Remediation of saline-sodic soil with flue gas desulfurization gypsum in a reclaimed tidal flat of southeast China

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• 作者：Yumei Mao¹ ; Xiaping Li¹ ; ^{xpli@sklec.ecnu.edu.cn" class="auth_mail" title="E-mail the corresponding author} ; Warren A. Dick² ; Liming Chen²
• 关键词：FGD-gypsum ; Saline&ndash ; sodic soil ; Tidal flat ; ESP ; Composition of soluble salt
• 刊名：Journal of Environmental Sciences
• 出版年：2016
• 出版时间：July 2016
• 年：2016
• 卷：45
• 期：Complete
• 页码：224-232
• 全文大小：710 K

文摘

Salinization and sodicity are obstacles for vegetation reconstruction of coastal tidal flat soils. A study was conducted with flue gas desulfurization (FGD)-gypsum applied at rates of 0, 15, 30, 45 and 60 Mg/ha to remediate tidal flat soils of the Yangtze River estuary. Exchangeable sodium percentage (ESP), exchangeable sodium (Ex_Na), pH, soluble salt concentration, and composition of soluble salts were measured in 10 cm increments from the surface to 30 cm depth after 6 and 18 months. The results indicated that the effect of FGD-gypsum is greatest in the 0–10 cm mixing soil layer and 60 Mg/ha was the optimal rate that can reduce the ESP to below 6% and decrease soil pH to neutral (7.0). The improvement effect was reached after 6 months, and remained after 18 months. The composition of soluble salts was transformed from sodic salt ions mainly containing Na⁺, HCO₃⁻ + CO₃^2 − and Cl⁻ to neutral salt ions mainly containing Ca^2 + and SO₄^2 −. Non-halophyte plants were survived at 90%. The study demonstrates that the use of FGD-gypsum for remediating tidal flat soils is promising.