Ali Jafar, Yang Yuesuo, Pan Gang
Key Lab of Groundwater Resources and Environment (Jilin University), Ministry of Education, Changchun 130021, China; Jilin Provincial Key Laboratory of Water Resources and Environment, Jilin University, Changchun 130021, China; College of New Energy and Environment, Jilin University, Changchun 130021, China.
Centre of Integrated Water-Energy-Food Studies, School of Animal, Rural and Environmental Sciences, Nottingham Trent University, Brackenhurst Campus, Southwell, NG25 0QF, United Kingdom; Jiangsu Jiuguan Institute of Environment and Resources, Yixing, China.
J Environ Manage. 2023 Apr 1;331:117281. doi: 10.1016/j.jenvman.2023.117281. Epub 2023 Jan 23.
Sediment hypoxia is a growing problem and has negative ecological impacts on the aquatic ecosystem. Hypoxia can disturb the biodiversity and biogeochemical cycles of both phosphorus (P) and nitrogen (N) in water columns and sediments. Anthropogenic eutrophication and internal nutrient release from lakebed sediment accelerate hypoxia to form a dead zone. Thus, sediment hypoxia mitigation is necessary for ecological restoration and sustainable development. Conventional aeration practices to control sediment hypoxia, are not effective due to high cost, sediment disturbance and less sustainability. Owing to high solubility and stability, micro-nanobubbles (MNBs) offer several advantages over conventional water and wastewater treatment practices. Clay loaded oxygen micro-nanobubbles (OMNBs) can be delivered into deep water sediment by gravity and settling. Nanobubble technology provides a promising route for cost-effective oxygen delivery in large natural water systems. OMNBs also have the immense potential to manipulate biochemical pathways and microbial processes for remediating sediment pollution in natural waters. This review article aims to analyze recent trends employing OMNBs loaded materials to mitigate sediment hypoxia and subsequent pollution. The first part of the review highlights various minerals/materials used for the delivery of OMNBs into benthic sediments of freshwater bodies. Release of OMNBs at hypoxic sediment water interphase (SWI) can provide significant dissolved oxygen (DO) to remediate hypoxia induced sediment pollution Second part of the manuscript unveils the impacts of OMNBs on sediment pollutants (e.g., methylmercury, arsenic, and greenhouse gases) remediation and microbial processes for improved biogeochemical cycles. The review article will facilitate environmental engineers and ecologists to control sediment pollution along with ecological restoration.
沉积物缺氧是一个日益严重的问题，对水生生态系统具有负面生态影响。缺氧会扰乱水柱和沉积物中磷（P）和氮（N）的生物多样性和生物地球化学循环。人为富营养化和湖床沉积物内部养分释放加速了缺氧，形成了死区。因此，减轻沉积物缺氧对于生态恢复和可持续发展是必要的。传统的曝气方法来控制沉积物缺氧，由于成本高、沉积物扰动和可持续性差而无效。由于微纳米气泡（MNBs）具有高溶解性和稳定性，与传统的水和废水处理方法相比具有几个优点。负载粘土的氧微纳米气泡（OMNBs）可以通过重力和沉降输送到深水沉积物中。纳米气泡技术为在大型天然水系统中经济高效地输送氧气提供了一条有前途的途径。OMNBs在操纵生化途径和微生物过程以修复天然水体中的沉积物污染方面也具有巨大潜力。这篇综述文章旨在分析使用负载OMNBs的材料减轻沉积物缺氧及后续污染的最新趋势。综述的第一部分重点介绍了用于将OMNBs输送到淡水水体底栖沉积物中的各种矿物质/材料。在缺氧沉积物水界面（SWI）释放OMNBs可以提供大量溶解氧（DO），以修复缺氧引起的沉积物污染。手稿的第二部分揭示了OMNBs对沉积物污染物（如甲基汞、砷和温室气体）修复以及改善生物地球化学循环的微生物过程的影响。这篇综述文章将有助于环境工程师和生态学家控制沉积物污染并进行生态恢复。
