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A contrast of lead immobilization via bioapatite under elevated CO 2 between acidic and alkaline soils
Author(s) -
Tian D.,
Lai Z.,
Zou X.,
Guo C.,
Tang L.,
Su M.,
Li Z.,
Hu S.
Publication year - 2018
Publication title -
soil use and management
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.709
H-Index - 81
eISSN - 1475-2743
pISSN - 0266-0032
DOI - 10.1111/sum.12448
Subject(s) - chemistry , dissolution , soil water , alkali soil , adsorption , soil ph , nuclear chemistry , environmental chemistry , saline , alkaline earth metal , inorganic chemistry , alkali metal , geology , medicine , soil science , organic chemistry
The feasibility of Pb immobilization via bioapatite ( BA p) and CO 2 in the acidic red soil ( RS ) and saline‐alkaline soil ( SS ) was compared in this study. The elevated CO 2 (10% in air) significantly promoted the dissolution of BA p in water, that is, the concentrations of released P were enhanced from 2 to 20 ppm as pH decreased from 6.9 to 5.6. Then, it was shown that 30–40% TCLP leached Pb was removed from RS and SS , with the combination of BA p addition and CO 2 elevation. In RS , the addition of BA p (even without CO 2 ) could significantly increase water‐soluble P. Moreover, some Pb cations were adsorbed onto iron (hydr)oxides within RS . In contrast, CO 2 elevation is essential for enhancing P release in SS as it dramatically increased the dissolution of phosphates. The released P then reacted with Pb cations to form insoluble pyromorphite. Therefore, this combination is effective for Pb immobilization in saline‐alkaline soil whereas adding solely BA p is feasible for acid soil.