Exploring the impact of visible light intensity on algae-bacterial symbiotic system treating aniline wastewater: Performance, microbial community and metabolic pathways

• Published in: Journal of water process engineering Vol. 68; p. 106415
• Main Authors: Chen, Jiajing, Zhang, Qian, Li, Meng, He, Jing, Lin, Bing, Wu, Nanping, Liu, Xunhao, Li, Siwei, Huang, Jialong, Dong, Xiaoqian, Wang, Hongyu
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.12.2024
• Subjects: Algae-bacteria symbiotic system; Aniline wastewater; Light intensity; Microbial community; Nitrogen removal; Algae-bacteria symbiotic system; Aniline wastewater; Nitrogen removal; Light intensity; Microbial community
• ISSN: 2214-7144; 2214-7144
• DOI: 10.1016/j.jwpe.2024.106415

Light intensity crucially modulated algae-bacteria interactions in ABSS (algae-bacteria symbiotic system), whereby its specific mechanisms under aniline stress remained unclear. Herein, experimental groups (S1, S2, S3) were established with light intensities of 30, 90, and 180 μmol/(m2·s) to treat 600 mg/L aniline wastewater, respectively. The degradation rates of aniline by all systems were above 99.9 %. Nonetheless, ammonia assimilation in S1 was suppressed and nitrification was hindered in S3. Due to the beneficial relationship between bacteria and algae, S2's total nitrogen removal rate of 65 % was higher than S1 and S3's by about 10 % and 7 %, separately. Light intensity would positively correlate with microalgal biomass, thereby resulting in elevated polysaccharide secretion levels. Furthermore, certain genera such as norank_f__Microscillaceae, g__Dokdonella and Dictyosphaerium that performed crucial tasks were enriched in S2. Moreover, S2 favored the expression of metabolic genes. This research enhanced understanding of ABSS under varying light intensities for aniline wastewater treatment. [Display omitted] •The optimal light intensity for nutrient removal by ABSS was determined.•Excessively high or low light intensity did not promote the elimination of NH4+-N.•High light intensity would quench polycarboxylic humic acid in EPS.•High light intensity (180 μmol/(m2·s)) changed the metabolic pathway of aniline.