3种单一及其混合碳源的生物反硝化脱氮效能

分别以乙酸钠、乙醇、葡萄糖及其两两混合物作为外碳源,对生活废水进行生物反硝化研究。结果表明,不同碳源系统均出现了NO2^--N的短时间积累,与单一碳源系统相比,对应混合碳源系统NO2^--N最大积累量较低。从培养初始至120 min时,随培养时间增加,单一和混合碳源系统中NO3^--N含量均大幅降低,乙酸钠、乙醇、葡萄糖、乙酸钠+乙醇、乙醇+葡萄糖、乙酸钠+葡萄糖系统的平均反硝化速率分别为6.9、5.1、4.3、7.2、5.7、6.0 mg/(g·h),至120 min时,各系统NO3^--N去除率分别为100%、77.8%、64.8%、100%、78.4%、85.1%。乙酸钠、乙酸钠+乙醇、乙酸钠+葡萄糖系统NO3^--N去除率分别在120、120、210 min时达到100%。从脱氮效果、碳源成本、环境风险角度,乙酸钠+.葡萄糖更适合作为工程应用上的外碳源。

Biological Denitrification Efficiency of Three Single and Mixed Carbon Sources

The biological denitrification of wastewater was studied by using sodium acetate,ethanol,glucose and their mixture as external carbon sources.The results showed that the short-term accumulation of NO2^--N has appeared in different carbon source systems.Compared with the single carbon source system,the maximum accumulation of NO2^--N in the corresponding mixed carbon source system were lower.From the initial culture to 120 min,with the increase of culture time,the content of NO3^--N in single and mixed carbon source systems decreased significantly.The average denitrification rates of sodium acetate,ethanol,glucose,sodium acctate+ethanol,ethanol+glucose,sodium acetate+glucose systems were 6.9,5.1,4.3,7.2,5.7,6.0 mg/(g·h)respectively.By 120 min,the removal rates of NO3^--N by each system were 100%,77.8%,64.8%,100%,78.4%and 85.1%,respectively.The removal rate of NO3^--N in sodium acetate,sodium acetate+ethanol,sodium acetate+glucose system reached 100%at 120,120,210 min respectively.From the perspective of denitrification effect,carbon source cost,environmental risk,sodium acetate+glucose is more suitable as an additional carbon source for engineering applications.