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The recovery of livestock manure, rich in nutrients, as fertilizer in agriculture, could pose the risk of an excessive load of nitrogen on the soil. Ammonia stripping is one of the available technologies for reducing the amount of nitrogen in the digestate obtained by the anaerobic digestion of manure. The study investigated the performance and energy consumption of a full-scale ammonia-stripping plant, equipped with a bubble reactor and working without the use of any alkaline reagent under semi-batch conditions. Stripping tests were conducted on the liquid fraction of the digestate, studying the current and optimized operative conditions of the plant. The main variables influencing the process were pH, temperature, airflow, and feed characteristics. In the experimental tests, the pH spontaneously increased to 10, without dosing basifying agents. Higher temperatures favoured the stripping process, the higher tested value being 68 °C. The airflow was kept equal to 15 Nm3 h−1 m−3digestate in the pre-stripping and to 60 Nm3 h−1 m−3digestate in the stripping reactors, during all tests. The energy requirement was completely satisfied by the CHP (combined heat and power) unit fed with the biogas produced by manure digestion. Results showed anaerobic digestion coupled with stripping to be a suitable solution for removing up to 81% of the ammonium with neither external energy input nor reagent dosage. [ABSTRACT FROM AUTHOR]

[Display omitted] Identify sustainable biological sewage sludge (BSS) management represents a current challenge. In this work, pre-thickened BSS taken from a large-scale urban wastewater treatment plant (WWTP) was fed continuously for about 9 months to a semi-industrial scale thermophilic biological fluidized bed reactor (TBFBR) operating in alternate conditions. The BSS treated in TBFBR was strongly reduced (89–92%) and the production was evaluated in 0.0007–0.0023 kg kg CODremoved −1 d−1 and 0.0004–0.0014 kg kg CODremoved −1 d−1 of TS and VS, respectively. The 92% of the P-PO 4 3- and P-org precipitated in inorganic form and accumulated in thermophilic biological sludge (TBS). In basic soils with chelating activity, phosphorus contained in TBS presented a higher bioavailability (84.0 ± 25.3%) with respect to untreated sludge. The analysis of four diverse scenarios highlighted that TBFBR located after pre-thickening could save 73–96% of operating costs with respect to current situation. [ABSTRACT FROM AUTHOR]

The sludge management represents a considerable amount of operational costs for wastewater treatment plants (WWTPs). Issues concerning the treatment and the recovery/disposal of biosolids are gaining importance especially in Lombardy region, where the biosolid landspreading on agricultural soils is a very common practice. The aim of this work was to evaluate the results obtained from a survey carried out on the biosolids/sludge, derived from WWTPs, ingoing to and outgoing from the STPs (sludge treatment plants—authorized for the treatment on behalf of third parties) located in Pavia Province. Moreover, the characterization of agricultural soils that receive the biosolids is carried out. Furthermore, the whole biosolid management chain, from production to landspreading on agricultural soils, was studied, highlighting the critical issues based on the survey results. The results obtained suggested the following actions: (a) the reduction of sludge production in WWTPs; (b) a more "controlled" production in terms of biosolid qualitative characteristics; (c) better "selection" of the sludge ingoing to STPs; and (d) more effective actions to control the "response" of the agricultural soils. Furthermore, full compliance with the best spreading practices on the soils is required, as well as a better use of agronomic skills to obtain a higher resource valorization. Practitioner points: In this work, the characteristics of biosolid spread in agricultural soils in Pavia Province were analyzed.The minimization of sludge production in WWTPs is encouraged in order to reduce critical issues related to biosolid management.The stabilization process in WWTPs should improve in order to obtain a better quality sludge.A better "selection" of the sludge ingoing to STPs and a more effective monitoring of the agricultural soils are encouraged. [ABSTRACT FROM AUTHOR]

