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The present study is aimed to assess and characterize the structure of bacterial community in advanced activated sludge systems. In particular, activated sludge samples were collected from an Integrated Fixed-film Activated Sludge – Membrane Bioreactor pilot plant under a University of Cape Town configuration with in-series anaerobic (Noair)/anoxic (Anox)/aerobic (Oxy) reactors – and further analyzed. The achieved results – based on Next Generation Sequencing (NGS) of 16S rDNA amplicons – revealed that the bacterial biofilm (bf) communities on plastic carriers of Oxy and Anox reactors had a greater diversity compared to suspended (sp) bacterial flocs of Oxy, Anox and Noair. Indeed, the Shannon diversity indices of both biofilm communities were higher than those of suspended growth samples (Oxy-bf = 4.1 and Anox-bf = 4.2 vs. Oxy-sp = 3.4, Anox-sp = 3.5 and Noair-sp = 3.4). The most striking differences have been reported in Rhodobacteraceae being more abundant in biofilm specimens than in suspended biomass samples. The vast majority of the identified bacteria differs from those obtained by culture dependent method, thus suggesting that NGS-based method is really suitable to analyze the bacterial community composition, even in advanced systems for wastewater treatment.

The production of polyhydroxyalkanoates (PHA) using industrial wastewaters as feedstocks is a current and challenging topic. This study investigated the production of biopolymers by a mixed microbial culture under different OLRs equal to 1 kgCOD m-3d-1 (Period 1), 2 kgCOD m-3d-1 (Period 2) and 3 kgCOD m-3d-1 (Period 3). The maximum PHA content was achieved in Period 2 (0.38 gPHA gTSS-1), whereas lower values were obtained in Period 1 (0.13 gPHA gTSS-1) and Period 3 (0.26 gPHA gTSS-1). Overall, the maximum PHA productivity resulted equal to 0.08 gPHA L-1h-1 (P2), 0.05 gPHA L-1h-1 (P1) and 0.04 gPHA L-1h-1 (P3), respectively. The molecular weight of the PHA increased from Period 1 (250 kDa) to Period 2 (417 KDa) and Period 3 (463 KDa), although resulting in a slight decrease of crystallinity degree. Microbial community analysis, revealed a reduction in bacterial diversity and a progressive shift of the microbial community with the increasing OLR. Alpha-diversity indexes based on Operational Taxonomic Units (OTUs) at 99% identity revealed higher species richness (Taxa (S) 280) and diversity (Shannon (H) 4,06) in Period 1, whereas Period 3 was characterized by reduced richness and diversity and higher dominance (Taxa (S) 133, Shannon (H) 2,40). Based on the results obtained, it was pointed out that the OLR variation determined significant effects on the process performances, as well as on the productivity and quality of the biopolymers. This means that OLR is a key control parameter to maximize the PHA production and control the physical-chemical characteristics of the polymers.

The integration of one anaerobic reactor in the mainstream (AMSR) of a pre-denitritication-MBR was evaluated with the aim to achieve simultaneous sludge minimization and phosphorous removal. The excess sludge production was reduced by 64% when the AMSR was operated under 8 h of hydraulic retention time (HRT). The highest nutrients removal performances referred to organic carbon (98%), nitrogen (90%) and phosphorous (97%) were obtained under 8 h of HRT. In contrast, prolonged anaerobic-endogenous conditions were found to be detrimental for all nutrients removal performances. Similarly, the lowest membrane fouling tendency (FR = 0.65∙1011 m−1 d−1) was achieved under 8 h of HRT, whereas it significantly increased under higher HRT. The highest polyphosphate accumulating organisms kinetics were achieved under HRT of 8 h, showing very high exogenous P-release (46.67 mgPO4-P gVSS−1 h−1) and P-uptake rates (48.6 mgPO4-P gVSS−1 h−1), as well as a not negligible P-release rate under endogenous conditions at low COD/P ratio (≈1).

