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 paper reports the results of a study aimed at evaluating the effectiveness of an innovative technology (SBBGR - Sequencing Batch Biofilter Granular Reactor) for treating environmentally relevant wastewater (i.e., municipal wastewater, textile industry effluents and sanitary landfill leachates). SBBGR is a periodic biofilter based on aerobic granular sludge featured by a low excess sludge production. The results have shown that for the selected wastewater SBBGR is able to remove, in a single stage, completely the biodegradable organic material and 80-90% of nitrogen and total suspended solids content even at an organic loading rate of 2.5 kg COD/m3.d. SBBGR operated at very high sludge age value (i.e., 150 to 800 d) and biomass concentration (i.e., 30-50 kgTSS/m3). Excess sludge production ranged from 0.05 to 0.1 kg of dry sludge per kg of COD removed.

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.

Granular sludge aggregates are particular types of biofilms that display significantly different metrics and physical-chemical characteristics than activated sludge flocs. The efficiency of intensified processes using granularsludge relies on selection pressures created by engineering operational conditions to force microorganisms toform specific intrinsic physiological, phenotypic, and metabolic traits for granulation and high-rate biological removalof nutrients and/or recalcitrant organic matter. Granular sludge and conventional activated sludge sharea core microbiome, while the distribution of the underlying populations can significantly differ in relative abundanceand localization in the architecture of granules and flocs. Analogous ecological principles of microbialselection apply from activated sludge to granular sludge ecosystems with the essential difference that granules are governed by diffusion limitations through which different redox potentials are created on micrometre scale. Integrating the microbiology dimension together with the physical-chemical features of granules in engineering practice will make a difference at process level, besides offering new opportunities for bioaugmentation of granules in existing infrastructure. With this review article we critically examine the macro-scale factors impacting granulation, the physical-chemical characteristics of granular sludge, and fundamental and applied questions driven by the microbial ecology of granular sludge, toward the generation of useful concepts for process design and evaluation in engineering practice.

In order to mitigate the potential effects on the human health which are associated to the use of treated wastewater in agriculture, antibiotic resistance genes (ARGs) are required to be carefully monitored in wastewater reuse processes and their spread should be prevented by the development of efficient treatment technologies. Objective of this study was the assessment of ARGs reduction efficiencies of a novel technological treatment solution for agricultural reuse of municipal wastewaters. The proposed solution comprises an advanced biological treatment (Sequencing Batch Biofilter Granular Reactor, SBBGR), analysed both al laboratory and pilot scale,followed by sand filtration and two different disinfection final stages: ultraviolet light (UV) radiation and peracetic acid (PAA) treatments. By Polymerase Chain Reaction (PCR), the presence of 9 ARGs (ampC, mecA, ermB, sul1, sul2, tetA, tetO, tetW, vanA) were analysed and by quantitative PCR (qPCR) their removal was determined. The obtained results were compared to the reduction of total bacteria (16S rDNA gene) and of a faecal contamination indicator (Escherichia coli uidA gene). Only four of the analysed genes (ermB, sul1, sul2, tetA) were detected in raw wastewater and their abundance was estimated to be 3.4±0.7 x104 - 9.6±0.5 x109 and 1.0±0.3 x103 to 3.0±0.1 x107 gene copies/mL in raw and treated wastewaters, respectively. The results show that SBBGR technology is promising for the reduction of ARGs, achieving stable removal performance ranging from1.0±0.4 to 2.8±0.7 log units,which is comparable to or higher than that reported for conventional activatedsludge treatments. No reduction of the ARGs amount normalized to the total bacteria content (16S rDNA),was instead obtained, indicating that these genes are removed together with total bacteria and not specifically eliminated. Enhanced ARGs removalwas obtained by sand filtration,while no reductionwas achieved by both UV and PAA disinfection treatments tested in our study.

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.

