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In the Nile Delta, a complex network of canals collects drainage water from surface-irrigated fields, but also municipal wastewater. The goal of this work was to assess the technical, environmental and financial feasibility of the upgrade of a drainage canal (DC) into either an in-stream constructed wetland (ICW) or a canalized facultative lagoon (CFL), in order to produce a water re-usable in agriculture according to the Egyptian law. The model-based design of the proposed technologies was derived from field experimental data for the ICW and laboratory data for the CFL. Both technologies, integrated by a sedimentation pond and a disinfection canal, led to the attainment of the water quality standards imposed by Egyptian Law 92/2013 for the reuse of drainage water. The life cycle assessment indicated that the upgrade of an existing DC to either an ICW or a CFL results in an extremely small environmental burden, ≤ 0.3% of that of a traditional activated sludge process. The cost/benefit analysis (CBA) was based on the assumptions that (i) farmers currently irrigate a non-food crop (cotton) with the low-quality drainage water present in the DC, and (ii) thanks to the upgrade to a ICW or CFL, farmers will irrigate a food crop characterized by a higher market price (rice). The CBA indicated that the DC upgrade to an ICW represents an attractive investment, as it leads to a financial rate of return > 10% over a wide range of cotton market prices. Conversely, the upgrade to a CFL is less attractive due to high investment costs. In conclusion, the upgrade of DCs to ICWs appears a promising option for the treatment of drainage canal water in the Nile Delta, thanks to the high pollutant removal performances, low cost and negligible environmental burden. This article is protected by copyright. All rights reserved.

In this study, the utilization of Sulzer Chemtech 15 mm SMV® static mixers for the KOH-catalysed transesterification of sunflower oil was studied by means of batch tests conducted in an experimental ring equipped with a 22 L reactor. Oil and methanol (containing the dissolved KOH) were initially loaded into two tanks, whose headspace was connected to a line of compressed gas. The two streams were mixed in a tee connection and then fed to the reactor by gas displacement. The methanol:oil molar ratio was set to 6, the temperature to 60 °C, and the KOH concentration to 0.8% of the initial oil mass. The effect of SM number (0-5) and superficial velocity (0.4-2.5 m/s) was investigated; the results were compared to those of analogous tests performed in batch conditions with only mechanical agitation, at different rotational speeds. The test conducted with one single SM at a 1.3 m/s superficial velocity (Re = 1490) resulted in a profile of sunflower oil conversion versus time equivalent to that obtained in the best-performing tests with mechanical agitation, characterized by the presence of two Rushton turbines operated at a rotational speed ≥ 400 rpm (Remixing ≥ 2870). In these tests, the equilibrium conversion was equal to 93-96%, and the time for the attainment of a conversion equal to 90% of the equilibrium value (t90) was equal to about 2.5 minutes. The tests conducted, with 1 SM, at superficial velocities higher than 1.3 m/s provided the same reaction profile as the test at 1.3 m/s. This observation, in agreement with an evaluation of the reaction and transport characteristic times, indicates that the test at 1.3 m/s was affected by a negligible mass transfer limitations (kinetically controlled condition). Conversely, a test conducted with 1 SM at a superficial velocity of 0.4 m/s resulted to be characterized by a significant mass-transfer resistance. In order to evaluate the actual contribution of the SM section in the generation of the methanol/oil dispersion, a further group of tests was conducted, with the same system for loading oil and methanol, in the absence of SM. The test conducted at a velocity in the empty SM section equal to 1.3 m/s (corresponding to 2.9 m/s in the piping) led to a 65% increase of t90. This result indicates on the one hand that the single SM provides a relevant contribution to the generation of the dispersion, but on the other that contribution of the simple “T” junction of the loading system is not negligible. Lastly, the mixing energy required for the generation of the methanol/oil dispersion with SM and with mechanical agitation was evaluated. In the SM test at 1.3 m/s, the specific energy requirement evaluated at an oil conversion equal to 90% of the equilibrium value (e90) resulted equal to 15 J/kgbiodiesel. In the batch tests with mechanical agitation with two Rushton turbines, in order to attain a similar energetic performance it was necessary to reduce the rotational speed to 250 rpm, which led to a 15-20 % increase of t90. These results show that, with both mechanical agitation and static mixing, the mixing energy for biodiesel production can be reduced to very low values by means of a careful evaluation of the optimal rotational speed or SM superficial velocity. On the whole, this study suggest that static mixing can be effectively applied to oil transesterification processes for biodiesel production.