The awareness that the wastewater sector represents a significant source of greenhouse gas emission has increased, and is the awareness is evident based on the numerous research papers published in technical literature in the last 10 years. This chapter is aimed at providing a timely overview on greenhouse gas production and emission from membrane bioreactors. Specifically, this chapter dedicates particular attention to nitrous oxide (N2O), considering both experimental and mathematical modeling approaches. Referring to the experimental data, the observed results highlighted the significant contribution of the aerated compartments toward nitrous oxide emission as well as the importance of specific wastewater features (i.e., carbon to nitrogen ratio or presence of recalcitrant compounds, like hydrocarbons), showing at the same time high emissions variability. In terms of mathematical modeling, the results highlighted that models combining the N2O formation contribution due to autotrophic (as nitrifiers and denitrifiers) and heterotrophic provide excellent results in terms of predicting the N2O emission from membrane bioreactors. Results have also demonstrated that these mathematical models represent excellent tools for predicting the MBR behavior under different operational conditions with the aim to reduce effluent pollutants (solid, liquid, and gaseous).

This chapter provides an overview on the development and application of integrated fixed film activated sludge-membrane bioreactor (IFAS-MBR) systems. IFAS-MBRs represent a novel configuration for advanced wastewater treatment, and only a few studies are available in literature. With this aim, the results of some studies on IFAS-MBR systems already published are discussed and compared in this chapter. Literature shows that the influent carbon to nitrogen ratio (C/N) strongly affects the biological process in IFAS-MBR. The organic matter removal efficiency (removed biologically) decreases from 60% to 23.5% with the decrease of influent C/N from 10 to 2 mgCOD mgTN− 1. Nitrogen removal processes have good performance in IFAS-MBR treating municipal wastewater even under different operating or influent conditions. In terms of membrane fouling, the type of fouling mechanism (internal pore blocking, or superficial cake deposition) in IFAS-MBR systems strongly depends on the development and characteristics of the cake layer deposited on the membrane surface. The presence of detached biofilm in the mixed liquor favors the formation of a cake layer with a good pre-filtering action and a reduction of “pore blocking.” Finally, future research perspectives are discussed, including the development of new media (i.e., sponge-based carriers) and membrane-fouling control strategies. Further, more lab-scale and pilot-scale studies are required to investigate the effects of operating conditions.

Contaminated marine sediments represent a critical threat towards human health and ecosystems, since they constitute a potential reservoir of toxic compounds release. In the present study, a bioslurry reactor was studied for the treatment of real marine sediments contaminated by petroleum hydrocarbons. The experimental campaign was divided in two periods: in the first period, microcosm trials were carried out to achieve useful indicators for biological hydrocarbon removal from sediments. The microcosm trials highlighted that the inoculum of halotolerant allochthonous bacteria provided the highest performance followed by autochthonous biomass. Based on the achieved results, in the second experimental period a bioslurry reactor was started up, based on a semisolid stirred tank reactor (STR) operated in batch mode. The process performances have been evaluated in terms of total petroleum hydrocarbon (TPH) removal, coupled with the characterization of microbial community through a Next Generation Sequencing (NGS) and phytotoxicity tests through the Germination Index (GI) with Lepidium Sativum seeds. The achieved results showed good hydrocarbons removal, equal to 40%, with a maximum removal rate of 220 mgTPH kg-1 d-1, but highlighting that high contaminant concentrations might affect negatively the overall removal performance. In general, the observed results were encouraging towards the feasibility of biological treatment of marine sediments contaminated by hydrocarbons. The microbiological analysis allowed the identification of taxa most involved in the degradation of TPH, highlighting after the treatment a shift in the microbial community from that of the raw sediment.

