Both the elemental sulfur-based autotrophic denitrification (ESAD) and the biomass‑sulfur-based mixotrophic (simultaneous autotrophic and heterotrophic) denitrification processes (BSMD) are efficient methods for removing nitrate from wastewater. However, a comparative analysis of the denitrification capacity of the BSMD and ESAD in the packed bed reactors is still lacking. In this paper, corncob powder was selected as the biomass source to prepare biomass‑sulfur-based composite filter (BSCF) for the BSMD process. The denitrification performances of the three identical lab-scale bioreactors packed with varying elemental sulfur-based composite filters (ESCFs) were compared under varying loading conditions, and the optimal ESCF of the ESAD system was 2:1 by weight ratio of sulfur powder to shell powder. In pilot-scale experiments, the results showed that BSCF could decrease the sulfate productivity and gave better denitrification performance than the ESCF with the optimal nitrate removal rate (NRR) of 504 ± 12.3 mg NO₃⁻-N·L⁻¹·d⁻¹. In addition, the two-stage flushing strategy (for the removal of aged sludge) can effectively improve the denitrification capacity, while the denitrification will be inhibited when the influent dissolved oxygen concentration was higher than 4.5 mg L⁻¹. Moreover, the heterotrophs and autotrophs were abundant in the reactors. Over time, the abundance of autotrophs increased while that of heterotrophs decreased. Overall, BSCF could be a promising and economic technology to improve the effluent quality.

基于元素硫的自养反硝化（ESAD）和基于生物质硫的混合营养（同时自养和异养）反硝化工艺（BSMD）都是去除废水中硝酸盐的有效方法。然而，目前还缺乏对填充床反应器中BSMD和ESAD反硝化能力的比较分析。本文以玉米芯粉为生物质源制备生物质硫基复合过滤器（BSCF），用于BSMD工艺。比较了三个相同的实验室规模生物反应器在不同负载条件下填充不同元素硫基复合过滤器 (ESCF) 的反硝化性能，ESAD 系统的最佳 ESCF 为硫粉与壳的重量比为 2:1粉末。在中试规模实验中，₃ ^- -N·L ^-1 ·d ^-1。此外，两级冲洗策略（去除老化污泥）可以有效提高反硝化能力，而当进水溶解氧浓度高于4.5 mg L ^-1时反硝化会受到抑制。此外，反应堆中的异养生物和自养生物丰富。随着时间的推移，自养生物的丰度增加，而异养生物的丰度减少。总体而言，BSCF 可能是一种有前景的经济技术，可改善出水水质。