Running a paint manufacturing plant comes with its own set of challenges—but none more persistent (or more complicated) than dealing with high-VOC wastewater. If you’re in the industry, you already know: the solvents, additives, and pigments that go into making top-quality paint also leave behind some pretty nasty water.

At Mapril, we work closely with manufacturers across sectors, and we’ve seen firsthand how tough this particular wastewater is to treat. But we’ve also seen what works—and what doesn’t. So here’s a breakdown of how to treat high-VOC wastewater from paint plants effectively, without the fluff.

Why Is VOC Wastewater Such a Headache?

Paint plant wastewater usually contains:

• Solvents like toluene, xylene, and acetone
• Resins and pigments
• Oils and suspended solids
• Very high COD and BOD levels
• Sometimes even heavy metals

That means it’s toxic, smelly, and hard to break down. Standard treatment systems usually just can’t handle it alone.

Step 1: Start With Source Segregation

One of the best things you can do? Don’t let all your wastewater mix together. Separate the high-VOC streams (like solvent washings or rinses) from your regular wash water.

From there, you can either:

• Run solvent-rich waste through a solvent recovery unit, or
• Use oil-water separators and equalization tanks to prep it for further treatment.

👉 Why it helps: It lightens the load on your main treatment system and gives you a cleaner, more manageable stream to work with.

Step 2: Go for Advanced Oxidation (aka: Break It Down!)

This is where the real magic happens. Advanced oxidation processes (AOPs) such as:

• Ozonation
• Fenton’s reagent
• UV + Hydrogen Peroxide

…help destroy VOCs at the molecular level.

👉 Why it helps: These methods don’t just “remove” the VOCs—they actually break them down into simpler, more biodegradable compounds. That sets the stage for the next step.

Step 3: Bring in the Biology

Once the VOCs have been partially broken down, it’s time for biological treatment. Think:

• SBRs (Sequential Batch Reactors)
• MBRs (Membrane Bioreactors)

These systems work well because they now have less toxic, more treatable water to work with thanks to the AOP step.

👉 Why it helps: It’s an efficient way to handle what’s left of the organics—plus, it helps reduce sludge and lowers operating costs.

Step 4: Polish It Off with Activated Carbon

Still got a bit of colour or VOCs lingering? Activated carbon filters are a great final touch. They absorb whatever’s left and ensure the water is clean enough for discharge or reuse.

👉 Why it helps: It adds an extra layer of safety—and gives you peace of mind.

Step 5: Want to Go Zero Discharge? You Can!

If your goal is to reuse every drop (and avoid any discharge at all), a Zero Liquid Discharge (ZLD) system is your best bet. These setups typically include:

• Reverse Osmosis
• Evaporators
• Crystallizers

👉 Why it helps: You recover up to 95% of the water and safely manage the remaining solids. It’s sustainable and increasingly necessary for regulatory compliance.

What We Recommend at Mapril

Every paint plant is different—so we never take a one-size-fits-all approach. At Mapril, we:

• Analyse your specific wastewater profile
• Run small-scale pilot tests
• Design a custom treatment solution using a mix of chemical, physical, and biological methods
• Automate and monitor it all for hassle-free performance

We make sure you get a system that actually works in the real world, not just on paper.

Final Take

VOC-laden wastewater is complex, no doubt. But with the right mix of steps—source separation, oxidation, bio-treatment, polishing, and recovery—you can take control of it.

Need help figuring out what works best for your plant? That’s where we come in.

👉 Talk to Mapril’s experts mapril@mapril.com and let’s solve your wastewater challenge, together.