This study proposes the evaluation of the suitability of mesophilic anaerobic digestion as a simple technology for the treatment of the citrus waste produced by small -medium agro-industrial enterprises involved in the transformation of Citrus fruits. Two different stocks of citrus peel waste were used (i.e., fresh and stored citrus peel waste), to evaluate the influence of waste composition (variability in the type of processed Citrus fruits) and of storage (potentially necessary to operate the anaerobic digester continuously over the whole year due to the seasonality of the production) on anaerobic degradation treatability. A thorough characterization of the two waste types has been performed, showing that the fresh one has a higher solid and organic content, and that, in spite of the similar values of oil fraction amounts, the two stocks are significantly different in the composition of essential oils (43% of limonene and 34% of linalyl acetate in the fresh citrus waste and 20% of limonene and 74% of linalyl acetate in the stored citrus waste). Contrarily to what observed in previous studies, anaerobic digestion was successful and no reactor acidification occurred. No inhibition by limonene and linalyl acetate even at the maximum applied organic load value (i.e., 2.72 gCOD(waste)/gVS(inoculum)) was observed in the treatment of the stored waste, with limonene and linalyl acetate concentrations of 104 mg/1 and 385 mg/1, respectively. On the contrary, some inhibition was detected with fresh citrus peel waste when the organic load increased from 2.21 to 2.88 gCOD(waste)/gVS(inocuium), ascribable to limonene at initial concentration higher than 150 mg/I. A good conversion into methane was observed with fresh peel waste, up to 0.33lCH(4)/gCOD(removed) at the highest organic load, very close to the maximum theoretical value of 0.35 lCH(4)/gCOD(removed), while a lower efficiency was achieved with stored peel waste, with a reduction down to 0.24 lCH(4)/gCOD(removed) at the highest organic load. (C) 2018 Elsevier Ltd. All rights reserved.

Three different chemical oxidation processes were investigated in terms of their capability to degrade organic chemical components of real mature landfill-leachate in combination with biological treatment run in a Sequencing Batch Biofilter Granular Reactor (SBBGR). H2O2, H2O2 + UV and O3 were integrated with SBBGR and respective effluents were analyzed and compared with the effluent obtained from biological SBBGR treatment alone. In agreement with their respective oxidative power, conventional bulk parameters (residual COD, TOC, Ntot, TSS) determined from the resulting effluents evidenced the following efficacy ranking for degradation: SBBGR/O3 > SBBGR/UV + H2O2 > SBBGR/H2O2 > SBBGR. A more detailed characterization of the organic compounds was subsequently carried out for the four treated streams. For this, effluents were first subjected to a sample preparation step, allowing for a classification in terms of acidic, basic, strongly acidic and strongly basic compounds, and finally to analysis by liquid chromatography/high resolution mass spectrometry (LC/HR-MS). This classification, combined with further data post-processing (non-target screening, Venn Diagram, tri-dimensional plot and Principal Component Analysis), evidenced that the SBBGR/H2O2 process is comparable to the pure biological oxidation. In contrast, SBBGR/O3 and SBBGR/UV + H2O2 not only resulted in a very different residual composition as compared to SBBGR and SBBGR/H2O2, but also differ significantly from each other. In fact, and despite of the SBBGR/O3 being the most efficient process, this treatment remained chemically more similar to SBBGR/H2O2 than to SBBGR/UV + H2O2. This finding may be attributable to different mechanism of degradation involved with the use of UV radiation. Apart from these treatment differences, a series of recalcitrant compounds was determined in all of the four treatments and partly identified as hetero-poly-aromatic species (humic acids-like species). ? 2018 Elsevier B.V.

The application of a biological treatment together with a chemical oxidation process was investigated. Inparticular, the effectiveness of the biological treatment followed by a UV/H2O2-based advanced oxidationprocess (AOP) used as an end treatment was compared with that in which the same AOP was integratedwith biological degradation for treating a medium age sanitary landfill leachate.The results show that better performance with removal efficiencies higher than 80% for all investigatingparameters was obtained when AOP was integrated with the biological treatment, thus allowing thedischarge limits to be met. This was due to the biological removal of the biodegradable compounds producedby UV/H2O2 treatment. Instead, UV/H2O2-based AOP biodegradability enhancement gave noadvantage when it was used as an end treatment. Finally, the results show that H2O2 alone (i.e., withoutUV power) was quite ineffective either as a mineralizing or as a biodegradability enhancing agent andthat the only reactive species was essentially the hydroxyl free radical OH.

This paper reports the results obtained using the sequencing batch biofilter granular reactor (SBBGR) for the treatment of the wastewater from a dyeing and finishing factory. SBBGR is a new innovative technology for biological wastewater treatment which possesses various promising features for textile wastewater treatment at each factory. Wastewater originating from dyeing textile factories is hard to depurate as it is usually characterised by considerable amounts of different pollutants, which are often recalcitrant, toxic and inhibitory. The results have shown that even at an organic load value as high as 2.4-2.6 kgCOD/m3.d SBBGR gives treatment efficiencies which allow the discharge into municipal sewer system. Furthermore, SBBGR was characterized by a sludge production as low as 0.1 kg of dry sludge per kg of COD removed. Finally, due to the presence of a relevant fraction of recalcitrant compounds in textile wastewater, a chemical oxidation step (e.g., ozone treatment) is required for enhancing SBBGR performance in order to permit the direct discharge.

