Dynamic characteristics of microbial community and soluble microbial products in partial nitrification biofilm system developed from marine sediments treating high salinity wastewater

• Published in: Journal of environmental management 2021-07, Vol.290, p.112586-112586, Article 112586
• Main Authors: Han, Fei, Zhang, Mengru, Liu, Zhe, Shang, Hongguo, Li, Qian, Zhou, Weizhi
• Format: Article
• Language: English
• Subjects: High salt wastewater; Marine sediments; Microbial community; Partial nitrification; Soluble microbial products
• ISSN: 0301-4797; 1095-8630
• DOI: 10.1016/j.jenvman.2021.112586

High salinity wastewater generally resulted in microorganism death and low treatment efficiency of nutrient in conventional activity sludge system. Marine sediments, containing a huge amount of natural salt-tolerant microorganisms, provide a feasible option for the rapid construction of halophilic biological treatment system. However, the dynamic of native microorganisms and the fate of soluble microbial products (SMP) in halophilic biofilm system developed from marine sediments needs to be further studied. In this study, a partial nitrification system was successfully established by inoculation of marine sediments in sequential batch biofilm reactor. Satisfactory chemical oxygen demand (COD) and NH4+-N removal efficiency (95% and 99%) and nitrite accumulation rate (NAR) (>90%) was achieved for treatment of synthetic seawater blackwater. High cell surface hydrophobicity (CSH) and proteins to polysaccharide ratio of extracellular polymeric substance (EPS) were beneficial to the initial biofilm formation. High-throughput sequencing results revealed Nitrosomonas halophila was the sole ammonia oxidizing bacteria (AOB). Thauera and Paracoccus were the main denitrifying bacteria in three biofilm samples. Excitation emission matrix (EEM) spectroscopy coupled with parallel factor analysis (PARAFAC) clarified that proteins were significantly degraded than the other two components (humic-like and fulvic acid-like substance). This study will provide a feasible approach for developing halophilic biological treatment system and present an in-depth insight of the dynamic characteristics of SMP in partial nitrification biofilm system. [Display omitted] •Partial nitrification biofilm system was developed by inoculation of marine sediments.•NH4+-N and COD was almost completely removed from high salinity wastewater.•High CSH and protein/polysaccharide ratio promoted the initial formation of biofilm.•Nitrosomonas halophila was the solo Nitrosomonas species in biofilm samples.•Protein component in SMP was sharply decomposed in the anaerobic and aerobic phase.