Inorganic Chemicals Industry ›› 2025, Vol. 57 ›› Issue (9): 104-109.doi: 10.19964/j.issn.1006-4990.2024-0538

• Environment·Health·Safety • Previous Articles     Next Articles

Study on leaching characteristics of soluble fluoride in phosphogypsum and soil

GAN Chundan1,2(), PAN Yunlian2, LIU Hengbo1,2(), YANG Jinyan2, ZHANG Yunjie1, LONG Quan1   

  1. 1. Sichuan Academy of Eco-Environmental Sciences,Chengdu 610000,China
    2. College of Architecture and Environment,Sichuan University,Chengdu 610000,China
  • Received:2024-10-10 Online:2025-09-10 Published:2024-11-25
  • Contact: LIU Hengbo E-mail:ganchundan1@stu.scu.edu.cn;lhb.scaes@qq.com

Abstract:

Phosphogypsum(PG),a by-product of the phosphate fertilizer industry,has become a significant environmental concern due to improper stockpiling,particularly regarding its potential to release fluoride,which poses a risk to ecosystems.The fluoride leaching characteristics of PG and soil was investigated under different conditions,including leaching time,solid-to-liquid ratio,temperature,and leachant pH.The results showed that fluoride release from PG was significantly higher than from soil,especially under acidic,high solid-to-liquid ratio,and elevated temperature conditions.With increased leaching time,fluoride release from both PG and soil gradually stabilized,with leaching rates reaching approximately 9.9% for PG and 2.0% for soil.As the pH of the leachant increased from acidic(pH=3.03) to near-neutral(pH=6.88),fluoride leaching decreased.Moreover,noticeable changes in the surface morphology of both PG and soil were observed after leaching,with reduced particle size and denser structures.These findings indicated a high potential for fluoride leaching from PG under acid rain and high-temperature conditions,particularly during the summer months with frequent high temperatures and heavy rainfall.The study underscored the importance of effective monitoring and management of PG stockpiles,especially in regions prone to high temperatures and heavy precipitation.

Key words: phosphogypsum, soil, leaching, fluoride pollution, acid rain

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