Wastewater purification of biogenic elements

The retention capacity of the ESPA-1 membrane for nitrates, nitrites, ammonium, and phosphates has been investigated. Its application was shown to be most effective for the removal of phosphates. In this case the membrane retention capacity amounts to ∼99.8%. Nitrates are removed on conditions of up to the 90% permeate conversion in case of their initial concentration of 400 mg/dm3 and up to the 70% conversion in the interval of initial concentrations of 400–700 mg/dm3. In the case of the initial concentration of ammonium ions equal to 300 mg/dm3 and 400 mg/dm3 their removal is possible up to the 70% and 60% permeate conversions, respectively. In relation to nitrites this membrane shows a low retention capacity; however the preliminary oxidation of the latter to nitrates makes it possible to ensure their sufficiently effective removal.