This paper reports the results obtained using the sequencing batch biofilter granular reactor (SBBGR) for the treatment of the wastewater from a dyeing and finishing factory. The treatment of such a wastewater is challenging as it usually contains considerable amounts of different recalcitrant, toxic and inhibitory pollutants, which results in low biodegradability and in the need for numerous treatment steps. Different operational conditions were tested in order to assess SBBGR performance as a function of the applied organic and hydraulic load and to verify its suitability for on-site dyeing wastewater treatment at each factory. The reported measurements demonstrate how this innovative biological technology exhibits various promising features for this purpose, as good treatment efficiencies can be achieved even at high organic load values (2.4-2.6 kgCOD m-3 d-1) and with hydraulic retention times lower than one day. Furthermore, the treatment is characterized by a sludge production as low as 0.1 kg of dry sludge per kg of COD removed. Therefore, SBBGR has proved to be an effective pre-treatment for dyeing textile wastewater before discharge into municipal sewer system, as it produces a suitable effluent using just only one biological step with high hydraulic and organic loadings and low sludge production.

Experimental study we present is a full-scale energy recovery system able to extract, by means of a water sourced heat pump, the leftover thermal bioenergy available in a Sequencing Batch Biofilter Granular Reactor (SBBGR) within the wastewater treatment process. Heat pump compressor engine was powered by a 5.1 kW Photovoltaic plant, thermal energy being recovered is accumulated by two phase change materials tanks (PCM) for heat and cold latent energy storage whose capacity is 0.3 and 0.5 m3 respectively, thermal energy excess was dissipated through evaporator and condenser devices. Thermal energy extracted from SBBGR ranged from 0 to 14.5 kWh as function of environmental temperature and temperature set point of SBBGR. It was largely affected by environmental temperature during radiation and no deterioration of SBBGR performances were recorded during energy extraction even at lowest temperature set point (i.e. 15 °C). Results obtained demonstrated that SBBGR technology, thanks to its particular process scheme, allows wastewater heat extraction within the treatment process operation, making it actually the only wastewater treatment system able to exchange energy at low temperature (15 °C) without prejudice to treatment performances and, at the same time, to operate a thermal regulation of the treatment reactors, integrating the optimization of thermo-dependent biological processes with energy recovery systems.

Enhanced performance of biological processes for xenobiotic removal in municipal and industrial wastewater treatment plants can be achieved by adopting the following general strategies based on different principles of operation: increase of the biomass concentration (i.e., using biofilm, immobilized cell, and granular sludge reactors); dynamic operating conditions able to modify the biocenosis composition and to induce alternative metabolic pathways required by xenobiotic biodegradation; two-phase systems, which optimize the substrate delivery to the microorganisms on the basis of their metabolic demand; and combined treatment processes utilizing synergistic physical/chemical methods. In this chapter, the three following strategies for enhancing the biological process are presented and discussed: Addition of adsorption or absorption media Advanced oxidation processes: UV and UV/H2O2 Bioreactors operated with attached and granular biomass The proposed alternatives have been chosen as representative examples of promising technological solutions still under investigation. For each alternative a short presentation including the principle of operation, the realized applications and potentialities, as well as a case study is reported. ? 2016 Springer International Publishing Switzerland.

The aim of this paper is to study the microbial and structural changes occurring during the transitionfrom flocculent (used as inoculum) to biofilm and granular sludge in a Sequencing Batch BiofilterGranular Reactor (SBBGR). SBBGR is a new and promising technology characterised by low sludge production (5-6 times lower than in conventional treatment plants), high biomass concentration (up to 35 g TSS/L bed), high COD conversion capacity, high effluent quality and operation flexibility. Molecular in situ detection methods and microscopy staining procedures were employed in combination with the traditional measurements (i.e., oxygen uptake rate, COD removal efficiency) to evaluate the microbial activity and composition of the granular biomass. The granules structure was investigated by electron scanning microscopy, phase contrast analysis of granule sections and specific extracellular polymeric substances (EPS) stainings. Evident changes in biomass composition was observed during the shift from activated to granular sludge while a stable presence of active bacterial populations (mainly Proteobacteria) was found within mature granules.

