Department of Chemical and Biomolecular Engineering, University of Houston, Houston, Texas 77204-4004, United States.
Shell Exploration and Production Company, Houston, Texas 77079, United States.
ACS Appl Mater Interfaces. 2020 Dec 9;12(49):55434-55443. doi: 10.1021/acsami.0c16653. Epub 2020 Nov 24.
Barium sulfate (barite) scale poses significant challenges for processes ranging from water treatment to fossil fuel production. Here, we identify alginate (a polysaccharide derived from brown algae) as a potent, "green" alternative to commercial barite demineralizing agents. Unlike conventional treatments of inorganic scales that require caustic conditions, alginate polymers dissolve barite at near-neutral conditions. In this study, we benchmark the demineralizing efficacy of alginate against a commercial dissolver, diethylenetriaminepentaacetic acid (DTPA), using a combination of bulk dissolution assays, scanning probe microscopy, and molecular dynamics simulations. Time-resolved rates of dissolution measured in a microfluidic device show that demineralization is enhanced more than an order of magnitude under flow. In situ atomic force microscopy reveals that alginate and DTPA exhibit distinct mechanisms of surface dissolution; and surprisingly, their binary combination in alkaline media results in a synergistic cooperativity that enhances the overall rate of barite dissolution. These studies collectively demonstrate a unique approach to demineralization using an inexpensive and abundant biopolymer that enables environmentally friendly treatment of inorganic scales.
硫酸钡（重晶石）结垢给从水处理到化石燃料生产等一系列过程带来了重大挑战。在这里，我们发现褐藻胶（一种源自褐藻的多糖）是一种有潜力的、“绿色”的商业重晶石脱矿剂替代品。与需要强碱条件的传统无机结垢处理方法不同，褐藻酸盐聚合物在近中性条件下溶解重晶石。在这项研究中，我们使用批量溶解实验、扫描探针显微镜和分子动力学模拟，将褐藻酸盐的脱矿效率与商业溶解剂二乙烯三胺五乙酸（DTPA）进行了基准比较。在微流控装置中测量的溶解时间分辨速率表明，在流动条件下，脱矿效率增强了一个数量级以上。原位原子力显微镜揭示了褐藻酸盐和 DTPA 表现出不同的表面溶解机制；令人惊讶的是，它们在碱性介质中的二元组合导致协同协同作用，从而提高了重晶石的整体溶解速率。这些研究共同证明了一种使用廉价且丰富的生物聚合物进行脱矿的独特方法，从而实现了对无机结垢的环保处理。
