Water4Crops Session; IFAT India th -10 th October, Mumbai, India

Transcription

1 Water4Crops Session; IFAT India 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

2 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

3 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 ( m 3 ) for of municipal (raw or after primary sedimentation) and industrial wastewaters (i.e. tannery, textile) Working on a 5000 PE SBBGR

4 Conventional WWTP VS SBBGR Preliminary Primary Secondary Conventional WWTP Tertiary Conventional WWTP Sludge WWTP based on SBBGR technology Preliminary SBBGR SBBGR SBBGR Dewatering Sludge

5 SBBGR operation - How does SBBGR work? drawing filling inf E V eff cycle recycle reaction air (or no air)

6 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

7 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

8 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

9 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

10 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: kgcod/m 3 d) Mean value standard deviation Influent [mg/l] Effluent [mg/l] 5 4 Removal [%] Influent [mg/l] Effluent [mg/l] 32 9 Removal [%] Influent [mg/l] Effluent [mg/l] Removal [%] Influent [mg/l] Effluent [mg/l] Removal [%] Influent [mg/l] 4 1 Effluent [mg/l] Removal [%] Parameter Mean value standard deviation ph Influent Effluent Conductivity Influent [ms/cm] Effluent [ms/cm] SAR Influent Effluent *SAR: Sodium Adsorption Ratio

11 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: kgcod/m 3 d) Mean value standard deviation Influent [mg/l] 420 1,007 Effluent [mg/l] 5 4 Removal [%] Influent [mg/l] 728 1,141 Effluent [mg/l] Removal [%] Influent [mg/l] Effluent [mg/l] Removal [%] Influent [mg/l] Effluent [mg/l] Removal [%] Influent [mg/l] Effluent [mg/l] Removal [%] Influent Effluent Sand filter effluent

12 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 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 [%]

13 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) Standard deviation Removal efficiency (%) Standard deviation Mean value (MPN/100mL) Standard deviation MPN: Most Probable Number. Removal efficiency (%) Standard deviation

14 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) Standard deviation Removal efficiency (%) Standard deviation Mean value (CFU/100mL) Standard deviation Removal efficiency (%) Standard deviation CFU: Colony Forming Units; PFU: Plaque Forming Units.

15 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 , Mean value standard deviation E. coli never exceded 50 MPN/100ml

16 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

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