This work is aimed at assessing the effects of pretreated aqueous wastes stream-fed to a biological nutrient removal (BNR)- activated sludge plant. Aqueous wastes (mainly landfill leachate and liquid residues from chemical and pharmaceutical factories) are pretreated by means of a traditional coagulation-flocculation stage and subsequently sent to the BNR stage together with municipal wastewater. Pretreated aqueous wastes contribute up to about 75% of the influent load, in terms of chemical oxygen demand (COD; average concentration 23,000 mg=L). The resilience of the system, that is, the capacity to maintain high and stable performances despite sudden perturbations of the input conditions, was evaluated by interrupting the aqueous waste dosage and then progressively restoring the initial condition. The consequent variation of the influent load and composition caused a reduction of the biomass activity, which led to a decrease of the nitrogen removal efficiency (from 89% down to 73%). More than 30 days were required for restoring typical working conditions (in terms of influent load, process performance, and biomass activity), the sludge retention time (SRT) being 23 days. [ABSTRACT FROM AUTHOR]

Abstract It is evident from many recent papers that release of colored wastewater into the environment is source of pollution and this is a problem that particularly affect textile, dyeing and food industries. The review: (i) presents an analysis of various mechanisms involved in the different processes for color removal; (ii) describes conveniences and disadvantages that may exist in adopting one type of treatment in spite of another; (iii) reports the results of approximately 180 experimental tests. Both examples of treatments already widely applied to the real scale and still in the experimental phase are reported. This work focuses on different types of chemical/physical, chemical, electrochemical and biological processes applied in the field of color removal from industrial wastewater. Common chemical/physical treatments such as coagulation/flocculation, adsorption and membrane filtration as well as chemical-type processes are discussed, both those that exploit the traditional oxidizing chemical agents such as Ozone, H 2 O 2 and reactive based on chlorine and those based on the principle of advanced chemical oxidation. In particular, both Hydroxyl radical based Advanced Oxidation Processes (AOPs) and Sulfate radical based AOPs are reported. The most commonly used Electrochemical processes for the removal of color are also presented as well as biological treatments. Based on more than 200 papers, this review provides important information on the use, effectiveness, advantages and downsides of the various treatments aimed at removing the color from the wastewater with a look at the technologies still under development. Highlights • Wastewater color removal is a process that must be assessed on a case-by-case basis. • Chemical/physical methods are certainly still common used. • Advanced chemical oxidation processes are the most promising ones today. • Electrochemical and biological processes must still be adequately studied. [ABSTRACT FROM AUTHOR]

A combination of thermophilic aerobic membrane reactor (TAMR) and conventional activated sludge (CAS) was studied by means of two pilot plants at semi-industrial scale in order to simulate the new configuration adopted in a full-scale facility for the treatment of high strength aqueous wastes. Aqueous wastes with high contents of organic pollutants were treated by means of the TAMR technology, progressively increasing the organic load (3–12 kg COD  m −3  d −1 ). A mixture of municipal wastewater and thermophilic permeate was fed to the CAS plant. The main results are the following: achievement of a high COD removal yield by both the TAMR (78%) and the CAS (85%) plants; ammonification of the organic nitrogen under thermophilic conditions and subsequent mesophilic nitrification; capacity of the downstream mesophilic process to complete the degradation of the organic matter partially obtained by the TAMR process and precipitation of phosphorus as vivianite and carbonatehydroxylapatite in the TAMR plant. [ABSTRACT FROM AUTHOR]

