Wastewater treatment plant rehabilitation – concrete protection against biogenic sulphuric acid corrosion in tanks, pumping stations and digesters

Wastewater treatment plant rehabilitation – concrete protection against biogenic sulphuric acid corrosion in tanks, pumping stations and digesters

In treatment plants, pumping stations and storm tanks, biogenic sulphuric acid, ammonium and soft water attack concrete; abrasion, frost and temperature changes add to the stress. Without suitable protection, structures lose concrete cover and load-bearing capacity. We organise the repair with resistant mineral or resin-bound systems – in sections during operation where technically safe.

Applications

• Primary, aeration and secondary clarifiers
• Sewage pumping stations, rising main outlets and inlet channels
• Storm overflow and stormwater retention tanks
• Digesters, sludge stores and gas spaces
• Industrial wastewater pre-treatment, e.g. in food plants

Scope of services

• Damage diagnosis: cause, concrete strength, chemical exposure and structural condition
• Removal of damaged concrete by high-pressure water jetting
• Reprofiling with mortars whose resistance to the actual exposure (e.g. biogenic sulphuric acid) has been verified
• Protective coating or lining for the relevant exposure class
• Execution in sections with dewatering, operational coordination and occupational safety (H₂S, oxygen deficiency, explosive atmospheres)

Exposure classes and components

In Germany, DIN 19573 defines exposure classes (XWW) for cementitious mortars in drainage systems; XWW4 stands for the special exposure to biogenic sulphuric acid corrosion. The class is one basis for system selection – what matters is the verified resistance of the specific system and the structure and operating conditions.

Digesters, gas spaces and pumping stations require special safety measures against hydrogen sulphide, oxygen deficiency and explosive atmospheres.

Typical components: inlet channels and screw pumps, grit and grease traps, clarifiers and aeration tanks, digesters and gas spaces, pumping stations and storm overflow tanks.

How your project works

1. Damage diagnosis: photos, structural data, H₂S measurements, concrete strength and structural condition
2. Definition of exposure and selection of a system with verified resistance
3. Safety and sequencing concept with dewatering or bypassing
4. Removal by high-pressure water jetting, reprofiling, coating or lining
5. Testing, documentation and recommissioning tank by tank

Information for your quotation

• Type of structure, dimensions and year of construction
• Type of wastewater, pH value, H₂S load (if measured)
• Damage with photos, expert report if available
• Options for taking out of service or bypassing
• Preferred execution period

Frequently asked questions

How do you recognise biogenic sulphuric acid corrosion?
Soft, powdery concrete above the water line, exposed aggregate and reinforcement – often in gas spaces, pumping stations and at rising main outlets.

Can the work be done during operation?
Usually in sections with dewatering or bypassing; tanks are taken out of service one after the other.

Related services

• Pipe Rehabilitation
• Separator rehabilitation – coating of oil, grease and light liquid separators
• Drinking water tank rehabilitation – service reservoirs, water storage and fire water tanks
• Pipe and sewer rehabilitation for industry and municipalities

Send inspection report, photos and documents by e-mail

Price on request – you receive an individual quotation after technical review. Use the “Request a quote” button or our contact form.