氧纳米气泡改性活性炭在河道底泥氨氮治理中的应用

Application of Oxygen Nanobubble Modified Activated Carbon in Treatment of Ammonia Nitrogen in River Sediment

氧纳米气泡改性颗粒物被广泛应用于对污染水体的界面增氧。为研究其对底泥-水界面增氧效果和底泥氨氮污染的修复能力,以活性炭作为负载材料制备氧纳米气泡,采用柱芯培养实验研究氧纳米气泡改性活性炭对河道底泥氨氮去除效果。结果表明:氧纳米气泡改性活性炭的加入将沉积物-水界面(sediment-water interface,SWI)的溶解氧(dissolved oxygen,DO)浓度由0.48 mg/L增加至6.10 mg/L,氧化还原电位(oxidation-reducation potential,ORP)由-34 mV增加至19 mV。利用薄膜梯度扩散技术监测实验期间SWI处氨氮和硝态氮的垂直浓度,上覆水中氨氮的浓度由1.65 mg/L降至0.54 mg/L,去除率为67.3%。沉积物中氨氮浓度由2.75 mg/L降至0.73 mg/L,去除率为37.5%。氨氮的释放通量降低了82.0%。氧纳米气泡改性活性炭既通过界面增氧促进硝化反应,降低了水体中氨氮浓度,也作为覆盖层隔绝沉积物中氨氮与上覆水的接触,降低沉积物中氨氮的释放。研究结果可为覆盖技术和曝气技术联合应用于削减河道底泥氮负荷提供基础数据支持。

Oxygen nanobubble modified particles are widely used to increase oxygen at the sediment interface with polluted water bodies.In order to study its ability to aerate sediment interface and to remediate ammonia pollution,activated carbon was used as a supporting material to prepare oxygen nanobubble,and a column core culture experiment was used to study the effect of oxygen nanobubble modified activated carbon on the removal of ammonia nitrogen in river sediments.Results show that the addition of oxygen nanobubble modified activated carbon to the sediment-water interface(SWI)increase its dissolved oxygen(DO)concentration increased from 0.48 mg/L to 6.10 mg/L,and its oxidation-reduction potential(ORP)increase from 34 mV to 19 mV.During the experiment,the diffusion gradients in thin-films technology was used to monitor the vertical concentration of ammonia nitrogen and nitrate at SWI.The addition of oxygen nanobubble modified activated carbon reduce the concentration of ammonia nitrogen in the overlying water from 1.65 mg/L to 0.54 mg/L,removing 67.3%.The concentration of ammonia nitrogen in the sediment is reduced from 2.75 mg/L to 0.73 mg/L,and the removal rate is 37.5%.The flux of ammonia nitrogen is reduced by 82.0%.Oxygen nanobubble modified activated carbon to promote the nitration reaction by the interfacial both oxygen,reducing the concentration of ammonia water,but also as a contact layer insulating cover overlying sediments with ammonia water,sediments reduce the release of ammonia.The combined application of overlay technology and interface oxygen nanobubble aeration technology,the research results can provide basic data support for reducing the ammonia nitrogen load in the river.