Cultivation and Identification of Flocculents NH-001Z and its Application of EPS-1 Flocculation

Microbial flocculants have garnered significant attention due to their non-toxicity, harmlessness, and exceptional flocculation performance. In this study, a high-efficiency bioflocculant-producing strain, NH-001Z, was isolated from forest soil and identified as Enterobacter asburiae via 16S rDNA gene sequencing. The extracellular polymeric substances (EPS) secreted by strain NH-001Z exhibited remarkable flocculation capabilities, which was named EPS-1. Kaolin suspension was employed as a standard test solution to evaluate the flocculation efficiency of EPS-1 under varying fermentation and operational conditions via single-factor experiments. The results show that the EPS-1 produced by NH-001Z has a flocculation efficiency of up to 92.42% for kaolin within 5 minutes, with adsorption bridging and sweeping-enmeshment as the main flocculation mechanisms, while electrostatic neutralization plays a supporting role. Assisted by the coagulant aid Ca²⁺, EPS-1 demonstrates exceptional flocculation efficiency for algae, achieving 90.47% removal within 60 minutes while maintaining intact algal cell structures. This finding underscores its promising application prospects in fields such as algae harvesting.