A novel strategy for rapid formation of biofilm: Polylactic acid mixed with bioflocculant modified carriers

Aiming at the resolving long biofilm formation period problem of the moving bed biofilm reactor, a method for preparing modified carriers of bioflocculant doped in polylactic acid (PLA) to promote biofilm formation is proposed. The micron-scale porous structure is verified by optical microscopy and scanning electron microscope. The modified material also has nano-scale pores in BET test. FTIR shows that the bioflocculant modified carriers have amino carboxyl and polysaccharide functional groups. The biofilm formation time is shortened, and the removal efficiency of COD and ammonia nitrogen are 14.14-21.15% and 6.08-15.41% higher than that of polyethylene carrier. Extend DLVO theory shows that bioflocculant modified carriers have lower energy barrier (149.18 kT) than other modified carriers. By immersing modified carriers and ordinary carriers in the bio-flocculant bacteria solution, the high-throughput sequencing reveals that the microorganisms attached on the carriers of bioflocculant doped in PLA have better biodiversity and abundance of functional gene expression than others.