Dahdal Y N, Pipich V, Rapaport H, Oren Y, Kasher R, Schwahn D
Zuckerberg Institute for Water Research, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev , Sede Boqer Campus, Beer-Sheva 8499000, Israel.
Langmuir. 2014 Dec 23;30(50):15072-82. doi: 10.1021/la502706k. Epub 2014 Dec 11.
Bovine serum albumin (BSA) coated on citrate capped gold nanoparticles (BSA-GNPs) was exposed to a simulated wastewater effluent (SSE) in order to study the mineralization and thereby mimic scaling at biofouled membranes of reverse osmosis (RO) wastewater desalination plants. RO is a leading technology of achieving freshwater quality as it has the capability of removing both dissolved inorganic salts and organic contaminants from tertiary wastewater effluents. The aim was to better understand one of the major problems facing this technology which is fouling of the membranes, mainly biofouling and scaling by calcium phosphate. The experiments were performed using the small-angle neutron scattering (SANS) technique. The nanoparticles, GNPs, stabilized by the citrate groups showed 30 Å large particles having a homogeneous distribution of gold and citrate with a gold volume fraction of the order of 1%. On the average two BSA monomers are grafted at 2.4 GNPs. The exposed BSA-GNPs to SSE solution led to immediate mineralization of stable composite particles of the order of 0.2 μm diameter and a mineral volume fraction between 50% and 80%. The volume fraction of the mineral was of the order of 10(-5), which is roughly 3 times larger but an order of magnitude smaller than the maximum possible contents of respectively calcium phosphate and calcium carbonate in the SSE solution. Considering the extreme low solubility product of calcium phosphate, we suggest total calcium phosphate and partially (5-10%) calcium carbonate formation in the presence of BSA-GNPs.
将包覆有牛血清白蛋白（BSA）的柠檬酸盐包覆金纳米颗粒（BSA-GNPs）暴露于模拟废水流出物（SSE）中，以研究矿化作用，从而模拟反渗透（RO）废水淡化厂生物污染膜上的结垢情况。RO是实现淡水水质的领先技术，因为它能够从三级废水流出物中去除溶解的无机盐和有机污染物。目的是更好地理解该技术面临的主要问题之一，即膜的污染，主要是生物污染和磷酸钙结垢。实验采用小角中子散射（SANS）技术进行。由柠檬酸盐基团稳定的纳米颗粒GNPs显示出直径为30 Å的大颗粒，金和柠檬酸盐分布均匀，金的体积分数约为1%。平均而言，两个BSA单体接枝在2.4个GNPs上。将BSA-GNPs暴露于SSE溶液中会导致直径约为0.2μm的稳定复合颗粒立即矿化，矿物体积分数在50%至80%之间。矿物质的体积分数约为10^(-5)，分别约为SSE溶液中磷酸钙和碳酸钙最大可能含量的3倍，但小一个数量级。考虑到磷酸钙极低的溶解度积，我们认为在BSA-GNPs存在的情况下会形成总磷酸钙和部分（5-10%）碳酸钙。