This study, focused on chloroform (CF) cometabolism by butane-grown bacteria, was conducted in a 2-m continuous-flow column reactor simulating a portion of saturated aquifer. The main goals were: a) to investigate the pulsed injection of growth substrate and oxygen as a tool to control clogging of the porous medium and to attain a wide bioreactive zone; b) to determine the minimum substrate/CAH ratio required to sustain the cometabolic process; and c) to determine the most suitable kinetic and fluid-dynamic model to fit the experimental data of butane utilization and CF cometabolism. The complete fluid-dynamic/kinetic model was utilized to run a series of simulations solved with Comsol Multiphysics, with the goal to design three types of injection of alternated pulses of growth substrate (butane) and oxygen, characterized by different values of the ratio of butane utilized to CF degraded (B/CF ratio). The column reactor was then run for three consecutive periods, characterized by the three above-mentioned pulsed injections. In these tests, the interstitial velocity was set to 0.5 m/d (corresponding to a 2-day hydraulic retention time), and the CF inlet concentration to about 0.4 mg/L. In conclusion, the experimental and modeling results show that: a) the pulsed injection of growth substrate and oxygen is an effective tool to prevent aquifer clogging as a result of an excessive biomass growth, and to attain a long bioreactive zone; b) in the specific case of our process of CF cometabolism with butane, the minimum ratio of substrate utilized / CAH degraded ranges between 1.6 and 2, with a good agreement between the results obtained in batch slurry assays and those deriving from the column tests; the corresponding ratio of substrate supplied / CAH supplied depends on several factors, among which the number of substrate and oxygen pulses in each cycle plays an important role; c) the kinetic parameters previously estimated in batch, single-strain assays, combined with the fluid-dynamic parameters evaluated in the first part of this work, allowed the development of an effective modeling tool for the design of the pulsed injection and for the interpretation of the experimental data. Overall, this work provides encouraging indications on the successful application of aerobic cometabolism for the in-situ remediation of sites contaminated by a wide range of CAHs.

Rhodococcus sp. strain BCP1 (DSM 44980) co-metabolizes chlorinated compounds and mineralizes a broad range of alkanes being highly tolerant to these toxic chemicals. Here, we present the high-quality draft genome sequence of strain BCP1 consisting of 6,231,823 bp, with a G+C content of 70.4%, 5,902 protein-coding genes, and 58 RNAs genes. Rhodococcus genus comprises Gram-positive, non-sporulating, aerobic bacteria that are widely distributed in the environment (1). Rhodococcus sp. strain BCP1 (formerly: Rhodococcus aetherovorans strain BCP1, DSM 44980) was selected from an aerobic butane-utilizing consortium as the prevailing isolate able to co-metabolize chloroform, vinyl chloride and trichloroethylene (2, 3). As BCP1 also catabolizes a wide range of aliphatic, alicyclic and carboxylated alkanes, it represents a strain of considerable environmental and industrial interest (4). The genome sequencing of Rhodococcus sp. BCP1 was performed using 454 sequencing technology (Roche GS FLX Titanium). The total number of sequence reads were 668,686 from one shotgun library and 353,744 from one paired-end library (8-kb inserts). All the reads were assembled using Newbler 2.6 into 123 contigs with an N50 length of 237,787 bp and an average genome coverage of 65x. Based on paired-end directional information, the contigs were further ordered into 3 scaffolds, giving a total genome size of 6.2 Mb with a G+C content of 70.4%.

