Influence of solution environment on hydrophobic effect in process of NOM adsorption at nano- Fe2O3/water interface
溶液环境对纳米Fe2O3/水界面NOM吸附过程中疏水效应的影响

Regarding the interaction between humic acid and Fe2O3 nanoparticles,the hydrophobic effect and the law about how the hydrophobic changes with the solution environment in the process of the humic acid’s adsorption are discussed with infrared spectroscopy and thermo-gravimetric analysis methods.The results shows that,when the ionic strength is 0,0.005,0.01 and 0.05 mol/kg and pH value changes from 7~12,the thermal weight loss of the complex decreases initially and then increases during adsorption.Meanwhile,the hydrophilic capacity reduces and hydrophobic enhances when the pH increases from 7~10,and shows opposite trends completely when the pH changes from 10~12.When the ionic strength is 0.001 mol/kg,and pH value changes from 7~12,the thermal weight loss of the complex decreases,which means the hydrophilic reduces and hydrophobic enhances.When the pH value is constant and the intensity of ionic changes,the thermal weight loss of the complex keeps changing and the hydrophilic and hydrophobic change alternately.The infrared spectroscopy results indicate that hydrophilic hydroxyl—OH,carbonyl CO and the hydrophobic alkane CH2 may play a major role in the hydrophilic and hydrophobic of the HA-Fe2O3 complex.