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Marco De Sanctis
Ruolo
III livello - Ricercatore
Organizzazione
Consiglio Nazionale delle Ricerche
Dipartimento
Non Disponibile
Area Scientifica
AREA 08 - Ingegneria civile e architettura
Settore Scientifico Disciplinare
ICAR/03 - Ingegneria Sanitaria-Ambientale
Settore ERC 1° livello
PE - PHYSICAL SCIENCES AND ENGINEERING
Settore ERC 2° livello
PE8 Products and Processes Engineering: Product design, process design and control, construction methods, civil engineering, energy processes, material engineering
Settore ERC 3° livello
PE8_3 Civil engineering, architecture, maritime/hydraulic engineering, geotechnics, waste treatment
An innovative process based on ozone-enhanced biological degradation, carried out in anaerobic granular biomass system (SBBGR e Sequencing Batch Biofilter Granular Reactor),was tested at pilot scale for tannery wastewater treatment chosen as representative ofindustrial recalcitrant wastewater. The results have shown that the process was able tomeet the current discharge limits when the biologically treated wastewater was recirculatedthrough an adjacent reactor where a specific ozone dose of 120 mg O3/Linfluent wasused. The benefits produced by using ozone were appreciable even visually since the finaleffluent of the process looked like tap water. In comparison with the conventional treatment,the proposed process was able to reduce the sludge production by 25e30 times andto save 60% of operating costs.Molecular in situ detection methods were employed in combination with the traditionalmeasurements (oxygen uptake rate, total protein content, extracellular polymericsubstances and hydrophobicity) to evaluate microbial activity and composition, and thestructure of the biomass. A stable presence of active bacterial populations was observed inthe biomass with the simultaneous occurrence of distinctive functional microbial groupsinvolved in carbon, nitrogen and sulphate removal under different reaction environmentsestablished within the large microbial aggregates. The structure and activity of the biomasswere not affected by the use of ozone.
This study was aimed at evaluating the effectiveness of an innovative compact biological system for treating at pilot scale municipal sewage produced in tourist areas characterised by intense seasonal water demand and wastewater discharge. The results obtained after a long term operation have shown that the proposed system was able to assure average removal efficiencies higher than 90% for COD (chemical oxygen demand), total suspended solids and TKN (total Kjeldahl nitrogen) independently of the influent concentration values and organic loading which ranged from 0.2 to 5.1 kgCOD/m3?d. Furthermore, the system was characterized by an excess sludge production 80% lower than that of conventional biological systems operating without a primary clarifier; an acceptable level of stabilization of excess sludge was also obtained indicating that a further stabilization process might no longer be required.
This pilot scale study aims to test the effectiveness of an innovative compact biological system (SBBGR - Sequencing Batch Biofilter Granular Reactor) for treating municipal wastewater in tourist areas characterised by intense seasonal water demand and wastewater discharge. The results obtained after a long term operation of 463 days have shown that the proposed system is able to assure average removal efficiencies higher than 90% for COD (chemical oxygen demand), total suspended solids and TKN (total Kjeldahl nitrogen) independently of the influent concentration values and organic loading, which ranged from 0.2 to 5.1 kgCOD/m3biofilter.d Furthermore, the plant showed a high degree of operation flexibility and stability in response to the organic load variations occurring in tourist areas. In fact, no significant deterioration in the plant's effluent quality was observed even during a sudden several-fold increase in organic loading. High nitrogen removal efficiencies (80%, on average) were also achieved thanks to the establishment of simultaneous nitrification-denitrification process favoured by the plant's high biomass concentration and operating conditions. Finally, the system was characterized by an excess sludge production much lower (60 to 80% lower) than that of conventional biological systems operating without a primary clarifier. An acceptable level of stabilization of excess sludge was also obtained so that a further stabilization process was no longer required.
