摘要
缺氧是城市污染河流水质持续恶化的关键诱因。本研究利用醇-水替换法将氧纳米气泡负载到膨润土、凹凸棒石和白云母矿物表面开发了氧纳米气泡改性矿物材料,并在室内开展了城市污染河流沉积物柱芯增氧除磷试验研究。结果表明,投加氧纳米气泡改性矿物材料使沉积物-水界面溶解氧含量快速提升,最高达7.0 mg/L以上,沉积物表层1.0 cm转变为好氧状态。与对照组相比,实验组柱芯上覆水体总磷含量降低90%以上。沉积物-水界面溶解氧的提升提高了表层沉积物氧化还原电位,抑制硫酸盐还原和还原态S^(2-)的形成,增加了沉积物铁氧化物对磷酸盐的固持能力。16S rRNA分析表明,投加氧纳米气泡改性矿物材料抑制了Longilinea和Syntrophomonas在表层沉积物中的生长,促进了Thermomonas的富集,微生物群落的变化显示了底栖生物生存环境的改善。Acidovorax和Acinetobacter丰度增加也反映了增氧过程中,硝酸盐还原亚铁氧化菌和聚磷菌对磷下降的作用。氧纳米气泡改性矿物材料能快速提升沉积物-水界面含氧性,有效抑制沉积物磷的释放,在城市河流水质改善和内源污染原位控制方面具有良好的应用前景。
Hypoxia is a key triger of continuous deterioration of water quality in urban polluted rivers.In this study,oxygen nanobubbles were loaded onto the surface of Bentonite,Attapulgite and Muscovite minerals by alcohol-water substitution method to develop oxygen nanobubble modified mineral materials(ONBMMs),and the oxygenation and phosphorus removal efficiencies of ONBMMs were tested in the simulated urban polluted water-sediment core system.The results showed that the dissolved oxygen at the sediment-water interface increased rapidly with the addition of ONBMMs,up to more than 7.0 mg/L,and the surface layer of the sediment was about 1.0 cm into an aerobic state.Compared with the control group,the total phosphorus in the overlying water of the experimental group decreased by more than 90%.The increase of dissolved oxygen at the sediment-water interface increased the redox potential of surface sediments,inhibited sulfate reduction and the formation of reduced S^(2-),and increased the retention ability of iron oxides to phosphate.16S rRNA analysis showed that the addition of ONBMMs inhibited the growth of Longilinea and Syntrophomonas in surface sediments,but promoted the enrichment of Thermomonas.The change of microbial community showed the improved living environment of benthic organism.The increase in the abundance of Acidovorax and Acinetobacter also reflected the role of nitrate-reducing ferrous oxidizing bacteria and phosphorus accumulating bacteria in the decrease of phosphorus during the oxygenation process.ONBMMs can rapidly improve the oxygen level at the sediment-water interface and effectively inhibit the release of sediment phosphorus,which has a good application prospect in the improvement of urban river water quality and in-situ control of endogenos pollution.
作者
徐述
王敬富
杨永琼
杨海全
朱正杰
陈敬安
XU Shu;WANG Jingfu;YANG Yongqiong;YANG Haiquan;ZHU Zhengjie;CHEN Jingan(School of Geography and Environment,Guizhou Normal University;State Key Laboratory of Environmental Geochemistry,Institute of Geochemistry,Chinese Academy of Sciences;University of Chinese Academy of Sciences;Baise University)
出处
《地球与环境》
CAS
CSCD
北大核心
2024年第2期213-220,共8页
Earth and Environment
基金
贵州省科技计划项目([2020]4Y006)
中央引导地方科技发展资金项目(黔科中引地[2021]4028号)
广西一流学科农业资源与环境(DC2200000413)。
关键词
氧纳米气泡
沉积物-水界面
增氧
抑磷
城市污染河流
oxygen nanobubbles
sediment-water interface
oxygenation
phosphorus inhibition
urban polluted river
