Performance, microbial community and fluorescent characteristic of microbial products in a solid-phase denitrification biofilm reactor for WWTP effluent treatment

Abstract

Microbial products, i.e. extracellular polymeric substance (EPS) and soluble microbial product (SMP), have a significant correlation with microbial activity of biologically based systems. In present study, the spectral characteristics of two kinds of microbial products were comprehensively evaluated in a solid-phase denitrification biofilm reactor for WWTP effluent treatment by using poly (butylene succinate) (PBS) as carbon source. After the achievement of PBS-biofilm, nitrate and total nitrogen removal efficiencies were high of 97.39 ± 1.24% and 96.38 ± 1.1%, respectively. The contents of protein and polysaccharide were changed different degrees in both LB-EPS and TB-EPS. Excitation-emission matrix (EEM) implied that protein-like substances played a significant role in the formation of PBS-biofilm. High-throughput sequencing result implied that the proportion of denitrifying bacteria, including Simplicispira, Dechloromonas, Diaphorobacter, Desulfovibrio, increased to 9.2%, 7.4%, 4.8% and 3.6% in PBS-biofilm system, respectively. According to EEM-PARAFAC, two components were identified from SMP samples, including protein-like substances for component 1 and humic-like and fulvic acid-like substances for component 2, respectively. Moreover, the fluorescent scores of two components expressed significant different trends to reaction time. Gas chromatography-mass spectrometer (GC-MS) implied that some new organic matters were produced in the effluent of SP-DBR due to biopolymer degradation and denitrification processes. The results could provide a new insight about the formation and stability of solid-phase denitrification PBS-biofilm via the point of microbial products.

Sustainable Plant Growth Promotion and Chemical Composition of Pyroligneous Acid When Applied with Biochar as a Soil Amendment

“…E x /E m = 230 nm/350 nm indicated the presence of a protein [ 28 , 29 ], likely a protein rich in tryptophan [ 30 , 31 ].…”

Pilot study on the filling rate of parallel AA‐MBBR fillers in plateau areas

“…Actinobacteria Actinobacteria includes some of the most common soil, freshwater and marine organisms that play important roles in the decomposition of organic substances (e.g., cellulose and xylan), thus in organic material turnover and carbon cycle. 29 Firmicutes can survive in certain extreme environments, and some species in the genus Firmicutes have heterotrophic nitrification, and in Li Yingying et al 30 Have shown that Firmicutes has some denitrification capacity. The relative abundance of Firmicutes was highest when the filling rate was increased to 40%, probably due to excessive discharge of excess sludge, resulting in selective enrichment of the microorganisms.…”

Influence mechanisms of macro‐infrastructure on micro‐environments in the recirculating aquaculture system and biofloc technology system

“…Decreasing HRT can increase the particle removal rate in the culture tank 38 and prevent water quality that compromises farmed animals' performance and welfare, 39 but it also increases the energy costs of the overall system. On the other hand, long HRT (2–24 h) can increase the nitrate‐N removal rate in bioreactor because it provides enough time for denitrification and thus significantly decrease the accumulation of nitrite 40,41 . However, it decreases the hydraulic load of the systems and reduces the sewage treatment capacity 42,43 .…”

“…On the other hand, long HRT (2-24 h) can increase the nitrate-N removal rate in bioreactor because it provides enough time for denitrification and thus significantly decrease the accumulation of nitrite. 40,41 However, it decreases the hydraulic load of the systems and reduces the sewage treatment capacity. 42,43 Considering all these constraints, improving the aquaculture environments by adjusting HRT cannot meet the demands for the sustainable development of aquaculture.…”