开孔陶粒的制备与同步硝化/反硝化生物反应器的构建

Preparation of porous ceramsite and construction of simultaneous nitrification/denitrification bioreactor

为了在常规淡水养殖条件下实现同步硝化/反硝化(SND)脱氮,研究了自制陶粒组建SND生物反应器的脱氮能力。结果表明,在陶土中添加1.5%(质量分数)纸纤维,900℃烧蚀6h,可制得内部具有丰富开孔孔隙结构的多孔陶粒;利用该陶粒构建SND生物反应器,在常规淡水养殖条件下,可顺利启动SND反应,亚硝态氮在第2天时开始显著积累,氨氮质量浓度在第6天起即可从15mg/L降至检测限以下;开孔陶粒借助内部孔隙形成好氧/厌氧微环境,抑制亚硝酸盐氧化细菌(NOB)生长并促使氨氧化细菌(AOB)成为优势菌,同时陶粒对溶液中氨氮具有选择吸附能力,促进了SND生物反应器的脱氮作用。

To achieve simultaneous nitrification/denitrification(SND)denitrification under conventional freshwater aquaculture conditions,ceramic grains with open porous structure were prepared by ablation of paper fibers.SND bioreactor with porous ceramic grains was constructed to verify the nitrogen removal efficiency of the reactor.The results showed that porous ceramic grains with abundant pore structure could be prepared by ablation of ceramic soil with paper fiber 1.5%(mass fraction)calcinated at 900℃for 6 hours.The SND bioreactor was constructed with the ceramic grains,and the SND reaction could take place under the condition of conventional freshwater aquaculture in this reactor.The mass concentration of ammonia nitrogen in solution decreased from 15 mg/L to lower than detection limit on the 6th day.The concentration of nitrite nitrogen began to accumulate significantly on the 2nd day.The aerobic/anaerobic microenvironment formed by internal pore of ceramic grains was beneficial to inhibit the growth of nitrite-oxidizing bacteria(NOB)and promote ammonia-oxidizing bacteria(AOB)to become dominant bacteria.Ceramic grains could selectively adsorb ammonia nitrogen in solution and was beneficial to SND bioreaction.