In this study a University of Cape Town (UCT) Integrated Fixed Film Activated Sludge (IFAS) Membrane BioReactor (MBR) wastewater treatment plant was monitored in terms of nitrous oxide (N2O) emissions. The short term effect on the N2O emission due to the influent carbon-to-nitrogen (C/N) ratio variation (C/N ratios of 2, 5 and 10 gCOD/gN) was evaluated. Since in a previous study, the effect of the C/N ratio was studied in the same system without biofilm (UCT-MBR configuration) the main aim here was to investigate the role of biofilms on N2O emissions. Under all the investigated C/N ratios, the N2O fluxes and the average emission factors were lower than that of previous studies with no biofilm presence. The total average N2O emission was 0.5% of the influent nitrogen with biofilm (IFAS system) and 3.5% without biofilm. This result emphasizes the potential role of the biofilms in attenuating the N2O emissions especially in the case of stress conditions (i.e., low C/N influent ratios). An increase of N2O flux from the anoxic reactor (till 28 mgN2O m−2h−1) occurred at the lowest influent C/N tested (2 gCOD/gN - phase III). At C/N equal to 2 gCOD/gN the anoxic reactor was the main source of N2O, contributing 45% of all produced N2O. This result was attributed to an incomplete denitrification caused by a lack of organic carbon and a slight increase of dissolved oxygen concentration.

The aim of the present paper was to investigate the effect of solids (SRT) and hydraulic (HRT) retention time on Integrated Fixed Film Activated Sludge (IFAS) University of Cape Town (UCT) membrane Bioreactor (MBR). In particular, three different pairs of SRT and HRT values were analysed, namely, Phase I 56 d/30 h, Phase II 31 d/15 h and Phase III 7 d/13 h. The short-term effect of these three SRT/HRT conditions was assessed by analysing several system performance indicators: organic carbon and biological nutrient (nitrogen and phosphorus) removal, biomass respiratory activity, activated sludge filtration properties and membrane fouling. The results showed that the decrease of SRT/HRT had a positive influence on system performance. Specifically, the IFAS-UCT-MBR showed excellent removal of organic matter - highest value (99%) at the shortest SRT/HRT (7 d/13 h). Also, the increase in organic loading rate resulting from the decrease of SRT and HRT led to improved nitrogen removal due to higher N removal by sludge wasting requiring less N removal (as N2) by denitrification. Complete nitrification of influent ammonia was achieved at all three SRT/HRT phases, guaranteed by the presence of biofilm carriers in the aerobic reactor, which ensured a higher media SRT than suspended biomass SRT. The increase of the organic loading rate and decrease in SRT led also to a higher heterotrophic activity as demonstrated by the respirometric batch tests, which is due to the increasing active biomass fraction of the volatile suspended solids as SRT decreases. The SRT/HRT decrease over the three phases resulted in an overall increase of the Extracellular Polymeric Substance concentration, which caused an increase in membrane fouling.

The influence of the main operational variables on N2O emissions from an Integrated Fixed Film Activated Sludge University of Cape Town membrane Bioreactor pilot plant was studied. Nine operational cycles (total duration: 340 days) were investigated by varying the value of the mixed liquor sludge retention time (SRT) (Cycles 1–3), the feeding ratio between carbon and nitrogen (C/N) (Cycles 4–6) and simultaneously the hydraulic retention time (HRT) and the SRT (Cycles 7–9). Results show a huge variability of the N2O concentration in liquid and off-gas samples (ranged from 10−1μg N2O-N L−1to 103μg N2O-N L−1). The maximum N2O concentration (1228 μg N2O-N L−1) in the off-gas samples occurred in the anoxic reactor at the lowest C/N value confirming that unbalanced C/N promotes the N2O emission during denitrification. The aerated reactors (aerobic and MBR) have been the major N2O emitters during all the three Phases.

