Water4Crops Session; IFAT India 2014 9 th -10 th October, Mumbai, India SEQUENCING BATCH BIOFILTER GRANULAR REACTOR (SBBGR) FOR WASTEWATER TREATMENT AND REUSE WATER RESEARCH INSTITUTE IRSA MARCO DE SANCTIS: desanctis@irsa.cnr.it
Conventional WWTP Preliminary Primary Secondary Tertiary Low settling speed (< 1 m/h) Sludge Low biomass concentration (4-6 kgtss/m 3 ) Low organic load rate (< 1 kgcod/m 3 d) High sludge production (40-60 g/pe d) Low flexibility High area requirement
Sequencing Batch Biofilter Granular Reactor main skills In comparison with the conventional systems, SBBGR technology is able: to perform in a single stage the entire wastewater train; to reduce area requirement; to offer higher operational flexibility and robustness; to reduce the sludge production (up to 80%); to produce an excess sludge already stabilized; to produce a high quality effluent. Already applied at pilot-scale level (0.3-1.5 m 3 ) for of municipal (raw or after primary sedimentation) and industrial wastewaters (i.e. tannery, textile) Working on a 5000 PE SBBGR
Conventional WWTP VS SBBGR Preliminary Primary Secondary Conventional WWTP Tertiary Conventional WWTP Sludge WWTP based on SBBGR technology Preliminary SBBGR SBBGR SBBGR Dewatering Sludge
SBBGR operation - How does SBBGR work? drawing filling inf E V eff cycle recycle reaction air (or no air)
SBBGR operation - What makes SBBGR better? Recirculation flow generates shear stress into packed zone of SBBGR BIOFILM attached biomass fraction High biomass concentration (30-50 kg/m 3 ) High sludge retention time ( 200 d) GRANULES granular biomass fraction
Aims The overall aim of this activity is the evaluation of SBBGR effectiveness for treating and reusing in agriculture wastewater produced by small communities Monitoring parameters Physico-chemical parameters: COD, suspended solids, nitrogen, phosphorus, ph, SAR, conductivity, heavy metals, boron, pesticides, aromatic compounds Microbiological parameters: Faecal Contamination Indicators (E.coli, Clostridia spores, Somatic E. coli bacteriophages), Specific and relevant pathogenic Protozoa (Cryptosporidium parvum and Giardia lamblia) and Salmonella. ITALIAN limit for pathogenic indicators: E. coli: 10 CFU/100 ML (< 100 CFU/100 ML in 80% of samples) Salmonella: absent
Strategies for wastewater reuse in agriculture Phase 1 UV lamp SBBGR alone; SBBGR followed by filtration and UV radiation; SBBGR followed by filtration and peracetic acid addition filtration unit SBBGR unit SBBGR effluent tank PAA disinfection unit
Strategies for wastewater reuse in agriculture Phase 2 BIOLOGICAL SISTEM chemical disinfectant (peracetic acid) Chemical disinfection E V eff. P R air P A Physical disinfection P D filter UV eff. inf. P R air P A
Main physical and chemical gross parameters TSS COD Parameter NH 4 + TN Ptot Results obtained from a lab-scale SBBGR Phase 1 (Volume: 30 L; HRT: 1 d; OLR: 1.15 0.36 kgcod/m 3 d) Mean value standard deviation Influent [mg/l] 215 103 Effluent [mg/l] 5 4 Removal [%] 97.2 1.9 Influent [mg/l] 492 146 Effluent [mg/l] 32 9 Removal [%] 93.2 2.2 Influent [mg/l] 42 11 Effluent [mg/l] 0.3 0.8 Removal [%] 99.4 1.8 Influent [mg/l] 58 13 Effluent [mg/l] 10.0 3.9 Removal [%] 82.6 6.1 Influent [mg/l] 4 1 Effluent [mg/l] 3.3 0.8 Removal [%] 15.3 14.2 Parameter Mean value standard deviation ph Influent 7.5 0.1 Effluent 7.8 0.2 Conductivity Influent [ms/cm] 891 88 Effluent [ms/cm] 680 44 SAR Influent 2.7 0.7 Effluent 3.5 0.4 *SAR: Sodium Adsorption Ratio
Removal of the main physical and chemical parameters TSS COD Parameter NH 4 + TN Ptot Results obtained from a pilot-scale SBBGR Phase 2 (Volume: 330 L; HRT: 1 d; OLR: 0.90 1.40 kgcod/m 3 d) Mean value standard deviation Influent [mg/l] 420 1,007 Effluent [mg/l] 5 4 Removal [%] 98.1 1.0 Influent [mg/l] 728 1,141 Effluent [mg/l] 43 21 Removal [%] 91.9 3.3 Influent [mg/l] 54.5 25.2 Effluent [mg/l] 0.4 1.8 Removal [%] 99.2 3.4 Influent [mg/l] 77.3 28.7 Effluent [mg/l] 14.3 6.7 Removal [%] 78.5 13.8 Influent [mg/l] 9.4 4.9 Effluent [mg/l] 3.5 0.7 Removal [%] 48.2 32.2 Influent Effluent Sand filter effluent
