Abstract
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•Novel Mass Bio System and ion exchange combined treatment method used in this study.•About 675 bed volumes (BV) raw water treated before effluent NO3− above 10 mg-N/L.•Breakthrough capacity 19.99 kgNO3−-N/m3-resin and removal rate was about 98.709%•The resin saturated with NO3− was regenerated with 3–5% NaCl solution.•NH4+-N removal capacity was 120 t/d.
The gradual increase of nitrate in surface waters over the last few decades have led to a great concern worldwide. The maximum acceptable concentration for nitrate is 45 mg/L in drinking water. Treatment methods for drinking water are relatively focused on nitrate removal. In this study, Mass Bio System (an advanced water purification product) and ion exchange (physicochemical process) methods were employed and combined for the removal of ammonia nitrogen (NH4+-N) in micro polluted water bodies. NH4+-N was nitrified to nitrate nitrogen (NO3−-N) by MBS in inner-circulated fluidized bed reactor continuously. Nitrate (NO3−) removal by IRA400JCl ion exchange resin was efficient and the process fit to Langmuir adsorption isotherm very well. Freundlich Isotherm was also applied. About 675 bed volumes (BV) raw water could be treated before effluent NO3− above 10 mg-N/L. Breakthrough capacity could reach 19.99 kgNO3−-N/m3-resin, and the removal rate was about 98.709%. The resin saturated with NO3− was regenerated smoothly and conveniently with 3–5% NaCl solution. The regeneration spent brine was treated by the anaerobic biological denitrification sequencing batch reactor (SBR) after two months of cultivation and acclimation. In the combined treatment system 2.5 m3 inner-circulated fluidized bed reactor with MBS (the filled rate of MBS in the reactor was 10%) and 0.25 m3 ion exchange columns were necessary while NH4+-N removal capacity was 120 t/d. The SV for biological part was about 48 m3/m3·d while 480 m3/m3·d for ion exchange part. This study is an approach in reducing exposure to nitrate from drinking water.