Product story

How one bacterium can lay waste to an entire wastewater system (and how Sewper® Liner will save it)

Meet Thiobacillus, a common bacteria found in marine and terrestrial habitats that oxidizes sulfur to generate sulfuric acid, in turn dissolving and corroding concrete and steel. Enter Sewper® Liner, Imerys’ most recent innovation designed especially for the protection of concrete elements of new wastewater infrastructure assets.

Sewer image Sewperliner

Fact. Wastewater conveyance or collection systems need protection. This is because hydrogen sulfide (H2S), which occurs naturally as a compound in wastewater infrastructure, can be released as a gas under acidic or turbulent conditions. Thiobacillus bacteria present in the system react with this hydrogen sulfide gas to form sulfuric acid, which, as mentioned before, corrodes sewer pipes, weakens concrete structures, and ultimately reduces an asset’s lifespan and increases the risk of dangerous sewer collapses.

The best solution, you guessed it, is to leave Thiobacillus out by protecting reactive surfaces. While there are multiple solutions available, these are not all born equal. A common solution today, when H2S biogenic corrosion is expected, is the spraying of polymer liners such as epoxy. Sadly, this option lacks durability and too often fails after only a few years.

Sewper Liner: A new chapter in the protection against H2S biogenic corrosion

Imerys’ new innovative calcium aluminate solution, Sewper Liner, is  especially designed to coat and protect new-build wastewater infrastructure and provide the highest level of durability against severe H²S biogenic corrosion. It achieves long-lasting protection on dry, flat and smooth walls of new concrete assets and is based on the same technology as Imerys’ highly successful SewperCoat® solutions. It is three to five times thinner than SewperCoat, making it ideal for the larger, flat surfaces of new wastewater concrete assets. It can be sprayed quicker, speeding up the construction process. This, in turn, keeps the costs down without compromising long term H2S corrosion resistance and durability associated with calcium aluminate technology. Sewper Liner also proves very effective on existing cracks, providing a thin layer of mineral protection that efficiently and rapidly bonds and covers a large surface area of dry concrete walls, resulting in higher durability with lower environmental impact (ISO 14040:2006).

Thiobacillus, no hard feelings. As Claire Brown, Imerys Global Marketing Manager for Infrastructure, puts it “Sewper Liner is yet another example of how Imerys know-how, insight, innovation and a clear demand from clients have helped craft a smart calcium aluminate solution that outperforms previous options on the market, paving the way for much longer-lasting and more sustainable means of protecting infrastructure challenges.