制革固体废弃物的吸附特性

分别研究了含铬废革屑和含单宁废革屑对染料和金属离子的吸附特性.结果表明：含铬废革屑对酸性染料和直接染料具有较强的吸附能力，而对碱性染料的吸附能力较弱；含单宁废革屑对Au3+、U6+、Th4+及Hg2+具有较强的吸附能力.含铬废革屑对染料的吸附平衡符合Langmuir方程；含单宁废革屑对Cu2+、U6+、Pb2+和Hg2+的吸附平衡符合Freundlich方程，而对Au3+及Th4+的吸附平衡符合Langmuir方程，因此含单宁废革屑对不同的金属离子可能具有不同的吸附机理.含铬废革屑对染料的吸附动力学以及含单宁废革屑对金属离子的吸附动力学均符合拟二级速度方程.含铬废革屑固定床对染料具有良好的吸附特性，固定床易再生和重复使用.含单宁废革屑固定床对Au3+的吸附量很大，但不易再生；而吸附其他金属离子后则容易再生，而且其吸附性能变化不大.

ADSORPTION BEHAVIOR OF SOLID WASTE OF LEATHER MANUFACTURE

The adsorption behavior of chrome-containing and tannins-containing solid waste originated from leather manufacture was investigated. The experimental results indicated that the chrome-containing leather waste could substantially adsorb acid dyes and direct dyes.However it was ineffective for the adsorption of alkali dyes.The adsorption equilibrium of chrome-containing leather waste to acid dyes and direct dyes could be described by the Langmuir equation and the pseudo-second-order rate model gave perfect fitting to the adsorption kinetics.The tannins-containing leather waste exhibited high adsorption capacities to Au3+、U6+、Th4+ and Hg2+.However the adsorption equilibrium of metal ions on the tannins-containing leather waste could not be described by single equation.The adsorption equilibrium of Cu2+、U6+、Pb2+ and Hg2+ could be described by the Freundlich equation, while that of Au3+ and Th4+ could be described by the Langmuir equation.These facts implied that the different adsorption mechanisms might be involved in the adsorption processes of metal ions on the tannins-containing leather waste. The pseudo-second-order rate model also gave perfect fitting to the adsorption rate data of metal ions on the tannins-containing leather waste. The adsorption column of chrome-containing leather waste could be easily regenerated after adsorption of dyes. Similarly, the adsorption column of tannins-containing leather waste could be also easily regenerated after adsorption of metal ions except Au3+. The change of adsorption behavior of the regenerated columns was not considerable, which indicated the potential value of a using solid waste of leather processing in environmental protection.