More than hundred million people in more than hundred cities across the world are benefitting from Yara’s solution to prevent the dangerous and unpleasant hydrogen sulfide gas.
Hydrogen sulfide (H2S) is a nasty gas that has to be treated both in big cities and smaller municipalities. The foul smell is just one of the problems it causes. An even more severe effect of this particular gas is the health risk it poses, in addition to the harm it does to the sewer line systems.
“Instead of dealing with the dangerous gas when it is already released, we are preventing H2S from even developing”
Bernhard Habermeier, Global Product Manager Nutriox in Yara
Even when exposed to a low concentration of H2S, workers in wastewater treatment plants can experience health problems – everything from respiratory disorder to headache and fatigue. At higher concentration short-term exposure can lead to brain damage and in worst case, death.
H2S develops due to lack of oxygen and nitrates in the wastewater systems. Put simply, there are “good” and “bad” bacteria in the system: The good bacteria are fed by oxygen and nitrates, while the bad bacteria consume sulfides and then produce H2S. In general there is limited oxygen in such sewer systems, as well as very little nitrates. And that is where Nutriox comes into the picture. The product is a liquid blend of calcium nitrates (CN), and by adding this to the wastewater system you are feeding the “good” bacteria.
“Basically, we are changing the mix of bacteria in the wastewater systems. Instead of dealing with the dangerous gas when it is already released, we are preventing H2S from even developing,” explains Bernhard Habermeier, Global Product Manager Nutriox.
However, Nutriox is not just about adding nitrates. This is a complete solution, including technology and services. The keyword – as with adding nitrogen fertilizers to the fields – is precision. Too much nitrates in the water system can create unwanted effects, while too little nitrates can lead to H2S developing.
And Yara has created a system for dynamic dosage, enabling the customers to add exactly the amount of nitrates when and where it is needed. This is beneficial both from an environmental and economic point of view.
Protecting passengers and the public
The Government Logistics Department of Hong Kong is one of the most recent customers that have chosen Yara's solution to tackle their H2S problems. Approximately 7 million people live in the city.
Hong Kong International Airport has also started using our solution. The airport is not only one of the busiest passenger airports in the world – it is the busiest cargo airport. With 73,000 employees and more than 60 million passengers travelling each year to almost 200 destinations worldwide, the airport is like a small community. And as every community it has challenges to deal with, including a well-functioning sewerage system.
Cost of corrosion
Growing urbanization is a key a driver for the market of H2S abatement. Another driver is the increased focus on HESQ standards (Health, Environment, Safety & Quality), in particular the need to safeguard the employees.
Another important aspect of the problem is the harm H2S causes on the sewer lines. The gas leads to corrosion of concrete, which is the typical material the lines are made of. Deterioration of the sewerage systems has a significant cost implication for the municipalities.
“When you consider the costs involved in closing off streets in a city and digging through the asphalt to replace the lines, there is a strong incentive to prevent the H2S gas from developing. It is far more
economical to protect the lines, thereby increasing the durability, yielding great savings to municipalities and the public,” explains Habermeier.