High-Gravity Technology-Enhanced Activated Sludge Process for Municipal
Wastewater Treatment
Abstract
Aerobic activated sludge process (AAS) is the most widely used
biological wastewater treatment process, but its treatment efficiency is
limited by low dissolved oxygen (DO) concentration and mass transfer
rate. Herein, high-gravity technology (Higee), an efficient mass
transfer enhancement technique, was used to enhance AAS to improve
municipal wastewater treatment efficiency. Higee-enhanced AAS
(Higee-AAS) rapidly reduced chemical oxygen demand and NH3-N to below
the discharge limits, and it was effective in removing the compounds
(e.g., aliphatic/proteins) that were stubborn in AAS. In Higee-AAS, DO
increased dramatically, and activated sludge became more dispersed with
smaller particle size, which facilitated contact between oxygen and
sludge, improving oxygen utilization rate and microbial activity. The
increases in extracellular polymeric substances and relative abundance
of microorganisms (Bacteroidete, Nitrosomonas, and Nitrospira) in
Higee-AAS were helpful to remove pollutants. Higee-AAS can effectively
improve wastewater treatment efficiency, and it has potential as a new
wastewater treatment technology.