The effect of the carbon-to-nitrogen (C/N) ratio in the influent on the nitrous oxide (N 2 O) emission from a University of Cape Town Membrane BioReactor pilot plant was investigated. The membrane was located in a separate tank to single out the production of N 2 O due to the biological processes from N 2 O stripping as a result of the extra aeration needed for the mitigation of membrane fouling. The experimental campaign was divided into two phases, each characterized by a different C/N ratio (namely, 10 and 5 mgCOD/mgTN, Phase I and Phase II, respectively). The decrease of the C/N ratio promoted the increase of N 2 O emissions in both gaseous and dissolved phases, mainly due to a decreased nitrification/denitrification capacity of the system. The highest N 2 O concentration in the dissolved phase was found in the permeate. This result suggests that the dissolved N 2 O in the permeate stream discharged from a MBR cannot be neglected. The total N 2 O emission was approximately of 0.01% and 0.1% of the total influent nitrogen load for the Phase I and Phase II, respectively. The findings suggest that the C/N ratio represents an indirect cause of N 2 O emission; the low C/N value (Phase II) led to the increase of pH and free ammonia causing a stress effect on the growth of nitrifying species increasing the N 2 O emission.

The paper reports the main results of an experimental campaign carried out on two bench scale pilot plants for the treatment of synthetic shipboard slops. In particular, two membrane bioreactors (MBRs) with submerged configuration were analyzed. One MBR pilot plant (namely, Line A) was fed with synthetic shipboard slop and was subjected to a gradual increase of salinity. Conversely, the second MBR pilot plant (namely, Line B) was fed with the same synthetic shipboard slop but without salt addition, therefore operating as a “control” unit. Organic carbon, hydrocarbons and ammonium removal, kinetic constants, extracellular polymeric substances (EPSs) production and membranes fouling rates have been assessed. The observed results highlighted a stress effect exerted by salinity on the biological performances, with lower removal efficiencies in the Line A compared to Line B. Significant releases of soluble EPS in Line A promoted an increase of the resistance related to particle deposition into membrane pores (pore fouling tendency), likely due to a worsening of the mixed liquor features. Such a condition enhanced the reduction of the “pre-filter” effect of the cake layer.

The main goal of this study was the evaluation of the excess sludge reduction in a MBR for biological nitrogen removal (BNR) through the implementation of the Oxic-Settling-Anaerobic (OSA) process. For this purpose, a MBR pilot plant (42 L volume) was realized according to a pre-denitrification scheme. The whole experimentation was divided into two periods, named Period 1 and Period 2, respectively. In Period 1 the pilot plant was started-up and the excess sludge production was evaluated. In Period 2 the plant configuration was partially modified by inserting an anaerobic reactor into the return activated sludge (RAS) line to realize an OSA configuration. In Period 1, the Yobs resulted equal to 0.39 gVSS g−1CODremoved, in accordance with the reference values for MBR plants reported in the literature (Wang et al. 2013). Similarly, all the kinetic and stoichiometric parameters, for both autotrophic and heterotrophic biomass, resulted in line with those reported in a MBR with a pre-denitrification scheme (Lubello et al. 2009). In contrast, in Period 2 the Yobs showed a significant decrease, reaching a pseudo steady-state value of 0.17 gVSS g−1CODremoved at the end of the experiments, highlighting a reduction of 55% compared to Period 1.

The paper reports the results of nitrous oxide (N 2 O) emissions from aerobic and anoxic tank of a Sequential Batch Membrane Bioreactor (SB-MBR) pilot plant. The influence of salinity variation on N 2 O emission was analyzed by gradually increasing the inlet salt concentration from 0 to 10 g NaCl L −1 . The observed results showed that the N 2 O concentration of the gaseous samples was strongly influenced by the salt concentration. This result was likely related to a worsening of the nitrification activity due to the effect of salinity on autotrophic bacteria. Dissolved oxygen concentration and salinity were found to be the key factors affecting N 2 O concentration in the gaseous samples withdrawn from the anoxic tank. Despite the fact that the N 2 O concentration in the anoxic tank was higher than in the aerobic one, it was found that the aerobic tank emitted around 25 times more N 2 O than the anoxic one.

