In this paper we present the results obtained from tests conducted on ultrafiltration treatment o... more In this paper we present the results obtained from tests conducted on ultrafiltration treatment of a secondary effluent designated for possible industrial reuse. Tests were carried out at Empoli Wastewater Treatment Plant (WWTP) (Florence, Italy) with the use of a hollow fiber pilot plant (mod. ZW-10, Zenon Environmental). Testing lasted for about 4 months, during which the pilot plant was fed by effluent from the wastewater treatment plant. Results show that the permeate was of high quality. The membranes were very efficient in reducing turbidity (94.5%) and TSS (98.7%). The reduction of COD (around 35%) was also good. The permeate also showed low SDI values (usually < 3%). With respect to microbiological parameters, treatment was shown to be above all efficient in the removal of Escherichia coli. The permeate already respects required quality standards set forth by a new technical law decree on water reuse, soon to be approved within Italian Legislation. Based on these test res...
In this paper, after a brief introduction on irrigation wastewater reuse, we take a closer look a... more In this paper, after a brief introduction on irrigation wastewater reuse, we take a closer look at Pistoia, the most important nursery area in Italy, which specializes in production of woody ornamental plants. Groundwater resources are used for irrigation in competition with urban use, causing serious shortage problems in summer. Treated municipal wastewater can be a good alternative source of
Sommario Il controllo della biomassa all'interno di un sistema biologico per la rimozione del... more Sommario Il controllo della biomassa all'interno di un sistema biologico per la rimozione dell'H 2 S da effluenti gassosi risultano fattori chiave per l'ottimizzazione dell'efficienza e la minimizzazione dei costi energetici del processo. Da uno studio a scala pilota e da un'analisi basata sull'utilizzo di modelli matematici e di dati riferiti agli attuali costi di trattamento, emerge come i vantaggi dell'applicazione di un biotrickling filter a letto mobile (MBBTF) ottimizzato abbiano potenziali ricadute quantificabili in una riduzione del consumo energetico fino al 60%%, della carbon footprint fino all' dell'80% e dei costi per Kg di S rimosso fino al 40%. L'analisi ha condotto allo sviluppo di un MBBTF da testare nell'ambito del progetto LIFE+ Biosur (Rotating BIOreactors for sustainable hydrogen SUlphide Removal) nel comprensorio conciario toscano. Summary The control of the biomass accumulation within a biological system for H 2 S rem...
6 7 8 9 The most important parameters for bioreactor design are those related to nitrification ki... more 6 7 8 9 The most important parameters for bioreactor design are those related to nitrification kinetics; in fact, the nitrification 10 process is the bottleneck from a kinetic point of view in a typical activated sludge treatment train and the solids 11 retention time is usually designed based on nitrifiers growth requirements. While for conventional activated sludge 12 (CAS) processes, nitrification kinetics areabundantly reported in the literature, it is still important to investigate whether 13 in membrane bioreactors (MBR) the same kinetic parameters can be used. In fact, the environmental conditions in MBR 14 and CAS are different from several points of view including: solid liquid separation processes and shear stress on flocs, 15 which imply a different size and density of the flocs. Two Membrane Bio Reactors (MBR1 and MBR2) and a CAS 16 reactor as control unit has been used to study nitrifiers kinetics. Most investigations conducted so far on the sludge 17 properties were ca...
Water science and technology : a journal of the International Association on Water Pollution Research, 2005
Textile industries carry out several fiber treatments using variable quantities of water, from fi... more Textile industries carry out several fiber treatments using variable quantities of water, from five to forty times the fiber weight, and consequently generate large volumes of wastewater to be disposed of. Membrane Bio-reactors (MBRs) combine membrane technology with biological reactors for the treatment of wastewater: micro or ultrafiltration membranes are used for solid-liquid separation replacing the secondary settling of the traditional activated sludge system. This paper deals with the possibility of realizing a new section of one existing WWTP (activated sludge + clariflocculation + ozonation) for the treatment of treating textile wastewater to be recycled, equipped with an MBR (76 l/s as design capacity) and running in parallel with the existing one. During a 4-month experimental period, a pilot-scale MBR proved to be very effective for wastewater reclamation. On average, removal efficiency of the pilot plant (93% for COD, and over 99% for total suspended solids) was higher t...
Water science and technology : a journal of the International Association on Water Pollution Research, 2005
In recent years a completely autotrophic nitrogen removal process based on Anammox biomass has be... more In recent years a completely autotrophic nitrogen removal process based on Anammox biomass has been tested in a few European countries in order to treat anaerobic supernatant and to increase the COD/N ratio in municipal wastewater. This work reports experimental results on a possible technical solution to upgrade the S. Colombano treatment plant which treats wastewater from the Florentine urban area. The idea is to use 50% of the volume of the anaerobic digester in order to treat external sewage sludge (as septic tank sludge) together with waste activated sludge and to treat the resulting effluent on a SHARON-ANAMMOX process in order to remove nitrogen from the anaerobic supernatant. Anaerobic co-digestion, tested in a 200 L pilot plant, enables low cost treatment of septic tank sludge and increases biogas production; however, it also increases the nitrogen load re-circulated to the WWTP, where nitrogen removal efficiency is already low (<50%), due to the low COD/N ratio, which l...