In the present work, the thermophilic aerobic membrane reactor technology was studied for the treatment of high strength aqueous wastes mainly containing dyes, surfactants and solvents. The thermophilic biomass resilience and the process stability under critical conditions (such as rapid rise of the mixed liquor pH, oxygen supply interruption, etc.) were also evaluated. The experimental work was carried out with the use of a pilot plant at semi-industrial scale, which was managed throughout for 14 months; the operation temperature was 49 °C and the organic loading rate was increased from 3 to 12 kgCOD m−3 d−1. Critical conditions, especially the interruption of oxygen supply, affected the pilot plant performance but did not cause a complete system break down. After the temporary reduction of process performance, also proven by the decrease in the oxygen consumption, the normal working conditions were restored. Moreover, the longer non-aerated phase involved a significant reduction (40%) of volatile suspended solids concentration in the biological reactor and the increase of 30% in foaming power; nevertheless, once the oxygen supply was reactivated, optimal conditions were rapidly restored. Therefore, the study showed the high resilience of the thermophilic biomass, which was able to recover full functionality after critical events. [ABSTRACT FROM AUTHOR]

A thermophilic aerobic membrane reactor (TAMR) treating high-strength COD liquid wastes was submitted to an integrated investigation, with the aim of characterizing the biomass and its rheological behaviour. These processes are still scarcely adopted, also because the knowledge of their biology as well as of the physical-chemical properties of the sludge needs to be improved. In this paper, samples of mixed liquor were taken from a TAMR and submitted to fluorescent in situ hybridization for the identification and quantification of main bacterial groups. Measurements were also targeted at flocs features, filamentous bacteria, and microfauna, in order to characterize the sludge. The studied rheological properties were selected as they influence significantly the performances of membrane bioreactors (MBR) and, in particular, of the TAMR systems that operate under thermophilic conditions (i.e., around 50°C) with high MLSS concentrations (up to 200 gTS L−1). The proper description of the rheological behaviour of sludge represents a useful and fundamental aspect that allows characterizing the hydrodynamics of sludge suspension devoted to the optimization of the related processes. Therefore, in this study, the effects on the sludge rheology produced by the biomass concentration, pH, temperature, and aeration were analysed. [ABSTRACT FROM AUTHOR]

The increase of sewage sludge production together with the high treatment and disposal costs in the last years has pushed to study different solutions aimed at sludge minimization. In this paper, the thermophilic membrane technology was evaluated as an alternative for municipal sewage sludge reduction. The experimentation (carried out by means of a pilot scale plant, 1 m 3 volume) was divided into two steps: the first one was aimed at confirming the results obtained in a previous research focused on industrial sludge treatment; the second step was devoted to define the best process conditions (in particular the optimization of the aeration phases) and to the chemical permeate characterization. The results of the experiments highlight that the hydraulic retention time (HRT) and aeration conditions play a crucial role on the overall process performance. The volatile suspended solids removal efficiency was greater than 80% under the following conditions: HRT even lower than 15 d; 2 h of aeration - 6 h of non aeration cycles; and organic loading rate of 2.0 kgCOD m −3 d −1 . The permeate showed a good biodegradability under mesophilic conditions thus being treatable by means of conventional biological processes. Moreover, ammonia (the permeate presenting high concentrations) could be recovered as a fertilizer (stripping and subsequent washing of the exhausted gas is an established technique). Finally, the ammonia-free permeate can be valorised as a carbon source in denitrification processes. [ABSTRACT FROM AUTHOR]

Abstract: The present work concerns an experimental investigation on the use of residues derived from fluidized bed incinerators as aggregates for concrete. Concrete mixtures were obtained from conventional mix designs used in the production of unreinforced precast elements by partial replacement of natural aggregates with recycled components. The characterization was performed by means of physical and mechanical tests according to the prescriptions of the Italian technical code for construction, with special attention to the probabilistic evaluation of the compressive strength and an investigation of the tensile behavior of the considered specimens. The simplified statistical analysis shows that mixtures containing recycled aggregates may achieve characteristic values of the compressive strength that are very close to the performance of conventional mix designs that are commonly used in the investigated applications. The average compressive strength and the material reliability, i.e., the scattering of results, of concretes containing recycled aggregates are both comparable with those of the reference concrete. Conversely, an investigation on the tensile strength points out a lower performance for mix designs including recycled aggregates. In both cases, the adoption of 42.5R cement is found to remarkably improve experimental results, i.e., to reduce the gap between the performance of concretes containing recycled aggregates and the reference concrete. [Copyright &y& Elsevier]

