Li Jianrui, Xu Yingming
Taiyuan Institute of Technology, Taiyuan 030008, China.
Agro-Environmental Protection Institute, Ministry of Agriculture, Tianjin 300191, China.
Ecotoxicol Environ Saf. 2017 Jul;141:107-112. doi: 10.1016/j.ecoenv.2017.03.021. Epub 2017 Mar 19.
We examined in situ remediation of sepiolite on cadmium-polluted soils with diverse water regimes, and several variables including brown rice Cd, exchangeable Cd, pH, and available Fe/P. pH, available Fe/P in soils increased gradually during continuous flooding, which contributed to Cd absorption on colloids. In control group (untreated soils), compared to conventional irrigation, brown rice Cd in continuous flooding reduced by 37.9%, and that in wetting irrigation increased by 31.0% (p<0.05). In contrast to corresponding controls, brown rice Cd in sepiolite treated soils reduced by 44.4%, 34.5% and 36.8% under continuous flooding, conventional irrigation and wetting irrigation (p<0.05), and exchangeable Cd in amended soils reduced by 27.5-49.0%, 14.3-40.5%, and 24.9-32.8% under three water management regimes (p<0.05). Compared to corresponding controls, decreasing amplitudes of exchangeable Cd and brown rice Cd in sepiolite treated soils were higher in continuous flooding than in conventional irrigation and wetting irrigation. Continuous flooding management promoted soil Cd immobilization by sepiolite.
我们研究了海泡石在不同水分条件下对镉污染土壤的原位修复情况，以及包括糙米镉、交换性镉、pH值和有效铁/磷在内的几个变量。在持续淹水过程中，土壤的pH值、有效铁/磷逐渐升高，这有助于胶体对镉的吸附。在对照组（未处理土壤）中，与常规灌溉相比，持续淹水条件下糙米镉含量降低了37.9%，而湿润灌溉条件下糙米镉含量增加了31.0%（p<0.05）。与相应对照组相比，海泡石处理土壤在持续淹水、常规灌溉和湿润灌溉条件下，糙米镉含量分别降低了44.4%、34.5%和36.8%（p<0.05），改良土壤中的交换性镉在三种水分管理模式下分别降低了27.5 - 49.0%、14.3 - 40.5%和24.9 - 32.8%（p<0.05）。与相应对照组相比，海泡石处理土壤中交换性镉和糙米镉的降低幅度在持续淹水条件下高于常规灌溉和湿润灌溉。持续淹水管理促进了海泡石对土壤镉的固定。
