Can a carbon-negative, bio-based molecule replace legacy phosphonates and help you use less azole—without sacrificing corrosion performance? In this episode, host Trace Blackmore, CWT, welcomes Matheus Paschoalino, PhD Senior Business Development Manager and Microbial Control SME of Solugen, to unpack polyhydroxycarboxylic acids (PHCs) and how they're changing cooling-water programs from the field up. We cover HEDP replacement in light-duty systems, azole enhancement in copper-challenged waters, a second-generation cut for heavy-duty heat flux, and PHC behavior with oxidizers and non-oxidizer biocides.
From Bioforge to Basin: How PHCs Are Made and Why It Matters
Paschoalino explains Solugen's chemo-enzymatic "Bioforge" approach that oxidizes sugars (corn-syrup feedstock) into PHCs with very high yield and no practical byproducts—a pathway validated as carbon-negative. He outlines how different "cuts" (monoacid-rich vs. diacid-rich) map to different use cases, and notes current manufacturing capacity and adoption across hundreds of towers.
Replacing HEDP in Light-Duty Programs
For hospitals, HVAC, and other light-duty systems, PHCs have fully replaced HEDP as the anodic corrosion inhibitor while keeping PBTC for scale, enabling lower total phosphorus formulations with equal or better performance compared to status-quo organics.
Azole Enhancement, Free Copper, and Real-World Cost
Field work showed PHCs chelate metals quickly, protecting azole demand when free copper is present (e.g., after oxidizer flushing) and reducing expensive azole overdosing. One university case dropped an adjunct 8-ppm azole feed by pairing the base 3–4 ppm azole with PHC, yielding both corrosion control and lower discharge costs.
Second-Generation PHCs for Heavy-Duty Heat Flux (Toward "Neutral Phosphorus")
At higher heat flux and stabilized-phosphate conditions, a diacid-rich second-generation PHC proved more stable, enabling orthophosphate reduction and opening a path toward "neutral phosphorus" programs that leverage background phosphate in municipal make-up. Bench data also show synergy with trace metals (e.g., zinc).
Biocide Potentiation and Where It Works Best
PHCs remain stable with oxidizers like chlorine dioxide and bleach. Their most compelling synergy shows up with non-oxidizers and peracetic acid (PAA): as a biocide potentiator, PHCs can reduce the need to overdose actives such as THPS, glutaraldehyde, quats, and DBNPA by first complexing interfering metals (e.g., Fe/FeS), letting the biocide perform as intended.
Not "Bug Food": Pilot Cooling Towers and Oxidizer Demand
To address the industry's biggest concern with bio-based chemistries, Solugen ran side-by-side outdoor pilot cooling towers under identical bleach control. Result: comparable oxidizer usage and consistently low counts versus HEDP—evidence that PHCs don't fuel biofilm.
Chelation Mechanics, Polymer Savings, and White Rust
PHCs chelate beyond acid-group stoichiometry thanks to multiple hydroxyls and conformational effects—critical for controlling dissolved metals and protecting films. In stressed heat-flux/chlorine conditions, PHCs reduced calcium-phosphate fouling versus HEDP, often allowing polymer dosage cuts. Early data also show promise for white-rust mitigation on galvanized systems, with the diacid-rich cut delivering the strongest reductions.
For practitioners, the message is pragmatic: PHCs aren't "lab curiosities." They're fielded at scale, enabling lower-phosphorus programs, protecting costly azole inventories, widening the operational window under oxidizer stress, and potentiating select biocides—while staying compatible with common metals. If you manage cooling assets under cost, compliance, and performance pressure, this episode gives you a clear technical playbook to evaluate.
Listen now, review the papers in the show notes, and test a pilot where it counts—on your heat exchangers.
Stay engaged, keep learning, and continue scaling up your knowledge!
Timestamps
02:15 - Trace Blackmore shares a quick personal open: spotting the Goodyear Blimp (100th anniversary), using memories as fuel rather than limits, and a mindset reset around the word "can't."
06:42 - Upcoming Events for Water Treatment Professionals
09:23 - Water You Know with James McDonald
11:41 - Interview with Matheus Paschoalino, Senior Business Development Manager and Microbial Control SME of Solugen
12:02 - HEDP replacement in light-duty programs; lower total phosphorus without losing performance
19:13 - Heavy-duty heat flux: second-generation (diacid-rich) PHCs and reducing orthophosphate
20:39 - "Neutral phosphorus" approach
27:42 - Biocide potentiation: synergy with PAA; strongest effects with non-oxidizers (e.g., THPS)
33:03 - "Bug food?" Pilot side-by-side cooling towers (Houston)
37:39 - HEDP systems fouled with calcium phosphate while PHC system showed only minor patching (CTI paper)
41:44 - Early evidence: white-rust mitigation on galvanized systems (seeking field partners)
Quotes
"Use your past as history, not as a limiter." - Trace Blackmore
"Plan where you'll be; you never know what you'll learn or who you'll meet." - Trace Blackmore
"First-gen PHCs let us replace HEDP in light-duty programs and keep performance with lower total phosphorus." - Matheus Paschoalino
"Non-oxidizing biocides work best with PHCs—we target the metals first so you stop over-dosing the biocide." - Matheus Paschoalino
"We like to be very conservative… we start with the laboratory; we start with light duty. Now we are going to heavy duty."
Connect with Matheus Paschoalino, PhD
Phone: 14847193979
Email: [email protected]
Website: Home - New - Solugen | Solugen
LinkedIn: Matheus P. Paschoalino, PhD | LinkedIn
Solugen: Overview | LinkedIn
Guest Resources Mentioned
I Must Betray You by Ruta Sepetys
Blog entitled "Achieving Phosphorus-Neutral Cooling Treatment Using Carbon-Negative Additives" by Solugen
Verza360® Enables Cost Savings with Effective Biocide Potentiation in Produced Water - Oil & Gas Solutions Case Study by Solugen
2025 Winter Issue of CTI Journal paper TP24-16, "Toward Phosphorus-Neutral Cooling Tower Treatment Using Carbon-Negative Environmentally Friendly Additive"
Presentation at AMPP entitled "Novel Biobased Carbon-Negative Corrosion Inhibitors Enabling Environmentally Friendliness"
Scaling UP! H2O Resources Mentioned
AWT (Association of Water Technologies)
Scaling UP! H2O Academy video courses
Submit a Show Idea
The Rising Tide Mastermind
Water You Know with James McDonald
Question: Back in the day, what was the treatment used for corrosion inhibition in cooling water systems that was banned around 1985 in the United States from widespread use due to its toxicological impact?
2025 Events for Water Professionals
Check out our Scaling UP! H2O Events Calendar where we've listed every event Water Treaters should be aware of by clicking HERE.