Il processo di trattamento a fanghi attivi rappresenta la tecnologia largamente più diffusa per il trattamento delle acque reflue sia civili che industriali. Tuttavia tale tecnologia presenta dei limiti dovuti alla bassa densità e concentrazione delle biomasse nelle vasche dei reazione (es. necessità di grandi spazi) ed all' elevato costo di smaltimento dei fanghi di supero. Si è quindi sviluppato un crescente interesse verso tecnologie di trattamento alternative. Fra queste una delle più promettenti è rappresentata dai sistemi SBBGR (Sequencing Batch Biofilter Granular Reactor). Gli studi fin qui condotti hanno mostrato che tali sistemi sono caratterizzati da bassa produzione di fango (5-6 volte inferiore a quella dei processi convenzionali), elevate prestazioni depurative e flessibilità operativa. In questi sistemi la biomassa si sviluppa in forma di granuli densi e compatti di elevate dimensioni (3-6 mm) in cui si può determinare l'instaurarsi di comparti di reazione diversi (aerobici-anossici-anaerobici) che permettono a specifici gruppi funzionali (es. nitrificanti, denitrificanti, solfato-riduttori, metanogeni) di degradare reflui complessi come quelli industriali. Inoltre, tali biomasse granulari hanno dimostrato di essere più resistenti ad eventuali shock conseguenti alla presenza di sostanze tossiche nell'influente e/o a variazioni di condizioni operative. In particolare, è stata presa in esame l'applicabilità di questa tecnologia al trattamento di reflui civili ed industriali (conciario, cartiero e percolato di discarica). Per ogni tipologia di refluo l'analisi di tali aggregati microbici è stata effettuata mediante FISH (Fluorescence In Situ Hybridation) applicata in combinazione con microscopia a scansione laser confocale. La struttura di tali aggregati è stata valutata anche in termini di composizione dell'EPS (Extracellular Polymeric Substances), la cui presenza, stimata mediante colorazioni specifiche, si suppone sia importante per determinare il processo di aggregazione microbica.
The Artificial Neural Networks by Multi-objectiveGenetic Algorithms (ANN-MOGA) model has been appliedto gross parameters data of a Sequencing Batch BiofilterGranular Reactor (SBBGR) with the aim of providing an effectivetool for predicting the fluctuations coming from touristicpressure. Six independent multivariate models, whichwere able to predict the dynamics of raw chemical oxygendemand (COD), soluble chemical oxygen demand (CODsol),total suspended solid (TSS), total nitrogen (TN), ammoniacalnitrogen (N-NH4+) and total phosphorus (Ptot), were developed.The ANN-MOGA software application has shown to besuitable for addressing the SBBGR reactor modelling. The R2found are very good, with values equal to 0.94, 0.92, 0.88,0.88, 0.98 and 0.91 for COD, CODsol, N-NH4+, TN, Ptot andTSS, respectively. A comparison was made between SBBGRand traditional activated sludge treatment plant modelling.The results showed the better performance of the ANNMOGAapplication with respect to a wide selection of scientificliterature cases.
In the present paper, the effectiveness of a Sequencing Batch Biofilter Granular Reactor (SBBGR) and its integration with different disinfection strategies (UV irradiation, peracetic acid) for producing an effluent suitable for agricultural use was evaluated. The plant treated raw domestic sewage, and its performances were evaluated in terms of the removal efficiency of a wide group of physical, chemical and microbiological parameters. The SBBGR resulted really efficient in removing suspended solids, COD and nitrogen with an average effluent concentration of 5, 32 and 10 mg/L, respectively. Lower removal efficiency was observed for phosphorus with an average concentration in the effluent of 3 mg/L. Plant effluent was also characterized by an average electrical conductivity and sodium adsorption ratio of 680 ?S/cm and 2.9, respectively. Therefore, according to these gross parameters, the SBBGR effluent was conformed to the national standards required in Italy for agricultural reuse. Moreover, hygienization performances of the SBBGR was higher than that of conventional municipal wastewater treatment plants and met the quality criteria suggested by WHO (E. coli < 1000 CFU/100mL) for agricultural reuse. In particular, the biological treatment by SBBGR removed 3.8 ? 0.4 log units of Giardia lamblia, 2.8 ? 0.8 log units of E. coli, 2.5 ? 0.7 log units of total coliforms, 2.0 ? 0.3 log units of Clostridium perfringens, 2.0 ? 0.4 log units of Cryptosporidium parvum and 1.7 ? 0.7 log units of Somatic coliphages. The investigated disinfection processes (UV and peracetic acid) resulted very effective for total coliforms, E. coli and somatic coliphages. In particular, a UV radiation and peracetic acid doses of 40 mJ/cm2 and 1 mg/L respectively reduced E. coli content in the effluent below the limit for agricultural reuse in Italy (10 CFU/100 mL). Conversely, they were both ineffective on Clostridium perfringens spores.
Raw leachate and a biological effluent coming from the same raw leachate that has been biologically treatedin a new type of biological reactor, were electrochemically treated. A batch-type electrolytic cell usingtwo patented DSA electrodes was employed. Raw leachate, treated for 240 min at a current density of200 mA/cm2, falls within the sewer discharge limits set by Italian legislation for the COD. Instead, effluentobtained through combined biological and electro-oxidation treatment (by using 83 mA/cm2 and133 mA/cm2) has a COD such that could be discharged into the sewer and, after applying a current densityequal to 200 mA/cm2 after 240 min, has a COD value such that can even discharged into receivingwater bodies. The electrochemical oxidation carried out is only effective on nitrogen ammonia throughindirect electro-oxidation; it is not effective on other nitrogen-containing species. In any case, whereammonia is present (i.e., in the raw leachate), 82% is removed by the end of the test (i.e., after240 min of electrolysis) at 200 mA/cm2. Also, for the raw leachate, chloramine formation is most markedat low current densities. Nevertheless, the toxicity does not appear to be affected; in fact, decreaseregardless of the applied current density.
