硝酸盐型厌氧亚铁氧化反应优化试验研究

Study on optimization of nitrate-dependent anaerobic ferrous oxidation

硝酸盐型厌氧亚铁氧化(NAFO)作为一种新发现的生物反硝化过程,可以在缺乏有机碳源的污水中有效地去除硝酸盐,具有良好的工程应用前景。为了降低反应的启动成本并提高处理效率,选择了厌氧池专用污泥和厌氧颗粒污泥对NAFO工艺的运行效果进行对比评估。构建了两个相同反应条件的CSTR反应器且连续运行了56 d。随后在对比运行实验的基础上研究了硝酸盐处理效果的影响因素,采用优势性能的厌氧颗粒污泥进行单因素实验,分别考察初始无机碳源与硝酸盐比值(IC/N)、初始亚铁与硝酸盐比值(Fe/N)和初始pH对硝酸盐去除性能的影响。结果表明:两个反应器在运行14 d后的硝酸盐处理效率稳定达到80%以上,其中投加厌氧颗粒污泥的反应器表现出较高的性能,硝酸盐平均及最高去除效率分别达到了79.4%和92.9%,硝酸盐平均去除速率为0.045 kg-N/(m^(3)·d);当选择厌氧颗粒污泥作为种子污泥进行反应时,在初始进水的IC/N为12.68、Fe/N为3.82以及pH为6.46的条件下,NAFO工艺处理硝酸盐的效果最佳。

Nitrate-dependent anaerobic ferrous oxidation(NAFO)is a newly discovered biological denitrification process that can effectively remove nitrate from wastewater lacking organic carbon source and has a good development prospect in practical engineering applications.In order to reduce the start-up cost of the reaction and improve the treatment efficiency,the special sludge for anaerobic tank and anaerobic granular sludge were selected to compare and evaluate the operation effect of the NAFO process.Two CSTR reactors with the same reaction conditions were constructed and were operated continuously for 56 days.Then,on the basis of comparative operation experiments,the influencing factors of the nitrate treatment effect were studied.The anaerobic granular sludge with superior performance was used for single factor experiments to investigate the effects of the initial inorganic carbon source to nitrate ratio(IC/N),the initial ferrous to nitrate ratio(Fe/N)and the initial pH on nitrate removal performance.The results showed that the nitrate treatment efficiency of the two reactors reached more than 80%after 14 days of operation,and the reactor with anaerobic granular sludge showed higher performance,with the average and maximum nitrate removal efficiency of 79.4%and 92.9%,respectively,and the average nitrate removal rate of 0.045 kg-N/(m^(3)·d);When anaerobic granular sludge was used as seed sludge for reaction,the NAFO process had the best effect on nitrate treatment under the conditions of IC/N of 12.68,Fe/N of 3.82,and pH of 6.46 for the initial influent.