Toxicity-related Impact Categories Research Articles

Reconsidering banning the imports of waste paper: The implications for the environmental, economic and health impacts

Waste paper (WP) has become indispensable raw materials for paper industry. China has banned all imported WP since 2021, this one-size-fits-all policy has caused wide debates due to lack of a multiple and systematic assessment. Herein, a three-dimensional comprehensive assessment of environment, economy and health risk was established to compare non-deinking paper (NP) and deinking paper (DP) with imported/domestic waste paper (IWP/DWP). Assessment indicated that IWP was strongly recommended for NP with 20.96 %, 17.39 % and 20.92 % lower than DWP in environment, economy and health risk, respectively. Although the health risk of IWP was 58.14 % higher than that of DWP, it did not exceed the threshold, IWP was still recommended for DP with 19.14 % and 4.18 % lower than DWP in environment and economy. Toxicity-related impact categories predominated at midpoint level, especially human carcinogenic toxicity (50.97–59.12 %), which was largely caused by the emission of large quantities of toxic pollutants from the key processes (e.g., electricity generation (25.14–38.28 %) and wood pulp (31.99 %)), especially chromium (VI) (51.08–60.21 %). While human health (93.89–95.1 %) dominated all endpoint impact categories, which was mainly attributed to the top substances (i.e., CO2) from electricity generation (28.47–42.78 %). Importantly, actual cost might be markedly underestimated without considering environmental cost, the ecosystems damage was the primary source of external cost, and the internal cost was concentrated in raw materials (47.57–61.67 %). The health risk of contaminants in WP was closely associated with their manufacturing process and raw materials. The major health risk resulted from heavy metals, particularly for As and Cr. In conclusion, banning all IWP should be deliberated carefully, high-quality IWP should be imported to decrease environmental and economic burdens via enhancing supervision, performing import subsidies and tax incentives, and administrative approvals (facilitating industry consolidation and merging small and medium-sized enterprises).

Life cycle assessment of high concentration organic wastewater treatment by catalytic wet air oxidation

There have been many studies on life cycle assessment in sewage treatment, but there are scarce few studies on the treatment of industrial wastewater in combination with advanced oxidation technology, especially in catalytic wet air oxidation (CWAO). There are no cases of using actual industrialized data onto life cycle assessment. This paper uses Simapro 9.0 software to establish a life cycle assessment model for the treatment of high-concentration organic wastewater by CWAO, and comprehensively explains the impact on the environment from three aspects: the construction phase, the operation phase and the demolition phase. In addition, sensitivity analysis and uncertainty analysis were performed. The results showed that the key factors affecting the environment were marine ecotoxicity, mineral resource consumption and global warming, the operation stage had the greatest impact on the environment, which was related to high power consumption during operation and emissions from the treatment process. Sensitivity analysis showed that electricity consumption has the greatest impact on abiotic depletion and freshwater aquatic ecotoxicity, and it also proved that global warming is mainly caused by pollutant emissions during operation phase. Monte Carlo simulations found slightly higher uncertainty for abiotic depletion and toxicity-related impact categories.

