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Updated: Jun 7, 2025

Calcium Carbonate Formation in the Presence of Biopolymeric Additives
Published on: May 14, 2019
Crystallinity and dissolution-recrystallization mechanism controlled As(V) retention by calcium phosphate
1CAS Key Laboratory of Mineralogy and Metallogeny & Guangdong Provincial Key Laboratory of Mineral Physics and Materials, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 511 Kehua Street, 510640 Guangzhou, China; CAS Center for Excellence in Deep Earth Science, 511 Kehua Street, 510640 Guangzhou, China; University of Chinese Academy of Sciences, 19 Yuquan Road, 100049 Beijing, China.
Amorphous calcium phosphate (ACP) significantly enhances arsenic (As(V)) retention compared to crystalline forms. This process involves dissolution and recrystallization, crucial for understanding pollutant behavior in mineral-water interactions.
Area of Science:
- Environmental Science
- Geochemistry
- Materials Science
Background:
- Mineral-water interactions are key to pollutant environmental behavior.
- The role of mineral crystallinity in toxic element retention is poorly understood.
Purpose of the Study:
- Investigate As(V) interaction with calcium phosphate (CaP) of varying crystallinities.
- Understand the influence of amorphous CaP (ACP) on As(V) retention and interaction mechanisms.
Main Methods:
- Studied As(V) and CaP interactions under oxic conditions.
- Varied As(V) concentrations and pH levels.
- Analyzed mineral crystallinity, liquid composition, and CaP transformation.
Main Results:
- ACP and poorly crystalline hydroxylapatite (HAP) showed 13.65x and 12.61x higher As(V) retention than highly crystalline HAP.
- As(V) retention occurs via ACP dissolution and As(V)-substituted HAP recrystallization.
- Lower pH promoted dissolution; higher pH enhanced recrystallization.
Conclusions:
- Amorphous and poorly crystalline CaP are pivotal for arsenic retention.
- Dissolution-recrystallization is the primary mechanism for As(V) sequestration.
- Mineral crystallinity significantly impacts toxic element fate in environmental systems.
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