Abstract: The aim of the present work was to study if municipal solid waste incinerator (MSWI) residues and aggregates derived from contaminated soil washing could be used as alternative aggregates for concrete production. Initially, chemical, physical and geometric characteristics (according to ) of municipal solid waste incineration bottom ashes and some contaminated soils were evaluated; moreover, the pollutants release was evaluated by means of leaching tests. The results showed that the reuse of pre-treated MSWI bottom ash and washed soil is possible, either from technical or environmental point of view, while it is not possible for the raw wastes. Then, the natural aggregate was partially and totally replaced with these recycled aggregates for the production of concrete mixtures that were characterized by conventional mechanical and leaching tests. Good results were obtained using the same dosage of a high resistance cement (42.5R calcareous Portland cement instead of 32.5R); the concrete mixture containing 400kg/m3 of washed bottom ash and high resistance cement was classified as structural concrete (C25/30 class). Regarding the pollutants leaching, all concrete mixtures respected the limit values according to the Italian regulation. [ABSTRACT FROM AUTHOR]

Minimizing the biological sewage sludge (BSS) produced by wastewater treatment plants (WWTPs) represents an increasingly difficult challenge. With this goal, tests on a semi-full scale Thermophilic Alternate Membrane Biological Reactor (ThAlMBR) were carried out for 12 months. ThAlMBR was applied both on thickened (TBSS) and digested biological sewage sludge (DBSS) with alternating aeration conditions, and emerged: (i) high COD removal yields (up to 90%), (ii) a low specific sludge production (0.02–0.05 kgVS produced/kgCODremoved), (iii) the possibility of recovery the aqueous carbon residue (permeate) in denitrification processes, replacing purchased external carbon sources. Based on the respirometric tests, an excellent biological treatability of the permeate by the mesophilic biomass was observed and the denitrification kinetics reached with the diluted permeate ((4.0 mgN-NO3−/(gVSS h)) were found comparable to those of methanol (4.4 mgN-NO3−/(gVSS h)). Moreover, thanks to the similar results obtained on TBSS and DBSS, ThAlMBR proved to be compatible with diverse sludge line points, ensuring in both cases an important sludge minimization. [ABSTRACT FROM AUTHOR]

To keep its leading role, the concrete industry must face the environmental issues linked to the manufacturing, by increasing the energy efficiency and adopting alternative fuels or raw materials. The present work analyses physical, mechanical, and environmental performances of concrete products incorporating waste from four main sources (construction and demolition waste, residues from waste treatment, metallurgical industry by-products and other sources), as substitutes of one of the three main components of concrete (binder, admixtures and water). The binder is the easiest component to be replaced in terms of number of alternatives, with the highest impact on concrete properties, while water easily reaches a full replacement level. Ground granulated blast furnace slag (GGBFS) showed the highest potential for the overall performance, with positive effects on compressive strength, durability, and workability of concrete samples, along with electric arc furnace dust (EAFD) and ceramic powder. • Use of wastes in concrete reduces energy consumption and CO 2 emissions. • Mechanical and environmental performance are the most investigated. • Use of wastes generally leads to a decrease of workability and density. • Binder is the easiest component to be replaced in terms of number of alternatives. • Water is the component that more easily reach a full replacement level. [ABSTRACT FROM AUTHOR]

