Department of Civil Engineering, New Mexico State University, Las Cruces, NM 88003, United States.
Department of Civil Engineering, New Mexico State University, Las Cruces, NM 88003, United States.
Water Res. 2021 Feb 15;190:116753. doi: 10.1016/j.watres.2020.116753. Epub 2020 Dec 14.
Reusing produced water (PW) as the subsequent hydraulic fracturing fluid is currently the most economical and dominant practice in the shale oil and gas industry. However, high Ca present in PW needs to be removed prior to reuse to minimize the potential for well clogging and formation damage. In this study, the microbially induced calcite precipitation (MICP), as an emerging biomineralization technique mediated by ureolytic bacteria, was employed to remove Ca and toxic contaminants from hypersaline PW for the first time. Batch and continuous studies demonstrated the feasibility of MICP for Ca removal from hypersaline PW under low urea and nutrient conditions. Throughout the continuous biofiltration operation with biochar as the media, high removal efficiencies of Ca (96%), organic contaminants (100%), and heavy metals (~100% for As, Cd, Mn and Ni, 92.2% for Ba, 94.2% for Sr) were achieved when PW co-treated with synthetic domestic wastewater (SDW) under the condition of PW:SDW = 1:1 & urea 4 g/L. Metagenomic sequencing analysis showed that a stable ureolytic bacterial consortium (containing Sporosarcina and Arthrobacter at the genus level) was constructed in the continuous biofiltration system under hypersaline conditions, which may play a crucial role during the biomineralization process. Moreover, the combination of the MICP and ammonium recovery could significantly reduce the acute toxicity of PW towards Vibrio fischeri by 72%. This research provides a novel insight into the biomineralization of Ca and heavy metals from hypersaline PW through the MICP technique. Considering the low cost and excellent treatment performance, the proposed process has the potential to be used for both hydraulic fracturing reuse and desalination pretreatment on a large scale.
将产出水（PW）再利用作为后续水力压裂液是目前页岩油和天然气行业中最经济和主要的做法。然而，PW 中存在的高浓度 Ca 需要在再利用之前去除，以最大限度地减少潜在的堵塞和地层损害。在这项研究中，微生物诱导碳酸钙沉淀（MICP）作为一种由脲酶细菌介导的新兴生物矿化技术，首次被用于去除高盐 PW 中的 Ca 和有毒污染物。批处理和连续研究表明，在低尿素和营养条件下，MICP 可用于从高盐 PW 中去除 Ca。在以生物炭为介质的连续生物过滤操作中，当 PW 与合成生活污水（SDW）以 PW:SDW=1:1 的比例共处理并添加 4 g/L 尿素时，可实现高达 96%的 Ca 去除率（96%）、有机污染物去除率（100%）和重金属去除率（As、Cd、Mn 和 Ni 去除率为 100%，Ba 去除率为 92.2%，Sr 去除率为 94.2%）。宏基因组测序分析表明，在高盐条件下的连续生物过滤系统中构建了稳定的脲酶细菌共生体（属水平上含有 Sporosarcina 和 Arthrobacter），这可能在生物矿化过程中发挥关键作用。此外，MICP 与氨氮回收的结合可使 PW 对发光菌 Vibrio fischeri 的急性毒性降低 72%。这项研究为通过 MICP 技术从高盐 PW 中生物矿化 Ca 和重金属提供了新的见解。考虑到低成本和优异的处理性能，该工艺有望大规模应用于水力压裂再利用和海水淡化预处理。