The paper reports the main results of an experimental campaign performed on a membrane bioreactor pilot plant designed to treat synthetic shipboard slops. The experimental campaign was divided into two phases: salinity acclimation up to 20 g NaCl L −1 (Phase I) and hydrocarbon (diesel fuel) dosing (Phase II). The observed results show that the carbon removal was not severely affected by the wastewater features. Conversely, respirometric tests showed that nitrification was strongly affected by the salinity (33% of nitrification efficiency at 20 g NaCl L −1 – Phase I) as a result of the salinity in the autotrophic biomass. Moreover, the sludge viscosity increased during Phase II due to the wastewater composition, leading to an increase in the membrane resistance, and severe degradation of the sludge dewaterability was also observed. Indeed, the capillary suction time increased by a factor of 3 times compared with that of Phase I.

Excess sludge minimization was studied in a MBR with pre-denitrification scheme. Sludge minimization, nitrogen removal performance and membrane fouling tendency were investigated in two configurations, characterized by a different position of the sludge retention reactor (SRR). In particular, the SRR was placed: i) in the return activated sludge line (Anaerobic Side-Stream Reactor – ASSR configuration) and ii) in the mainstream between the anoxic and aerobic reactor (Anaerobic Main-Stream Reactor – AMSR configuration). The achieved results demonstrated that the ASSR enabled a higher excess sludge reduction (74% vs 32%), while achieving lower biological nitrogen removal (BNR) (TN = 63% vs 78%) and membrane fouling tendency (FR = 2.1 · 1012 m−1 d−1 vs 4.0 · 1011 m−1 d−1) than the AMSR. It was found that metabolism uncoupling, destruction of EPS and endogenous decay simultaneously occurred in the ASSR. Conversely, selective enrichment of bacteria population with low biomass yield was found the main mechanism affecting sludge minimization in the AMSR.

A University of Cape Town Integrated Fixed-Film Activated Sludge Membrane Bioreactor (UCT-IFAS-MBR) pilot plant was operated at different values of the sludge retention time (SRT). Three SRTs were investigated at different durations: indefinitely, 30 and 15 days. The organic carbon, nitrogen and phosphorus removal, kinetic/stoichiometric parameters, membrane fouling tendency and sludge filtration properties were assessed. The findings showed that by decreasing the SRT, the pilot plant could maintain excellent carbon removal efficiencies throughout the experiments. In contrast, the biological carbon removal showed a slight nitrification and was slightly affected by the decrease of the SRT, showing high performance (approximately 91%, on average). Thus, the biofilm might have helped sustain the nitrification throughout the experiments. The average phosphorus removal performance increased slightly with a decrease in SRT, achieving the maximum efficiency (61.5%) at a SRT of 15 days. After a 30-day SRT, an increase in resistance due to pore blocking and a general worsening of the membrane filtration properties occurred.

In the present paper, the feasibility of citrus wastewater treatment with aerobic granular sludge sequencing batch reactors (AGSBR) was investigated. Two AGSBRs (named R1 and R2, respectively) were operated for 90 days under different organic loading rates (OLR) and pH in two experimental periods. The OLR ranged approximately between 3.0 kg TCOD m−3d−1 and 7 kg TCOD m−3d−1 during Period I, whereas between 7 kg TCOD m−3d−1 and 15 kg TCOD m−3d−1 during Period II. pH was maintained at 7.0 and 5.5 in R1 and R2, respectively. The results revealed that under high OLR and unbalanced feast/famine regime (Period I), the development of fast-growing microorganisms (fungi and filamentous bacteria) was favoured in both reactors, resulting in granular sludge instability. An extended famine phase and a proper balancing between feast and famine periods (Period II) were favourable for the development of bacteria with low growth rates (0.05 d−1) thus enhancing the granules stability. To the benefit of granular sludge stability and effluent quality, the length of the feast period should not exceed 25% of cycle length. Moreover, under OLR lower than 7 kg TCOD m−3d−1 the removal efficiency of total chemical oxygen demand (TCOD) was approximately 90% in R1 and R2 and no side effects on the organic carbon removal performance related to the pH were observed. In contrast, at higher OLR a significant decrease in the removal efficiency (from 90% to less than 75%) was observed in R2. Results revealed also that under low pH, hydrolysis of proteins occurred and a decrease in the biological kinetic rates proportionally to the applied OLR was observed.

