摘要
为研究镉污染土壤修复方法,选取粉煤灰、磷矿粉、生物炭3种钝化剂单独施加或与叶面喷施硅肥联合开展田间试验,研究它们对水稻产量、水稻籽粒吸收镉与土壤有效态镉的影响,同时采用比表面积孔径孔容(BET)、表面形貌(SEM)、红外光谱(FTIR)、元素组成(EDS)等多种表征手段研究钝化剂的表观性质。结果表明:生物炭具有疏松多孔的结构特征和较大的BET比表面积(达146.83 m2·g-1),且含有较多的羧基等含氧官能团,这种官能团能与镉形成络合物而使得重金属有效态降低。田间试验结果表明,各处理均可升高土壤pH和降低土壤镉的有效性,其中,生物炭处理降低土壤有效态镉含量的效果最好,降低幅度达41.53%,其次为粉煤灰和磷矿粉,有效态镉含量分别降低了27.92%和25.97%。在降低土壤有效镉含量方面,钝化剂与叶面硅肥配施的处理与钝化剂单施的处理无显著差异。此外,各处理均降低了水稻籽粒中镉的含量,其中生物炭与叶面硅肥配施的处理降低籽粒镉含量的能力最强,降低幅度达17.59%。在水稻产量的方面,除了单施生物炭处理,单施磷矿粉和粉煤灰处理均不能提高产量,钝化剂与叶面硅肥配施的处理均能显著提高产量。研究表明,生物炭与叶面硅肥配施能同时显著降低土壤中有效态镉含量和水稻籽粒镉含量,并具有显著的增产作用。
Field experiments were conducted to investigate the effects of three amendments(fly ash, phosphate rock, and biochar)combined with foliar silicon fertilizer on the available Cd content in soil and Cd uptake by rice grain, as well as rice growth. BET surface area,scanning electron microscope(SEM), fourier transform infrared spectroscopy(FTIR), and energy dispersive spectrometer(EDS)were employed to characterize the textural properties of three immobilizing agents. The combination of characterization techniques showed that the biochar had loose and porous structure with larger BET surface area(146.83 m2·g-1)and higher amount of oxygen-containing functional groups, such as carboxyl group, which can reduce the available Cd content by forming a complex with Cd. In comparison with those of the control treatment, all treatments increased the pH values and reduced the available Cd content in soil. The treatment with biochar resulted in the highest reduction in available Cd content, which was 41.53%, followed by the single use of fly ash and phosphate rock with the reduction of 27.92% and 25.97%, respectively. Additional spraying of foliar silicon fertilizer did not affect the available Cd content evidently,which maybe because foliar silicon fertilizer was applied by foliar spraying and silicon precipitated with heavy metal mainly in rice. All treatments reduced the Cd content in rice grains, in which the combination of biochar and foliar silicon fertilizer had the highest efficiency with 17.59% reduction compared with that of the control. Furthermore, only biochar increased rice yield in terms of single use of amendments, whereas, biochar combined with foliar silicon fertilizer exhibited a better effect on rice growth. It is concluded that biochar combined with foliar silicon fertilizer can simultaneously reduce the available Cd content in soil and Cd content in rice grains, as well as increase rice yield, presenting a good prospect of application.
作者
陈思慧
张亚平
李飞
沈凯
岳修鹏
CHEN Si-hui;ZHANG Ya-ping;LI Fei;SHEN Kai;YUE Xiu-peng(Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education,School of Energy and Environment,Southeast Univer?sity,Nanjing 210096,China)
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2019年第3期563-572,共10页
Journal of Agro-Environment Science
基金
国家重点研发计划项目(2018YFD0800304)
省土地开发整理财政专项资金项目(苏财建【2015】447号)
关键词
钝化剂
农艺措施
土壤修复
镉
水稻
amendments
agronomic measure
soil remediation
Cd
paddy rice
