Department of Applied Chemistry, University of Johannesburg, South Africa.
Int J Biol Macromol. 2013 Nov;62:370-8. doi: 10.1016/j.ijbiomac.2013.09.023. Epub 2013 Sep 26.
This article reports the biosorption potential of Gum ghatti (Gg)-grafted-acrylic acid (AA) polymer and its susceptibility to biodegradation by Bacillus subtilis (BS) in two different liquid media, i.e. phosphate buffered saline (PBS) and mineral salt medium (MSM). The progress of biodegradation was monitored after every 15 days using FT-IR and SEM techniques. The degradation of the polymer was further evidenced by a loss of weight of 23.2% and 27% in BS-MSM and BS-PBS, respectively, after 60 days. The AA-grafted polymer was then utilized for the removal of Pb(II) and Cu(II) from aqueous solution. The adsorption isotherm data were studied using Langmuir, Freundlich, Temkin, Flory-Huggins and Dubinin-Kaganer-Radushkevich isothermal models. High values of correlation coefficients confirmed the applicability of Langmuir isotherm model used to determine the adsorption capacity of the AA-grafted polymer. The maximum adsorption capacity was found to be 84.74 mg/g for Cu(II) and 310.55 mg/g for Pb(II). Kinetic data were evaluated using pseudo first order, pseudo second order, Elovich, intraparticle diffusion and liquid film diffusion models. The experimental kinetic data fitted well with the pseudo second order rate model.
本文报道了 Gum ghatti（Gg）接枝丙烯酸（AA）聚合物的生物吸附潜力及其在两种不同液体介质中的生物降解性，即磷酸盐缓冲盐水（PBS）和无机盐培养基（MSM）。使用傅里叶变换红外光谱（FT-IR）和扫描电子显微镜（SEM）技术，每 15 天监测一次生物降解的进展。在 60 天后，BS-MSM 和 BS-PBS 中的聚合物分别损失了 23.2%和 27%的重量，进一步证明了聚合物的降解。然后，AA 接枝聚合物被用于从水溶液中去除 Pb（II）和 Cu（II）。使用 Langmuir、Freundlich、Temkin、Flory-Huggins 和 Dubinin-Kaganer-Radushkevich 等温模型研究了吸附等温线数据。高相关系数值证实了 Langmuir 等温模型适用于确定 AA 接枝聚合物的吸附容量。对于 Cu（II）和 Pb（II），最大吸附容量分别为 84.74 mg/g 和 310.55 mg/g。动力学数据通过拟一级、拟二级、Elovich、内扩散和液膜扩散模型进行评估。实验动力学数据与拟二级速率模型拟合良好。
