This paper presents the results of a broad-scale survey of resource recovery implementation in Italian wastewater treatment plants (WWTPs). To the best of our knowledge, this is the first survey ...comprising a large number of WWTPs done in Europe: more than 600 plants were investigated, representing a treated load of around 20 million population equivalent (≈25% of the total in Italy). Conventional and innovative options for both material and energy recovery along the water and sludge line were surveyed, in order to i) offer a real and complete picture of the current state of resource recovery in WWTPs, and ii) underline key aspects and potential areas for improvements, as a baseline for future developments in the direction of more sustainable plants.
Survey outcomes showed that resource recovery is just in its infancy in sewage treatment: only 40% of plants perform at least one option for material/energy recovery. The action most often implemented is recovery of material from surplus sludge for agricultural purposes and the internal reuse of treated effluent as water for various types of plant maintenance. The production of energy from biogas also occurs frequently but only in large plants. On the other hand, some well-known options, such as external reuse of treated effluent or nutrients recovery, were implemented only in a minority of plants: this is likely due to limitations resulting either from strict regulation or difficulty placing recovered products on the market. In conclusion, an overall explanation of these driving forces within the system is explored.
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•This survey monitors sewage resources recovery in Italian scenario.•More than 60% of Italian plants does not perform any kind of recovery action.•Reuse of sludge (agriculture) and effluent (internal) are the most common options.•Further efforts are needed to reduce barriers against wastewater resource recovery.
Wine production is one of the leading sectors of the food processing industry. The wine industry produces a large amount of wastewater characterized by a high strength in terms of organic pollution ...and large variability throughout the year. Most of the organic matter is soluble and easily biodegradable. On the other hand, nitrogen and phosphorous are lacking. The aerobic and anaerobic processes are largely applied for winery wastewater treatment because they can quickly react to changes in the organic loading. This review analyzes e applied biological systems, considering both aerobic and anaerobic processes, and different reactor configurations. The performances of different biological processes are evaluated in terms of operational conditions (organic loading rate and hydraulic retention time). Aerobic processes can guarantee chemical oxygen demand removal up to 98% for organic loading rates of some 1-2 kg of chemical oxygen demand m
−3
d
−1
but requires good aeration systems to supply the required process oxygen. The management cost of these processes could be high considering the power density in the range 60-70 W m
−3
reactor
and that nutrients should be added to support biomass growth. On the other hand, anaerobic processes are able to face high organic loads with low running costs, but COD removal is generally limited to 90%. Combination of the two treatment systems (anaerobic followed by aerobic) could reduce management costs and meet high discharge standards.
Although the recovery and beneficial reuse of organic matter and nutrients from sludge represents an important move towards environmental sustainability, the accumulation of chemicals in ...biosolid-amended soils could pose serious environmental and human health risks. However, (eco)toxicological profiling of complex chemical mixtures in biosolids is currently limited. In particular, the effect of anaerobic digestion (AD), the most common stabilization process for sewage sludge, on the (eco)toxicity of those complex mixtures is poorly studied. In this work, we fill this research gap by applying an effect-based monitoring approach to screen sludge samples (n = 4) from a full-scale sewage treatment plant before and after conventional mesophilic (37 °C) AD using a battery of cell-based in vitro bioassays for four types of hormonal activity: estrogenic, androgenic, progestagenic and glucocorticoid activity, both in agonist and antagonist modes. We detected estrogenic, glucocorticoid and anti-progestagenic activity in all sludge samples. The glucocorticoid and anti-progestagenic activity remained mostly unchanged after AD treatment, but estrogenicity increased three-fold, likely as a result of bioactivation processes in the digestor. This study presents the first report on the concentration and fate of glucocorticoid and anti-progestagenic activity in AD. Future research should apply bioanalytical tools to a wider range of sludge samples to get a better understanding of the typical hormonal activity in sludge and develop effect-based trigger (EBT) values for biosolids to help interpret the risk posed by the hormonal activity detected in sludge.
•Endocrine activity analysed in sludge from Australian sewage treatment plant.•Estrogenic, glucocorticoid and anti-progestagenic activity detected.•Anaerobic digestion had no effect on glucocorticoid and anti-progestagenic activity.•Estrogenicity in sludge increased three-fold after anaerobic digestion.
