草酸作用下海洋疏浚物中Cr的释放动力学研究

采用恒温振荡实验装置,系统研究了有机酸草酸降解海洋疏浚物中重金属Cr的动力学过程。结果表明,恒温振荡6 h后,浓度为0.05~0.4 mol/L的草酸可使Cr的释放百分率达到24%~44%。Cr的释放总体上可分为快速反应和慢速反应2个阶段,0~2 h为快反应阶段,解吸速率快,2~6 h后为慢反应阶段。草酸对Cr的释放动力学数据可用双常数方程很好的拟合,说明在草酸的存在下,疏浚物颗粒表面对Cr的释放可能更多表现出能量的不均匀性。温度升高时Cr的解吸量增加,反应速度加快,根据阿累尼乌斯公式估算出的活化能为26.53 kJ/mol。

Study on the Release Kinetics of Cr From Marine Dredged Materials With Oxalate Acid

The kinetic release behavior of heavy metal Cr from marine dredged material with oxalate acid solution is investigated by isotherm shaking device.The results show that the release percentage of Cr from dredged material with 0.05～0.4 mol/L oxalate acid in six hours reaches 24%～44%.The kinetic characteristics of heavy metal Cr is divided into two stage reactions of rapid and low desorption.When using oxalate acid as extracting solution,the data of release kinetics of Cr from dredged material conforms to the double constant equation,it implies that organic acid induced the energy uniformity of the release of Cr from dredged material.The amount of desorption increases and velocity of desorption speeds up with the increase of temperature.The activation energy calculated according to Arrhenius equation should be 26.53 kJ/mol.