EPR spectroscopy was applied to obtain qualitative and quantitative information on the radicals p... more EPR spectroscopy was applied to obtain qualitative and quantitative information on the radicals produced in disinfection processes of wastewater for agricultural reuse. The DEPMPO spin trap was employed to detect hydroxyl and carbon-centered short living radicals in two different peracetic acid solutions and a hydrogen peroxide solution used for water disinfection either in the absence or in the presence of UV-C irradiation. Moreover, three different kinds of water (wastewater, demineralized water, distilled water) were analysed in order to assess the contribution of Fenton reactions to the radical production. The spectroscopic results were discussed in relation to the efficiency of the different oxidizing agents and UV irradiation in wastewater disinfection evaluated as Escherichia Coli, Faecal and Total Coliforms inactivation.
ABSTRACT In this paper we present the results of an experimental study aimed at estimating the ef... more ABSTRACT In this paper we present the results of an experimental study aimed at estimating the efficiency and comparing the operating costs of a low pressure lamp and a medium pressure lamp in the H2O2/UV process for colour removal. Trials have been carried out on the secondary effluent of a wastewater treatment plant which treats part of the effluents of one of the largest textile industries district in Italy. Because of the great irregularity of the effluent composition it is very difficult to monitor all the variables and assess their influence on the decolorization process. For this reason the H2O2/UV efficiency in colour removal has been also evaluated using synthetic solutions: demineralized water or groundwater added with five different dyes. In this latter case we determined the single effect of the control parameters on the process. From the experimental results we can assess that the H2O2/UV process guarantees a very high colour removal efficiency (up to 90%), which mainly depends on H 2O2 dosages, dye concentration and characteristics, water quality (above all water hardness) and UV intensity. In our experimental conditions, the low pressure lamp showed to be more cost-effective both to remove colour and to reduce TOC and COD.
In questo lavoro si presentano i risultati di un’indagine sperimentale rivolta a verificare l’app... more In questo lavoro si presentano i risultati di un’indagine sperimentale rivolta a verificare l’applicabilità e l’efficacia dei bioreattori a membrana (MBR) nel trattamento dei reflui dell’industria del cuoio.
In this paper we present the results obtained from tests conducted on ultrafiltration treatment o... more In this paper we present the results obtained from tests conducted on ultrafiltration treatment of a secondary effluent designated for possible industrial reuse. Tests were carried out at Empoli Wastewater Treatment Plant (WWTP) (Florence, Italy) with the use of a hollow fiber pilot plant (mod. ZW-10, Zenon Environmental). Testing lasted for about 4 months, during which the pilot plant was fed by effluent from the wastewater treatment plant. Results show that the permeate was of high quality. The membranes were very efficient in reducing turbidity (94.5%) and TSS (98.7%). The reduction of COD (around 35%) was also good. The permeate also showed low SDI values (usually < 3%). With respect to microbiological parameters, treatment was shown to be above all efficient in the removal of Escherichia coli. The permeate already respects required quality standards set forth by a new technical law decree on water reuse, soon to be approved within Italian Legislation. Based on these test res...
In this paper, after a brief introduction on irrigation wastewater reuse, we take a closer look a... more In this paper, after a brief introduction on irrigation wastewater reuse, we take a closer look at Pistoia, the most important nursery area in Italy, which specializes in production of woody ornamental plants. Groundwater resources are used for irrigation in competition with urban use, causing serious shortage problems in summer. Treated municipal wastewater can be a good alternative source of
Sommario Il controllo della biomassa all'interno di un sistema biologico per la rimozione del... more Sommario Il controllo della biomassa all'interno di un sistema biologico per la rimozione dell'H 2 S da effluenti gassosi risultano fattori chiave per l'ottimizzazione dell'efficienza e la minimizzazione dei costi energetici del processo. Da uno studio a scala pilota e da un'analisi basata sull'utilizzo di modelli matematici e di dati riferiti agli attuali costi di trattamento, emerge come i vantaggi dell'applicazione di un biotrickling filter a letto mobile (MBBTF) ottimizzato abbiano potenziali ricadute quantificabili in una riduzione del consumo energetico fino al 60%%, della carbon footprint fino all' dell'80% e dei costi per Kg di S rimosso fino al 40%. L'analisi ha condotto allo sviluppo di un MBBTF da testare nell'ambito del progetto LIFE+ Biosur (Rotating BIOreactors for sustainable hydrogen SUlphide Removal) nel comprensorio conciario toscano. Summary The control of the biomass accumulation within a biological system for H 2 S rem...
