1. The problem
While during the biotreatment of non inhibitory chemical effluents containing 30 to 60 g/L salt the main part of organic pollutants (TOC, COD) do become degraded, is the nitrification of the present NH4N by suspended biomass because of high osmotic pressure in the reactor not possible.
2. The solution
Lab scale tests have shown, that nitrification of these high saline effluents become possible by immobilising the nitrifying biomass.
Nitrification of 55 g/L salt containing chemical effluents with suspended (days 1 to 10) and with immobilised nitrifying organisms (days 11 to 40)
During the nitrification with suspended organisms the process crashed within one day because of the high osmotic pressure, respectively the resulting cell disrupture, indicated by increased concentrations of ammoniacal nitrogene and reduced dry solids.. After a new start in the presence of 12 vol.% LEVAPOR (day 12) nitrification has been established within 10 days, remaining stable also after a stepwise increased N-loading rate.