Nowadays, it is widely accepted that wastewater treatment plants (WWTPs) are significant sources of greenhouse gas (GHG) emission, contributing to the anthropogenic sources. Among the GHG emitted from WWTPs, nitrous oxide (N2O) has been identified of having the major interest/concern, since its high global warming potential (GWP), is 298 times higher than that of CO2 and also to its capability to react with stratospheric ozone causing the layer depletion. Up to now, most of the experimental investigations have been carried out on conventional activated sludge (CAS) processes. The knowledge of N2O emission from advanced technologies such membrane bioreactors (MBRs) is still very limited. The present paper is aimed at providing a picture of the GHG emissions from MBR systems. In particular, data of N2O acquired from pilot plant systems monitoring are here presented. The key aim of the study was to highlight the effect of wastewater features and operational conditions on N2O production/emission from MBRs.

Two pilot plant systems were investigated for the treatment of wastewater subject to a gradual increase of salinity. In particular, a membrane bioreactor (MBR) and a moving bed biofilm membrane bioreactor (MB-MBR) were analyzed. Carbon and ammonium removal, kinetic constants and membranes fouling rates have been assessed. Both plants showed very high efficiency in terms of carbon and ammonium removal and the gradual salinity increase led to a good acclimation of the biomass, as confirmed by the respirometric tests. Significant biofilm detachments from carriers were experienced, which contributed to increase the irreversible superficial cake deposition. However, this aspect prevented the pore fouling tendency in the membrane module of MB-MBR system. On the contrary, the MBR pilot, even showing a lower irreversible cake deposition, was characterized by a higher pore fouling tendency.

The excess biomass produced during biological treatment of municipal wastewater represents a major issue worldwide, as its disposal implies environmental, economic and social impacts. Therefore, there has been a growing interest in developing technologies to reduce sludge production. The main proposed strategies can be categorized according to the place inside the wastewater treatment plant (WWTP) where the reduction takes place. In particular, sludge minimization can be achieved in the wastewater line as well as in the sludge line. This paper presents the results of two pilot scale systems, to evaluate their feasibility for sludge reduction and to understand their effect on biomass activity: (1) a pilot plant with an ozone contactor in the return activated sludge (RAS) stream for the exposition of sludge to a low ozone dosage; and (2) an oxic-settling-anaerobic (OSA) process with high retention time in the anaerobic sludge holding tank have been studied. The results showed that both technologies enabled significant excess sludge reduction but produced a slight decrease of biomass respiratory activity.

Methane (CH(4)) diffuse emissions from Municipal Solid Waste (MSW) landfills represent one of the most important anthropogenic sources of greenhouse gas. CH(4) is produced by anaerobic biodegradation of organic matter in landfilled MSW and constitutes a major component of landfill gas (LFG). Gas recovery is a suitable method to effectively control CH(4) emissions from landfill sites and the quantification of CH(4) emissions represents a good tool to evaluate the effectiveness of a gas recovery system in reducing LFG emissions. In particular, LFG emissions can indirectly be evaluated from mass balance equations between LFG production, recovery and oxidation in the landfill, as well as by a direct approach based on LFG emission measurements from the landfill surface. However, up to now few direct measurements of landfill CH(4) diffuse emissions have been reported in the technical literature. In the present study, both modeling and direct emission measuring methodologies have been applied to the case study of Bellolampo landfill located in Palermo, Italy. The main aim of the present study was to evaluate CH(4) diffuse emissions, based on direct measurements carried out with the flux accumulation chamber (static, non-stationary) method, as well as to obtain the CH(4) contoured flux map of the landfill. Such emissions were compared with the estimate achieved by means of CH(4) mass balance equations. The results showed that the emissions obtained by applying the flux chamber method are in good agreement with the ones derived by the application of the mass balance equation, and that the evaluated contoured flux maps represent a reliable tool to locate areas with abnormal emissions in order to optimize the gas recovery system efficiency.

