Effects of the exogenous N-acylhomoserine lactones on the performances of microalgal-bacterial granular consortia
Wanlin Lyu, Shujia Zhang, Yijia Xie, Rongfan Chen, Xiaoling Hu, Bin Wang, Wenbin Guo, Hongyu Wang, Jie Xing, Dao Zhou
Abstract
Chlorella sorokiniana, the dominant microalgal strain with fast growth rate and high nutrients’ adsorption rate, was selected from the mature MBGS system. After adding C6-HSL and 3-oxo-C12-HSL to the MBGS consortia formed by combining it with mature AGS, it could also be found that C6-HSL accelerated the denitrification rate and improved the removal rate of TIN and TP effectively. Besides, the promoting effect of C6-HSL was slightly higher than that of 3-oxo-C12-HSL. By adjusting the concentration of C6-HSL (5 × 10−9, 7.5 × 10−7 and 2.5 × 10−5mol/L), the results revealed that adding 5 × 10−9mol/L C6-HSL significantly improved the efficiency of nitrogen and phosphorus removal in MBGS consortia. However, adding higher concentration of C6-HSL (7.5 × 10−7mol/L) would lead to deterioration of TIN and COD degradation. The content of EPS secreted by bacteria was regulated by different concentrations of AHLs, and the PS/PN value decreased with the increasing trend of C6-HSL concentration.