The depletion of nitrogen and phosphorus represents a significant problem. Two real high strength wastewaters were treated by Thermophilic Aerobic Membrane Reactor (TAMR), an advanced biological process, obtaining significant removal of pollutants. Unlike the previous works, this paper does not focus on the optimization of the performance of the TAMR, but it studied the possible reuses of liquid (permeate) and solid (biological excess sludge) matrices to recover organic carbon, nitrogen and phosphorus and promote a circular economy model. The high nitrogen content of permeate can be exploited stripping ammonia with performances higher than 80% in best conditions to produce ammonium sulphate (useful as fertilizer). Moreover, the respiromeric tests demonstrated that permeate can be used in conventional active sludge systems as external source of organic carbon granting similar denitrification rate as methanol. In the sludge residue extracted from TAMR a significant presence of organic carbon and phosphorus (as hydroxyapatite) were revealed demonstrating the feasibility of recover this residue in land application. A preliminary management costs estimation showed that TAMR, coupled with a stripping and adsorption system to recover nutrients, is economically sustainable. Image 1 • Chemical oxygen demand (42–78%) and phosphorus (70–79%) were removed. • More than 80% of ammonia in permeate can be stripped to produce ammonium sulphate. • Permeate and methanol allow similar denitrification rate. • Hydroxyapatite was detected in sludge of thermophilic aerobic membrane reactor. • Preliminary management costs analysis highlights the economic feasibility. [ABSTRACT FROM AUTHOR]

Based on the rapid spread of the CoViD-2019, a lockdown was declared in the whole Northern Italy by the Government. The application of increasingly rigorous containment measures allowed to reduce the impact of the CoViD-2019 pandemic on the Italian National Health System but at the same time these restriction measures gave also the opportunity to assess the effect of anthropogenic activities on air pollutants in an unprecedented way. This paper aims to study the impact of the partial and total lockdown (PL and TL, respectively) on air quality in the Metropolitan City of Milan. As results, the severe limitation of people movements following the PL and the subsequent TL determined a significant reduction of pollutants concentration mainly due to vehicular traffic (PM 10 , PM 2.5 , BC, benzene, CO, and NO x). The lockdown led to an appreciable drop in SO 2 only in the city of Milan while it remained unchanged in the adjacent areas. Despite the significant decrease in NO 2 in the TL, the O 3 exhibited a significant increase, probably, due to the minor NO concentration. In Milan and SaA the increase was more accentuated, probably, due to the higher average concentrations of benzene in Milan than the adjacent areas that might have promoted the formation of O 3 in a more significant way. Unlabelled Image • The effect of lockdown on air quality in Milan was assessed. • The trends of 9 pollutants in meteorologically comparable periods were studied. • Lockdown determined a significant reduction of PM 10 , PM 2.5 , BC, benzene, CO and NO x. • SO 2 remained unchanged in the more peripheral areas. • Part of the ozone increase was probably due to the lower NO measured during lockdown. [ABSTRACT FROM AUTHOR]

Sludge recovery/disposal represents one of the most crucial aspects related to the management of wastewater treatment plants. The most widely diffused technology for the treatment of industrial and municipal wastewaters is the conventional activated sludge (CAS) process, which is characterized by a relatively high excess sludge production. Different technical solutions are proposed in the literature for sludge minimization and they can be applied either on wastewater line (WL) or sludge line (SL). This work is focused on different approaches based on the use of Thermophilic Aerobic Membrane Reactor (TAMR): this can be added to a CAS plant, and integrated to WL or SL, yielding a significant sludge reduction. The process performance was analysed in terms of volatile solids (VS) reduction and specific sludge production. The TAMR was tested both at full-scale and pilot-scale with different feeding substrates: industrial wastewater for the full-scale plant; industrial wastewater, sludge and a mix of these for the pilot-scale plants. The results obtained are: (i) good solids removal (38–90% and 40–50% in terms of VS for sludge and mix of industrial wastewater and sludge, respectively), (ii) low specific sludge production (0.01–0.09 kg VSS produced kg COD removed −1 for industrial wastewater and 0.014–0.069 kg VSS produced kg COD removed −1 for mix of industrial wastewater and sludge) and (iii) a significant reduction of sludge when CAS is improved with the TAMR technology. Image 1 • Different substrates were fed to Thermophilic Aerobic Membrane Reactor. • Upgrading of conventional activated sludge system were studied. • Up to 90% of volatile solids reduction was obtained. • Sludge production is one order of magnitude lower than other biological processes. [ABSTRACT FROM AUTHOR]

