Modeling a Three-Stage Biological Trickling Filter Based on the A2O Process for Sewage Treatment

Jiabin Liang,Yuan Yuan,Shijie You,Zimeng Zhang,Yixing Yuan

doi:10.3390/w13091152

Abstract

Biological trickling filters are widely used for sewage treatment. This study models a biological trickling filter based on an anaerobic–anoxic–oxic process (A2O–BTF), established by a combination of aerobic and anaerobic technology. The performance and operational parameters were analyzed using Sumo, a commercially available wastewater treatment process (WWTP) simulation software. The wastewater treatment performance of the anaerobic–anoxic–oxic process biological trickling filter (A2O–BTF), the conventional three-stage biological trickling filter (Three-Stage–BTF), and the single-stage biological trickling filter (Single–BTF) was compared, which indicated the higher performance of A2O–BTF in terms of COD, TN, NH3-N, and TP removal. The operational parameters of A2O–BTF were optimized by Sumo simulation software, and the results showed that the removal efficiency of pollutants was increased by raising the temperature to the range of 13.94–21.60 °C. The dissolved oxygen (DO) in the aerobic reactor enhanced removal efficiency under a saturation concentration of 2.2–2.6 g O2/m3. In addition, the optimization of the reflux ratio promoted the removal efficiency of the pollutants, indicated by the maximum removal efficiency of COD and TN, achieved at the reflux ratio of 2.25, and that of NH3-N and TP, achieved at a reflux ratio of 0.75. This study provides a proof-in-concept demonstration that software modeling can be a useful tool for assisting the optimization of the design and operation of sewage treatment processes.

Highlights

Biological methods are widely used for wastewater treatment processes (WWTPs) [1,2]
The wastewater treatment performances of Single–Biological trickling filters (BTFs), Three-Stage–BTF, and A2O–BTF were compared, and the simulation results were compared with the experiment results
For NH3-N, because of the magnitude of the effluent pollutant, which is generally less than 0.3 g N/m3, there would be a bit of error in the measurement process of the experiment

Summary

Introduction

Biological methods are widely used for wastewater treatment processes (WWTPs) [1,2]. As biological reinforcement is a simple and effective technology, it is widely used in wastewater treatment at present [3]. It is of particular importance to maintain the treatment effect of microorganisms in different climatic conditions. WWTPs refer to the establishment of an effective wastewater treatment method based on related technologies [9]. Anaerobic–anoxic–oxic (A2O) [10,11], sequence batch reactor (SBR) [12,13], moving bed biofilm reactor (MBBR) [14,15], and integrated fixed-film activated sludge (IFAS) [14] are the commonly used WWTPs. Among them, A2O is the most popular process for nitrogen and phosphorus removal. It operates alternately through anaerobic, anoxic, and aerobic reactions by returning the mixture of liquid and sludge through reflux to achieve the removal of COD, nitrogen, and phosphorus

Methods

Results

Conclusion