Department of Chemistry, Bindura University of Science, P. Bag 1020, Bindura, Zimbabwe.
Environ Technol. 2010 Oct;31(11):1221-8. doi: 10.1080/09593331003646604.
The potential of Eichhornia crassipes biomass for the adsorption of three metal ions, Pb(II), Cd(II) and Zn(II), from aqueous solution was studied using five two-parameter adsorption isotherm equations--Langmuir, Freundlich, Flory-Huggins, Temkin and Redlich-Peterson isotherms. The equilibrium adsorption data were obtained at different initial metal ion concentrations (C0 = 10-60 mg/L), 3 h contact time, 30 degrees C temperature, a dosage of 2 g/L, agitation rate of 150 rpm and buffered at pH 4.84. Langmuir isotherms gave monolayer sorption capacities (qm) of 26.32, 12.60 and 12.55 mg/g for Pb(II), Cd(II) and Zn(II) metal ions, respectively. The same trend of metal uptake was indicated by plots of sorption favourability (S(F)). Negative values of deltaGads0 indicated that the adsorption was spontaneous and exothermic in nature, and values from the Temkin isotherm constant, bT, suggested a mechanism consistent with an ion-exchange process. The results from these studies indicated that E. crassipes biomass has promising potential for the removal of toxic metals from aquatic environments.
水葫芦生物质对水溶液中三种金属离子（Pb(II)、Cd(II)和 Zn(II)）的吸附潜力进行了研究，采用了五种双参数吸附等温线方程——朗缪尔、弗伦德利希、弗洛里-哈金斯、坦金和 Redlich-Peterson 等温线。在不同的初始金属离子浓度（C0=10-60mg/L）、3 小时接触时间、30°C 温度、2g/L 用量、150rpm 搅拌速度和 pH 值为 4.84 的缓冲条件下，获得了平衡吸附数据。朗缪尔等温线给出了 Pb(II)、Cd(II)和 Zn(II)金属离子的单层吸附容量（qm）分别为 26.32、12.60 和 12.55mg/g。吸附有利度（S(F)）的图表明了金属摄取的相同趋势。ΔGads0 的负值表明吸附是自发的和放热的，并且来自 Temkin 等温线常数 bT 的值表明了与离子交换过程一致的机制。这些研究结果表明，水葫芦生物质具有从水环境中去除有毒金属的巨大潜力。