A chemical and bio-analytical protocol is proposed as a holistic monitoring framework for the assessment of WWTPs (Wastewater Treatment Plants) performance. This combination of tests consists of: i) ...an analysis of emerging contaminants, to be added to the established physico–chemical parameters in order to understand the causes of (new) pollution phenomena and ii) some of the bio-analytical tools most widely applied in the field of wastewater research, which provide information on groups of chemicals with a common mode of toxic action (baseline toxicity, estrogenicity and mutagenicity/genotoxicity, selected as the most representative for human health). The negative effects of the discharge can thus be highlighted directly and used to assess the global environmental impact of WWTPs.
As a validation, this multi-tiered approach was applied to a full-scale WWTP (150,000 p.e.), where different measurements were carried out: EDCs (Endocrine Disrupting Compounds) detection; algal growth inhibition, bioluminescence inhibition and acute toxicity test (for baseline toxicity); an E-Screen-like assay (for estrogenic activity); Ames, Allium cepa and Comet tests (for mutagenic/genotoxic activity). As a result, the WWTP showed good performance for all these issues, displaying its ability to enhance effluent quality, except for residual mutagenic behaviour, probably due to the by-products generated by the tertiary ozonation.
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•A framework for an integrated monitoring of WWTPs is proposed as a puzzle of assays.•It is applied to a full-scale WWTP for a holistic evaluation of its performances.•Chemical (4 EDCs) and biological (3 assays) tests are presented.•The promotion of a multitiered approach is crucial for a real integrated evaluation.
A key issue in biological Waste Water Treatment Plants (WWTPs) operation is represented by the sludge management. Mechanical dewatering is a crucial stage for sludge volume reduction; though, being a ...costly operation, its optimization is required. We developed an original experimental methodology to evaluate the technical (dewatering efficiency) and financial (total treatment costs) performance of dewatering devices, which might be used as a DSS (Decision Support System) for WWTP managers. This tool was then applied to two real case studies for comparing, respectively, three industrial size centrifuges, and two different operation modes of the same machine (fixed installation vs. outsourcing service). In both the cases, the best option was identified, based jointly on economic and (site-specific) technical evaluations.
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•An innovative DSS is developed to assess performance of sludge dewatering devices.•The output of tool is represented by dewatering efficiency and total treatment costs.•Decision making process is driven by economic and technical criteria.•The new methodology is successfully applied to two real case studies.
Several decision support systems have been developed in recent years, aimed at judging environmental technologies under the lens of a multi-criteria analysis. This has also been applied in the field ...of wastewater treatment, where different factors (techno-economic-environmental) are inherent to the process and have to be balanced. The aim of this work is to calculate the damage on human health as a key factor for the evaluation of different wastewater treatment processes. The damage due to emissions into both water and air was taken into account. Indeed, the benefits related to the improved effluent quality after treatment could be counteracted by the negative effects when computing atmospheric emissions related to energy requirement. While a set of specific cost factors was applied for air pollution, a highly innovative perspective was adopted in the case of water pollution: several biological assays were used to weight waterborne diseases. Their application in the framework of a decision making process represents a novel approach in the wastewater domain. In short, we found that the economic equivalent of the impact on human health is remarkably affected by the selected treatment train, ranging from ≈2 €/PE/y for advanced systems up to ≈3 €/PE/y for conventional activated sludge plants. In particular, the most advisable schemes consist of an activated sludge plant integrated with either i) activated carbon and sand filtration or ii) sand filtration and ozonation. Finally, the applicability of the proposed procedure is also discussed and compared with the conventional life cycle assessment (LCA) approach, and the main difference is pointed out: for the former, biological assays and related diseases are used for endpoint calculation while the latter is based on the effect of each single compound.
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•An innovative appraisal framework is applied to rank wastewater treatment trains.•The impacts on both water and air (cross-media effects) are taken into account.•The human health damage is expressed as an economic value to compare technologies.•The 3ary treatment with activated carbon or O3 proves to be the most beneficial.
This opinion paper focuses on the role of eco-toxicological tools in the assessment of possible impacts of emerging contaminants on the aquatic ecosystem, hence, on human health. Indeed, organic ...trace pollutants present in raw and treated wastewater are the pivot targets: a multidisciplinary approach allows defining the basic principles for managing this issue, from setting a proper monitoring campaign up to evaluating the optimal process treatment. Giving hints on trace pollutants fate and behaviour, attention is focused on the choice of the bioassay(s), by analysing the meaning of possible biological answers. Data interpretation and exploitation are detailed with the final goal of providing criteria in order to be able to select the best targeted treatment options.
The manuscript deals with conventional and innovative analytical approaches for assessing toxicity, by reviewing laboratory and field assays; illustrative real scale and laboratory applications integrate and exemplify the proposed approach.