Heavy fluctuations in wastewater composition, such as those typical of tourist areas, can lead to a deteri-orationintreatmentplantperformanceifnoactionistakeninadvance.Mathematicalmodelling,appliedto treatment plant performance prediction, can provide valuable information to address the stress issue.The present study shows that the evolutionary polynomial regression methodology (EPR) is able to pre-dicttheperformancesofanattachedgranularbiomasssystemsothatitispossibletomakethenecessaryoperatingchangesinadvance,avoidingdeteriorationinthequalityoftheeffluentdischarged.ThepresentpapershowstheresultsofEPRapplicationtogrossparametersofagranularattachedbiomassreactor.Foreach parameter, a model capable of predicting the effluent value was assessed, based on the knowledgeoftheinfluentcharacteristics.Coefficientsofdeterminationvalues(CoD)obtainedduringthemodelsval-idation phase, can be said to be more than satisfactory, varying between 84.2% and 94.6%. Moreover, theapplied tests showed typical behaviours commonly found when observed and predicted values are quitesimilar. This paper reports the first application attempt for modelling this kind of emerging treatmentsystem and gross parameters.

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.

Three innovative technical solutions for sludge minimization in wastewater treatment are under investigation in Routes project ("Novel processing routes for effective sewage sludge management") co-funded by the European Commission in the framework of the Seventh Framework Programme: 1) the use of Sequencing Batch Biofilter Granular Reactor (SBBGR) based technology, 2) the integration of membrane bioreactors with anaerobic side-stream process (MBR+AnSSR), and 3) the adoption of alternate cycles process applied in the sludge line (ACSL).The results obtained have shown that: 1) SBBGR is able to reduce up to 75% the sludge production during raw municipal wastewater treatment, and to offer satisfactory performances allowing the discharge limits to be met; 2) MBR+AnSSR offers a sludge production reduction comparable or even greater than that obtained in a conventional system (MBR + aerobic digestion), and 3) ACSL permits to obtain an Observed Yield reduction on average equal to 46% compared with the expected one, without a worsening of the final effluent quality.

Textile effluents are among the most difficult industrial wastewaters to treat because of their compositional variability and of the presence of numerous different chemicals intentionally designed to resist degradation. Though biological technologies offer a cheaper and more environmental friendly alternative for the treatment of textile effluents, an additional step to remove recalcitrant compounds is still needed. Integrated biological and chemical treatment is a rather new approach that allows improving treatment performance and stability without increasing too much treatment costs. Ozone integration in a sequencing batch biofilter granular reactor was tested at laboratory scale for treating a printing wastewater characterized by high concentrations of surfactants and nitrogen. The process was optimized in terms of applied organic load and ozone dose. The results have shown that the process assures the possibility to comply with the limits for direct discharge for all investigated parameters by operating at an organic load value lower than 1.5 kgCOD/m3 d and with an ozone dose of 135 mg/l. A synergetic biological and chemical oxidation activity was observed with a ratio between ozone dose and COD removed lower than 0.75. Finally, the process was characterized by a sludge production as low as 0.17 kgTSS/kgCODremoved due to the high biomass concentration in the biological system used.

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.

The electrochemical degradation of six of the most widely used iodinated contrast media was investigated. Batch experiments were performed under constant current conditions using two DSA (R) electrodes (titanium coated with a proprietary and patented mixed metal oxide solution of precious metals such as iridium, ruthenium, platinum, rhodium and tantalum). The degradation removal never fell below 85% (at a current density of 64 mA/cm(2) with a reaction time of 150 min) when perchlorate was used as the supporting electrolyte; however, when sulphate was used, the degradation performance was above 80% (at a current density of 64 mA/cm(2) with a reaction time of 150 min) for all of the compounds studied. Three main degradation pathways were identified, namely, the reductive de-iodination of the aromatic ring, the reduction of alkyl aromatic amides to simple amides and the de-acylation of N-aromatic amides to produce aromatic amines. However, as amidotrizoate is an aromatic carboxylate, this is added via the decarboxylation reaction. The investigation did not reveal toxicity except for the lower current density used, which has shown a modest toxicity, most likely for some reaction intermediates that are not further degraded. In order to obtain total removal of the contrast media, it was necessary to employ a current intensity between 118 and 182 mA/cm(2) with energy consumption higher than 370 kWh/m(3). Overall, the electrochemical degradation was revealed to be a reliable process for the treatment of iodinated contrast media that can be found in contaminated waters such as hospital wastewater or pharmaceutical waste-contaminated streams. (C) 2014 Elsevier B.V. All rights reserved.