Waste settlement as well as consolidation phenomena, which occur inside a landfill for municipal solid waste (MSW), can cause a decrease in waste permeability. This can lead to a reduction in conveyance of the leachate drainage system. It is therefore possible that a so-called perched leachate zone will form. Such a zone is constituted by an area in the body of the landfill where the leachate is temporarily trapped and is unable to infiltrate downward. This phenomenon is influenced by many factors, which include rain infiltration rate, waste moisture and composition, landfill height, and so on. The main aim of the paper is to elucidate the role played by landfill height in the formation of perched leachate zones using a one-dimensional (1D) mathematical model. The model allows for the simulation of the perco- lation fluxes throughout an MSW landfill based on mass-balance equations. The results showed a different response in terms of flow rates throughout the landfill, highlighting the important role of landfill height in the formation of perched leachate zones. Landfill height influences not only the formation of perched leachate zones but also their extension throughout the body of the landfill.

The effect of a sharp variation of C/N ratio in a moving bed membrane bioreactor (MB-MBR) pilot plant treating high strength wastewater has been investigated. The experimental campaign was divided into two periods, each characterized by a different C/N ratio (namely, 2.5 and 15, Period 1 and Period 2, respectively). The MB-MBR system was analyzed in terms of organic carbon removal, nitrification efficiency, biokinetic activity and fouling behavior. The results showed that the nitrification process was severely affected by lower C/N value and by high concentration of ammonia. It was noticed an extensive stress effect on the autotrophic bacteria. Furthermore, it was observed an increase of the resistance related to particle deposition into membrane pores, likely due to a worsening of the cake layer features, with a reduction of the “pre-filter” effect, also related to the increase of the total Extracellular Polymeric Substances production with the C/N ratio.

The effect of intermittent aeration (IA) on a MBR system was investigated. The study was aimed at ana- lyzing different working conditions and the influence of different IA cycles on the biological performance of the MBR pilot plant, in terms of organic carbon and ammonium removal as well as extracellular poly- meric substances (EPSs) production. The membrane modules were placed in a separate compartment, continuously aerated. This configuration allowed to disconnect from the filtration stage the biological phenomena occurring into the IA bioreactor. The observed results highlighted good efficiencies, in terms of organic carbon and ammonium removal. It was noticed a significant soluble microbial products (SMPs) release, likely related to the higher metabolic stress that anoxic conditions exerted on the biomass. How- ever, the proposed configuration, with the membranes in a separate compartment, allowed to reduce the EPSs in the membrane tank even during the non-aerated phase, thus lowering fouling development.

Objectives: In this study we evaluated the association between chronic prostatitis syndrome (CPS), varicocele and hemorrhoids as manifestations of a pelvic venous disease.

A hybrid activated sludge/biofilm process was investigated for wastewater treatment in a cold climate region. This process, which contains both suspended biomass and biofilm, usually referred as IFAS process, is created by introducing plastic elements as biofilm carrier media into a conventional activated sludge reactor. In the present study, a hybrid process, composed of an activated sludge and a moving bed biofilm reactor was used. The aim of this paper has been to investigate the performances of a hybrid process, and in particular to gain insight the nitrification process, when operated at relatively low MLSS SRT and low temperatures. The results of a pilot-scale study carried out at the Department of Hydraulic and Environmental Engineering at the Norwegian University of Science and Technology in Trondheim are presented. The experimental campaign was divided into two periods. The pilot plant was first operated with a constant HRT of 4.5 hours, while in the second period the influent flow was increased so that HRT was 3.5 hours. The average temperature was near 11.5°C in the overall experimental campaign. The average mixed liquor SRT was 5.7 days. Batch tests on both carriers and suspended biomass were performed in order to evaluate the nitrification rate of the two different biomasses. The results demonstrated that this kind of reactor can efficiently be used for the upgrading of conventional activated sludge plant for achieving year-round nitrification, also in presence of low temperatures, and without the need of additional volumes.

