College of Resources and Environment, Chengdu University of Information Technology, Chengdu, Sichuan, 610225, China,
Appl Microbiol Biotechnol. 2014;98(14):6431-41. doi: 10.1007/s00253-014-5681-z. Epub 2014 May 10.
This paper focuses on the effectiveness of removing Pb(II) from aqueous solution using bioflocculant MBFR10543 and a series of experimental parameters including MBFR10543 dose, calcium ions concentration, solution pH, and temperature on Pb(II) uptake was evaluated. Meanwhile, the flocculation mechanism of MBFR10543 was discussed. Results have demonstrated that the removal efficiency of Pb(II) reached 94.7 % (with the sorption capacity of 81.2 mg · g(-1)) by adding MBFR10543 in two stages, separately, 3 × 10(-2) % (w/w) in the 1.0 min's rapid mixing (180 rpm) and 4 × 10(-2) % (w/w) after 2.0 min's slow mixing (80 rpm) with pH value fixed at 6. Pb(II) flocculation process could be described by the Langmuir isotherms model and pseudo-second-order kinetic model. The negative Gibbs free energy change indicated the spontaneous nature of the flocculation. Fourier transform infrared spectra analysis indicated that functional groups, such as -OH, C=O, and C-N, were existed in MBFR10543 molecular chains, which had strong capacity for removing Pb(II). Furthermore, both charge neutralization and bridging being the main mechanisms involved in Pb(II) removal by MBFR10543.
本文主要研究了利用生物絮凝剂 MBFR10543 从水溶液中去除 Pb(II)的效果，并评估了一系列实验参数，包括 MBFR10543 剂量、钙离子浓度、溶液 pH 值和温度对 Pb(II)吸附的影响。同时，探讨了 MBFR10543 的絮凝机理。结果表明，分两步添加 MBFR10543 可将 Pb(II)的去除率达到 94.7%（吸附容量为 81.2mg·g(-1)），其中在 1.0min 的快速混合（180rpm）中添加 3×10(-2) %（w/w），在 2.0min 的慢速混合（80rpm）中添加 4×10(-2) %（w/w），pH 值固定在 6。Pb(II)絮凝过程可用 Langmuir 等温线模型和准二级动力学模型来描述。负的吉布斯自由能变化表明了絮凝过程的自发性。傅里叶变换红外光谱分析表明，MBFR10543 分子链上存在-OH、C=O 和 C-N 等官能团，对去除 Pb(II)具有很强的能力。此外，电荷中和和桥联是 MBFR10543 去除 Pb(II)的主要机制。
