Leveraging Data-Driven Dashboards To Facilitate Effective Start-up of Sidestream Enhanced Biological Phosphorus Removal (S2EBPR) Processes

Introduction
Startup of a new treatment process or facility expansion can often be stressful; this is especially true when considering the commissioning of a nutrient removal/recovery process. Months of planning can be halted abruptly due to unforeseen circumstances. This endeavor is made both simpler and more challenging through the utilization of internet-enabled tools capable of performing real-time measurements in conjunction with typical laboratory measurements. Pre- and ad-hoc data collection and analysis can ease some of the inherent pressures of startup and can help engineers and operators alike diagnose issues with greater rapidity. However, these data are typically challenging to access and organize, hindering anyone from uncovering actionable insights from this information. Moreover, disparate sampling frequencies between online and lab-analyzed data further complicate unifying these data sets. As such, there is a need for tools that can combine multiple datasets while simultaneously empowering users to leverage the data to obtain useful, actionable insights for their facility.
Background
Enhanced biological phosphorus removal (EBPR) and sidestream EBPR (S2EBPR) aim to facilitate phosphorus removal and/or recovery by creating selective pressures that will promote the growth and metabolism of phosphorus accumulating organisms (PAOs) over other organisms, especially ordinary heterotrophic organisms (OHOs) and glycogen accumulating organisms (GAOs). Selective pressures can include pH, alkalinity, temperature, relative fractions of carbonaceous oxygen demand (COD), and the presence/absence of dissolved oxygen (DO). Given that PAOs are comparatively slower-growing, facilities must be designed to help PAOs outcompete other organisms for resources. As such, EBPR processes leverage an anaerobic zone prior to aeration wherein PAOs can store bioavailable COD that will later be utilized to aerobically metabolize phosphorus. The primary differentiation between EBPR and S2EBPR is where the influent is pumped in the treatment train; if the anaerobic zone is not subjected to incoming influent, the train is being operated as an S2EBPR process (Figure 1). In addition to the aforementioned selective pressures, operational decisions such as total solids retention time (SRT), anaerobic SRT, RAS diversion percentage, and supplemental carbon addition can determine phosphorus removal efficiency. While certain 'rules-of-thumb' for these operational decisions can be applied during design, they must be fine-tuned for each facility. Apart from EBPR/S2EBPR, phosphorus can also be removed through chemical means (i.e., precipitation). Though phosphorus can form numerous complexes, struvite and brushite (formed when phosphorus complexes with magnesium or calcium, respectively) are the most common precipitates at WRRFs. If phosphorus concentrations are too high (e.g., after anaerobic processes), these precipitates can naturally form and damage the inner linings of pipes or block them all together. Struvite and/or brushite can be intentionally precipitated in dedicated reactors to both alleviate downstream issues as well as generate a saleable product. Centrisysâ„¢ has two technologies to facilitate these chemical reactions: CalPrex® for brushite and MagPrex® for struvite. Figure 1. Sample layouts of typical EBPR and S2EBPR processes.
Methods
Startup data of two facilities (i.e., one MagPrex® and one S2EBPR) at Fox River Water Reclamation District (FRWRD) were provided on a weekly basis and were gathered into a database in Microsoft Power BI (Figures 2-5). Data were comprised of online monitor data (15-minute frequency) and lab analyses (daily frequency). In addition to visualization of the raw data, Power BI was also utilized to assess data validity and ameliorate any invalid data (e.g., ensuring mass balances within the process close). Figure 2. MagPrex operation summary from dashboard Figure 3. Online date from MagPrex reactor as shown on dashboard Figure 4. S2EBPR feed and performance data from dashboard Figure 5. Primary sludge fermenter operation and performance from dashboard, used to aid S2EBPR performance issues
Results and Conclusions
Weekly coordination between Black & Veatch and FRWRD has greatly improved the startup process. Issues to treatment performance are regularly discussed, leading to proactive operational recommendations that stave off potential larger-scale problems. One such example was that phosphorus removal in the MagPrex® reactor was highly variable for a period of time. By examining the data, it was determined that fluctuations in operation were causing this variability. Once operation stabilized, average phosphorus removal increased. A similar issue occurred with the S2EBPR process, wherein phosphorus removal performance was low due to insufficient carbon entering the anaerobic zone. However, a primary sludge (PS) fermenter should have provided the requisite carbon. The discrepancy was due to insufficient transfer between the thickened fermented PS pump and the anaerobic zone. Fermentate had been primarily flowing by gravity, so no liquid was transferring between the PS fermenter and the anaerobic zone of the S2EBPR process. Once this was amended, phosphorus removal performance improved substantially. When leveraged effectively, data analysis and visualization can provide WRRF staff with a more holistic view of their facility, enabling them to shift away from a reactive mindset – responding to issues as they appear – and embrace a proactive mentality to rectify issues before they become a larger problem. Having a better handle on data allows a WRRF to maintain a high-quality effluent and potentially reducing treatment costs. Those employed in the water and wastewater sector are charged with protecting human health and the environment without creating too great of an economic burden. To meet this goal, we need to utilize every tool at our disposal.
Benefits and Novelty of this Presentation
This presentation is novel in its approach to data handling and visualization. It will provide a practical example and case study of how to aggregate big data with lab data within a visual dashboard to gain insights into startup and long-term operation of a phosphorus removal facility. While collecting data is critical for evaluating WRRF performance, understanding the relationship between facility operation and treatment efficiency can only be achieved when the data are utilized meaningfully. The dashboard was built with the intent of maximizing function and usability while minimizing effort and complexity. The methods behind formulating each of this tool will also be demonstrated by a Microsoft-certified Data Analyst, such as: layering graphics to create custom visualizations, conditionally displaying information, and how to combine multiple datasets cohesively. During this WEFTEC presentation, the following benefits of data dashboards during startup of chemical and biological processes will be discussed: - Consolidated data source: Operators, engineers, and the contractor were all able to reference an aggregated dataset within the dashboard to understand how the process is operating, with the added aid of key performance indicators. - Collaboration: Having one consolidated data source, effective collaboration for interpretation of findings and results was possible. This allowed for the quick discovery of the fermentate flow issue identified above. - Operational decisions: The collaborative analysis provided the means for confident operational decisions to address identified optimization points.