A Study on Ammonia Nitrogen, Phosphorus and Organic Pollutants Removal of Zeolites by Salt Modification
In this study, the zeolites were treated by NaCl and FeCl3 as an active agent, combined with calcination modification. We studied the ammonia nitrogen (NH3-N) and phosphorus (P) removal of the modified zeolites. The results showed that concentration of NaCl and FeCl3 affected NH3-N and P removal of Secondary sewage effluent greatly. The optimal concentrations of NaCl and FeCl3 were 2.0% and 0.4%. At this condition, the NH3-N and P removal rate of zeolites reached the peak. Application experiments revealed that NH3-N removal rate reached 80.9%, P removal rate reached 83.4%, and COD removal rate reached 96.0%, when the dosage of modified zeolites was 3.0g/L and adsorption duration was 2h for Secondary sewage effluent with 6.0mg/L NH3-N concentration and 1.5mg/L P concentration. After the treatment, the NH3-N and P concentration met Reclaimed Water Quality Standards. The adsorption capability of modified zeolites was better when the pH ranged from 3 to 6. The reason of using NaCl+FeCl3 was that Na+ could exchange the NH3-N in the effluent; Fe3+was able to combine with PO43- in the sewage and formed precipitate; and Fe3+ could also oxidize the organic pollutants.
H. Lin et al., "A Study on Ammonia Nitrogen, Phosphorus and Organic Pollutants Removal of Zeolites by Salt Modification", Advanced Materials Research, Vols. 383-390, pp. 947-952, 2012