首页|Effect of alternating wetting and drying cycles on selenium aging in three soils amended with selenate/selenite
Effect of alternating wetting and drying cycles on selenium aging in three soils amended with selenate/selenite
扫码查看
点击上方二维码区域，可以放大扫码查看
原文链接
NETL
NSTL
Springer Nature
Abstract Purpose The application of exogenous Se to soil is commonly practiced to elevate the Se content in crops, but how the alternating wetting and drying (AWD) cycles caused by precipitation or irrigation influences the environmental fate of Se is still unclear. This study aimed to explore the effects of the AWD cycles on Se aging in loess soil (LS), black soil (BS), and krasnozem (KS) treated with selenate/selenite during 140 d.Method The measurement of Se species and fractions, as well as the kinetic simulation of the available Se fraction, aims to clarify the impact of the AWD cycles on the Se aging process. Soil pH, redox potential (Eh), and dissolved organic carbon (DOC) were determined to investigate the influencing factors of Se aging.Results The AWD cycles elevated the pH and reduced the Eh in LS and KS, while both the pH and Eh in BS were reduced. In addition, the DOC contents of BS were higher than that of LS and KS. The dominant Se species in the available Se fractions of LS and BS treated with selenate shifted from Se(VI) to Se(IV) as the AWD cycles progressed. The AWD cycles transformed the available Se to residual Se in soils treated with selenate/selenite. The equilibrium time for the aging of selenate or selenite in KS was only 42 d, whereas achieving equilibrium for Se aging in LS and BS required 98 to 126 d. The available Se content and Se aging rate of KS were greater than those of LS and BS in the selenate treatments. Furthermore, the selenate aging rates were accelerated compared to the selenite rates in BS and LS.Conclusions The AWD cycles had different effects on the aging of selenate and selenite in different types of soil. This study can offer a comprehensive understanding of the effects of the precipitation and irrigation on the environmental fate of Se.
NETL
NSTL
Springer Nature
