Application of pyrite to water pollutant removal: A review

Pyrite (FeS₂), a prevalent metal sulfide mineral on Earth, has garnered substantial attention for its resource utilization amidst environmental concerns stemming from its conventional disposal as low-value tailings and the associated acid mine drainage (AMD) issues. Leveraging its exceptional adsorption capacity, formidable reducing strength, and heightened surface catalytic activity, pyrite has emerged as a versatile material in water pollution control and remediation. This paper presents a comprehensive review of pyrite's utilization in water pollutant treatment, elucidating the unique characteristics that underpin its effectiveness. Specifically, the release of Fe²⁺ ions and sulfide species, functioning as electron-rich donors, imparts pyrite with robust reducing capabilities, rendering it an ideal candidate as a reducing agent. Furthermore, the positively charged surface of pyrite, coupled with the formation of complexes during redox reactions, synergistically enhances its capacity to adsorb and sequester pollutants, thereby acting as a potent adsorbent. Notably, pyrite's self-regulating pH mechanism and its sustained, controlled release of Fe²⁺ ions confer distinct advantages in advanced oxidation processes, broadening its application horizon. This review meticulously summarizes the research advancements in harnessing pyrite's adsorption, reduction, and catalytic properties for the removal of heavy metals, inorganic contaminants, and organic pollutants from aqueous environments. It critically examines the underlying mechanisms that govern pyrite's pollutant removal capabilities and appraises the environmental factors that modulate its removal efficiency. By offering a holistic perspective, this comprehensive overview not only deepens our understanding of pyrite's role in water remediation but also serves as a valuable resource for researchers seeking to explore and optimize the application of this multifaceted mineral in addressing water pollution challenges.