1. Environmental and sanitary engineering Reserach group
FIU – Italy WORKSHOP
WATER AND ENVIRONMENTAL GLOBAL CHALLENGES:
INTERNATIONAL WATER INFRASTRUCTURES AND SECURITY
FIU- MMC OE 112 May 25, 2017
Riccardo Gori
Environmental and sanitary engineering Reserach group
University of Florence

2. Who?
– Professors and researchers
Claudio Lubello Piero Sirini Riccardo Gori and Giulio Munz
- PhD Students, Post_Doc, Fellows and Collaborators
Cecilia Caretti, Giuseppe Cocchi, Tommaso Lotti,
Alberto Mannucci, Sara Sguanci, Laura Palli
Giacomo Bellandi, Francesco Spennati,
Cecilia Polizzi, Iacopo Ducci

3. HOW? Department of civil and environmental engineering 10 km
Prato WWTPs (GIDA SPA)
School of Engioneering
Starting point: strong network with local municipalities and industries
Florence WWTP (UNALAB joint lab
Cuoiodepur WWTP (CER2CO joint lab)

4. HOW? Department of civil and environmental engineering CARBALA PROJECT
EU Exchange projects
CARBALA PROJECT
Carbon Balancing for nutrient removal
Biosur PROJECT
Rotating Bioreactors for Sustainable Hydrogen Sulphide Removal
Starting point: strong network with local municipalities and industries
Biocloc PROJECT
BIOprocess ControL through Online titrimetry to reduce Carbon footprint in wastewater treatment
LESSWATT PROJECT
Innovative wireless tool for reducing energy consumption and GHGs emission of WRRFs

5. HOW? Department of civil and environmental engineering
PRIN project "Emerging contaminants in air, soil, and water: from source to the marine environment"
PRIN project "Energy consumption and GreenHouse Gas (GHG) emissions in the wastewater treatment plants: a decision support system for planning and management"
M.E.TA. PROJECT
Matter and Energy from Tannery Sludges
Starting point: strong network with local municipalities and industries
Use of fungi for the removal of recalcitrant compounds from industrial wastewater
Use of fungi for the removal of micropollutants from urban wastewater
Applicability of the Anammox process for swine wastewater treatment

6. To construct an innovative tool for monitoring the biological processes in activated-sludge plants (continuous online differential titrimetry); 1
To use this tool for the monitoring and control of operating conditions in a real plant (Calice wastewater treatment plant); 2
To quantify the improvement of the effluent’s quality and the reduction in energy and environmental costs. 3

7. Differential because the instrument calls for the use of two identical reactors that work under the same operating conditions, similar to those of the oxidation tanks from which they are fed. There are numerous processes responsible for pH variations in activated sludge. To isolate only the contribution of nitrification, the only difference between the two reactors is the fact that one of them includes an inhibitor of the nitrification process. In this way, the difference in the soda dosage in the two reactors (one inhibited, the other one not inhibited) is directly linked to the nitrification rate.
Online because the tool functions as a process probe.
Continuous because the tool is continuously fed with activated sludge taken from the oxidation tanks.

10. 1. CONTROL OF AERATION SYSTEM
The nitrification rate, which is continuously returned by the instrument, makes it possible to calculate the optimal dissolved-oxygen value to be maintained in the oxidation tank in order to ensure the removal of nitrogen in compliance with the limits for the discharged water.

11. 2. TIMELY IDENTIFICATION OF INHIBITION PHENOMENA
The trend of the nitrification rate permits the real-time detection of the effects of any compounds that are toxic or inhibit the nitrification process and that may influence the plant.
3. INNOVATIVE PROCEDURE FOR THE CALIBRATION OF THE KINETIC PARAMETERS OF THE NITRIFYING BIOMASS
The maximum nitrification rate, measured continuously, permits a more precise calibration of the kinetic parameters of the nitrifying biomass compared to the calibration carried out with conventional batch kinetic tests.

12. Mass balance of oxygen in gas phase
OFF-GAS TEST
The off-gas method is a tecnique developed for monitoring the oxygen transfer efficiency of air diffused aeration systems (Redmon et al., 1983).
Mass balance of oxygen in gas phase
Oxygen transferred to the liquid phase = oxygen removed from the gas phase

13. OFF-GAS TEST 1. Hood for off-gas collection
2. Connection pipe between the hood and the analyzer
3. LDO probe
4. Oxymeter
5. Off-gas analyzer

14. OFF-GAS TEST
Off-gas analyzer

15. OFF-GAS TEST Transfer efficiency in process conditions (OTE, %):
Transfer efficiency in standard conditions in process water (αSOTE, %):
Cs,20: saturation 20°
Cs,pwT: saturation process conditions
α-factor:
α = αSOTE/SOTE
β = 1- (0.01 TDS)/1000
oxygen transfer rate (OTR, KgO2/h):
Aeration efficiency (AE, Kg02/kWh):
AE = OTR/P

16. IMPROVEMENT OF AIR FLOW RATE CONTROL
Air flow rate management was shifted from a DO set-point control to an ammonia-DO cascade control
BEFORE:
Air flow rate managed on the basis of
DO set-point
AFTER:
Air flow rate managed on the basis of N-NH4+ in the effluent and DO set-point

17. IMPROVEMENT OF AIR FLOW RATE CONTROL
Comparison of OTE between the two different strategies
DO set-point control
OTE ≈22-30%
ammonia-DO cascade control
OTE ≈24-35%
Il picco è dovuto al fatto che lo scorrimento delle schiume non avviene contemporaneamente in tutte le linee.
Quando l’aerazione nella linea 1 è spenta la linea 2 (dove si trova il sensore dell NH4) sta continuando ad aerare, risponde con un ritardo alla salita del NH4.
The new strategy for air flow rate control allowed to reduce the average DO concentration in the oxidation tank which in turn allowed to increase the oxygen transfer efficiency

18. Thank you for your attention!