Effects of Hydraulic Loading Rate on Nutrients Removal from Anaerobically Digested Swine Wastewater by Multi Soil Layering Treatment Bioreactor.

Junyuan Guo,Yijin Yang,Cheng Chen,Yuling Zhou,Jiajing Xu

doi:10.3390/ijerph15122688

Abstract

A multi soil layering (MSL) treatment bioreactor was developed aiming at nutrients removal from anaerobically digested swine wastewater (ADSW). The start-up of the MSL bioreactor and its performance in nutrients removal at different hydraulic loading rate (HLR) were investigated. Results showed that the MSL bioreactor was successfully started up after operation for 28 days, and at this time, the removal efficiencies of ammonia-N, total nitrogen (TN) and total phosphorus (TP) in the ADSW reached 63.6%, 58.5%, and 46.5%, respectively. The MSL bioreactor showed a stable performance during the whole working process with varying HLR from 80 to 200 L/(m2·day). Maximum removal efficiencies of ammonia-N, TN and TP were obtained at 160 L/(m2·day), and was appeared as 94.2%, 94.4%, and 92.5%, respectively. It was worth noting that iron scraps were the key factor that enhanced the independent capability of the MSL bioreactor in TP removal, because there was only 21.4–25.8% of the TP was removed when the MSL bioreactor run with no iron addition.

Highlights

Nowadays, swine wastewater was considered as one of the biggest culprits for the severe agricultural non-point pollution, because of its high concentration of ammonia, organic pollutants, and phosphorus were not managed properly [1,2]
Anaerobic digestion was thoroughly investigated and applied technology in the treatment of the swine wastewater all over the world, residual nutrients were still considerable in the liquid named “anaerobically digested swine wastewater (ADSW)” [3]
The multi soil layering (MSL) bioreactor was known as an effective soil-based technology in the conventional poorly functioning sewage treatment via the enhancing inherent ability of soil [5]

Summary

Introduction

Swine wastewater was considered as one of the biggest culprits for the severe agricultural non-point pollution, because of its high concentration of ammonia, organic pollutants, and phosphorus were not managed properly [1,2]. The MSL (multi soil layering) bioreactor was known as an effective soil-based technology in the conventional poorly functioning sewage treatment via the enhancing inherent ability of soil [5]. This system has been tested to remove pollutants from polluted river water [6] and domestic wastewater [7], but there was no research related to nutrients removal from swine wastewater. Why can nutrients be effectively removed by the MSL bioreactor from ADSW? In case of natural ventilation or manual intervention ventilation, aerobic environments were formed in the zeolite layers due to its porous structures, when

Methods

Results

Conclusion