21 July 2016
Many waste-water plants suffer from the effects of hydrogen sulphide degradation. In this short article, Mark Lemon, Managing Director of CSC Services, looks at what it is and what can be done to protect assets from degradation:
“Hydrogen sulphide results from septic conditions during the collection and treatment of wastewater. This colourless gas, known for its rotten egg smell, is produced by the biological reduction of sulphates and the decomposition of organic material. It forms at virtually all points of a waste water system from interceptors to holding tanks and drying beds and is highly corrosive.
Polyurea is a protective coating. It is highly resistant to hydrogen sulphide and hydrocarbons also commonly found in wastewater systems. It is a highly elastic waterproof coating resistant to chemicals and abrasion.
Polyurea cures in seconds. It has rapid re-use times. When coated with polyurea systems, substrates such as concrete and steel can be submerged or buried. In contrast, traditional and even fast-cure epoxies can take a week to 10 days to completely cure.
Because of their elasticity, polyurea coatings are ideal for substrates such as concrete, which tend to crack. As an elastomer, these coatings have the ability to stretch and bridge gaps. Due to this flexibility, polyurea coatings are not limited by extremes of temperature, while rigid coatings tend to crack as the substrate expands or contracts under these conditions.
Polyurea can be built to any thickness in one coat so costs associated with application are reduced. Polyurea coatings also offer excellent adhesion. They are regularly tested at up to 2000 psi, compared with conventional epoxy coatings at 600 to 800 psi. Aliphatic polyurea coatings have exceptional UV light resistance, so they will withstand weathering and exposure to sunlight when applied to exterior surfaces.
Clarifying agents, chemicals used for PH correction and disinfection in clean water tanks structures also have damaging effects on concrete and steel structures. Polyurea is pending DWI approval which will significantly open up opportunities to protect structures across the clean water sector in the near future.
Polyurea is an extremely versatile coating that has applications across industries. In the power sector it can also be used to protect steel storage tanks, concrete bunds, internal and external pipe-work.”
CSC Services are an approved installer of Polyurea. For more information about Polyurea and the other coatings that CSC Services provide visit www.csc-services.co.uk/coatings