Rapid initiation of a single-stage partial nitritation-anammox process treating low-strength ammonia wastewater: Novel insights into biofilm development on porous polyurethane hydrogel carrier

How to Provide Nitrite Robustly for Anaerobic Ammonium Oxidation in Mainstream Nitrogen Removal

“…111 Meanwhile, the one-stage PN/A based on biofilm under a high DO concentration (3.0 ± 0.2 mg/L) has proved feasible. 112 In this system, the outer AOB layer could protect the internal AnAOB from oxygen inhibition, and the nitrite competition between AnAOB and NOB in biofilm would favor the stable NOB suppression. 113 Although suppressing NOB in granular and biofilm systems under high DO concentration is effective in the laboratory, challenges still remain for its practical application in mainstream treatment.…”

“…AOB with a high biological activity and a faster growth rate would form a thick external boundary layer of the biofilm, and thus the oxygen available for NOB in the biofilm could be reduced . Meanwhile, the one-stage PN/A based on biofilm under a high DO concentration (3.0 ± 0.2 mg/L) has proved feasible . In this system, the outer AOB layer could protect the internal AnAOB from oxygen inhibition, and the nitrite competition between AnAOB and NOB in biofilm would favor the stable NOB suppression …”

Surface Modification of Polyurethane Sponge with Zeolite and Zero-Valent Iron Promotes Short-Cut Nitrification

“…Different types of biofilm carriers, such as polyethylene plastic, polyurethane sponge, and activated carbon, are commonly used in MBBR technology [ 22 ]. Among all types of carriers, polyurethane sponge carriers are considered ideal for microbial immobilization and attached-growth cultivation [ 21 , 23 ] due to their durability, chemical resistance [ 24 ], large specific surface area, high porosity [ 25 ], good fluidization properties [ 26 ], and biocompatibility [ 27 ]. However, the polyurethane sponge has a single composition, which limits the actual treatment efficiency of the MBBR.…”