胶原纤维固化黑荆树单宁吸附Cr(VI)的研究

研究了胶原纤维固化黑荆树单宁对Cr(VI)的吸附.采用不同温度、pH值等条件进行吸附研究,并进一步探讨了固化黑荆树单宁的吸附动力学和吸附柱动力学及其吸附机理.结果表明,该材料对Cr(VI)的吸附平衡符合Freundlich方程,温度对吸附平衡的影响不明显;吸附动力学可用拟二级速度方程来描述,该材料同时具有良好的柱动力学特性;Cr(VI)的吸附过程可能存在3个反应,即Cr(VI)与吸附剂之间发生氧化还原反应生成Cr(III),Cr(III)和-COOH之间发生离子交换反应,以及Cr(III)与单宁的邻位羟基发生螯合.图8表2参10

Adsorption of Cr (VI) by Collagen Fibre Immobilized Black Wattle Tannin

The adsorption of Cr (VI) by collagen fibre immobilized black wattle tannin, as well as the adsorption kinetics, column adsorption kinetics of Cr (VI) and adsorption mechanism were studied under different temperatures and pH values. The results showed that adsorption isotherms of Cr (VI) by immobilized black wattle tannin Cr (VI)could be described by the Freundlich model and the effect of temperature on adsorption isotherms was unobvious. About 30 percent of Cr (VI) in treated solution was reduced into Cr (III) by the adsorbent. The adsorption rate could be well fitted by pseudo-second-order rate model. The collagen fibre immobilized black wattle tannin possessed excellent properties of column adsorption kinetics. The adsorption mechanism probably included three reaction steps: redox between Cr (VI) and adsorbent, ion exchange between Cr (III) and -COOH, and chelation between Cr (III) and the adjacent hydroxylphenyl groups in the immobilized black wattle tannin. Fig 8, Tab 2, Ref 10