Characteristics of nutrient element migration in electrodeionization process

Abstract

In this work, a constructed five-compartment electrodeionization (EDI) device was used to treat simulated wastewater with ammonium and phosphate ions. The voltage and influent concentration in the EDI system were examined. Meanwhile, the ion migration characteristics in the EDI were studied. Results showed that at optimal conditions, operating at 15 V, with an ammonia nitrogen concentration of 1500 mg/L, and a phosphate concentration of 300 mg/L, the removal rates of ammonia nitrogen and phosphate were 98.50 % and 73.85 %, respectively. The energy consumption of ammonia and phosphorus was 1.347 kWh/mol and 43.629 kWh/mol. The ion migration characteristic experiments revealed that adsorption and desorption rates of the resin do not impose limitations on ion migration in EDI; the ion migration in EDI device is mainly through the resin phase and the rate of ion migration is intricately influenced by the concentration of nutrient ions present on the resin.