SHARON

Recommendations

Info

SHARON N-Removal Over Nitrite Results of rejection water treatment SHARON Rotterdam parameter dimension value Nkj influent mg/l 1.000 - 1.500 N-removal % > 95 HRToxic day 1,0 - 1,5 temperature 0 C 30 - 40 pH - 7,0 - 7,5 oxygen ppm 1,0 - 1,5 + NH4 + NH4 NITRIFICATION + + 1,5 O2 2 O2 DENITRIFICATION - NO2 + H2O + 2H + - NO3 25% ENERGY SAVED + H2O + 2H + - - 6 NO2 + 3CH3OH + 3 CO2 3N2 + 6 HCO3 +3 H2O - - 6 NO3 + 5CH3OH + CO2 3N2 + 6 HCO3 +7 H2O 40 % METHANOL SAVED In conventional aerobic systems the biological ammonia So in a system without sludge retention they can oxidation comprises of two steps. survive at shorter residence times. First the oxidation of ammonia to nitrite by Nitrosomonas and In a reactor with a temperature of 30 to 40 o C and a subsequently the oxidation of nitrite to nitrate by Nitrobacter. short residence time mainly ammonia oxidation to At higher temperatures Nitrosomonas prove to have significantly nitrite occurs because Nitrobacter is washed out of higher maximum growth rates than Nitrobacter. the system. PROCESS FEATURES FULL SCALE PLANTS • no sludge retention • location: WWTP Utrecht (NL) • simple process capacity: 400.000 pe • nitrite route reduces up to: influent: rejection water 25% oxygen demand N-load: 900 kg Nkj/d 40% methanol requirement operational: 1997 40% sludge production • maximum usage of alkaline buffer • location: WWTP Rotterdam (NL) capacity: 470.000 pe influent: rejection water APPLICATION load: 850 kg Nkj/d • rejection water of sludge digestion operational: 1999 • leachate water of landfill site • waste water of composting process • location: WWTP Zwolle (NL) • condensate of sludge drying capacity: 200.000 pe influent: rejection water N-load: 410 kg Nkj/d operational: 2003 Grontmij Water & Waste Management Utrechtseweg 2 3732 HB De Bilt Postbus 14 3730 AA De Bilt The Netherlands Information: ir. R. van Kempen ir. H.W. de Mooij T. + 31 30 694 32 10 F. + 31 30 695 63 66 • location: WWTP Beverwijk (NL) capacity 320.000 pe influent: rejection water and condensate sludge drying N-load: 1.200 kg Nkj/d operational: 2003
3 Operating experience in The Netherlands with a high rate process for total nitrogen control SHARON at Rotterdam and Utrecht INTRODUCTION This paper presents the performance results of the start-up and continuing operations of the SHARON process at the Utrecht and Rotterdam, Dokhaven Waste Water Treatment plants in the Netherlands. The concepts for the SHARON process were initially developed by Delft University of Technology, Water Board ZHEW, and Grontmij, a Dutch engineering and construction company. These concepts were pilot tested at Utrecht and Rotterdam; then they were implemented full scale. The full-scale operations illustrate that the claims for the SHARON process have been successfully achieved. THE SHARON PROCESS The SHARON process is a new and innovative process for total nitrogen removal which allows for nitrification/denitrification at minimal SRT values, resulting in a substantially smaller reactor volume than is currently required for conventional total nitrogen removal. In addition the process allows for both a savings of NITRIFICATION + NH4 + NH4 - + 1,5 O2→ NO2 - + 2 O2→ NO3 DENITRIFICATION twenty five percent (25%) in oxygen transfer energy and forty percent (40%) in carbon feed for denitrifying bacterial growth as compared to conventional processes because of the unique metabolic pathway used (Figure 1). The pathway is conversion of ammonia to nitrite and conversion of nitrite to nitrogen, the chemical species nitrate is not produced or converted. The core concept on which the process is based is that at temperatures above 15°C, and especially between 30- 40°C, the growth rates of the nitrifying bacteria are greater than the nitrafying bacteria. This allows for the design of a selector reactor where in nitroso-genera bacteria (nitrifying) predominate over the nitro-genera bacteria (nitrafying) (Figure 2). The nitrite produced is converted to nitrogen gas by denitrifying bacteria under anoxic conditions. This two step reaction can occur in either space or time (Figure 3). SHARON at UTRECHT Design basis The City of Utrecht is located in central Netherlands 25 miles Southeast of Amsterdam on the Amsterdam- Rijnkanaal. Utrecht is the fourth largest city in the Netherlands with a population of approximately 260,000. The city can trace its roots to Roman times. The waste waster plant is a two step ammonia removal plant. Both the aeration tanks and intermediate sedimentation tanks are covered. The thickened biosolids are treated by anaerobic digestion and then dewatered in centrifuges. The recycled centrifuge decant is treated by the SHARON process. The SHARON process at this plant is a two-stage system with separate reactors for nitrification/nitrafication and denitrification/denitrafication (Figure 4). That is the reactions are separated in space, two stages. The centrifuge’s decant being recycled is pumped through screening unit and into the first reactor which is equipped with high efficiency jet-aerators (Korting) that hjGrontmij + H2O + + H2O + + 2 H + + 2 H + 25% REDUCTION ENERGY COSTS - - 6 NO2 + 3 CH3OH + 3 CO2 → 3 N2 + 6 HCO3 - - 6 NO3 + 5 CH3OH + CO2 → 3 N2 + 6 HCO3 40% REDUCTION METHANOL COSTS Figure 1 Biochemistry + 3 H2O + 7 H2O Min. SRT (day) 6,0 5,0 4,0 3,0 2,0 1,0 0,0 0 10 20 Temperature (oC) 30 40 Nitrosomonas Nitrobacter Figure 2 Growth rates
Page 1 and 2: Influent Effluent (Alkalinity) C-so
Page 3 and 4: Contents hjGrontmij 1 Introduction
Page 5: SHARON N-Removal Over Nitrite SHARO
Page 9 and 10: mg/l and usually below 100 mg/l fro
Page 11 and 12: Start-up The SHARON at the Rotterda
Page 13 and 14: OTHER FACILITIES The success of the
Page 15 and 16: Project SHARON pilot test WWTP Deur
Page 17 and 18: SHARON Utrecht (NL) Overview SHARON
Page 19 and 20: SHARON Beverwijk (NL) SHARON Beverw
Page 21 and 22: SHARON Garmerwolde (NL) CLIENT(S) W
Page 23: 6 Contact Grontmij Nederland bv Wat

SHARON

Create successful ePaper yourself

Delete template?

Save as template?