Rapid MOBilization: Case Study On The Accelerated Adoption Of The Mobile Organic Biofilm (MOBâ„¢) Process Intensification Technology

Introduction
The adoption of new technologies in the wastewater industry is typically characterized by the Rogers bell curve (Figure 1) which starts with innovators followed by early adopters driving a technology to the market where it can be vetted by the industry such that those late to adoption develop enough confidence for consideration. The ultimate goal of any company is to accelerate adoption for recovery of development costs and profitability for solvency. In the water industry, especially in the U.S. public sector, adoption of novel technologies is inherently complicated due the multiple partners that may have differing views such as (in no particular order):
Manufacturers/technology providers who develop the innovations and need a fiscal incentive
Engineers/consultants/designers who develop the design documents and need to ensure the utility and regulators that the process will meet the design intent and criteria
Plant operations staff who will operate the technology and need to understand how to make it work and maintain any equipment.
Utility staff need to make sure staff is trained and O&M funds are identified
Regulators who review the design and need to be comfortable that it will
These partners need to all be willing to understand the potential rewards for adoption of a new technology in contrast to the risks for adoption with potential mitigations identified. For the technology developer, the more information that is available to quantify both the risks and rewards, then generally the faster a technology can be adopted.
The past decade has seen a surge in new technologies that focus on process intensification in secondary treatment, including aerobic granular sludge (AGS), mixed liquor densification (i.e. InDENSEâ„¢), membrane aerated biofilm reactor (MABR), and Mobile Organic Biofilm (MOBâ„¢). Compared to previous eras in our industry, the rapid adoption and application of these technology has been unprecedented. This paper will provide a review how Jacobs and Nuvoda worked together to identify challenges, conduct systematic testing and develop solutions and mitigation strategies to allow the Mobile Organic Biofilm (MOBâ„¢) intensification process to be rapidly adopted in the industry.
Methodology and Results
The development and rapid adoption of the MOBâ„¢ technology was carried out via the following four-step process developed collaboratively between Jacobs and Nuvoda:
Step 1: Bench Scale Demonstration and Comparison against Conventional Technologies
Step 2: Simulator Model Development
Step 3: Full Scale Equipment Testing
Step 4: Full Scale Testing and Adoption The following sections provide brief overviews of each step in this process, which will be expanded upon in the full paper.
Step 1: Bench Scale Demonstration and Comparison against Conventional Technologies
Development of the MOBâ„¢ began with lab scale demonstration to compare the performance of the MOBâ„¢ against a typical plastic carrier media configuration (integrated fixed film activate sludge or IFAS) and a standard activated sludge system (Figures 2 and 3). The testing illustrated that the technology was a viable competitor (Table 1) to the other technologies as well as identify issues that needed to be tested in a full-scale environment that likely were not well represented in a lab scale demonstration.
Step 2: Simulator Model Development
The unconstrained movement of the MOBâ„¢ organic media (kenaf) required a new understanding of biofilm modeling. Commercial simulators had a model structure for activated sludge with the movement of flocs through the system and a biofilm model where the media was constrained within a particular reactor. The MOBâ„¢ process bridged these two models requiring the development of a new model (See Figure 4). Model development is considered a key step for a novel technology because it provides a generalized understanding of the how the process works. This allows process designers the ability to simulate the novel technology thereby enabling it to become part of engineering conceptual alternatives evaluations carried out early on in projects. In addition, it provides researchers the ability to further test the system for independent verification as well increase available performance data and potentially identify additional risks and opportunities. Jacobs and Nuvoda worked closely with Dynamita, using the Sumoâ„¢ simulation platform, to develop the new model of the MOBâ„¢ process (Sabba et al, 2016).
Step 3: Full Scale Equipment Testing
In parallel with the model development, the key equipment for the MOBâ„¢ process is the separation of the mobile biofilm media from the wastage stream, as identified from the lab scale demonstration. Nuvoda installed a large-scale pilot of a 500-micrometer rotary drum screen (Figure 5) fed with a wastewater and mobile media mixture. This testing not only illustrated the effectiveness of the unit at capturing the media, but also highlighted the need for good influent screening, at least 6-millimeter preferably perforated plate style, as the unit was also quite effectively at capturing and maintain trash in the biroeactors.
Step 4: Full Scale Testing and Adoption
The final testing required full scale installations to demonstrate that the technology could withstand real world operating conditions. These installations included Moorefield, WV in 2017 (Figures 6 and 7) and Mebane, NC in 2018 (Figure 8) including critical papers (Schauer, 2021) that identified mechanistic issues for design consideration. Testing in Moorefield, WV (Wei et al, 2021) tracked settling performance which significantly reduced from 200 ml/g to below 50 ml/g over the 5-month testing period. In addition, specific activity testing found that specific phosphorus uptake rates were similar or higher than SBR-type granular systems while the specific ammonia uptake rate was lower. Full scale demonstration testing in Mebane, NC (Johnson et al, 2021) over 18 months found a similar increase in settling performance with stable ammonia removal. However, total nitrogen removal was unstable which was attributed to the aeration system operation. Mebane utilizes a pair of large bioreactors, each equipped with six (6) mechanical aerators that alternate on/off operation to facilitate simultaneous nitrification and denitrification. Longer aeration times required to nitrify resulted in less available time to denitrify. Reverting back to a higher SRT was able to stable nitrogen removal later in the pilot. Overall, these series of steps that started in 2014 and have continued to today has allowed to MOBâ„¢ process to become a commonly mentioned and evaluated intensification technology in 5 to 6 years.
Presentation and Relevance
This paper will present how the collaborative relationship and systematic testing allowed the MOBâ„¢ process to provide the necessary information to Utilities, Operators and Engineers thereby allowing the technology to rapidly become an adoptable technology option. Participants will develop an understanding of key steps necessary in developing novel technologies and how these steps are necessary to ensure risks and rewards are thoroughly identified to aid potential users.