一株耐高氨氮菌株的筛选及脱氮性能研究

Screening and Denitrification Performance of a Highly Ammonia Nitrogen-Tolerant Strain

关键词:  氨氮  生物脱氮  硝化-反硝化  Acinetobacter junii  降解性能

Key words:  ammonia nitrogen  biological denitrification  nitrification-denitrification  Acinetobacter junii  degradation performance

摘要:

硝化-反硝化生物脱氮被认为是目前有效的氨氮废水处理技术之一，其关键是高效脱氮微生物的筛选。本研究从养猪厂污水处理池中筛选异养硝化-好氧反硝化细菌，并探究其生长性能和脱氮性能。结果筛选出一株异养硝化-好氧反硝化细菌Acinetobacter junii YQ-1，当温度为30 ℃、转速为200 r/min、初始pH值为8、接种量为2.0%(V/V)、培养时间为48 h时，菌株YQ-1具有最高的菌体密度(OD₅₉₅=0.999)，且脱氮效果最好。在最佳生长条件下，当初始氨氮浓度、亚硝态氮和硝态氮浓度均为200 mg/L时，菌株YQ-1在48 h对这3种形式氮素的降解率分别达到89.73%、63.51%和70.19%。且当氨氮浓度为1 000 mg/L时，菌株YQ-1仍能较好地生长，其生长情况符合BidoseResp模型，培养基中 化学需氧量(Chemical Oxygen Demand,COD)变化情况符合ExpDec2模型，培养基中化学需氧量(Chemical Oxygen Demand,COD)的减少速率与菌株YQ-1的生长速率呈正相关关系。本研究为异养硝化-好氧反硝化菌处理高浓度氨氮污水的实际应用提供了参考。

Abstract:

Biological nitrogen removal by nitrification and denitrification is considered as one of the effective technologies of ammonia nitrogen-containing wastewater treatment,the key of which is the screening of efficient denitrifying microorganisms.In this study,a heterotrophic nitrifying-aerobic denitrifying bacterial strain,named Acinetobacter junii YQ-1,was isolated from a swine wastewater treatment pond,and the growth performance and denitrification capability of strain YQ-1 were investigated.The results showed that the highest cell density (OD₅₉₅=0.999) was achieved at 30 ℃ after 48 h of cultivation with a rotation speed of 200 r/min,initial pH value 8,and an inoculum amount of 2.0%(V/V).Under the optimal growth conditions,strain YQ-1 showed the nitrogen removal rates of 89.73%,63.51%,and 70.19% within 48 h against ammonia nitrogen,nitrite nitrogen,and nitrate nitrogen at the initial concentration of 200 mg/L,respectively.Strain YQ-1 exhibited good growth even when the ammonia nitrogen concentration was 1 000 mg/L,with the growth fitting the BidoseResp model.The changes in Chemical Oxygen Demand (COD) in the culture medium followed the ExpDec2 model,and the rate of decrease in COD was positively correlated with the growth rate of YQ-1.This study provides a reference for the application of heterotrophic nitrifying-aerobic denitrifying bacteria in processing the wastewater containing high-concentration ammonia nitrogen.