包埋硫铁生物填料的制备及自养反硝化性能

采用包埋固定化技术制备了包埋硫铁生物填料(ESI Filler),基于升流式自养反硝化反应器开展动态实验研究,通过改变水力停留时间(HRT)、pH值、溶解氧(DO)等运行条件,探究ESI Filler反应器的脱氮效果及微生物群落结构组成。结果表明,当进水硝酸盐氮(NO₃^--N)浓度为30mg/L,HRT为10h时,NO₃^--N去除率不断上升至99.80%。当HRT缩短为2.5h时,NO₃^--N去除率降至61.35%。ESI Filler反应器对pH值和DO的改变具有较高的稳定性,NO₃^--N平去除率可维持在82.5%以上。但对低温的耐受性较差,当温度从35℃降低至15℃时,NO₃^--N平均去除率由90.12%降低至68.80%。运行164d后,球体未出现破裂散落的现象,表现出较长的使用寿命。通过扫描电镜发现,填料表面疏松多孔,附着大量杆状细菌,已成为微生物的良好载体。高通量测序结果表明,包埋颗粒中优势菌属为典型的自养反硝化功能菌Thiobacillus,丰度为80.79%。

Preparation and autotrophic denitrification properties of embedded sulfur/iron biological filler

The embedded sulfur/iron biological filler (ESI Filler) was prepared by embedding and immobilization technology, and dynamic experimental research was carried out based on the upflow autotrophic denitrification reactor. By changing hydraulic retention time (HRT), pH, dissolved oxygen (DO) and other operating conditions, the denitrification performance and microbial community structure composition of ESI Filler reactor were explored. When the influent nitrate nitrogen (NO₃^--N) concentration was 30mg/L and the HRT was 10h, the NO₃^--N removal rate increased continuously to 99.80%. When the HRT was shortened to 2.5h, the removal rate of NO₃^--N decreased to about 61.35%. ESI Filler reactor had high stability to the changes of pH and DO, and the average removal rate of NO₃^--N could be maintained above 82.5%. However, the tolerance to low temperature was poor. When the temperature was reduced from 35℃ to 15℃, the average removal rate of NO₃^--N decreased from 90.12% to 68.80%. After running for 164days, the spheres did not break and scatter, showing a long service life. It was found by scanning electron microscopy that the surface of the filler was loose and porous, and a large number of rod-shaped bacteria were attached, which had become a good carrier of microorganisms. The results of high-throughput sequencing showed that the dominant bacterial genus in the embedded granules was the typical autotrophic denitrifying bacteria Thiobacillus, with an abundance of 80.79%.