• A real pharmaceutical wastewater has been treated with photo-electrocatalysis (PEC). • H 2 O 2 -assisted PEC allowed to obtain the best decolorization. • H 2 O 2 -assisted PEC best performed in increasing the biodegradability of the wastewater. • PEC combined with a single-step dosage of H 2 O 2 optimized energy costs. In recent years, photoelectrocatalysis (PEC) for the treatment of industrial wastewaters (IWWs) has been repeatedly proposed. However, despite the number of tests reported in literature, only a few of them were conducted on real IWWs. In this study, real pharmaceutical IWWs showing an intense recalcitrant color were treated by PEC and H 2 O 2 -assisted PEC (UV/TiO 2 /Bias and UV/H 2 O 2 /TiO 2 /Bias, respectively) on TiO 2 meshes having sub-micrometric features obtained by Plasma Electrolytic Oxidation. Photolysis (UV), chemical oxidation (H 2 O 2) and H 2 O 2 -assisted photolysis (UV/H 2 O 2) were tested in the same reactor for comparison. The configuration UV/H 2 O 2 /TiO 2 /bias showed the best results in term of decolorization efficiency and rate, where decolorization was 55 % (single-step H 2 O 2 dosing) and 44 % (three-step H 2 O 2 dosing), after 2 h of contact time. In the same contact time, UV and UV/TiO 2 /Bias processes did not give decolorization. A more effective COD removal was measured for the PEC processes, UV/H 2 O 2 /TiO 2 /Bias (-24 %) and UV/TiO 2 /Bias (-20 %), while COD removal by UV was almost 0 %. Correspondingly, the SOUR values showed that PEC combined with a single-step H 2 O 2 dosage was the most effective configuration, leading to the highest biodegradability of the treated IWW with respect to the other processes. The energy consumption analysis demonstrated that PEC+H 2 O 2 (single-step dosage) optimized energy costs. [ABSTRACT FROM AUTHOR]

• The effect of lockdown on NO 2 in London, Milan and Paris was assessed. • Data from 52 air quality control units were studied. • Comparison with 2017−2019 highlighted a high decrease in NO 2 due to low traffic. • Despite low traffic, NO 2 concentrations > 40 μg m−3 were registered for several days. • Rethink the vehicles, the city and its vehicular traffic are strongly suggested. Nitrogen dioxide (NO 2) can have harmful effects on human health and can act as a precursor for the formation of other air pollutants in urban environment such as secondary PM 2.5 and ozone. The lockdown measures for CoViD-19 allowed to simulate on a large scale the massive and prolonged reduction of road traffic (the main source for NO 2 in urban environment). This work aims to selectively assess the maximum impact that total traffic blocking measures can have on NO 2. For this reason, three megacities (London, Milan and Paris) were chosen which had similar characteristics in terms of climatic conditions, population, policies of urban traffic management and lockdown measures. 52 air quality control units have been used to compare data measured in lockdown and in the same periods of previous years, highlighting a significant decrease in NO 2 concentration due to traffic (London: 71.1 % - 80.8 %; Milan: 8.6 % - 42.4 %; Paris: 65.7 % - 79.8 %). In 2020 the contribution of traffic in London, Milan and Paris dropped to 3.3 ± 1.3 μg m−3, 6.1 ± 0.8 μg m−3, and 13.4 ± 1.5 μg m−3, respectively. Despite the significant reduction in the NO 2 concentration, in UT stations average NO 2 concentrations higher than 40 μg m−3 were registered for several days. In order to reduce the pollution, the limitation of road traffic could be not enough, but a vision also aimed at rethink the vehicles and their polluting effects should be developed. [ABSTRACT FROM AUTHOR]