Toxicity impacts in the environmental footprint method: calculation principles

PurposeThe EU environmental footprint (EF) is a life cycle assessment (LCA)-based method which aims at assessing the environmental impacts of products and organisations through 16 midpoint impact categories, among which three address toxicity-related impacts. This paper presents the principles underpinning the calculation of the set of characterisation factors (CFs) for the toxicity-related impact categories in the EF version 3.0: freshwater ecotoxicity (ECOTOX), human toxicity cancer (HTOX_c) and human toxicity non-cancer (HTOX_nc).MethodsIn order to respond to the issues that emerged during the EF pilot phase, the input data and the calculation principles of the USEtox® model were updated. In particular, (i) robustness factors (RFs) were introduced to reduce the dominance of metals and to balance the lackness of a robust fate modelling for non-organic compounds in USEtox®; (ii) high-quality data were selected from databases of EU agencies (European Chemicals Agency and European Food Safety Authority) to guarantee the transparency and the reliability of input data; and (iii) a new approach based on HC20 (hazard concentration killing 20% of the exposed population) was implemented to derive freshwater ecotoxicity effect factors (EfF).Results and discussionThe new approach increased the number of characterised chemicals in the three impact categories: ECOTOX (6038 chemicals, + 140%), HTOX_c (1024 chemicals, + 70%) and HTOX_nc (3317 chemicals, + 660%). Moreover, specific derivation principles were defined for assigning CFs also to relevant groups of chemicals (e.g. polycyclic aromatic hydrocarbons), and specific strategies were implemented to better align LCA toxicity data with data used for risk assessment purposes.ConclusionsThe new set of CFs was calculated to ensure a broader coverage of characterised chemicals and to overcome some limitations of the USEtox® model identified during the environmental footprint pilot phase.

Environmental impact of strawberry production in Italy and Switzerland with different cultivation practices

In this study, the environmental impact of strawberry production in Italy and Switzerland was evaluated using the Life Cycle Assessment (LCA) approach. The main differences between the two countries are the cultivation practices: crop cycle duration (1 year in Switzerland and 2 or 3 years in Italy), soil management and cultivation in open and protected fields.For all the environmental impact categories evaluated with LCA, strawberry production in Switzerland shows higher impacts respect to the Italian production. The impact reduction related to the Italian production in open fields without soil sterilisation ranges from 96% (for photochemical oxidant formation) to 35% (for freshwater eutrophication). For Swiss production, soil sterilisation is by far the main environmental hotspot for all the evaluated environmental effects except for toxicity-related impact categories and for resources consumption (i.e. manufacturing, maintenance and disposal of tunnel). Conversely, the main hotspot in Italy differs depending on the considered categories. Moreover, the 3-years cycle duration has a higher impact respect to the 2-years one because of the low yield in the third year that worsens the outcomes.Finally, sensitivity and uncertainty analysis were performed. The environmental results are deeply affected by yield variation and only slightly by changes in the life span of the tunnels while the uncertainty related to the selection of the data source, the model imprecision, and the variability of data does not affect significantly the results, except for the toxicity-related impact categories.

Is SCENA a good approach for side-stream integrated treatment from an environmental and economic point of view?

The environmental and economic benefits and burdens of including the first Short Cut Enhanced Nutrient Abatement (SCENA) into a real municipal wastewater treatment plant were evaluated using life cycle assessment (LCA) and life cycle cost (LCC). The implications of accomplishing nitrogen (N) removal and phosphorus (P) recovery via nitrite in the side stream were assessed taking into account the actual effluent quality improvement, the changes in the electricity and chemical consumption, N2O, CO2 and CH4 emissions and the effects of land application of biosolids, among others. In addition, a case-specific estimation of the P availability when sludge is applied to land, therefore replacing conventional fertilizer, was performed. Furthermore, to account for the variability in input parameters, and to address the related uncertainties, Monte Carlo simulation was applied.The analysis revealed that SCENA in the side stream is an economic and environmentally friendly solution compared to the traditional plant layout with no side-stream treatment, thanks to the reduction of energy and chemical use for the removal of N and P, respectively. The uncertainty analysis proved the validity of the LCA results for global warming potential and impact categories related to the consumption of fossil-based electricity and chemicals, while robust conclusions could not be drawn on freshwater eutrophication and toxicity-related impact categories. Furthermore, three optimization scenarios were also evaluated proving that the performance of the WWTP can be further improved by, for instance, substituting gravitational for mechanical thickening of the sludge or changing the operational strategy to the chemically enhanced primary treatment, although this second alternative will increase the operational cost by 5%. Finally, the outcomes show that shifting P removal from chemical precipitation in the main line to biologically enhanced uptake in the side stream is key to reducing chemicals use, thus the operational cost, and increasing the environmental benefit of synthetic fertilizers replacement.

