Phosphorus recovery by Donnan dialysis: Membrane selectivity, diffusion coefficients, and speciation effects
Phosphorus recovery by Donnan dialysis: Membrane selectivity, diffusion coefficients, and speciation effects
复制标题
唐南透析磷回收：膜选择性、扩散系数和形态效应
DOI：
10.1016/j.cej.2021.129626
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发表时间：
2021
影响因子：
15.1
通讯作者：
Blaney, Lee
中科院分区：
文献类型：
--
作者：
Shashvatt, Utsav;Amurrio, Fabian;Portner, Charles;Blaney, Lee
当离子交换膜两侧的离子存在电化学电位梯度时，发生唐南透析。我们认为，可以利用这一现象来开发一种可持续的工艺，从废水中回收养分。在这项工作中，我们进行了一项基础研究的关键参数，控制正磷酸盐（P（V））的去除和恢复唐南透析。首先，建立了一个新变量，即汲取液和废液之间的最小汲取离子浓度比（Rd/w），作为Donnan透析的主要设计参数。然后，以下变量进行了评估，其对P（V）的去除和回收的影响：废液成分;绘制阴离子类型和浓度;和，膜的选择性，厚度，和水合作用。废液的pH值控制了P（V）对阴离子交换膜的吸附，HPO 42-表现出比H2 PO 4-更高的亲和力。对于Rd/w为10，分别使用100 mN和218 mN NaCl汲取溶液从10 mM P（V）废液中去除90.7%的H2 PO 4-和98.4%的HPO 42-。P（V）去除效率取决于汲取溶液浓度，48（Rd/w= 2）、115（Rd/w= 5）和218 mM（Rd/w= 10）NaCl汲取溶液分别实现77.1%、95.3%和98.4%的HPO 42 −去除。使用HCOO−汲取阴离子的P（V）回收率比使用Cl−的快，这是由于（i）与Cl−（1.27）相比，P（V）对HCOO−（7.28）的分离因子更高，以及（ii）HCOO−汲取溶液的膜水合程度更大。总体而言，本工作建立了一个新的设计参数（Rd/w），并将该参数应用于通过唐南透析优化磷回收的汲取溶液化学。
Donnan dialysis occurs when an electrochemical potential gradient exists for ions on either side of an ion-exchange membrane. We posit that this phenomenon can be leveraged to develop a sustainable process for nutrient recovery from wastewater. In this work, we conducted a fundamental study of the key parameters that control orthophosphate (P(V)) removal and recovery by Donnan dialysis. First, a new variable, namely the minimum draw ion concentration ratio between the draw and waste solutions (Rd/w), was established as the principal design parameter for Donnan dialysis. Then, the following variables were evaluated for their effects on P(V) removal and recovery: waste solution composition; draw anion type and concentration; and, membrane selectivity, thickness, and hydration. The waste solution pH controlled P(V) sorption to the anion-exchange membrane, with HPO42−exhibiting a higher affinity than H2PO4−. For an Rd/wof 10, 90.7% of H2PO4−and 98.4% of HPO42−were removed from a 10 mM P(V) waste solution using 100 mN and 218 mN NaCl draw solutions, respectively. The P(V) removal efficiency was dependent on draw solution concentration, and 77.1%, 95.3%, and 98.4% HPO42−removal was achieved with 48 (Rd/w= 2), 115 (Rd/w= 5), and 218 mM (Rd/w= 10) NaCl draw solutions, respectively. The rate of P(V) recovery was faster with HCOO−draw anions than with Cl−due to (i) the higher separation factor for P(V) over HCOO−(7.28) compared to Cl−(1.27) and (ii) the greater extent of membrane hydration with HCOO−draw solutions. Overall, this work established a new design parameter (Rd/w) and applied that parameter to optimize the draw solution chemistry for phosphorus recovery by Donnan dialysis.