The potential impact of concrete mixtures containing steel slag (SS) as a partial replacement of natural aggregates (NA) on the terrestrial ecosystem was assessed using a battery of plant‐based bioassays. Leaching tests were conducted on four concrete mixtures and one mixture containing only NA (reference concrete). Leachates were tested for phytotoxicity using seeds of Lepidium sativum, Cucumis sativus, and Allium cepa. Emerging seedlings of L. sativum and A. cepa were used to assess DNA damage (comet test). The genotoxicity of the leachates was also analyzed with bulbs of A. cepa using the comet and chromosome aberration tests. None of the samples caused phytotoxic effects. On the contrary, almost all the samples supported the seedlings; and two leachates, one from the SS‐containing concrete and the other from the reference concrete, promoted the growth of C. sativus and A. cepa. The DNA damage of L. sativum and A. cepa seedlings was significantly increased only by the reference concrete sample. In contrast, the DNA damage in A. cepa bulbs was significantly enhanced by the reference concrete but also by that of a concrete sample with SS. Furthermore, all leachates caused an increase in chromosomal aberrations in A. cepa bulbs. Despite some genotoxic effects of the concrete on plant cells, the partial replacement of SS does not seem to make the concrete more hazardous than the reference concrete, suggesting the potential use of SS as a reliable recycled material. Environ Toxicol Chem 2023;42:2193–2200. © 2023 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. [ABSTRACT FROM AUTHOR]

The wastewater treatment process is based on complex chemical, physical and biological mechanisms that are closely interconnected. The efficiency of the system (which depends on compliance with national regulations on wastewater quality) can be achieved through the use of tools such as monitoring, that is the detection of parameters that allow the continuous interpretation of the current situation, and experimental tests, which allow the measurement of real performance (of a sector, a single treatment or equipment) and comparison with the following ones. Experimental tests have a particular relevance in the case of municipal wastewater treatment plants fed with a strong industrial component and especially in the case of plants authorized to treat aqueous waste. In this paper a case study is presented where the application of management tools such as careful monitoring and experimental tests led to the technical and economic optimization of the plant: the main results obtained were the reduction of sludge production (from 4,000 t/year w.w. (wet weight) to about 2,200 t/year w.w.) and operating costs (e.g. from 600,000 €/year down to about 350,000 €/year for reagents), the increase of resource recovery and the improvement of the overall process performance. [ABSTRACT FROM AUTHOR]

Thermophilic biological fluidized bed reactors operating in aerobic/anoxic alternate conditions proved to be a feasible solution for sewage sludge minimization. However, to date, no data about energy released by thermophilic biota (ThBio) are available in literature. This work aims to estimate specific thermal energy released by ThBio highlighting the influence of daily anoxic conditions. A pilot-scale reactor (1 m3) was fed continuously with mesophilic sewage sludge and monitored for more than four months and a thermophysical model was applied to estimate thermal energy released by ThBio (k T,biota and k T,COD). Results suggested that the increase of daily anoxic time stimulated COD removal (92.7 ± 1.3 % vs. 81.3 ± 4.9 %, with 6 h and 0 h of daily anoxic time, respectively). The thermal energy released by ThBio was strictly dependent on anoxic conditions. In fact, increasing anoxic conditions from 0 h d−1 to 6 h d−1, k T,biota and k T,COD reduced from 1.8 ± 1.3 Mcal kg−1 VS kg−1 COD and 26.6 ± 13.7 Mcal kg−1 COD to 0.5 ± 0.1 Mcal kg−1 VS kg−1 COD and 15.6 ± 4.2 Mcal kg−1 COD , respectively. Although, biological mechanism responsible of this behaviour is not completely clear, this work can serve as reference for future studies about the optimization of conditions to maximize thermal energy release from ThBio during organic substance degradation alternate aerobic/anoxic, in view of subsequent energy recovery. [Display omitted] [ABSTRACT FROM AUTHOR]

