Nitrogen reduction by aerobic denitrifying fungi isolated from reservoirs using biodegradation materials for electron donor: Capability and adaptability in the lower C/N raw water treatment

• Published in: The Science of the total environment 2023-03, Vol.864, p.161064-161064, Article 161064
• Main Authors: Zhang, Haihan, Li, Haiyun, Ma, Manli, Ma, Ben, Liu, Hanyan, Niu, Limin, Zhao, Daijuan, Ni, Tongchao, Yang, Wanqiu, Yang, Yansong
• Format: Article
• Language: English
• Subjects: Aerobic denitrification; Aerobiosis; Biodegradable; Denitrification; Electrons; Fungi; Micro-polluted water treatment; Nitrates; Nitrogen; Nitrogen balance; Polyesters; Water Purification - methods
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2022.161064

Biological denitrification was considered an efficient and environmentally friendly way to remove the nitrogen in the water body. However, biological denitrification showed poor nitrogen removal performance due to the lack of electron donors in the low C/N water. In this study, three novel aerobic denitrifying fungi (Trichoderma sp., Penicillium sp., and Fusarium sp.) were isolated and enhanced the performance of aerobic denitrification of fungi in low C/N water bodies combined with polylactic acid/polybutylene adipate-co-terephthalate (PLA/PBAT). In this work, the aerobic denitrifying fungi seed were added to denitrifying liquid medium and mixed with PLA/PBAT. The result showed that Trichoderma sp., Penicillium sp., and Fusarium sp. could reduce 89.93 %, 89.20 %, and 87.76 % nitrate. Meanwhile, the nitrate removal efficiency adding PLA/PBAT exceeded 1.40, 1.68, and 1.46 times that of none. The results of material characterization suggested that aerobic denitrifying fungi have different abilities to secrete proteases or lipases to catalyze ester bonds in PLA/PBAT and utilize it as nutrients in denitrification, especially in Penicillium brasiliensis D6. Besides, the electron transport system activity and the intracellular ATP concentration were increased significantly after adding PLA/PBAT, especially in Penicillium brasiliensis D6. Finally, the highest removal efficiency of total nitrogen in landscape water by fungi combined with PLA/PBAT was >80 %. The findings of this work provide new insight into the possibility of nitrogen removal by fungi in low C/N and the recycling of degradable resources. [Display omitted] •Three novel aerobic denitrifying fungi were isolated from low C/N water.•The NO3−-N and DOC reduction was higher than 87 % and 90 % by fungi.•Biodegradable material was hydrolysed into monomers as nutrition by fungi.•Biodegradable material promoted growth and activities of fungi.•The total nitrogen reduction of fungi in landscape water exceeded 80 %.