6 7 8 9 The most important parameters for bioreactor design are those related to nitrification ki... more 6 7 8 9 The most important parameters for bioreactor design are those related to nitrification kinetics; in fact, the nitrification 10 process is the bottleneck from a kinetic point of view in a typical activated sludge treatment train and the solids 11 retention time is usually designed based on nitrifiers growth requirements. While for conventional activated sludge 12 (CAS) processes, nitrification kinetics areabundantly reported in the literature, it is still important to investigate whether 13 in membrane bioreactors (MBR) the same kinetic parameters can be used. In fact, the environmental conditions in MBR 14 and CAS are different from several points of view including: solid liquid separation processes and shear stress on flocs, 15 which imply a different size and density of the flocs. Two Membrane Bio Reactors (MBR1 and MBR2) and a CAS 16 reactor as control unit has been used to study nitrifiers kinetics. Most investigations conducted so far on the sludge 17 properties were ca...
Water science and technology : a journal of the International Association on Water Pollution Research, 2005
Textile industries carry out several fiber treatments using variable quantities of water, from fi... more Textile industries carry out several fiber treatments using variable quantities of water, from five to forty times the fiber weight, and consequently generate large volumes of wastewater to be disposed of. Membrane Bio-reactors (MBRs) combine membrane technology with biological reactors for the treatment of wastewater: micro or ultrafiltration membranes are used for solid-liquid separation replacing the secondary settling of the traditional activated sludge system. This paper deals with the possibility of realizing a new section of one existing WWTP (activated sludge + clariflocculation + ozonation) for the treatment of treating textile wastewater to be recycled, equipped with an MBR (76 l/s as design capacity) and running in parallel with the existing one. During a 4-month experimental period, a pilot-scale MBR proved to be very effective for wastewater reclamation. On average, removal efficiency of the pilot plant (93% for COD, and over 99% for total suspended solids) was higher t...
Water science and technology : a journal of the International Association on Water Pollution Research, 2005
In recent years a completely autotrophic nitrogen removal process based on Anammox biomass has be... more In recent years a completely autotrophic nitrogen removal process based on Anammox biomass has been tested in a few European countries in order to treat anaerobic supernatant and to increase the COD/N ratio in municipal wastewater. This work reports experimental results on a possible technical solution to upgrade the S. Colombano treatment plant which treats wastewater from the Florentine urban area. The idea is to use 50% of the volume of the anaerobic digester in order to treat external sewage sludge (as septic tank sludge) together with waste activated sludge and to treat the resulting effluent on a SHARON-ANAMMOX process in order to remove nitrogen from the anaerobic supernatant. Anaerobic co-digestion, tested in a 200 L pilot plant, enables low cost treatment of septic tank sludge and increases biogas production; however, it also increases the nitrogen load re-circulated to the WWTP, where nitrogen removal efficiency is already low (<50%), due to the low COD/N ratio, which l...
EPR spectroscopy was applied to obtain qualitative and quantitative information on the radicals p... more EPR spectroscopy was applied to obtain qualitative and quantitative information on the radicals produced in disinfection processes of wastewater for agricultural reuse. The DEPMPO spin trap was employed to detect hydroxyl and carbon-centered short living radicals in two different peracetic acid solutions and a hydrogen peroxide solution used for water disinfection either in the absence or in the presence of UV-C irradiation. Moreover, three different kinds of water (wastewater, demineralized water, distilled water) were analysed in order to assess the contribution of Fenton reactions to the radical production. The spectroscopic results were discussed in relation to the efficiency of the different oxidizing agents and UV irradiation in wastewater disinfection evaluated as Escherichia Coli, Faecal and Total Coliforms inactivation.
ABSTRACT In this paper we present the results of an experimental study aimed at estimating the ef... more ABSTRACT In this paper we present the results of an experimental study aimed at estimating the efficiency and comparing the operating costs of a low pressure lamp and a medium pressure lamp in the H2O2/UV process for colour removal. Trials have been carried out on the secondary effluent of a wastewater treatment plant which treats part of the effluents of one of the largest textile industries district in Italy. Because of the great irregularity of the effluent composition it is very difficult to monitor all the variables and assess their influence on the decolorization process. For this reason the H2O2/UV efficiency in colour removal has been also evaluated using synthetic solutions: demineralized water or groundwater added with five different dyes. In this latter case we determined the single effect of the control parameters on the process. From the experimental results we can assess that the H2O2/UV process guarantees a very high colour removal efficiency (up to 90%), which mainly depends on H 2O2 dosages, dye concentration and characteristics, water quality (above all water hardness) and UV intensity. In our experimental conditions, the low pressure lamp showed to be more cost-effective both to remove colour and to reduce TOC and COD.
In questo lavoro si presentano i risultati di un’indagine sperimentale rivolta a verificare l’app... more In questo lavoro si presentano i risultati di un’indagine sperimentale rivolta a verificare l’applicabilità e l’efficacia dei bioreattori a membrana (MBR) nel trattamento dei reflui dell’industria del cuoio.
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Papers by C. Lubello