Adsorption of recalcitrant phosphorus compounds using the phosphate-selective binding-protein PstS
Adsorption of recalcitrant phosphorus compounds using the phosphate-selective binding-protein PstS
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使用磷酸盐选择性结合蛋白 PstS 吸附顽固的磷化合物
DOI：
10.1016/j.chemosphere.2022.135311
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发表时间：
2022
期刊：
影响因子：
8.8
通讯作者：
Mayer, Brooke K.
中科院分区：
文献类型：
--
作者：
Mallick, Synthia P.;Hussein, Faten B.;Husted, Shayla;Mayer, Brooke K.
目前已有的废水磷(P)处理技术针对的是活性磷的去除，选择性吸附更难降解的可溶性非活性磷(SNRP)可以提高磷的去除和回收。将磷酸盐选择性磷酸结合蛋白(PBP)PstS固定在NHS活化的珠子上，以评估这种新型生物吸附剂去除(吸附)和随后恢复(解吸)一系列sNRP化合物的能力。本研究选取了四种代表废水sNRP的sNRP化合物：植酸(PA)、三磷酸钠(Trp)、β-甘油磷酸(BGP)和六偏磷酸钠(HMP)。使用PBP，所有sNRP化合物的吸附都是热力学上有利的。与PBP的典型靶标正磷酸盐相比，PBP对PA的结合亲和力几乎相同，尽管它与其他sNRP化合物的亲和力较低。吸附遵循准二级反应动力学，95%的最大吸附发生在4min内。与文献中的其他吸附剂相比，这大大加快了sNRP的吸附速度。吸附用朗缪尔等温式模拟，反映一个磷酸盐分子结合在一个PBP结合位上。值得注意的是，这种选择性的1：1附着导致了高P含量的sNRP分子的较高的总P去除。随着pH的升高，结合部位失去活性，因此，在pH为12时达到最大解吸率，使系统易于去除sNRP并可控制回收。
Currently available wastewater phosphorus (P) treatment technologies target removal of reactive forms of P. Selective adsorption of more recalcitrant soluble non-reactive phosphorus (sNRP) can improve P removal and recovery. A phosphate-selective phosphate-binding protein (PBP), PstS, was immobilized onto NHS-activated beads to assess the ability of this novel bioadsorbent to remove (adsorb) and subsequently recover (desorb) a range of sNRP compounds. Four sNRP compounds representative of wastewater sNRP were selected for use in this study: phytic acid (PA), sodium triphosphate (TrP), beta-glycerol phosphate (BGP), and sodium hexametaphosphate (HMP). Using PBP, adsorption of all sNRP compounds was thermodynamically favorable. The PBP had nearly equivalent binding affinity for PA compared to PBP's typical target, orthophosphate, although it had less affinity for the other sNRP compounds. Adsorption followed pseudo-second order reaction kinetics, with 95% of maximum adsorption occurring within 4 min. This was substantially faster sNRP adsorption compared to other adsorbents in the literature. Adsorption was modeled using the Langmuir isotherm, reflecting that one phosphate molecule attached to one PBP binding site. Notably, this selective 1:1 attachment resulted in higher total P removal for sNRP molecules with high P content. The binding site lost activity with increasing pH, and as such, highest desorption was achieved at pH 12, making the system amenable to sNRP removal as well as controlled recovery.