Textile industry releases highly polluted and complex wastewaters, which are difficult to treat and require numerous treatment steps. Innovative technologies for on-site treatment at each factory would permit cost reduction and water recycling. For this reason, we run a lab-scale study to assess the suitability of sequencing batch biofilter granular reactor (SBBGR) for textile wastewater treatment, testing four different types of wastewater chosen as representative of the main processes and varying operational parameters. Results demonstrate that textile wastewater characteristics greatly affect the reactor efficiency. Therefore, a pre-study is advisable to define the best operational conditions and the maximum treatment capability for the wastewater under analysis. Nevertheless, SBBGR has shown to be a valuable biological treatment, effective in the reduction of pollutant load with stable performances despite the variability in wastewater composition. Tests with ozone integration have demonstrated that it is possible to dose small quantities of ozone to obtain an effluent suitable for direct discharge. However, a dynamic ozone dosage should be used to optimize the process as the correct ozone dose strongly depends on the wastewater composition.

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.

There is a need for a reliable sustainable option to effectively manage the landfill leachate generation. This study presents a simple procedure for the revegetation of the walls of closed landfills, employing the leachate as a fertirrigant. The native plants Lepidium sativum, Lactuca sativa, and Atriplex halimus, which suit the local climate, were chosen for this study in Southern Italy. The methodology was structured into three phases (i) early stage toxicity assessment phase (apical root length and germination tests), (ii) adult plant resistance assessment phase, and (iii) soil properties verification phase. The rationale of the proposed approach was first to look at the distinctive qualities and the potential toxicity in landfill leachates for fertigation purposes. Afterwards, through specific tests, the plants used were ranked in terms of resistance to the aqueous solution that contained leachate. Finally, after long-term irrigation, any possible worsening of soil properties was evaluated. The results demonstrated the real possibility of using blended leachate as a fertigant for the revegetation of the walls of closed landfills. In particular, the plants maintained good health when leachate was blended at concentrations of lower than 25 and 5 %, respectively for A. halimus and Lepidium sativum. Irrigation tests showed good resistance of the plants, even at dosages of 112 and 133.5 mm m(-2), at maximum concentrations of 25 and 5 %, respectively, for A. halimus and Lepidium sativum. The analysis of the total chlorophyll content and of aerial parts dried weight confirmed the results reported above.

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.

The present paper reports the results of an investigation aimed at evaluating the effectiveness of magnesiumammonium phosphate precipitation (MAP), commonly called struvite, for removing ammonia froma mature municipal landfill leachate. MAP precipitation was carried out at laboratory scale by addingphosphoric acid and magnesium oxide as external sources of phosphorus and magnesium, respectively,and regulating the pH at 9.0. The effect of Mg:NH4:PO3 ratio was studied. Due to the low solubility ofMgO, a low ammonia removal efficiency (i.e. 67%), with a rather high residual concentration, wasobtained when the stoichiometric molar ratio was applied. However, by doubling the amount of magnesiumoxide (i.e. by using a molar ratio of 2:1:1), ammonia removal efficiency increased up to 95% with aresidual concentration compatible with a successive biological treatment. The struvite produced in thepresent study showed a composition close to the theoretical one. Furthermore, the precipitate was characterizedby a heavy metal content much lower than that of typical raw soil, excluding any concern aboutheavy metal contamination in the case of its use as a fertilizer. The economic analysis of the processshowed that ammonia can be removed at a cost of 9.6 EUR/kg NH4-Nremoved. This value can be greatlyreduced, however, if the value of the struvite produced is considered.

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).

Municipal landfill leachates are considered one of the types of wastewater with the greatest environmental impact because of high concentrations of ammonium, salts and organic matter. Usually, recalcitrant pollutants and ammonia removals represent the steps of greatest concern. An innovative process based on ozone enhanced biological degradation, carried out in an aerobic granular biomass system (SBBGR - Sequencing Batch Biofilter Granular Reactor), was tested at lab-scale for treating a typical medium-age landfill leachate. The results have shown that ozonation greatly improves the biological treatment effectiveness allowing the current limits for discharging into the sewer system to be met by using a specific ozone dose of 600 mg O3/Linfluent; an operating cost of about 4 EUR per m3 of leachate was obtained. A strong synergy between ozone and biological degradation was noticed with a O3 consumed/CODremoved ratio of about 0.6.