Assessment of the Environmental Sustainability of a Treatment Aimed at Soil Reuse in a Brownfield Regeneration Context

SummaryA combined stabilization/solidification (S/S) and granulation treatment was shown to be effective, at lab scale, to produce secondary aggregates from a Brownfield soil slightly contaminated by metals. This treatment, as opposed to the frequently adopted “dig and dump” option, allows to combine soil management with site regeneration, minimizing landfill disposal. But is this treatment actually more environmentally sustainable than excavated soil management by dig and dump? To answer this question, we analyzed and compared by life cycle assessment the environmental impacts resulting from the application of the above‐mentioned treatment versus dig and dump on the basis of the results of lab tests performed on a Brownfield soil sample, including leaching test results. The impacts related to the production of all the reagents used in the on‐site treatment, as well as the avoided impacts due to the replacement of raw aggregates with recycled ones, were included. Results showed that the proposed S/S‐granulation process may allow a drastic decrease of the impacts related to land use and resource depletion in comparison to dig and dump, with beneficial effects also with regard to toxicity‐related impact categories. Conversely, the proposed treatment yielded higher impacts, in terms of acidification, water resource depletion, and, in particular, climate change, almost entirely related to the manufacturing of the cement employed for stabilization. However, an average 40% reduction of overall impacts was noted when fly ash cement was assumed to be used as binder instead of Portland cement.

Supporting a transition towards sustainable circular economy: sensitivity analysis for the interpretation of LCA for the recovery of electric and electronic waste

PurposeThe interpretation is a fundamental phase of life cycle assessment (LCA). It ensures the robustness and the reliability of the overall study. Moving towards more circular economy requires that different waste management options are systematically scrutinized to assess the environmental impacts and benefits associated to them. The present work aims at illustrating how a sensitivity analysis could be applied to the impact assessment step supporting the interpretation of a LCA study applied to a waste management system that includes material recovering. The focus is on toxicity-related and resource-related potential impacts as they are considered among the most critical ones, which may affect the way the final benefit from material recovery is evaluated.MethodsPossible alternatives in terms of impact assessment assumptions and modelling are tested by performing a sensitivity analysis on a case study on electric and electronic waste. For the toxicity-related impact categories, first, a sensitivity analysis is performed using different sets of characterization factors for metals aiming at identifying how they are affecting the final results. Then, an analysis of the relative contribution of long-term emissions in upstream processes is carried out aiming at unveiling critical issues associated to their inclusion or exclusion. For the resource depletion impact category, a sensitivity analysis has been performed, adopting different sets of characterization factors based on existing models for minerals and metals as well as recently proposed sets accounting for critical raw materials.Results and discussionThe indicator of the ecotoxicity impact category obtained by applying the updated characterization factors is about three times higher than the corresponding obtained by the USEtox model. The long-term emission result is responsible for the major part of all the toxicity impact indicators. Moreover, for the ecotoxicity indicator, excluding the long-term emissions changes the total results from being negative into positive. The sensitivity analysis for the resource depletion impact category shows that all the models applied result in a total avoided impact. A quantitative comparison among all the results is not possible as the different models use different units of measure.ConclusionsThe application of LCA is crucial for assessing avoided impacts and uncovers potential impacts due to recycling. However, contrasting results may stem from the application of different assumptions and models for characterization. A robust interpretation of the results should be based on systematic assessment of the differences highlighted by the sensitivity, as guidance for delving into further analysis of the drivers of impacts and/or to steer ecoinnovation to reduce those impacts.