Adsorption represents one of the most promising process for phosphorous (P) removal and recovery from municipal wastewater, but questions about its long-term stability remain. The goals of this work were (i) to assess changes in morphology and adsorption performances of hybrid anion exchanger (HAIX) LayneRT after 2.5 years of operation in a 10 m3 d-1 demonstration plant fed with secondary-treated municipal wastewater, (ii) to optimize the LayneRT regeneration procedure, and (iii) to evaluate the suitability of the ion exchange model to describe P adsorption on LayneRT. LayneRT is composed of hydrated ferric nanoparticles dispersed in a strong base anion exchange resin. Batch and continuous flow adsorption/desorption tests were conducted with the resin used for 2.5 years, regenerated with two alternative solutions: NaOH, reactivating mainly the iron nanoparticles active sites, and NaOH + NaCl, also regenerating the active sites of the ion exchange media. The physicochemical characterization by Scanning Electron Microscope indicated that regeneration by NaOH significantly reduced the deterioration of the resin surface, even after 59 adsorption/desorption cycles. Lab-scale continuous flow tests showed that the resin regenerated with either solution featured P adsorption performances very close to that of the virgin resin. The isotherm tests showed that P adsorption by LayneRT was effectively simulated with the ion exchange model. This study confirms that LayneRT is a durable, resistant and promising media for P recovery from wastewater.

BACKGROUND: Olive mill wastewater (OMW) represents an environmental problem due to its high organic load and relevant concentration of phenolic compounds (PCs). OMW treatment and disposal represents a relevant challenge and cost for olive mills and multi-utilities in charge of waste management in Mediterranean countries. The goal of this study was to develop an anaerobic co-digestion (co-AD) process of OMW and sewage sludge (SwS) from municipal wastewater treatment. RESULTS: Different volumetric OMW:SwS ratios up to 100% OMW were fed in continuous 1.7-L bioreactors. The reactors fed with raw OMW (rOMW) performed better than those fed with OMW dephenolized by adsorption (dOMW). At a 23-day hydraulic retention time, the best performances were obtained in the reactor fed with 25% rOMW, with a 105% increase in methane yield in comparison to the 100% SwS test. At a 40-day hydraulic retention time, the reactor fed with 40% rOMW attained a 268 NLCH4/kgvolatile solids methane yield. The conversion of phenolic compoundsreached 70% when the hydraulic retention time was increased from 23 to 40 days. A cost–benefit analysis indicated that both rOMW co-AD in existing digesters and phenolic compounds recovery from OMW followed by co-AD of dOMW can lead to relevant additional revenues for the multi-utilities in charge of wastewater management. CONCLUSION: This work proves that, using the existing network of SwS anaerobic digesters, it is feasible to co-digest the entire OMW production in regions characterized by intense olive oil production, thus attaining a relevant increase in methane production yield (a 144% increase in comparison to 100% SwS).

BACKGROUND: Olive mill wastewaters (OMWs) represent a major environmental concern due to their high organic load and phytotoxic activity. The selective recovery of phenolic compounds (PCs) from OMW is promising, thanks to the antioxidant and antimicrobial properties of PCs. The goal of this work was to perform a life cycle assessment (LCA) and cost–benefit analysis (CBA) of a full-scale process of PC adsorption/desorption on resin Amberlite XAD16N. The industrial process was designed on the basis of laboratory tests aimed at performing a preliminary process optimization. RESULTS: Adsorption tests were conducted at different velocities in a 1.8-m column packed with XAD16N. The optimal superficial velocity and retention time (2.78 m h –1 and 0.56 h) allowed the attainment of satisfactory performances in terms of resin operating capacity (0.46), PC adsorption yield (0.92), PC mass fraction in the sorbed product (0.50 g PC /g VS ) and specific antioxidant activity (3–6 g ascorbic acid /g PC ). Six consecutive adsorption/desorption cycles, operated with the same resin load, resulted in stable process performances. The LCA indicated that the environmental impact of the process could be decreased markedly through the addition of an anaerobic digestion step for the production of irrigation-quality water and fertilizers from the dephenolized OMW. The PC market price required for the generation of a positive business case resulted relatively low (€1.7–13.5 kg PC–1 ). CONCLUSION: The results indicate that the proposed PC adsorption/desorption technology, if integrated with an anaerobic digestion step, represents a promising solution for the treatment and valorization of OMW, a major agro-industrial waste in Mediterranean countries.

