A high-selective and stable melamine form with economic and simple decoration for purification of thallium(I)-contaminated water

Abstract

In natural freshwater and wastewater environments, thallium (Tl) is an infrequent yet exceptionally toxic heavy metal, presenting a formidable peril to human health. The arsenal of substances accessible for Tl(I) adsorption encompasses biochar, activated carbon, metal oxides, and diverse materials. The adsorption capabilities of activated carbon and biochar are limited, while metal oxide materials are expensive and challenging to regenerate. Developing cost-effective materials with high selectivity for Tl(I) removal poses an ongoing challenge in material technology. In this investigation, a novel composite denoted as PB@PDA/PEI-MF has been successfully synthesized, comprising Melamine Foam (MF) co-supported with Prussian blue nanoparticles (PB NPs) via the incorporation of polydopamine (PDA) and polyethyleneimine (PEI). The PB@PDA/PEI-MF material demonstrates remarkable efficacy in the efficient sequestration of Tl(I) across a broad pH spectrum, ranging from 6 to 10. Moreover, even in the incidence of various coexisting metal ions (e.g., Na+, K+, or Ca2+), the Tl(I) removal rate by PB@PDA/PEI-MF remains consistently high, exceeding or equal to 90%. Its high selectivity, anti-ion interference ability, and ease of recycling address the most prominent shortcomings of previous materials. Leveraging these advantages, the PB@PDA/PEI-MF material demonstrates exceptional proficiency in the remediation of real-world Tl(I)-contaminated Pearl River water, aligning with the stringent industrial wastewater standards. The conclusive outcomes affirm that PB@PDA/PEI-MF presents a viable technological solution for the effective removal of Tl(I) in intricate environmental contexts.