Phosphate Removal in Relation to Structural Development of Humic Acid-Iron Coprecipitates

Autor: Yu-Ting Liu, Fang-Yu Tsao, Ya-Ting Chan, Liang-Ching Hsu, Yen-Lin Cho, Yi-Cheng Hsieh, Kai Yue Chen, Yu-Min Tzou
Jazyk: angličtina
Rok vydání: 2018
Předmět:
Zdroj: Scientific Reports, Vol 8, Iss 1, Pp 1-10 (2018)
Scientific Reports
ISSN: 2045-2322
DOI: 10.1038/s41598-018-28568-7
Popis: Precipitation of Fe-hydroxide (FH) critically influences the sequestration of PO4 and organic matter (OM). While coatings of pre-sorbed OM block FH surfaces and decrease the PO4 adsorption capacity, little is known about how OM/Fe coprecipitation influences the PO4 adsorption. We aimed to determine the PO4 adsorption behaviors on humic acid (HA)-Fe coprecipitates in relation to surface and structural characteristics as affected by HA types and C/(C + Fe) ratios using the Fe and P X-ray absorption spectroscopy. With increasing C/(C + Fe) ratios, the indiscernible changes in the proportion of near-surface C for coprecipitates containing HA enriched in polar functional groups implied a relatively homogeneous distribution between C and Fe domains. Wherein PO4 adsorbed on FH dominated the P inventory on coprecipitates, yielding PO4 sorption properties nearly equivalent to that of pure FH. Structural disruptions of FH caused by highly associations with polar functional groups of HA enhanced the C solubilisation. While polar functional groups were limited, coprecipitates consisted of core FH with surface outgrowth of HA. Although surface-attached HA that was vulnerable to solubilisation provided alternatively sites for PO4 via ternary complex formation with Fe bridges, it also blocked FH surfaces, leading to a decrease in PO4 adsorption.
Databáze: OpenAIRE
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