铁铝复合氧化物对两种细菌的吸附作用研究

铁铝氧化物是土壤的重要组分之一,其对土壤中有机无机组分的迁移具有重要影响.本文以枯草芽孢杆菌和荧光假单胞菌为研究对象,通过批吸附实验和DLVO理论,探究铁铝复合氧化物对细菌的粘附作用及其作用机制.结果表明,铁铝复合氧化物对细菌的粘附随着平衡浓度的增加而增加,吸附过程可用Langmuir方程拟合.铁铝1∶3复合氧化物对枯草芽孢杆菌和荧光假单胞菌的最大吸附量分别为3717.43和2792.29 mg·g~(-1),铁铝3∶1复合氧化物对枯草芽孢杆菌和荧光假单胞菌的最大吸附量分别为3455.58和2760.33 mg·g~(-1).随着pH值的增大,两种铁铝复合氧化物对两种细菌的吸附量均呈下降趋势.铁铝1∶3复合氧化物对两种细菌的吸附量均大于铁铝3∶1复合氧化物.静电吸引力是铁铝复合氧化物与细菌之间相互作用的主要因素之一.

Study on the adsorption of Bacillus subtilis and Pseudomonas fluorescens on iron-aluminum composite oxides

Iron (Fe) and aluminum (Al) oxides are important components of soil, playing a crucial role in controlling the migration of organic and inorganic components in soil. In this study, batch adsorption experiment and DLVO theory were employed to examine the adhesion characteristics and mechanism of Bacillus subtilis and Pseudomonas fluorescens on Fe-Al composite oxides. The results show that bacterial adhesion on Fe-Al composite oxides increased with increasing equilibrium concentration. The bacterial adsorption process could be fitted by the Langmuir equation. The maximum adsorption capacity of B. subtilis and P. fluorescens on Fe:Al 1:3 composite oxide was 3717.43 and 2792.29 mg·g^-1, while that on Fe:Al 3:1 composite oxide was 3455.58 and 2760.33 mg·g^-1, respectively. Furthermore, the bacterial adsorption on the two Fe-Al composite oxides is weakened with increasing solution pH, and the adsorption capacity of both the bacteria was higher on Fe:Al 1:3 oxide than that on Fe-Al 3:1 oxide. Electrostatic attraction was noted to be one of the main factors responsible for bacterial adhesion on Fe-Al composite oxides.