摘要
为探究长期反硝化过程中复合释碳填料释碳能力及脱氮效能的提高途径,采用机械粉碎(JX)、机械粉碎+碱处理(JJ)、机械粉碎+生物处理(JS)3种方法对玉米芯进行预处理后作为填料核心基材,掺杂海绵铁提高复合释碳填料释放电子供体能力,生成的Fe^(2+)、Fe^(3+)充当碳源-微生物-硝酸盐之间的电子转移中间体,聚乙烯醇作为粘结剂将其与海绵铁粘结,制备了JX、JJ和JS 3种生物膜载体复合释碳填料。研究3种填料的释碳性能及静态反硝化特性。结果表明:3种填料在60 d内的静态释碳过程可分3个阶段,释碳累积量为JJ填料(116.139 mg·g^(−1))>JX填料(93.200 mg·g^(−1))>JS填料(78.079 mg·g^(−1)),二次污染物TN释放量接近于0 mg·(g·d)^(−1);采用准二级动力学拟合释碳过程,JJ填料的C_(m)、t_(1/2)值最大,具有较好的释碳能力和稳定的释放速率,Ritger-Peppas方程拟合结果为3种填料N<0.45,释放机制均为扩散;3种填料释放出的可溶荧光性有机物均为酪氨酸/色氨酸、酪氨酸/色氨酸蛋白类物质,易被生物降解,机械粉碎+碱处理后的玉米芯结构使碳源的释放更加多而稳定,且适合微生物附着生长;3种填料静态反硝化稳定期,对TN的去除率均能达到90%以上,JJ填料组对TN的去除率最高达97.3%,JX、JJ、JS填料在10~45 d反硝化过程中COD平均值分别为15.412、29.690、19.877 mg·L^(−1),JJ填料组对COD理论利用率稳定在90.34%。研究结果表明,玉米芯经机械粉碎+1%NaOH碱处理与海绵铁、聚乙烯醇复合后,更适合作为长期反硝化复合释碳填料。
In order to explore the ways to improve the carbon-releasing and denitrifying performance of composite carbon-releasing fillers during the long-term denitrification process,three methods of mechanical pulverization(JX),mechanical pulverization+alkali treatment(JJ),and mechanical pulverization+biological treatment(JS)were used to treat corncob.After pretreatment,it was used as the core substrate of the filler,and sponge iron was added to improve the electron donors release ability of the composite carbon-releasing filler.The generated Fe^(2+)and Fe^(3+)acted as electron transfer intermediates between carbon source,microorganisms and nitrate,and polyvinyl alcohol was used as binder for the adhension of the core substrate and sponge iron.Three kinds of biofilm carrier composite decarburization fillers,JX,JJ and JS filler,were prepared.Their release performance and static denitrification characteristics were studied.The results showed that the 60 d static carbon release process of the three fillers was divided into three stages,and the accumulation amount of carbon release was JJ filler(116.139 mg·L^(−1))>JX filler(93.200 mg·L^(−1))>JS filler(78.079 mg·L^(−1)),and the secondary pollutant TN release was close to 0.Pseudo-second-order kinetics were used to fit the carbon release process.JJ filler had the largest C_(m) and t_(1/2) values,and better carbon release ability and stable release rate.The fitting result of Ritger-Peppas equation was following:N values of 3 kinds of fillers were lower than 0.45,and their release mechanisms were diffusion.The soluble fluorescent organic matter released from the three fillers were tyrosine/tryptophan amino acid and tyrosine/tryptophan protein,which were easily biodegradable,and the structure of corncob after mechanical crushing+alkali treatment made carbon source release more abundant and stable,which was suitable for microbial attachment and growth.In the static denitrification process of the three fillers,TN removal rate was higher than 90%during the stabilization period,and the highest TN removal rate of 97.3%was achieved by the JJ filler group.The average COD concentrations of JX,JJ and JS fillers in the 10-45 d denitrification experiments were 15.412,29.690 and 19.877 mg·L^(−1),respectively.The theoretical utilization rate of COD in JJ filler group was stable at 90.34%.In conclusion,the results showed that corncob was suitable for long-term denitrification composite carbon release filler after mechanical crushing+1%NaOH alkali treatment and compounding with sponge iron and polyvinyl alcohol.
作者
李鹏程
王宝山
许亚兵
汪光宗
张继成
张洋
LI Pengcheng;WANG Baoshan;XU Yabing;WANG guangzong;ZHANG Jicheng;ZHANG Yang(School of Environmental and Municipal Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China;Key Laboratory of Yellow River Water Environment in Gansu Province,Lanzhou 730070,China)
出处
《环境工程学报》
CAS
CSCD
北大核心
2022年第10期3291-3301,F0002,共12页
Chinese Journal of Environmental Engineering
基金
国家自然科学基金资助项目(51368029)
甘肃省2020年度重点人才项目(2020RCXM082)。
关键词
反硝化
复合释碳填料
玉米芯
脱氮效能
动力学
denitrification
composite carbon release filler
corncob
denitrification efficiency
kinetics