Pharmaceutically active compounds (PhACs) are common contaminants found in surface and groundwaters, often due to their inefficient removal from wastewater treatment plants. One way in which these compounds can be removed is via aerobic cometabolism, a process that involves oxygenases produced by microorganisms. Limited work has been done examining the efficacy of cometabolism in the removal of PhACs. Therefore, the aim of this work was to investigate the use of an alkane (pentane) in the aerobic cometabolic transformations of paracetamol, ibuprofen, naproxen, diclofenac, and nimesulide. Both paracetamol and ibuprofen (single aromatic compounds) were readily transformed, with net specific biodegradation rates equal to 1.6 and 3.2 μmol/gcell/day, respectively. Conversely, the two aromatic ring PhACs showed slower (naproxen and nimesulide) or no transformation (diclofenac). In addition, four of the tested PhACs (ibuprofen, paracetamol, naproxen and nimesulide) did not inhibit pentane uptake.

none 7 si Rhodococcus sp. strain BCP1 was initially isolated for its ability to grow on gaseous n-alkanes, which act as inducers for the co-metabolic degradation of low-chlorinated compounds. Here, both molecular and metabolic features of BCP1 cells grown on gaseous and short-chain n-alkanes (up to n-heptane) were examined in detail. We show that propane metabolism generated terminal and sub-terminal oxidation products such as 1- and 2-propanol, whereas 1-butanol was the only terminal oxidation product detected from n-butane metabolism. Two gene clusters, prmABCD and smoABCD—coding for Soluble Di-Iron Monooxgenases (SDIMOs) involved in gaseous n-alkanes oxidation—were detected in the BCP1 genome. By means of Reverse Transcriptase-quantitative PCR (RT-qPCR) analysis, a set of substrates inducing the expression of the sdimo genes in BCP1 were assessed as well as their transcriptional repression in the presence of sugars, organic acids, or during the cell growth on rich medium (Luria–Bertani broth). The transcriptional start sites of both the sdimo gene clusters were identified by means of primer extension experiments. Finally, proteomic studies revealed changes in the protein pattern induced by growth on gaseous- (n-butane) and/or liquid (n-hexane) short-chain n-alkanes as compared to growth on succinate. Among the differently expressed protein spots, two chaperonins and an isocytrate lyase were identified along with oxidoreductases involved in oxidation reactions downstream of the initial monooxygenase reaction step. Martina Cappelletti;Alessandro Presentato;Giorgio Milazzo;Raymond J. Turner;Stefano Fedi;Dario Frascari;Davide Zannoni Martina Cappelletti;Alessandro Presentato;Giorgio Milazzo;Raymond J. Turner;Stefano Fedi;Dario Frascari;Davide Zannoni

The main goal of this Chapter is to take the reader to the unconventional concept that if hydrogen is used as an energy carrier, there are consistent benefi ts to be expected, depending on how hydrogen is generated. As it will be illustrated, the technical problems lying ahead of the creation of an apparent “Hydrogen Based Society” are of technical nature although we are all confi dent that they can be solved within a reasonable period of time.

Questo lavoro descrive la produzione di idrogeno per digestione anaerobica di siero di latte, glucosio e melasso utilizzando 4 ceppi Thermotoga termofili. Tutte i 4 ceppi di Thermotoga testati (T. neapolitana, T. maritima, T. naphtophila, T. petrophila) sono stati in grado di produrre H2 dal siero di latte, glucosio e melasso, sia in prove con biomassa sospese che adesa. Con tutti i tre substrati, le migliori prestazioni sono state ottenute con T. neapolitana. Sono state condotte alcuni test per selezionare il supporto ottimale per le condizioni con biomassa adesa. Sono stati testati 4 tipi di supporti, 3 in vetro sinterizzato e uno in materiale ceramico; il supporto scelto è stato Biomax.