A regression tree model has been used to make predictions of six gross parameters (COD, CODsol, N-NH4 +, TN, Ptot and TSS) of an innovative SBBGR reactor. R2 values ranging from 0.94 to 0.97 were found forammonia and total phosphorus, respectively. This application showed its usefulness as a decision support system for wastewater treatment plants in tourist areas which typically operate under high stressconditions due to the sharp fluctuations of wastewater flow and composition. A forecast of the bioreactor's performance would help the plant manager to put in place the required practices and procedures.The regression tree model could be part of the automation and control system of the SBBGR plant, allowing the change of operating conditions to be carried out automatically and in an effective way to face thetouristic stress issue.
The applicability of Sequencing Batch Biofilter Granular Reactor technology (SBBGR)working at low recirculation flow was evaluated in order to reduce process energydemand. The system maintained some of the main advantages of this technology andsimultaneous presence of aerobic and strictly anaerobic metabolisms (nitrification,denitrification, fermentation, methanogenesis, sulphate reduction) in the system wasobserved. To better characterize the system traditional physical-chemical analysis wascoupled with Fluorescence In Situ Hybridization (FISH).
The water availability is becoming limiting in several European Countries. Agriculture represents the main water user therefore the reuse of wastewater in agriculture could provide a valuable increase in freshwater resources for other needs. A plan for an effective wastewater reuse should be based on compact delocalized treatment plants located in the same area where water has to be reused. Sequencing Batch Biofilter Granular Reactor (SBBGR) technology could deal with this requirement. This system is characterized by excellent treatment performances in removing organic pollutants, suspended solids and nitrogen. However these parameter couldn't ensure a safely wastewater reuse because water could still contain microbial pathogens. The aim of this study was to evaluate the effectiveness of raw domestic sewage treatment by SBBGR for agricultural reuse. Particular attention was dedicated to microbiological quality of water monitoring a wide group of microbial indicators (total coliforms, E. coli, Salmonella, C. perfringens, Somatic coliphages, G. lamblia and C. parvum). The possibility of SBBGR enhancement with physical and chemical disinfection processes was also evaluated.
This paper reports the results of the treatment of a yarn dyeing effluent using an integrated biological-chemical oxidation process. In particular, the biological unit was based on a sequencing batch biofilter granular sludge reactor (SBBGR), while the chemical treatment consisted of an ozonation step. Biological treatment alone was first performed as a reference for comparison. While biological treatment did not produce an effluent for direct discharge, the integrated process assured good treatment results, with satisfactory removal of chemical oxygen demand (up to 89.8 %), total nitrogen (up to 88.2 %), surfactants (up to 90.7 %) and colour (up to 99 %), with an ozone dose of 110 mg of ozone per litre of wastewater. Biomass characterization by fluorescence in situ hybridization has revealed that filamentous bacteria represented about 20 % of biomass (coherently with high sludge volume index values); thanks to its special design, SBBGR guaranteed, however, stable treatment performances and low effluent suspended solids concentrations, while conventional activated sludge systems suffer from sludge bulking and even treatment failure in such a condition. Furthermore, biomass characterization has evidenced the presence of a shortcut nitrification-denitrification process. © 2013 Islamic Azad University (IAU).
The availability of high quality water has become a constraint in several countries. Agriculture represents the main water user, therefore, wastewater reuse in this area could increase water availability for other needs. This research was aimed to provide a simplified scheme for treatment and reuse of municipal and domestic wastewater based on Sequencing Batch Biofilter Granular Reactors (SBBGRs). The activity was conducted at pilot-scale and particular attention was dedicated to the microbiological quality of treated wastewater to evaluate the risk associated to its reuse. The following microorganisms were monitored: Escherichia coli, Salmonella, Clostridiumperfringens, somatic coliphages, adenovirus, enterovirus, Giardia lamblia and Cryptosporidiumparvum. The possibility of SBBGR enhancement with sand filtration was also evaluated. The SBBGR removed >90% of suspended solids and chemical oxygen demand, and 80% and 60% of total nitrogen and phosphorous, respectively. SBBGR was also effective in removing microbial indicators, from 1 (for C. perfringens) up to 4 (for E. coli) log units of these microorganisms. In particular, the quality of SBBGR effluent was already compatible with the WHO criteria for reuse (E. coli <=103 CFU/100 mL). Sand filtration had positive effects on plant effluent quality and the latter could even comply with more restrictive reuse criteria.
