ODOR AND CORROSION PROBLEMS IN CONCRETE SANITARY SEWERAGE SYSTEMS IS A WIDESPREAD PROBLEM.
Sewerage system corrosion is estimated to cost around $110 million per year in Australia.
When dissolved oxygen levels in a system fall below 0.1mg/L, water becomes anaerobic allowing bacteria to reduce dissolved sulphates in the system to hydrogen sulphide gas (rotten egg smell). Hydrogen sulphide is the major cause of odor and corrosion in waste water systems.
WHAT IS MAGNESIUM HYDROXIDE
Magnesium hydroxide is an inorganic compound with the chemical formula Mg(OH)2. As a suspension in water, it is often called ”milk of magnesia” because of its milk-like appearance. ACTI-Mag™ is a concentrated stabilized suspension of magnesium oxide.
HOW DOES IT WORK?
One of the easiest and most cost effective ways to reduce hydrogen sulphide generation is to change the pH of the system. Soluble hydrogen sulphide is present due to anaerobic mechanisms at low pH (5). As pH approaches 7, approximately 50% of the dissolved hydrogen sulphide is released to the air. This has two undesirable effects:
• Odor release (rotten egg gas)
• Hydrogen sulphide is converted into strong sulphuric acid (by the action of Thiobacillus Bacteria) which can cause extensive corrosion to infrastructure.
• Magnesium hydroxide has a higher neutralizing value per dry kilo when compared with caustic and lime (traditionally used, which lowers chemical consumption, making magnesium hydroxide a cost competitive option due to the reduction in plant and equipment requirements. It is also much safer to handle, as it is non-hazardous to humans and the environment, non-toxic and noncorrosive.