【摘要】 我国华北地区超过80%的地下水受到污染,其中硝酸盐氮的污染日益严重,威胁着人类健康。基于单质铁去除地下水中硝酸盐氮,因伴随氨氮的产生而受限制;生物反硝化脱氮因地下水中碳源不足无法满足脱氮要求。采用自制的微电解化学催化固体颗粒与天然生物质构成耦合生物载体,通过自养与异养反硝化耦合深度脱除地下水中硝酸盐氮,并建立了地下水易位好氧、厌氧深度脱氮新工艺。结果表明:好氧反应器在HRT为12 h、DO为2.0～3.0 mg·L-1的条件下,硝酸盐氮平均去除率≥91.24%;厌氧反应器在HRT为14 h的条件下,硝酸盐氮平均去除率≥96.32%;反应器中微电解化学催化固体颗粒可为自养反硝化菌提供电子,生物质可为微生物提供必要的有限碳源,硝酸盐氮的脱除是自制微电解化学催化固体颗粒与生物膜耦合作用的结果。出水均无亚硝酸盐氮和氨氮积累。此技术可为受污染地下水的修复提供理论依据。更多还原

【Abstract】 Currently, there is over 80% contaminated groundwater in north China. Among various pollutants, nitrate has become more and more serious and threatened human health. Usually, the nitrate was removed by zero-valent iron reduction method with ammonia production, which could not be efficiently removed by the biological denitrification method due to insufficient carbon sources in groundwater. Thus, in this study, a novel self-made biofilm carrier,which combined micro-electrolysis chemistry-catalyzed granule with natural biomass loofah, was developed for deep N removal in groundwater through autotrophic and heterotrophic denitrification coupling process. Then a new process for deep N removal was put forward for ex-situ aerobic or anaerobic denitrification, and the corresponding mechanism was discussed. The results showed that the average nitrate removal rate was higher than 91.24% in aerobic reactor at hydraulic retention time(HRT) of 12 hours and dissolved oxygen(DO) of 2.0 to 3.0 mg·L-1. Then the average nitrate removal rate reached above 96.32% in anaerobic reactor at the HRT of 14 hours. Moreover, the coupling functions of micro-electrolysis chemistry-catalyzed granule and biofilm contributed to nitrate removal in groundwater.Micro-electrolysis chemistry-catalyzed granule provided electrons for autotrophic denitrifying bacteria in biofilm,and natural loofah provided necessary carbon source for microorganism. Miseq high-throughput also revealed the dominant genus related to denitrifying. In addition, the effluent of the treatment process had no nitrite and ammonia accumulation. This new technology may provide theoretical basis for contaminated groundwater restoration.更多还原