氨基膦酸树脂对铅的吸附性能及机理

Adsorption behavior and mechanism of amino methylene phosphonic acid resin for Pb^(2+)

研究了Pb2 + 在氨基膦酸树脂上的吸附行为 ,结果表明 :树脂的静态饱和吸附容量为 82 2mg/ g ;用 0 .5mol/L的HCl和 0 .2～ 0 .3mol/L的EDTA洗脱 ,洗脱率分别为 97%和 99%以上。测得吸附热力学参数分别为 :ΔH =9.0 4kJ/mol,ΔG =- 3.99kJ/mol,ΔS =43.7J/ (mol·K)。等温吸附服从Freundlich经验式 ;表观活化能Ea=13.8kJ/mol;表观速率常数k2 98=2 .2 8× 10 -5s-1;树脂功能基与Pb2 + 的配位比为 2∶3。用化学和红外光谱的方法探讨了树脂对Pb2 + 的吸附机理。

The adsorption behavior of amino methylene phosphonic acid resin(APAR)for lead(Ⅱ) is investigated. Experimental results show that statically saturated adsorption capacity is 822?mg/g. Pb(Ⅱ) adsorbed on APAR can be eluted with 0.5?mol/L HCl and 0.2～0.3?mol/L EDTA. The elution percentages are 97% and over 99%, respectively. The adsorption parameters of thermodynamic are ΔH =9.04?kJ/mol, ΔG=-3.99?kJ/mol, ΔS=43.7?J/mol·K, respectively. The adsorption behavior of APAR for Pb 2+ obeys the Freundlich isotherm. The apparent activation energy is E a=13.8?kJ/mol. The apparent adsorption rate constant is k 298=2.28×10 -5?s -1. The coordination molar ratio of the functional group of APAR to Pb(Ⅱ) is 2∶3. The adsorption mechanism of resin for Pb 2+ is examined by chemical analysis and IR spectra.