Sustainable hydrogen production is a topic of great interest since hydrogen is considered a clean, high-energy content and a low emission fuel. According to this, biological hydrogen production, especially from organic residues, is an attractive process, combining clean energy generation with waste material recycling[1]. Since hydrogen fermentative production at high temperature benefits of general and thermodynamics advantages, hyperthermophilic Thermotoga species are considered ideal organisms for H2 production[2]. The aim of this study is to investigate the feasibility of a cost-effective process of biological H2 production from food industry wastes under thermophilic conditions. The H2-producing performances of 4 Thermotoga strains (Th. neapolitana, Th. petrophila, Th. naphtophila, Th. maritima) were compared at 77 °C by means of tests conducted in 120-mL batch bioreactors containing 40 mL of a nutrient-rich growth medium (ATCC 1977)[3] supplemented with glucose, molasses or whey as main carbon sources. For all the substrates tested, Th. neapolitana resulted the best-performing strain, with a H2 specific production rate of 0.50-0.68 mmol gdry weight-1 h-1 at a 10 g L-1 initial substrate concentration. The H2-producing capacities of the 4 strains were also evaluated under biofilm-growth conditions by using a porous ceramic support utilized in the field of biofiltration as biomass carrier. Also under attached-growth conditions, Th. neapolitana resulted the best strain for all the 3 substrates tested, with a H2 specific production rate of 0.09-0.18 mmol gdry weight-1 h-1. Further tests were aimed at optimizing the growth medium composition. As a result, a significantly more simple – and thus more economical – medium was obtained that allowed the development of a more cost-effective process, even though the resulting H2 production rates were lower than those obtained by growing Thermotoga on the rich medium ATCC 1977. Finally, the preliminary results of a kinetic study of H2 production by attached cells of Th. neapolitana with glucose, molasses and whey indicated a substrate inhibition effect above 20 g L-1 for glucose and whey, but not for molasses.

This work represents the first step of a wider study aimed at evaluating the feasibility of a cost-effective process of biological H2 production from food industry wastes under thermophilic conditions. The H2-producing performances of 4 Thermotoga strains (Th. neapolitana, Th. petrophila, Th. naphtophila, Th. maritima) were compared at 77 °C by means of tests conducted in 120-mL batch bioreactors containing 40 mL of a nutrient-rich growth medium (ATCC 1977; Van Ooteghem et al., Biotechnol. Lett., 2004, 26:1223) additioned with glucose, molasses or whey as carbon source. For all the substrate tested, Th. neapolitana resulted the best-performing strain, with a 0.50-0.68 mmol gdry weight-1 h-1 H2 specific production rate at a 10 g L-1 initial substrate concentration. To compare the H2-producing capacities of the 4 strains also under attached-growth conditions, preliminary tests were conducted with Th. neapolitana, with the goal to select the best biomass carrier among 4 porous materials utilized in the field of biofiltration. The best results were obtained with a porous ceramic product characterized by a 9 m2 g-1 interfacial area. Also under attached-growth conditions, Th. neapolitana resulted the best strain for all the 3 substrates tested, with a 0.09-0.18 mmol gdry weight-1 h-1 H2 specific production rate. Further tests aimed at optimizing the growth medium composition allowed the attainment of H2 production rates slightly lower than the above-reported values, with a significantly more simple – and thus more economical – medium composition. The preliminary results of a kinetic study of H2 production by attached cells of Th. neapolitana with glucose, molasses and whey indicate a substrate inhibition effect above 20 g L-1 for glucose and whey, but not for molasses. Finally, the process scale-up to an innovative 19-L attached-cell agitated reactor is in progress.

