Chemical Engineering Department, Amirkabir University of Technology, Tehran, Iran.
Colloids Surf B Biointerfaces. 2011 Nov 1;88(1):108-14. doi: 10.1016/j.colsurfb.2011.06.018. Epub 2011 Jun 21.
The importance of solute adsorption in the biofouling membrane has been clearly verified for the performance of membrane bioreactor (MBR). In order to quantify the mechanism of static adsorption in biofouling during of MBR process, we characterize membrane biofouling caused by model solutions containing a protein (bovine serum albumin, BSA), a humic substance (humic acid, HA) and a polysaccharide (alginic acid, Alg) on commercial hydrophilic polyethersulfone (PES) membrane. For static adsorption experiments, membranes were immersed in well-defined model solutions in three temperatures (298, 308 and 318 K) to obtain equilibrium data. To determine the characteristic parameters for this process, 7 isotherm models were applied to the experimental data. Three error analysis methods; the coefficient of nonlinear regression (R(2)), the sum of the squared errors (SSE) and standard deviation of residuals (S(yx)), were used to evaluate the data and determine the best fit isotherm for each model solutions. The error values demonstrated that the Sips isotherm model provided the best fit to the experimental data. AFM images were used for determination of changes in membrane surface after adsorption. These images confirmed the results obtained from adsorption isotherm study. Thermodynamic parameters such as standard free energy (Δ(r)G(θ)), enthalpy (Δ(r)H(θ)) and entropy (Δ(r)S(θ)) changes were determined; these adsorption processes were found to be feasible and endothermic but not spontaneous. The distribution of the substances adsorbed on PES surface were more chaotic than that in the aqueous solutions. Parameters obtained in this study can be used to determine the "fouling potential" of a given feed stream and a membrane.
在膜生物反应器（MBR）的性能中，已经清楚地验证了溶质吸附在生物污垢膜中的重要性。为了量化 MBR 过程中生物污垢中静态吸附的机制，我们对含有蛋白质（牛血清白蛋白，BSA）、腐殖质（腐殖酸，HA）和多糖（褐藻酸，Alg）的模型溶液引起的膜生物污垢进行了表征在商业亲水聚醚砜（PES）膜上。对于静态吸附实验，将膜在三个温度（298、308 和 318 K）下浸入明确定义的模型溶液中以获得平衡数据。为了确定该过程的特征参数，将 7 种等温线模型应用于实验数据。使用三种误差分析方法；非线性回归系数（R(2)）、平方和误差（SSE）和残差标准差（S(yx)），用于评估数据并确定每个模型溶液的最佳拟合等温线。误差值表明，Sips 等温线模型最适合实验数据。AFM 图像用于确定吸附后膜表面的变化。这些图像证实了吸附等温线研究的结果。确定了热力学参数，如标准自由能（Δ(r)G(θ)）、焓（Δ(r)H(θ)）和熵（Δ(r)S(θ)）变化；这些吸附过程是可行的、吸热的但不是自发的。吸附在 PES 表面的物质的分布比在水溶液中的分布更混乱。本研究中获得的参数可用于确定给定进料流和膜的“污垢潜力”。
