible spectroscopy, FTIR spectroscopy, and zeta potential measurements. Thirteen students participated in the three-week lab module (three sessions per week). Pre- and postlab assessments were conducted to evaluate learning outcomes. The prelab assessment focused on baseline knowledge of forensic hair analysis, as well as student expectations and confidence. The postlab assessment evaluated knowledge gained, technical insights, application of techniques, self-reflection, conceptual understanding, and practical skill development. This design helped students comprehend the effects of chemical treatments that significantly influence hair’s capacity to adsorb ETS residues by altering its physical and chemical properties. Integration of this experiment into the forensic chemistry curriculum led to measurable gains in student understanding, technical competency, and appreciation for real-world forensic applications. This method offers a valuable teaching and investigative tool for assessing individual ETS exposure in forensic contexts.

Perfluorooctanoic acid (PFOA) is a persistent environmental contaminant with the potential to disrupt soil-plant systems. This study investigated the impacts of PFOA on soil microbial viability and community composition under aerobic and anaerobic conditions, to understand microbial resilience and adaptability to pollutant stress. Soil samples from an uncontaminated agricultural field (2.26 ng/g) were amended with varying PFOA concentrations (0, 40, 60, 80, and 100 mg/kg) and incubated under controlled conditions for 7 days. Microbial viability was assessed through colony-forming unit (cfu) counts, while community composition was characterized via 16S rRNA gene sequencing. Results showed a significant decline (8-79%) in microbial viability at higher PFOA concentrations across both environments, with anaerobic soils exhibiting greater sensitivity, underscoring the role of oxygen availability in microbial pollutant tolerance. Taxonomic analysis revealed concentration-dependent shifts, with Actinobacteria and Proteobacteria dominating under aerobic conditions, and Chloroflexi, Bacteroidetes, and Acidobacteria prevailing under anaerobic conditions. The novelty of this study lies in its systematic comparison of microbial community responses and adaptive mechanisms under both aerobic and anaerobic soil conditions, providing critical insights into the differential impacts of PFOA that have previously not been explored.The findings highlight the ecological significance of resilient taxa in sustaining carbon and nutrient turnover in contaminated soils.