• SARS-CoV-2 has been found in faeces and, in some cases, urine of infected people. • Wastewater and sewage sludge from infected area can contain SARS-CoV-2 RNA. • To date, virulence of SARS−COV-2 in sewage sludge has not been determined. • Wastewater monitoring could help to understand epidemic situation of urban areas. • Identify and sharing protocols for SARS-CoV-2 detection and analysis are fundamental. As for the SARS coronavirus in the 2003 epidemic, the presence of SARS-CoV-2 has been demonstrated in faeces and, in some cases, urine of infected people, as well as in wastewater. This paper proposes a critical review of the state of the art regarding studies on the presence of SARS-CoV-2 in wastewater and sewage sludge, the factors affecting its inactivation and the main proposed treatments. In-vitro tests demonstrated low resistance of SARS-CoV-2 to high temperature, while even significant changes in pH would not seem to determine the disappearance of the virus. In real wastewater and in sewage sludge, to date studies on the influence of the different parameters on the inactivation of SARS-CoV-2 are not available. Therefore, studies involving other HCoVs such as SARS-CoV and HCoV-229E have been also considered, in order to formulate a hypothesis regarding its behaviour in sewage and throughout the steps of biological treatments in WWTPs. Finally, SARS-CoV-2 in wastewater might track the epidemic trends: although being extremely promising, an effective and wide application of this approach requires a deeper knowledge of the amounts of viruses excreted through the faeces and the actual detectability of viral RNA in sewage. [ABSTRACT FROM AUTHOR]

In recent years, rapid population growth and industrialization have increased the use of natural resources and the production of waste. To develop a circular economy, it is necessary to study and promote alternative long-term solutions for waste disposal, such as reuse and recovery. Wastewater treatment plants (WWTPs) can be an important part of circular sustainability if re-oriented to function as a water resource recovery facilities (WRRFs). In this context, biological sewage sludge (SS) can be treated in order to produce more stabilized residues: biosolids (BS). This paper aims to review the possible alternatives to reuse the BS in order to increase matter recovery. Around 250 papers, reviews, books and conference proceedings have been examined. Authors explored the application of BS on land, such as soil amendment/fertilizer both in agriculture and for interventions on abandoned mine sites, and on engineering fields, in partial or total substitution of virgin materials. The reuse of BS as adsorbent materials and as a source of phosphorus is also discussed. • Population perceives the reuse of biosolids as dangerous for human and environment. • In agricultural reuse of biosolids, heavy metals effects continue to be studied. • Feasibility of the utilization of biosolids for brick construction. • Conversion into adsorbent material and source of phosphorus is also presented. • Further investigation on emerging organic contaminants would be conducted. [ABSTRACT FROM AUTHOR]

• A real laundry wastewater has been treated for the removal of surfactants. • A full-scale plant has been monitored for more than three months. • The yields of six possible combinations of processes have been evaluated. • TAMR has been able to perform an effective pre-treatment activity. • Costs analysis suggested that TAMR + NF was the optimal solution. Surfactants are considered emerging contaminants, that can represent a source of problems for environment and human health. This paper aims to quantify the effect of a thermophilic aerobic membrane reactor (TAMR), nanofiltration (NF) and adsorption on activated carbon (AC) for the removal of non-ionic surfactants (TAS) and anionic surfactants (MBAS) from a real laundry wastewater. This study included daily monitoring of a full-scale plant for more than three months. The results showed that the TAMR process has been able to withstand high stress conditions (sudden load peaks) and resist to a high concentration of surfactants, allowing it to perform an effective pre-treatment activity. Both in the case of the removal of TAS and of MBAS, the combination of processes made it possible to obtain higher removal yields. Evaluating the operating costs, the results suggested that TAMR + NF represented the optimal combination of processes for the removal of TAS and MBAS. The TAMR + NF + AC sequence allowed almost complete removal of TAS (> 95%) and high removal of MBAS (> 76%) but the costs per unit of mass removed were high. [ABSTRACT FROM AUTHOR]