摘要
采用0.5mol·L-1NaHCO3(pH8.5),0.5mol·L-1NaH2PO4和0.1mol·L-1HCl等3种浸提剂,对福建省酸性水稻土和酸性菜地土壤有效砷的提取效果以及相关的提取条件进行了研究。结果表明,3种浸提剂所提取的土壤有效砷与作物可食用部分砷含量之间均存在显著相关,其中0.5mol·L-1NaH2PO4提取的有效砷与糙米和蔬菜地上部砷含量的相关性最高,相关系数分别是0.628和0.824,是三者中最佳的浸提剂。对NaH2PO4的提取条件的研究表明,在15∶1的液土比条件下以250r·min-1的速度振荡120min是最佳的酸性土壤有效砷的提取方法。
In order to choose a best extractant for predicting the availability of arsenic in acid soils, three extractants, 0.5 mol·L-1 NaHCO3 (pH8.5), 0.5 mol·L-1 NaH2PO4 and 0.1 mol·L-1 HCl, were compared by using some acid paddy soils and vegetable soils as well as the edible parts of rice and the vegetables grown in the soils collected from Fujian Province. The pH values of the soils ranged from 3.92 to 7.03. The best extraction conditions for the chosen extractant were also studied. The amounts of the available arsenic extracted by the three extractants decreased in the order of 0.1 mol·L-1 HCl>0.5 mol·L-1 NaH2PO4>0.5 mol·L-1 NaHCO3 (pH8.5). The available arsenic extracted by the three extractants all showed significant correlations with the arsenic content of the rice grains (air-dried basis) and the aboveground parts of the vegetables (fresh basis), indicating that all the extractants were good for predicting the availability of the soil arsenic. Among the three extractants, NaH2PO4 was best because the correlation was most significant between the available As extracted by it and As contents of both the rice grains and the aboveground parts of the vegetables, the correlation coefficients (r) being 0.628 and 0.824, respectively. The extracted arsenic of the soils rich in available arsenic by NaH2PO4 increased with increasing ratio of solution to soil until 15∶1, with increasing shaking time until 120 min, and with increasing shaking velocity until 250 r·min-1. The soils poor in available arsenic reached their maximal extracted amounts when the ratio of solution to soil was less than 2, the shaking time was less than 60 min, and the shaking velocity was less than 250 r·min-1. For ensuring the complete extraction from both the soils with higher and lower available As, the best extraction conditions by NaH2PO4 were 15∶1 of the ratio of solution to soil, 120 minutes of shaking time with the shaking velocity of 250 r·min-1.
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2005年第3期610-615,共6页
Journal of Agro-Environment Science
基金
福建省科技厅重点攻关项目(2003Y026)
关键词
酸性土壤
有效砷
浸提剂
浸提时间
液土比
振荡速度
acid soil
available arsenic
extractant
extraction time
ratio of solution to soil
shaking velocity
