A novel approach for harnessing biofilm communities in moving bed biofilm reactors for industrial wastewater treatment

Joe A Lemire,Howard Ceri,Raymond J Turner,Marc A Demeter,Iain George

doi:10.3934/bioeng.2015.4.387

Abstract

Moving bed biofilm reactors (MBBRs) are an effective biotechnology for treating industrial wastewater. Biomass retention on moving bed biofilm reactor (MBBR) carriers (biofilm support materials), allows for the ease-of-operation and high treatment capacity of MBBR systems. Optimization of MBBR systems has largely focused on aspects of carrier design, while little attention has been paid to enhancing strategies for harnessing microbial biomass. Previously, our research group demonstrated that mixed-species biofilms can be harvested from an industrial wastewater inoculum [oil sands process water (OSPW)] using the Calgary Biofilm Device (CBD). Moreover, the resultant biofilm communities had the capacity to degrade organic toxins (naphthenic acids—NAs) that are found in OSPW. Therefore, we hypothesized that harnessing microbial communities from industrial wastewater, as biofilms, on MBBR carriers may be an effective method to bioremediate industrial wastewater. Here, we detail our methodology adapting the workflow employed for using the CBD, to generate inoculant carriers to seed an MBBR. In this study, OSPW-derived biofilm communities were successfully grown, and their efficacy evaluated, on commercially available MBBR carriers affixed within a modified CBD system. The resultant biofilms demonstrated the capacity to transfer biomass to recipient carriers within a scaled MBBR. Moreover, MBBR systems inoculated in this manner were fully active 2 days post-inoculation, and readily degraded a select population of NAs. Together, these findings suggest that harnessing microbial communities on carriers affixed within a modified CBD system may represent a facile and rapid method for obtaining functional inoculants for use in wastewater MBBR treatment systems.

Highlights

One of the consequences of this last century’s industrialization has been the rapid anthropogenic release of complex pollutants into the environment - threatening the long-term quality of our water resources
In attempting to resolve this issue, our current work introduces a novel method for harnessing biofilm communities for industrial wastewater treatment in Moving bed biofilm reactors (MBBRs) systems, and focuses on 3 main goals: 1) demonstrating that oil sands process water (OSPW)-derived mixed-species biofilms can grow on industry approved wastewater biofilm support carriers designed for MBBR systems, 2) demonstrating that biofilm carriers developed using the Calgary Biofilm Device (CBD) approach are logistically practical seeds for starting-up MBBR systems, and 3) verifying that OSPW-derived biofilms grown on carriers, and can be used to inoculate an MBBR system that retains the ability to rapidly degrade NAs as observed in our prior studies
The first objective of this study was to confirm and evaluate the growth of OSPW-derived biofilms on MBBR carriers grown within our modified CBD system

Summary

Introduction

One of the consequences of this last century’s industrialization has been the rapid anthropogenic release of complex pollutants into the environment - threatening the long-term quality of our water resources. Advantages of the MBBR system when compared to traditional activated sludge systems include, i) an increased treatment capacity, ii) lack of sludge bulking, and iii) no need for sludge recycling as the biomass is retained on the biofilm carriers [4,5,6]. For these reasons, the MBBR process has had great commercial success and is being used to treat wastewater in more than 22 countries worldwide [7]. In 2014, Nakhli et al evaluated the importance of allowing biofilm communities to acclimate to the targeted wastewater to improve bioremediation efforts [9]

Methods

Results

Conclusion