Disinfection efficiency of SBBGR Results obtained from a lab-scale SBBGR Phase 1 Parameter Mean value standard deviation Total coliforms E. coli Clostridium perfringens spores Somatic coliphages (virus) Giardia lamblia Cryptosporidium parvum Salmonella Influent[MPN/100mL] Effluent [MPN/100mL] Influent[MPN/100mL] Effluent [MPN/100mL] Influent [CFU/100mL] Effluent [CFU/100mL] Influent [PFU/100mL] Effluent [PFU/100mL] Influent [cysts/l] Effluent [cysts/l] Influent [oocysts/l] Effluent [oocysts/l] Influent Effluent 4.8 4.5 10 6 5.9 3.2 10 4 5.1 6.8 10 5 0.9 1.2 10 3 2.7 2.4 10 5 2.9 1.9 10 3 6.3 9.8 10 4 3.8 6.5 10 3 4.1 6.2 10 4 5.0 6.4 2.8 3.3 10 2 0.9 1.2 Present Not present MPN: Most Probable Water4Crops Number; Session :IFAT CFU: India Colony 2014, 9th Forming & 10th Oct Units; 2014, Mumbai, PFU: India Plaque Forming Units Removal [%] 99.18 0.78 99.45 0.65 98.68 0.82 90.49 7.31 99.99 0.02 99.39 1.00
E. COLI TOTAL COLIFORMS Disinfection efficiency of SBBGR followed by filtration and UV or Peracetic acid Results obtained from a lab-scale SBBGR Phase 1 UV PAA (1 mg/l) PAA (2 mg/l) PAA (3 mg/l) Mean value (MPN/100mL) 8.0 10 1 7.0 10 2 2.4 10 2 5.9 10 1 Standard deviation 1.1 10 2 1.1 10 3 4.6 10 2 1.3 10 2 Removal efficiency (%) 99.01 94.00 97.58 99.39 Standard deviation 1.30 11.29 4.79 1.36 Mean value (MPN/100mL) 3.4 6.3 0 0 Standard deviation 5.5 1.2 0 0 MPN: Most Probable Number. Removal efficiency (%) 98.48 95.23 100.00 100.00 Standard deviation 2.24 10.61 0.00 0.00
CLOSTRIDIUM PERFRINGES SOMATIC COLIPHAGES Disinfection efficiency of SBBGR followed by filtration and UV or Peracetic acid Results obtained from a lab-scale SBBGR Phase 1 UV PAA (1 mg/l) PAA (2 mg/l) PAA (3 mg/l) Mean value (PFU/100mL) 2.0 10 1 2.9 10 3 4.9 10 2 8.3 10 1 Standard deviation 2.0 10 1 4.9 10 3 7.9 10 2 9.5 10 1 Removal efficiency (%) 94.78 71.62 92.40 95.90 Standard deviation 5.53 35.05 5.24 5.12 Mean value (CFU/100mL) 1.8 10 3 2.0 10 3 1.3 10 3 1.3 10 3 Standard deviation 1.7 10 3 1.8 10 3 1.5 10 3 1.1 10 3 Removal efficiency (%) 21.11 23.37 38.55 51.62 Standard deviation 24.70 17.84 8.33 24.17 CFU: Colony Forming Units; PFU: Plaque Forming Units.
Disinfection efficiency Parameter Total coliforms E. coli Clostridium perfringens spores Somatic coliphages Results obtained from a pilot-scale SBBGR Phase 2 Influent [MPN/100ml] Effluent [MPN/100ml] Removal [%] Removal after sand filt. [%] Influent [MPN/100ml] Effluent [MPN/100ml] Removal [%] Removal after sand filt.[%] Influent [CFU/100ml] Effluent [CFU/100ml] Removal [%] Removal after sand filt. [%] Influent [PFU/100ml] Effluent [PFU/100ml] Removal [%] Removal after sand filt. [%] Mean value standard deviation 1.4 3.4 10 7 1.1 2.9 10 5 98.81 1.43 99.94 0.05 4.9 4.4 10 4 4.6 3.7 10 1 99.85 0.17 99.97 0.02 2.7 1.4 10 5 0.7 1.0 10 5 77.84 23.27 99.16 0,77 4.7 7.8 10 4 2.7 4.7 10 3 94.44 1.33 99.52 0.61 Mean value standard deviation 1.1 1.6 10 1 E. coli never exceded 50 MPN/100ml
Preliminary conclusions SBBGR alone is able to remove about 99% of all the investigated pathogenic indicators, thus indicating that it acts also as a good disinfection system; The microbiological quality of SBBGR effluent was much higher than that of the conventional municipal wastewater plants. SBBGR system up-grated with sand filtration is able to produce an effluent with a physical and chemical quality that conforms to the standards required in Italy for agricultural reuse; (SBBGR + UV) or (SBBGR + PPA-1mg/L) reduce the E. coli content below 10 CFU/100mL; THANK FOR YOUR ATTENTION