This paper reports the results of an investigation aimed at evaluating the performance ofan innovative technology (SBBGR system - Sequencing Batch Biofilter Granular Reactor),characterised by a low sludge production, for treating municipal wastewater at demonstrativescale. The results have shown that even at the maximum investigated organic load(i.e., 2.5 kg COD/m3 d), the plant removed 80% of COD, total suspended solids and nitrogencontent with relative residual concentrations lower than the Italian limits for dischargeinto soil. The process was characterised by a very low sludge production (i.e., 0.12-0.14 kgTSS/kg CODremoved) ascribable to the high sludge age in the system (qc >120 d). Molecular insitu detection methods and microscopy staining procedures were employed in combinationwith the traditional measurements (oxygen uptake rate and total protein content) toevaluate both the microbial activity and composition, and the structure of the biomass.A stable presence of active bacterial populations (mainly Proteobacteria) was found withincompact and dense aggregates.
The Sequencing Batch Biofilter Granular Reactor (SBBGR) is a promising wastewater treatment technologycharacterized by high biomass concentration in the system, good depuration performance and lowsludge production. Its main drawback is the high energy consumption required for wastewater recirculationthrough the reactor bed to ensure both shear stress and oxygen supply. Therefore, the effect of lowrecirculation flow on the long-term (38 months) performance of a laboratory scale SBBGR was studied.Both the microbial components of the granules, and their main metabolic activities were evaluated (heterotrophicoxidation, nitrification, denitrification, fermentation, sulphate reduction and methanogenesis).The results indicate that despite reduced recirculation, the SBBGR system maintained many of itsadvantageous characteristics.
Textile effluents are characterised by high content of recalcitrant compounds and are often discharged (together with municipal wastewater to increase their treatability) into centralized wastewater treatment plants with a complex treatment scheme. This paper reports the results achieved adopting a granular sludge system (sequencing batch biofilter granular reactor - SBBGR) to treat mixed municipal-textile wastewater. Thanks to high average removals in SBBGR (82.1% chemical oxygen demand, 94.7% total suspended solids, 87.5% total Kjeldahl nitrogen, 77.1% surfactants), the Italian limits for discharge into a water receiver can be complied with the biological stage alone. The comparison with the performance of the centralized plant treating the same wastewater has showed that SBBGR system is able to produce an effluent of comparable quality with a simpler treatment scheme, a much lower hydraulic residence time (11h against 30h) and a lower sludge production. © 2014 Elsevier Ltd.
Two advanced biological solutions for sludge minimization in wastewater treatment are tested. The first solution, particularly suitable for new installations, is based on the application of the sequential batch biofilter granular reactor (SBBGR). The second one, mostly appropriate for existing plants, is the alternate cycles process applied in the sludge line (ACSL) of conventional activated sludge systems. The results of treating raw municipal wastewater show that the SBBGR system is able to reduce the quantity of sludge up to 80%. Furthermore, the produced excess sludge requires no longer stabilization compared with the usual aerobic/anaerobic one. As regards the ACSL process, the results obtained in the full scale have shown an observed sludge yield reduction up to 54% with an increase in the specific oxygen uptake rate up to 20 mgO<inf>2</inf>/gVSS/h. Finally, applying the ACSL process low specific consumption of energy is required.
In recent years the availability of high quality water is becoming a constraint in several countries. Agriculture represents the main world water user therefore, wastewater reuse in this area could increase the water availability for other needs. However conventional approach for wastewater treatment and reuse requires large and complex plants which include tertiary disinfection processes (i.e. NaClO, UV radiation). The aim of this research was to provide a compact scheme for treatment and reuse of municipal wastewater based on Sequencing Batch Biofilter Granular Reactors (SBBGR). Particular attention was dedicated to microbiological quality of water monitoring a wide group of indicators (Escherichia coli, Salmonella, Clostridium perfringens, Somatic coliphages, Giardia lamblia and Cryptosporidium parvum). The possibility of SBBGR enhancement with sand filtration was also evaluated. The SBBGR removed more than 90% of suspended solids and chemical oxygen demand (COD), and about 80% and 50% of total nitrogen and phosphorous respectively. SBBGR resulted effective also towards microbial indicators removing from 1 up to 4 log units of these microorganisms. The addition of sand filtration increased the disinfection efficiency of the system obtaining an additional removal of 1-2 log units. In conclusion, the biological treatment by SBBGR produced an effluent with properties already compatible with its agricultural reuse according to the WHO's quality criteria. Furthermore, combining SBBGR and sand filtration the plant effluent could even comply more restrictive reuse criteria.
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