碱性生物炭强化脱氮效能及定向调控机制

Enhanced Nitrogen Removal Efficiency of Alkaline Biochar and Its Targeted Regulatory Mechanism

生物脱氮是污水处理厂氮污染物去除的主流方法,具有低碳、低成本的优势。面向城市污水为代表的低碳氮比废水,如何强化反硝化功能菌群、稳定生物脱氮效能仍有待研究。该研究以玉米秸秆为原料,通过酸、碱改性制备2种强化脱氮功能生物炭载体,构建强化反硝化脱氮工艺。研究结果表明:与未投加生物炭的系统相比,投加生物炭后系统总氮去除率提高了7.29%~29.51%。经过酸、碱改性生物炭定向强化脱氮效能分析,较未改性生物炭系统总氮去除率分别提高19.37%和29.55%,其中碱改性生物炭系统总氮去除率最高可达59.76%。在电子转移活性和亚硝酸盐还原酶活性方面,碱改性生物炭强化系统较未投加生物炭系统分别提高了91.8%和47.1%。高通量测序结果表明碱改性生物炭中参与反硝化作用相关菌群占比约为67.3%,具有反硝作用的芽孢杆菌属(Bacillus)、陶厄氏菌属(Thauera)为碱改性生物炭系统的优势菌属,碱改性生物炭比酸改性生物炭更能促进脱氮菌群的生长,从而构建反硝化脱氮能力定向调控。

Biological nitrogen removal is the main method of nitrogen pollution removal in sewage treatment plants.It has the advantages of low carbon and low cost.For the low carbon nitrogen ratio wastewater represented by municipal sewage,how to strengthen the denitrification functional flora and stabilize the biological nitrogen removal efficiency remains to be studied.In this study,two kinds of biochar carriers with enhanced nitrogen removal function were prepared by acid and alkali modification.And the enhanced denitrification nitrogen removal process was established.The research results showed that the total nitrogen removal rate of the system after adding biochar was increased by 7.29%~29.51%compared with the system without adding biochar.The nitrogen removal efficiency of acid and alkali modified biochar was improved by 19.37%and 29.55%,respectively,compared with that of the unmodified biochar system.The maximum nitrogen removal rate of alkali modified biochar system was 59.76%.In terms of electron transfer activity and nitrite reductase activity,the alkali-modified biochar enhanced system increased by 91.8%and 47.1%,respectively,compared with the non-added biochar system.At the same time,the high-throughput sequencing results showed that 67.3%of the bacteria involved in denitrification in the alkali-modified biochar system.Bacillus and Thauera with denitrification were the dominant strains in the alkali-modified biochar system.The alkali-modified biochar promoted the growth of denitrifying bacteria more than the acid-modified biochar.Therefore,the target regulation of denitrification and nitrogen removal ability was established.