基于生物滴滤氨氮硝化的猪场沼液控氨固氮运行参数优化OA

To address the nitrogen loss caused by ammonia volatilization during the storage and land application of biogas slurry from swine farm,a bio-trickling filter reactor equipped with micro-foam packing was designed in this study.Sequential batch single-factor experiments were conducted to investigate the effects of key parameters,inclu-ding circulating water flow,packing height,and influent ammonia nitrogen(NH4+-N)concentration,on the ammo-nia nitrogen nitrification efficiency of biogas slurry.The results indicated that under ambient temperature conditions,the reactor exhibited excellent nitrification performance when the circulating water flow was 2.0-3.0 L·min-1,the packing height was 90 cm,and the influent NH4+-N concentration ranged from 80 to 100 mg·L-1.The maximum 24 h NH4+-N conversion rate reached 86.6%,the total nitrogen(TN)loss rate was 6.5%-13.8%,and the ratio of nitrate nitrogen(NO3--N)production to NH4+-N conversion[Δ(NO3--N)/Δ(NH4+-N)]in effluent was as high as 0.90 or above.Microbial community analysis of the reaction processes with different influent NH4+-N concentra-tions revealed that the dominant bacterial phylum in the packing biofilm was Proteobacteria,with a relative abun-dance exceeding 85%.This phylum showed higher relative abundance when the influent NH4+-N concentration was 125-150 mg·L-1,indicating its major role in the nitrification process.However,excessively high influent NH4+-N concentrations exerted inhibitory effect on the dominant bacterial communities in the biofilm.