Top Water Treatment Challenges in the Pulp and Paper Industry – And How to Solve Them

Water plays a huge role in the pulp and paper industry. It’s involved in just about every step of the process-from pulping and bleaching to paper forming and finishing. But with all that water use comes a set of challenges that mills have to manage daily. If you work in the industry, you already know how tricky it can be to keep water systems running smoothly, stay in compliance, and keep costs under control.

Over the years, we’ve worked with mills across the country, and we’ve seen firsthand the issues that tend to pop up again and again. Below, we’re breaking down the biggest water treatment challenges pulp and paper operations face—and how you can tackle them with the right combination of strategy and chemistry.

Dealing with High BOD and COD

One of the most common issues we see is high levels of BOD (Biological Oxygen Demand) and COD (Chemical Oxygen Demand) in mill wastewater. That’s not surprising—pulping creates a lot of organic material, and all that lignin, fiber, and extractives end up in the water. If those organics aren’t removed effectively, they can cause problems at your discharge point or wastewater plant.

To get BOD and COD under control, it usually takes a mix of approaches. Coagulants and flocculants can help bind up the solids and organics so they’re easier to remove. In many cases, biological treatment systems—whether aerobic or anaerobic—do the heavy lifting on breaking down what’s left. For tougher compounds, some mills are turning to advanced oxidation processes. The key is tailoring the treatment to the makeup of your water.

Getting a Handle on Suspended Solids and Sludge

Another big one is suspended solids-especially when they start building up in the treatment system and creating more sludge than your equipment can handle. Fine fibers and other solids can be tricky to capture, and when they slip through, they increase your TSS (Total Suspended Solids) and eventually end up as sludge that you have to dewater, haul, and dispose of.

Better solids management often starts with better chemistry. Using the right polymer-and getting the dose just right—can make a huge difference in how well solids settle out. We also recommend taking a close look at your mechanical systems. Equipment like DAF units, clarifiers, and sludge dewatering equipment need to be working efficiently to keep volumes under control. And don’t underestimate the power of regular jar testing-it’s one of the simplest ways to dial things in.

Foam: Small Problem, Big Headache

Foam might seem like a minor annoyance, but it can turn into a major disruption if it gets out of hand. In the paper world, foam can show up in process water loops, biological treatment systems, and just about anywhere water and surfactants meet. It can throw off flow measurements, cause tank overflows, and generally make life harder for your operators.

The good news is that foam is usually controllable. The trick is picking the right type of defoamer/antifoam and applying it correctly. There are a variety of defoamer chemistries that behave differently, so what works in one part of the mill might not work in another. It’s also worth looking at what’s upstream-sometimes the best way to control foam is to stop it from forming in the first place.

Corrosion and Scale: The Silent System Killers

Corrosion and scaling problems often sneak up slowly-but when they hit, they hit hard. Boilers, cooling towers, and heat exchangers are all vulnerable, and when scale builds up or corrosion sets in, your system loses efficiency and starts eating into your maintenance budget.

Preventing these issues starts with good water chemistry. That means monitoring pH, hardness, and alkalinity—and adjusting as needed. Antiscalants and corrosion inhibitors are your first line of defense. And don’t forget routine testing and inspections. Catching a problem early is always cheaper than dealing with a failure later.

Navigating Changing Regulations

Let’s face it-environmental regulations aren’t getting any looser. Discharge limits for BOD, TSS, phosphorus, ammonia, nitrogen and other compounds are getting tighter, and mills are expected to do more with less.

It can feel like a moving target, especially if you’re dealing with different limits at different facilities. The best approach is to stay proactive. Know your permit, monitor your trends, and work with a team that understands the regulatory landscape. We’ve seen a lot of success with mills that take a forward-thinking approach-investing in better monitoring tools and exploring reuse strategies before they’re forced to.

Using Chemicals Efficiently Without Wasting Money

Here’s something we talk about with every customer: chemical dosing. Too much and you’re wasting money—or causing problems downstream. Too little and you’re not getting the performance you need. It’s a balancing act, and the right answer depends on your water quality, system setup, and production schedule.

This is where having a dialed-in treatment program makes all the difference. Automated feed systems, jar testing, and regular performance checks can help you stay right in the sweet spot. We also recommend training your operators on what to look for. Empowering your team can lead to better decisions and better results.

Final Thoughts

Water treatment in a paper mill is never simple. But it doesn’t have to be overwhelming either. With the right tools, chemistry, and support, most of the major headaches can be avoided, or at least kept in check.

If you’re running into any of these issues or just want to tighten up your water systems we’d be happy to take a look. Every mill is different, so we work closely with you to build a treatment plan that fits your operation and your goals.

Interested in a second opinion or a fresh set of eyes on your system? Get in touch. We’re here to help.