The focus of this microcosm study was to monitor the performances of 17 butane-utilizing microcosms during a long-term (100-250 days) aerobic cometabolic depletion of chloroform (CF). The depletion of the contaminant began after a lag-time variable between 0 and 23 days. All microcosms quickly reached a pseudo steady-state condition, in terms of biomass concentration (with an average of 9.3 x 106 CFU ml(-1)), chloroform depletion rate (5 micromol l(-1) d(-1)) and butane utilization rate (730 micromol l(-1) d(-1)). After about 100 days of CF depletion, a sudden 5- to 7-fold increase of the chloroform rate was observed in two microcosms, where the highest amount of contaminant had been depleted. In one of these high-performing microcosms, an experiment of chloroform depletion in the absence of butane resulted in the depletion of a surprisingly high amount of contaminant (765 micromolCF kg(-1) dry soil in 2 months) and in a marked selection of a single bacterial strain. Bioaugmentation assays conducted with the biomass selected in this microcosm and with a pure culture of the selected strain immediately resulted in very high chloroform depletion rates. Preliminary results of a study conducted with resting cells of the selected strain indicated that it can degrade chloroform concentrations up to 119 microM (14.2 mg l(-1)) without any sign of substrate toxicity, and that it is able to transform vinyl chloride and 1,1,2-trichloroethane.

In questo studio vengono presentati i risultati ottenuti nella degradazione di cloroformio (CF) ad opera di microrganismi aerobi butano-utilizzatori in microcosmi slurry; l’obiettivo è stato quello di determinare le migliori modalità operative per ottenere e mantenere una biomassa efficace nei processi di degradazione. Per quanto riguarda l’adattamento della biomassa indigena al substrato di crescita, fra le varie modalità testate quella che è risultata più idonea è stata la fornitura in continuo di substrato a bassa concentrazione (concentrazioni anche pari a 0.1 mg/L sono risultate efficaci per l’adattamento); nei siti in cui non è presente una biomassa attiva nella degradazione dei contaminanti l’avvio del processo può essere conseguito mediante l’introduzione di modeste quantità di biomassa precedentemente “adattata”; la biomassa sviluppatasi è in grado di continuare il processo degradativo per lunghi periodi con velocità di degradazione relativamente costanti purché venga alimentato butano (B) in quantità proporzionata al CF presente (il rapporto CF/B in massa non deve superare 0.15), mentre in assenza o in carenza del substrato primario (B) la biomassa butano-utilizzatrice viene progressivamente inattivata, fino al completo arresto della degradazione di CF.

In this microcosm study we have monitored the performances of 12 butane-utilizing consortia during a long-term aerobic cometabolic degradation of chloroform (CF). After approximately 100 days of continuous CF depletion, a sudden improvement of the biodegradative performances (7-fold increase of chloroform degradation rate) was observed in two microcosms in which the highest amount of depleted CF (> 70 mg / kg of dry soil) was observed. Two bacterial strains, isolated from the CF-degrading microcosms, were identified as belonging to the genera Rhodococcus and Stenotrophomonas, respectively. A strain, named F, was further characterized to establish the involvement of the butane-monooxygenase in CF degradation.

The effect of several operational conditions on the adaptation of indigenous biomasses was investigated in a microcosms study of chloroform (CF) cometabolic degradation with butane. The objective was to minimize the duration of the adaptation phase and the amount of growth substrate to provide in field applications. The adaptation to butane and CF was monitored at 5 concentrations of butane (1.50, 1.00, 0.50, 0.25 and 0.10 mg/L), at 3 concentrations of CF (1, 5 and 10 mg/L), at 4 temporal sequences of exposition to butane (continuous, 5 h/d, 7 h/d, 24 h every other day) and at 3 temperatures (15, 25 and 30°C). The results indicate that the most favorable condition for the adaptation of indigenous biomasses consists in the continuous exposition to a very low concentration of growth substrate (0.1 mg/L). In all the tests the degradation of CF started within 48 days. The microbiological characterization of the consortia indicated that the prolonged degradation of CF led to the selection of 3 specific butane-utilizing strains.