Effect of moisture condition on the immobilization of Cd in red paddy soil using passivators

In this study, the immobilization of cadmium (Cd) was evaluated in red paddy soil amended with four different passivators (biochar, lime (CaO), calcium dihydrogen phosphate (Ca(H2PO4)2) and zeolite (modified with NaOH)) for three moisture regimes (70% water-holding capacity (WHC), continuous floodin...

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Veröffentlicht in:Environmental technology. - 1993. - 40(2019), 20 vom: 01. Aug., Seite 2705-2714
1. Verfasser: Huang, Bin (VerfasserIn)
Weitere Verfasser: Li, Zhongwu, Li, Dingqiang, Yuan, Zaijian, Nie, Xiaodong, Huang, Jinquan, Zhou, Yaoyu
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2019
Zugriff auf das übergeordnete Werk:Environmental technology
Schlagworte:Journal Article Cadmium biochar immobilization moisture regime red paddy soil Soil Soil Pollutants 00BH33GNGH Water 059QF0KO0R
Beschreibung
Zusammenfassung:In this study, the immobilization of cadmium (Cd) was evaluated in red paddy soil amended with four different passivators (biochar, lime (CaO), calcium dihydrogen phosphate (Ca(H2PO4)2) and zeolite (modified with NaOH)) for three moisture regimes (70% water-holding capacity (WHC), continuous flooding (CF) and wetting-drying cycle (WDC)). The results showed that: the pH of the soil was obviously influenced by the moisture regimes and decreased in the general order of CF > WDC > 70% WHC, and the addition of lime and Ca(H2PO4)2 could obviously enhance and reduce the values to some extent, respectively. Flooding condition could enhance soil pH and increase the content of free Fe-oxides, amorphous Fe-oxides and water-soluble organic/inorganic carbon in paddy soil. The efficiency in decreasing the exchangeable Cd of different moisture regimes followed the order: CF > 70%WHC > WDC. CF combined with lime was the most effective treatment for reducing exchangeable Cd. The transformation of Cd fractions mainly occurred between the acid-extractable and reducible fractions in the immobilization experiments. The most effective passivator is Ca(H2PO4)2, and CF is the most favorable regime in promoting the transformation of Cd in red paddy soil from acid-extractable to reducible fraction
Beschreibung:Date Completed 09.09.2019
Date Revised 09.09.2019
published: Print-Electronic
Citation Status MEDLINE
ISSN:1479-487X
DOI:10.1080/09593330.2018.1449900