In the pursuit of eco-friendly solutions to combat selenium (Se) contamination, a groundbreaking study has emerged, showcasing the transformation of iron-containing industrial waste, specifically paper-mill sludge (PS), into a powerful environmental ally. The research, conducted through the pyrolysisPyrolysis is a thermochemical process that converts waste biomass into bio-char, bio-oil, and pyro-gas. It offers significant advantages in waste valorization, turning low-value materials into economically valuable resources. Its versatility allows for tailored products based on operational conditions, presenting itself as a cost-effective and efficient More process under a nitrogen atmosphere, resulted in the creation of a zero-valent iron (Fe0)-loaded biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More, named PS/BC-750.

This newly developed PS/BC-750 exhibited remarkable adsorption capacity for two prevalent Se species, Se(VI) and Se(IV). The study delved into the adsorption kinetics and isotherms, revealing a dependence on pHpH is a measure of how acidic or alkaline a substance is. A pH of 7 is neutral, while lower pH values indicate acidity and higher values indicate alkalinity. Biochars are normally alkaline and can influence soil pH, often increasing it, which can be beneficial More conditions. Impressively, the pseudo-second-order kinetics showcased equilibrium for Se(VI) and Se(IV) within 1440 and 60 minutes, respectively.

The Fe-biochar’s efficacy was attributed to its porous carbon structure embedded with reduced iron phases (Fe0 and FeO). The adsorption mechanisms were deciphered through X-ray photoelectron spectroscopy, shedding light on the specific binding sites where Se(VI) and Se(IV) chemisorbed onto PS/BC-750.

The research addresses a critical environmental concern as Se contamination, often stemming from mining activities, poses health risks and ecological damage. This Fe-biochar composite presents a promising avenue for remediating Se pollution, offering a sustainable solution to repurpose Fe-containing waste.

As the world grapples with the aftermath of mining activities, the potential of this innovative approach extends beyond Se remediation, showcasing the broader applicability of pyrolytic processes in converting industrial waste into effective environmental solutions. This study serves as a beacon of hope, highlighting the transformative power of scientific ingenuity in the face of environmental challenges.