Wastewaters generated by many economically relevant activities contain non biodegradable pollutants which pass unaltered through biological stage of the treatment plant making it difficult to meet the discharge limits currently in force. Therefore, an additional treatment is usually required to remove these compounds. The combination of biological treatment with ozonation is one of the most effective approaches. The synergistic effect between biological and ozonation stage is, however, a crucial key factor for giving a considerable cost advantage. The synergistic effect in existing plants and in an innovative system (SBBGR - Sequencing Batch Biofilter Granular Reactor) is compared in the present study for treating landfill leachates. The results obtained have shown that in the innovative system the synergistic effect measured as (g ozone/g reduced COD) is up to 2 times stronger than in existing plants.

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.

The possibility of reusing leachate substances for agronomical purposes might be of interest, especially in arid areas when used in addition to the leachate water content. This study presents a simple procedure for the revegetation of the walls of closed landfills, reusing the leachate as a fertigant. The results demonstrated the real possibility of employing blended leachate as a fertigant for the revegetation of the walls of closed landfills. The native plants Lepidium sativum, Lactuca sativa and Atriplex halimus, which suit the local climate, were chosen for this study in Southern Italy. The methodology was structured into three phases: (i) early-stage toxicity assessment phase (apical root length and germination tests), (ii) adult plant resistance assessment phase and (iii) soil properties verification phase. The rationale of the proposed approach was first to look at the distinctive qualities and the potential toxicity in landfill leachates for fertigation purposes. Afterwards, through specific tests, the plants used were ranked in terms of resistance to the aqueous solution that contained leachate. Finally, after long-term irrigation, any possible worsening of soil properties was evaluated. In particular, the plants maintained good health when leachate was blended at concentrations of lower than 25% and 5%, respectively, for Atriplex halimus and Lepidium sativum. Irrigation tests showed good resistance of the plants, even at dosages of 112 and 133.5 mm/m2, at maximum concentrations of 25% and 5%, respectively, for Atriplex halimus and Lepidium sativum. The analysis of the total chlorophyll content and of aerial parts dried weight confirmed the results reported above. ? 2016 Springer International Publishing Switzerland.

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.

Effluents from textile industries are usually characterized by the presence of high quantities of different pollutants, which are often intentionally designed to resist degradation (for example dyes). Therefore, traditional methods based on the combination of biological and simple physico-chemical treatments are not able to remove these refractory compounds. Ozone integration in a Sequencing Batch Biofilter Granular Reactor (SBBGR) could be considered as an optimal treatment. In fact, on the one hand, the setup of the biological reactor allows improving treatment stability and efficiency of this step. On the other hand, ozonation can be easily integrated, ensuing in a synergic chemical and biological oxidation. This paper compares the results obtained in the treatment of a textile wastewater by SBBGR alone and after ozone integration with a low ozone dose (i.e., 40 mg/l). For the latter one, successful removal of all the monitored analysed pollutants was achieved, with effluent concentrations amply below the limits for discharge in superficial water bodies. A strong synergic ozone-biological oxidation was noticed, with an ozone consumption of about one third of the chemical oxygen demand removed.

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.

This paper is aimed at evaluating, from a techno-economic and environmental point of view, the performance of an existing wastewater treatment plant in which the traditional biological section is upgraded with an innovative Sequencing Batch Biofilter Granular Reactor. Two scenarios were simulated in order to model and assess the performances of conventional (CAS, Conventional Activated Sludge) and innovative solutions, based on mass balances, techno-economic evaluation and environmental assessment. The results showed that converting the activated sludge process into an {SBBGR} allows to achieve a drastic reduction in sludge production (up to 75% as volatile suspended solids). Furthermore, the secondary sedimentation and sludge stabilization units can be dismissed, reducing the area requirement (up to 50%). The technical assessment is mainly positive, with the electric energy consumption being the only critical item. The higher energy demand of the upgraded plant (about 25% more than the conventional treatment) is mainly associated with the recycle flow in the {SBBGR} system. Although the economic sustainability of the upgraded plant depends on local conditions, it can be considered to be likely favourable: sludge disposal and materials &amp; reagents costs, together with the investment for plant reconstruction are those items that should be carefully evaluated before upgrading the {CAS} plant with {SBBGR} technology. The environmental assessment shows also mostly positive results, although it points to the increased phosphorus concentration in the effluent as a potentially critical issue and it highlights the electricity use and the increased nitrous oxide generation as other matters that need to be carefully checked in real case application.

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.