Steven De Laet

Steven De Laet did not set out to work in water. He is a chemical engineer by training (a KU Leuven graduate with an executive MBA on top), and he spent the first two decades of his career inside big industry, at Bayer and BASF in process engineering and production, then in steel at ArcelorMittal, in paper and coating at Mondi, and in brewing at AB InBev. Around the age of thirty he hit the question a lot of people in stable corporate jobs quietly ask themselves, which was whether he wanted to do this until retirement, and the answer turned out to be no.

Steven De Laet's real turning point was a thing he kept seeing across all that industry, and could not unsee. Hazardous wastewater, the toxic side-streams that come off chemical and pharmaceutical production, was being loaded onto trucks and driven to an incinerator to be burned, even when the actual problem component was present at parts per million or parts per billion in a big volume of water. In one case he describes streams being shipped from Ireland by truck and boat to Antwerp just to be incinerated. "We're living in 2010, 2012," he remembers thinking, "and we're still driving around with waste streams and putting them in an incinerator. We should be able to do something else with it." In 2015 he turned that into a company, founding InOpSys as a spin-out of KU Leuven, in collaboration with the university's chemical department.

Steven De Laet describes what InOpSys treats as a "soup". A waste stream off a pharmaceutical line is not water with one contaminant in it, it is a mixture of additives, sugars, surfactants, metals, solvents and active pharmaceutical ingredients all at once, and no single water technology cleans that. So InOpSys builds a modular, mobile treatment plant (the easy shorthand is a plant on a truck) and drops it onto the customer's own site, running a train of three or four technologies in series, with advanced oxidation (a chemistry that breaks stubborn molecules apart) usually doing the heavy lifting. The clever commercial part is that InOpSys keeps owning the unit and charges per use, so the polluter does not have to sink capital into an environmental project that might outlive the medicine it was built for, and when a contract ends the unit gets refurbished and sent to the next customer.

Steven De Laet is the first to admit InOpSys was never supposed to do the thing it became known for. "We stated in our business plan we will never do metal recovery," he says, "and the first unit we have built was a unit to recover metals out of wastewater." A customer pushed him into it, the metal was zinc, and once the zinc was out the water was no longer toxic and could be reused instead of incinerated. Then he went one better and found a home for the recovered metal, teaming up with the zinc producer Nyrstar (REACH paperwork and all) to feed it back in as raw material. After zinc came palladium, which at one point was worth more than gold at seventy to eighty thousand euros a kilo, so pulling it out of a side-stream at ppm concentrations turns a disposal cost into a genuine revenue line. That is the InOpSys pitch in one move: take a stream you used to pay to destroy, and get paid for what comes out of it.

Steven De Laet is candid that none of this was fast. It took four or five years and a few brave early customers, the first being Janssen Pharmaceutical (part of Johnson & Johnson), to build enough credibility that the rest of the industry would let a startup park its own units inside an explosion-proof production environment. He frames the whole bet with a line that doubles as his philosophy: "Is it brave and visionary, or is it just stupid? There's a thin line between both, and the question is which side of the line are you on." InOpSys landed on the right side. In 2024 it was acquired by the waste-management group Indaver, with Steven De Laet staying on as CEO, which for a company built on the unfashionable idea of not burning your wastewater is about as clear a vote of confidence as the sector gives.

“I know zinc is a toxic metal, because I tried it at home when I was a young boy. I had some algae in my aquarium and wanted to get rid of them, and I read in a book that a little bit of zinc oxide could help. I was quite impatient, so I did a little bit more, and it worked, despite the fish.”

Steven De Laet is, in the end, the rare founder who turned a twenty-year insider's irritation into a business model: he spent long enough inside chemical plants to know exactly which streams everyone had given up on, and then built the company that refused to give up on them.