川西北沙化土壤对双酚A的吸附特征

研究了川西北地区4种受试土壤（PS：泥炭土壤，ND：未沙化土壤，LD：轻度沙化土壤，MD：中度沙化土壤）对双酚A（BPA）的吸附行为，探讨了土壤有机质（SOM）含量、土层深度和土壤团聚体对吸附作用的影响.结果表明：4种受试土壤对BPA的吸附过程符合双室一级动力学模型（R²≥0.98）.Freundlich和Langmuir模型吸附等温式可以较好地描述BPA的吸附行为（R²≥0.98），吸附表现出较强的非线性（N， 0.52~0.70）.沙化后，吸附非线性增强，饱和吸附量下降3.7~5.7倍.4种受试土壤的最大吸附量Q_m依次为：PS（8901mg/kg），ND（7011mg/kg），LD（1506mg/kg）和MD（1050mg/kg），Q_m与其SOM含量呈显著正相关（r > 0.999，P < 0.01）.土层深度增加BPA吸附性能下降，沙化后，下降幅度增大（MD > LD > ND > PS）.团聚体粒级增大，其吸附性能先增加后减小.沙化后，各粒级团聚体的吸附性能差异显著增大，吸附贡献率分布也不同.5种粒级的团聚体对未沙化土壤ND吸附BPA的贡献率基本相当，而沙化土壤LD和MD吸附BPA主要来自小团聚体（< 0.25、0.25~0.5mm）的贡献（86%~88%）.

The characteristic sorption of bisphenol A on sandy soil in northwest Sichuan

In this work, four different types of soils from Northwest of Sichuan were collected to study the influences of soil organic matter (SOM), depth of soil and the soil agglomerates structure on the sorption of biphenol A (BPA) on these materials which were peat soil (PS), non-sandified soil (ND), lightly sandified soil (LD), middle level sandified soil (MD) respectively. The study showed that the sorption kinetics of biphenol A on all four types of soils was fitted well with two-compartment first order kinetic model (R²≥0.98). And their sorption isotherms were fitted satisfactorily with both Freundlich and Langmuir models (R²≥0.98). The results revealed an obvious non-linearity sorption process (N, 0.52~0.70). When the soil was sandified, the degree of non-linear sorption increased, and the maximum sorption were dropped 3.5~5.7 times. The maximum sorption capacity (Q_m) of BPA on the four studied soils were 8901(PS), 7011(ND), 1506 (LD) and 1050 mg/kg (MD), respectively. The coefficient of correlation between Q_m and SOM in the soils samples was remarkably high (r > 0.999, P < 0.01). As the soil goes depth, the Q_m decreased remarkably in following order:MD > LD > ND > PS. With the increase of agglomeration of soil, the sorption capacity increased first, then decreased. The sandification made the sorption capacity remarkably different, therefore the contribution in sorption process varies greatly. The sorption contribution level of BPA was basically the same with five different sizes of agglomerates of non-sandified soil, whereas for the sandified soils LD and MD, the sorption of BPA was mainly contributed by the smaller agglomerates, with a 86%~88% contribution.