塿土不同发生层铬(Ⅵ)吸附特性及还原容量研究

Absorption characters and reduction capacities of different Lu soil layers to Cr(Ⅵ)

研究了土娄土对Cr( )的吸附特性、影响因素及还原容量。结果表明:1土娄土不同土层对Cr( )的吸附量大小顺序为粘化层>犁底层+老耕层>耕层>钙积层;土壤对Cr( )的吸附量与土壤中Fe2O3、粘粒含量和pH有关;2土娄土中Cr( )被吸附的主要形态是HCrO4-;3土壤对Cr( )的等温吸附可以用Langmuir模型和Freundlich模型较好描述。根据Langmuir模型求得土娄土粘化层对Cr( )的最大吸附量最高,为228.3μg/g;4土娄土各土层的测定还原容量在9323～17318mg/kg之间,与土壤有机质有关;土娄土各土层对Cr( )的有效(条件)还原容量只有其测定还原容量的1/1844-1/3586。

Absorption characters and affecting factors and reduction capacities of Lu soil to Cr(Ⅵ) were studied. The results showed that: ①The absorption amount of different soil layers to Cr(Ⅵ) were in an order of argillic layer> plow pan>top soil>calcic layer. The absorption amount of Lu soil to Cr(Ⅵ) had relations with contents of physical clay、Fe_2O_3 and pH value. ② Absorption of Lu soil to Cr(Ⅵ) was in the form of HCrO_4^-. ③ Langmuir and Freundlich equation were suitable to describe isotherm absorption of Cr(Ⅵ). The maximum absorption of argillic soil layer calculated by Langmuir equation was 228.3 μg/g, the highest among those of all layer. ④ Measured reduction capacities of different soil layers were 9 323~17 318 mg/kg, which was related to contents of organic matters. Available (conditional) reduction capacities of Lu soil to Cr(Ⅵ) amounted to 1/1844-1/3586 of measured reduction capacities.