Simulation and optimization of different reflux ratio of AAO process in STOAT wastewater plant
LIU Lele
GUO Wuzhen
ZENG Xusheng
LIU Xinze
GAO Yunan
XU Song
Abstract：In this study,the STOAT software was utilized to simulate the performance of an anaerobic-anoxic-oxic(AAO)process in a wastewater treatment plant in northern China.The aim was to investigate the influence of different return ratios on the removal of total nitrogen,ammonia nitrogen,total phosphorus,chemical oxygen demand(COD),and suspended solids(SS),and to analyze the optimal return ratio.The results indicated that the STOAT software accurately and realistically simulated the AAO treatment process of the wastewater treatment plant.Through simulation analysis,it was observed that the return ratio had a relatively minor impact on COD and SS removal.The removal efficiency of total nitrogen increased synchronously with the increase in the return ratio,while the removal of total phosphorus was mainly influenced by the sludge return ratio.The optimal operating conditions were identified with a sludge return ratio of 80%and a mixed liquid return ratio of 400%,resulting in removal efficiencies of 79%for total nitrogen,98.02%for ammonia nitrogen,and 92.33%for total phosphorus.Both before and after optimization,there was a significant improvement in the removal efficiency of total nitrogen,ammonia nitrogen,and total phosphorus.This approach can serve as a technical reference for optimizing the operation of AAO processes in northern wastewater treatment plants.
Keywords：STOATAAOnitrogen and phosphorus removaloptimal reflux ratioprocess optimization
Publication Date：2024-07-30
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：8( 49-56 )