Medium optimization and dust suppression performance analysis of microbial-based dust suppressant compound by response surface curve method

Abstract

At present, microbial dust suppressants based on microbial communities lack necessary systematic analysis of factors affecting dust suppression performance. Therefore, in this study, the response surface curve method was used to optimize the culture conditions for enrichment of urease-producing microorganisms from activated sludge. The results indicated that when urea = 9.67 g L^-1, NH₄Cl = 5.21 g L^-1, and pH = 9.57, the maximum urease activity of urease-producing microbial community (UPMC) was 8.22 mM min^-1. The UPMC under optimized culture conditions reached a mineralization rate of 98.8% on the 1st day of mineralization. Ureolysis is one of the biological mechanisms that trigger microbial mineralization with the consequent effect of dust suppression. The analysis of microbial community structure indicated that the urease-producing bacteria Sporosarcina sp. had the highest abundance at the genus level in the microbial-based dust suppressant compound. Jeotgalicoccus sp. plays an important role in improving and maintaining the stability of urease. In addition, the optimal UPMC had low pathogenicity, which is extremely attractive for the safe application of microbial dust suppressants.

Keywords: Medium optimization; Microbial dust suppressant; Microbially induced carbonate precipitation; Response surface curve; Urease-producing microbial community (UPMC).