一株高耐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最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出一株异养硝化-好氧反硝化细菌Acinetobacter junii YQ-1，并探究了菌株YQ-1的生长性能和脱氮性能。结果表明，当温度为30℃、转速为200 rpm、初始pH为8.0、接种量为2%（V/V）时，培养时间为48 h，菌株YQ-1具有最高的菌体密度（OD595=0.999），且氨氮浓度1000 mg/L时，菌株YQ-1仍有较好的生长，菌株YQ-1生长情况符合BidoseResp模型，培养基中COD变化情况符合ExpDec2模型，培养基中COD的减少速率与菌株YQ-1的生长速率呈正相关关系。在最佳生长条件下，菌株YQ-1的脱氮性能为：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的对这三种氮素形式的降解率分别达到89.7%、63.5%和70.2%。本项目对YQ-1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:

Nitrification-denitrification biological denitrification is currently considered to be one of the most effective technologies for ammonia nitrogen wastewater, and the key to this is the screening of high-efficiency denitrification microorganisms. In this study, a heterotrophic nitrification-aerobic denitrification bacterium, named as 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°C, with a rotation speed of 200 rpm, initial pH of 8.0, and an inoculum size of 2%（V/V） after 48 hours of cultivation. Strain YQ-1 exhibited good growth even when the ammonia nitrogen concentration was 1000 mg/L, and its growth conformed to the BidoseResp model. Changes in 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. Under optimal growth conditions, the denitrification performance of strain YQ-1 was as follows: with initial concentrations of ammonia nitrogen, nitrite nitrogen, and nitrate nitrogen are all at 200 mg/L, strain YQ-1 degraded these three forms of nitrogen by 89.7%, 63.5%, and 70.2% within 48 hours. This study on YQ-1 provides a reference for the practical application of heterotrophic nitrification-aerobic denitrification bacteria in processing high-concentration ammonia nitrogen wastewater.