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•Bioassays must be chosen by taking into account the meaning of biological responses.•Lab and in situ bioassays must be integrated, based on reliability and applicability.•Trace pollutants can cause unpredictable and non-linear biological responses.•Wastewater composition and flowrate variability affects any toxicity assessment.•Environmental and socio-economic aspects underpin sewage treatment scheme choice.
A major source of the wide presence of EDCs (Endocrine Disrupting Compounds) in water bodies is represented by direct/indirect discharge of sewage. Recent scientific literature reports data about ...their trace concentration in water, sediments and aquatic organisms, as well as removal efficiencies of different wastewater treatment schemes. Despite the availability of a huge amount of data, some doubts still persist due to the difficulty in evaluating synergistic effects of trace pollutants in complex matrices. In this paper, an integrated assessment procedure was used, based on chemical and biological analyses, in order to compare the performance of two full scale biological wastewater treatment plants (either equipped with conventional settling tanks or with an ultrafiltration membrane unit) and tertiary ozonation (pilot scale).
Nonylphenol and bisphenol A were chosen as model EDCs, together with the parent compounds mono- and di-ethoxylated nonylphenol (quantified by means of GC–MS). Water estrogenic activity was evaluated by applying the human breast cancer MCF-7 based reporter gene assay. Process parameters (e.g., sludge age, temperature) and conventional pollutants (e.g., COD, suspended solids) were also measured during monitoring campaigns.
Conventional activated sludge achieved satisfactory removal of both analytes and estrogenicity. A further reduction of biological activity was exerted by MBR (Membrane Biological Reactor) as well as ozonation; the latter contributed also to decrease EDC concentrations.
► The fate of selected EDCs in two WWTPs was investigated. ► Similar performances were observed in the two different plants (CAS and MBR). ► Biological assays showed that MBR was more efficient in estrogenicity reduction. ► Rate constants of ozonation, described by first order kinetics, were calculated. ► In addition to EDC reduction, ozonation yielded an appreciable estrogenicity decrease.
Trace concentration of EDs (endocrine disrupting compounds) in water bodies caused by wastewater treatment plant effluents is a recognized problem for the health of aquatic organisms and their ...potential to affect human health. In this paper we show that continuous exposure of male mice from early development to the adult life (140days) to unrestricted drinking of wastewater collected from a municipal sewage treatment plant, is associated with an increased adipose deposition and weight gain during adulthood because of altered body homeostasis. In parallel, bisphenol A (BPA) at the administration dose of 5μg/kg/body weight, shows an increasing effect on total body weight and fat mass. In vitro, a solid phase extract (SPE) of the wastewater (eTW), caused stimulation of 3T3-L1 adipocyte differentiation at dilutions of 0.4 and 1 % in the final culture medium which contained a concentration of BPA of 40nM and 90nM respectively. Pure BPA also promoted adipocytes differentiation at the concentration of 50 and 80μM. BPA effect in 3T3-L1 cells was associated to the specific activation of the estrogen receptor alpha (ERα) in undifferentiated cells and the estrogen receptor beta (ERβ) in differentiated cells. BPA also activated the Peroxisome Proliferator Activated Receptor gamma (PPARγ) upregulating a minimal 3XPPARE luciferase reporter and the PPARγ-target promoter of the aP2 gene in adipose cells, while it was not effective in preadipocytes. The pure estrogen receptor agonist diethylstilbestrol (DES) played an opposite action to that of BPA inhibiting PPARγ activity in adipocytes, preventing cell differentiation, activating ERα in preadipocytes and inhibiting ERα and ERβ regulation in adipocytes.
The results of this work show that the drinking of chemically-contaminated wastewater promotes fat deposition in male mice and that EDs present in sewage are likely responsible for this effect through a nuclear receptor-mediated mechanism.
•Sewage watewaters (TW) sampled from a Municipal Treatment Sewage Plant are biologically active in mice and in vitro.•In male mice TW promotes an increase in adipose mass deposition following exposure from foetal to adult life. A similar effect is produced by BPA.•The expression of key genes of the adipose metabolism is increased in epidydimal fat both by TW and BPA.•An extract from the TW which concentrated the contained chemicals by a factor of 1000, is able to stimulate 3T3-L1 adipocyte differentiation.•The major chemicals contained in the TW, bisphenol A and nonylphenol, are able to promote adipocyte differentiation at the low environmentally relevant doses as are found in the TW.
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