The paper presents a 1D mathematical model for the simulation of the percolation fluxes throughout a landfill for municipal solid waste (MSW). Specifically, the model was based on mass balance equations, that enable simulation of the formation of perched leachate zones in a landfill for MSW. The model considers the landfill divided in several layers evaluating the inflow to and outflow from each layer as well as the continuous moisture distribution. The infiltration flow was evaluated by means of the Darcy’s law for an unsaturated porous medium, while the moisture distribution evaluation has been carried out on the basis of the theory of the vertically distributed unsaturated flow. The solution of the model has been obtained by means of the finite difference method. The model has been applied to a semi-idealized landfill located in Palermo landfill (Bellolampo). Specifically, field measurements were conducted to determine the relationship between waste density and applied vertical strain. This relationship was then used to relate vertical strain to waste porosity. The inflow rate to the system was simulated via a synthetic hyetograph whose characteristics have been identified in a previous hydrologic study. Three simulations, each with a different initial moisture content, were conducted. The model results showed a different response of the landfill in terms both of flow rates throughout the landfill and moisture profile. Indeed, the initial moisture content drastically influenced not only the formation of perched leachate zones but also their extension. The model can be a useful tool in predicting potential for the formation of perched leachate zones.

Introduction: The aim of our study is to verify the effects of doxazosin on sexual function in patients with benign prostatic hyperplasia (BPH). Materials and Methods: We enrolled 102 patients with BPH, selected by nine Italian Urology Departments. Patients were evaluated with the International Prostatic Symptom Score (I-PSS) and divided into two groups: those with intact sexual activity and those with erectile dysfunction. According to the International Index of Erectile Function (IIEF), the second cohort was divided into three subgroups on the basis of the degree of erectile dysfunction degree (severe, moderate or mild). All patients underwent 3 months of therapy with doxazosin. The effects of doxazosin on sexual activity and on voiding symptoms were monitored at 1, 2 and 3 months with IIEF and I-PSS scales. Results: Eighty-six of the 102 initial patients (84%) were monitored until follow-up was completed. The follow-up at 1 month showed a significant decrease in the I-PSS (p < 0.0001) from 20.2 ± 2.01 (base visit) to 13.1 ± 2.21. The mean IIEF was 19.24 ± 6.59 at baseline and 1 month later the score reached 21.44 ± 5.40, thus showing a statistically significant increase (p = 0.0177). This is more evident in the group presenting with severe to moderate erectile dysfunction. I-PSS and IIEF do not significantly change at the 2- and 3-month follow-ups. Conclusions: The use of doxazosin improved sexual function in patients with BPH.

Transrectal ultrasonography was performed in 121 patients with the chronic prostatitis syndrome (CPS), and in 20 patients with urological pathology not involving the prostate gland. The ultrasonographic aspects of the seminal vesicles (SV) in normal subjects and in patients with the CPS are described. In the latter group, characteristic ultrasonographic patterns can often be obtained, even in patients affected by prostatodynia, in whom all the other clinical and laboratory findings were absent. They consisted of: (a) dyshomogeneous echo-structure of the prostate; (b) constant dilatation of the periprostatic venous plexus, greater than 150 mm2; (c) dilated, elongated SV, with thickening of their inner septa (they are sometimes asymmetrical), and (d) bladder neck hypertrophy.