The discharge of N-NH4 and N-NO3 into the environment is harmful the fertilizers enhance growth of algae and bacteria in natural water bodies. Input of nutrients into the water above a natural balanced level causes so called, eutrophication of the water body and can result in fish kill and a loss of biodiversity.

There have been several attempts already to clean this type of waste water e.g by means of biological treatment methods. But it was found that this method is very costly since with conventional nitrification / denitrification huge amounts of organic material have to be dosed to the waste water to feed the micro organisms with a carbon source. In addition to that nitrogen feed concentrations are relatively high. As a result it is very difficult to accomplish emission limits of 1.5 mg/L N-NH3 to 10 mg/ L N-N03: This would equal a removal rate of 95 % and more, which would mean at least a multi-stage plant and most likely a polishing step. Hence to rely on biological treatment would mean high costs and resource consumption, and nelther ammonia nor nitrate would be recovered.

A solution for this situation is offered by the so called FERTAREX water treatment process which has been developed by the ‘ARIONEX Wasseraufbereitung’a company that is based in Switzerland. Slx plants of this type have been built in Europe and Asla. The first unit was installed in 1975, and over the last 35 years the economics and reliability of the process has been demonstrated.