Control microbial risks in effluent water reuse with BactoSense Core

CONTEXT: "Can sustainability meet water quality standards?"

Water reuse is becoming a key sustainability strategy for industries with high water demand, especially in biopharmaceutical manufacturing.

In 2024, a leading Swiss biopharma company partnered with Ekopak to explore the feasibility of treating and reusing its effluent water to meet drinking water standards with the following objectives:

Transform effluent water to meet drinking water quality standards to achieve sustainability targets.
Overcome limitations of traditional bacterial testing (slow results, no online monitoring).
Evaluate overall system performance under real-world conditions with a mobile pilot unit.

Testing set up

Ekopak deployed a modular pilot system, integrating UF, two-stage Reverse Osmosis, and BactoSense CORE for automated microbial monitoring at four points.

The system was housed in a unit enabled with SCADA-based remote monitoring and multiple sampling points for detailed water quality analysis.

BactoSense enabled rapid detection of total cell counts (TCC) in just 20 minutes, providing operators with real-time microbial insights to optimise treatment performance.

Figure 1: Schema of the Pilot Module for water reuse treatment train including BactoSense CORE — **Figure 1:** Schema of the Pilot Module for water reuse treatment train including BactoSense CORE

Role of BactoSense Across End-to-End Water Reuse Pilot System

To measure the efficacy of Ultrafiltration, Prefiltration, and Reverse Osmosis through log reduction of bacterial count across each point. The pilot also studied variables impacting bacterial count: feed water quality, feed flow rate, duration of stagnation, presence of biofilm, and equipment cleaning.

KEY FINDINGS

1. Membrane filtration and microbial regrowth influence the overall microbiological profile.

Continuous monitoring with BactoSense enabled early detection of microbial hotspots in RO prefilters and storage tanks, allowing immediate corrective actions, such as prefilter replacements

Figure 2: Total cell counts along water reuse treatment train — **Figure 2:** Total cell counts along water reuse treatment train

2. Stagnation (duration of it) drives biofouling and impacts final water quality.

Short-term stagnation led to temporary TCC surges in RO permeate, while long-term stagnation caused persistent deterioration in water quality, requiring additional flushing steps. With BactoSense, we detected signs of stagnation early on.

Figure 3: RO permeate cell counts took 1.5 days to normalize. — **Figure 3:** RO permeate cell counts took 1.5 days to normalize.

3. Membrane scaling reduces permeate flow rate and increases bacterial levels.

Without antiscalant dosing, permeate flow dropped, and BactoSense alarmed TCC rise quickly, highlighting the need for proactive scaling prevention.

Figure 4: Graph depicting the relation between RO flow rate and TCC — **Figure 4:** Graph depicting the relation between RO flow rate and TCC

4. Optimising operational parameters enhances membrane filtrate quality

Minor feed pressure adjustments drastically affect microbiological quality in permeate, highlighting the necessity for precise operational controls and real-time monitoring to optimise membrane performance.

Figure 5: Graph depicting the relation between feed pressure and TCC — **Figure 5:** Graph depicting the relation between feed pressure and TCC

KEY BENEFITS

Immediate Microbiological Insights: BactoSense enabled operators to quickly understand the proposed solution's microbiological performance in real-time.
Comprehensive Microbiological Overview: Initial grab sampling provided a complete microbiological profile of the treatment train, including membrane performance and microbial regrowth in prefilters and pipes.
Real-Time Monitoring: Online monitoring installations allowed for continuous tracking of microbial dynamics, providing ongoing insights into membrane filtration unit performance.
Filtration Performance Management: Data from BactoSense helped assess the impact of prefilter maintenance, stagnation, scaling, and operational parameter adjustments on water quality.
Proactive Membrane Management: Enabled precise monitoring of microbial trends, facilitating timely interventions to maintain optimal system performance and water quality.

"We are very happy to have been able to contribute to the success of this pilot with comprehensive and actionable microbiological data. The collaboration with Ekopak was superb and allowed us to experience firsthand how much value such containerised pilot installations bring to clients."

Silvan Kaufmann, Solutions Programme Manager

Book a demo today to explore how BactoSense CORE can make sustainability and water quality standards meet.