关键词: 泡沫混凝土;泡沫掺量;孔结构;铅离子;吸附机理

Abstract: The foamed concrete was prepared by using compressed air foaming method with P · O 42.5 Portland cement as the main raw material.The foamed concrete pore structure under different foam content was observed and characterized by stereomicroscope.The adsorption of Pb2+ on foamed concrete was studied based on different pore structures.The results show that when the amount of foam is 3.77％ -5.28％,the roundness increases with the increase of foam content,the average chord length and the pore spacing coefficient increase with the increase of the foam content,the pore content of less than 0.2 mm is gradually reduced,the pore content of 0.2 mm to 2 mm is increased,and the pore content of 2 mm to 4 mm is significantly increased.The adsorption of Pb2+ on foamed concrete is in accordance with the Pseudo-first-order kinetic model,isothermal adsorption conforms to Langmuir adsorption isotherm,adsorbed Pb2+ via chemical adsorption.The adsorption capacity of Pb2+ in foam concrete is high,the adsorption rate is fast.It can be widely used in the adsorption of Pb2+.

Key words: foamed concrete;foam content;pore structure;Pb2+;adsorption mechanism