Full-Scale Implementation of a Vertical Membrane Bioreactor for Simultaneous Removal of Organic Matter and Nutrients from Municipal Wastewater

So-Ryong Chae,Hang-Sik Shin,Seok-Tae Kang,Jin-Ho Chung,Sang-Min Lee,Yong-Rok Heo

doi:10.3390/w7031164

Abstract

In nutrient-sensitive estuaries, wastewater treatment plants (WWTPs) are required to implement more advanced treatment methods in order to meet increasingly stringent effluent guidelines for organic matter and nutrients. To comply with current and anticipated water quality regulations and to reduce the volume of produced sludge, we have successfully developed a vertical membrane bioreactor (VMBR) that is composed of anoxic (lower layer) and oxic (upper layer) zones in one reactor. Since 2009, the VMBR has been commercialized (Q = 1100–16,000 m3/d) under the trade-name of DMBRTM for recycling of municipal wastewater in South Korea. In this study, we explore the performance and stability of the full-scale systems. As a result, it was found that the DMBRTM systems showed excellent removal efficiencies of organic substances, suspended solids (SS) and Escherichia coli (E. coli). Moreover, average removal efficiencies of total nitrogen (TN) and total phosphorus (TP) by the DMBRTM systems were found to be 79% and 90% at 18 °C, 8.3 h HRT and 41 d SRT. Moreover, transmembrane pressure (TMP) was maintained below 40 kPa at a flux of 18 L/m2/h (LMH) more than 300 days. Average specific energy consumption of the full-scale DMBRTM systems was found to be 0.94 kWh/m3.

Highlights

Eutrophication is a key driver causing a number of pressing environmental problems including reductions in light penetration and increases in harmful algal blooms
We developed and optimized a novel vertical membrane bioreactor (VMBR) to reduce the problems on pollutant removal from wastewater and the volume of produced sludge from a bench-scale to field-scale systems
During the long-term operation of the field-scale DMBRTM systems treating municipal wastewater, it was found that organic matter (BOD5 > 99%), particles (SS removal efficiency > 99%), and E. coli

Summary

Introduction

Eutrophication is a key driver causing a number of pressing environmental problems including reductions in light penetration and increases in harmful algal blooms. It is known as that wastewater is an important point source for N and P loading in many aquatic environments [1]. In nutrient-sensitive estuaries, municipal and industrial WWTPs are required to implement more advanced treatment methods in order to meet increasingly stringent effluent guidelines for nutrients. Biological nutrient removal (BNR) processes that incorporate coupled nitrification/denitrification have the potential to remove TN down to about 5–12 mg/L, in selected cases, down to 3 mg/L. The TN concentration in effluent is known as less than 10 mg/L at most inland municipal WWTPs [2]. It is thought difficult to remove bacteria effectively from the effluent of WWTPs using the conventional activated sludge (CAS) process without a disinfection facility

Methods

Results

Conclusion