TY - JOUR
T1 - Unravelling key factors controlling homogeneous crystallization during phosphorus recovery
T2 - From the perspective of crystallization kinetics
AU - Li, Xiang
AU - Hu, Xin
AU - Shen, Shuting
AU - Wan, Rui
AU - Dai, Hongliang
AU - Lu, Xiwu
N1 - Publisher Copyright:
© 2025
PY - 2025/1/20
Y1 - 2025/1/20
N2 - Phosphorus (P) recovery from wastewater is a critical process for addressing environmental concerns associated with P pollution and promoting resource sustainability through the closure of the P cycle. However, the efficiency of P recovery is often hindered by homogeneous crystallization. This study aims to elucidate the role of homogeneous crystallization in hydroxyapatite (HAP) formation and its influence on P recovery efficiency. We employed pH monitoring to assess the induction time for homogeneous crystallization, while simultaneously tracking changes in calcium and P concentrations during both formation and transformation stages. Our findings indicate that adjusting operational parameters significantly influences P removal efficiency and the induction time for phase transition in the crystallization process. Specifically, increasing the pH from 8 to 10 resulted in an enhancement of P removal efficiency, rising from 36 % to 99 %. However, this increase in pH corresponded with a substantial prolongation of the induction time for phase transition, extending from 0.53 h to 15.8 h. In contrast, raising the temperature from 15 °C to 35 °C improved P removal efficiency from 23.62 % to 56.80 % while concurrently decreasing the induction time for phase transition from 10.45 h to 1.31 h. The transformation to HAP occurs primarily through the dissolution-recrystallization of ACP. By carefully regulating operational parameters, we can control the formation and transformation of the homogeneous precipitate, thereby enhancing P recovery efficiency. This research provides valuable insights into the composition, formation, and transformation mechanisms of fine particles during P recovery, while also offering a novel perspective for assessing the risks associated with homogeneous precipitates.
AB - Phosphorus (P) recovery from wastewater is a critical process for addressing environmental concerns associated with P pollution and promoting resource sustainability through the closure of the P cycle. However, the efficiency of P recovery is often hindered by homogeneous crystallization. This study aims to elucidate the role of homogeneous crystallization in hydroxyapatite (HAP) formation and its influence on P recovery efficiency. We employed pH monitoring to assess the induction time for homogeneous crystallization, while simultaneously tracking changes in calcium and P concentrations during both formation and transformation stages. Our findings indicate that adjusting operational parameters significantly influences P removal efficiency and the induction time for phase transition in the crystallization process. Specifically, increasing the pH from 8 to 10 resulted in an enhancement of P removal efficiency, rising from 36 % to 99 %. However, this increase in pH corresponded with a substantial prolongation of the induction time for phase transition, extending from 0.53 h to 15.8 h. In contrast, raising the temperature from 15 °C to 35 °C improved P removal efficiency from 23.62 % to 56.80 % while concurrently decreasing the induction time for phase transition from 10.45 h to 1.31 h. The transformation to HAP occurs primarily through the dissolution-recrystallization of ACP. By carefully regulating operational parameters, we can control the formation and transformation of the homogeneous precipitate, thereby enhancing P recovery efficiency. This research provides valuable insights into the composition, formation, and transformation mechanisms of fine particles during P recovery, while also offering a novel perspective for assessing the risks associated with homogeneous precipitates.
KW - Amorphous calcium phosphate
KW - Homogeneous crystallization
KW - Hydroxyapatite
KW - Introduction time
KW - Phosphorus recovery
UR - http://www.scopus.com/inward/record.url?scp=85215085554&partnerID=8YFLogxK
U2 - 10.1016/j.jclepro.2025.144782
DO - 10.1016/j.jclepro.2025.144782
M3 - Article
AN - SCOPUS:85215085554
SN - 0959-6526
VL - 490
JO - Journal of Cleaner Production
JF - Journal of Cleaner Production
M1 - 144782
ER -