Rice fertilised with urban sewage sludge and possible mitigation strategies: an environmental assessment

Among the different cereals, rice plays a relevant role in terms of production and dietary intake. Although the highest rice producers are Asian countries, this crop is also cultivated in Europe and, within Europe, Italy is the most relevant country. There are not studies evaluating in detail the environmental load arising from the application of urban sewage sludge in rice fields that, being flooded, are characterized by anaerobic conditions. The goal of this study was to evaluate the environmental performance of rice cultivation fertilised with urban sewage sludge in the Pavia district. Moreover, three mitigation strategies have been proposed and evaluated: the substitution of urban sewage sludge with compost, the introduction of an additional aeration and the collection of straw.The results suggest that the main contributors to the environmental impact of rice are methane emissions associated with the degradation of the organic matter during the flooding period, nitrogen emissions associated with the application of fertilisers, and diesel used for the field operations. The differences among the proposed alternative scenarios are considerable, suggesting that strategies to improve the environmental performance of rice are possible. In more details, in order to reduce the environmental burdens of rice fertilised with urban sewage sludge, the two most effective possibilities are: the substitution of urban sewage sludge with compost and the implementation of an additional aeration period during the cultivation. The first option determines an improvement in all the categories analysed, and particularly in toxicity-related impact categories, with reductions of 99.6%, 78.8% and 68.7% for human toxicity-cancer effects, human toxicity-non cancer effects and freshwater ecotoxicity, respectively, followed by Climate Change (−25.4%) and Mineral Fossil Resource Depletion (−19.2%). The introduction of an additional aeration is beneficial for the Climate Change and Photochemical Oxidant Formation, with a reduction of 9.7% and 1.6%, respectively.Concerning the results of the Climate Change impact category, the use of standard emission factors for the estimation of methane emission involves uncertainty; the development of country-specific emission factors would be instrumental in overcoming this point of weakness. Finally, despite the focus on the Italian context, this study proposes different mitigation strategies, which can be applied to other rice systems in order to reduce their environmental impact.

Assessing eco-innovations in green chemistry: Life Cycle Assessment (LCA) of a cosmetic product with a bio-based ingredient

Enhancing and promoting eco-innovation solutions in cosmetic industry requires robust methods for assessing the environmental impacts and reducing burden shifting amongst life cycle stages and typology of impacts. This study aims at comparing the environmental profile of eco-innovation options for a cosmetic product by means of Life Cycle Assessment (LCA) methodology. We present a case study in which synthetic ingredients are replaced by others derived from natural compounds, following green chemistry principles. A C16–18 triglycerides mixture (INCI name “palmitic/stearic triglycerides”) derived from olive oil industry by-products is used both as single ingredient (Innovation I) and as part of a preformulated one (Innovation II), replacing the starting formulation (Benchmark) caprylic/capric triglyceride. Options are compared through LCA applying International Life Cycle Data impact assessment focusing the analysis to water and energy consumption, sources of raw materials and previous manufacturing stages thereof. In order to test the robustness of the results, we performed a set of sensitivity analyses: i) changing assumptions about transports and irrigation of olive trees; ii) comparing results of the application of two life cycle impact assessment methods (CML and IMPACT 2002). The results show that the impacts derived from the selection of ingredients are more significant than those due to water and energy consumption. Applying different methods, results show significant differences, especially in toxicity-related impact categories. Overall, an alleged “eco-friendly” ingredient (such as a natural by-product derived one) could result in a less preferable environmental profile if assessed in a life cycle perspective. This supports the need of adopting life cycle based methods to ensure that green chemistry options respond to the need of reducing environmental in all life cycle stages.

Environmental sustainability of bark valorisation into biofoam and syngas

Conventional foams derived from petroleum are extensively used for insulating uses. Research into alternative sources to petroleum based chemicals is attracting a great deal of attention. Softwood bark and in special, maritime pine bark from European forests is an abundant co-product from forest industries. In this study, the production of formaldehyde-free tannin based biofoams to be used as building insulation materials was environmentally assessed using the Life Cycle Assessment methodology (cradle-to-grave approach) as well as their valorisation into bioenergy (electricity and thermal energy) at end of their life cycle by means of their gasification into tar-free syngas and its further combustion in a CHP unit. The production chain was divided into four subsystems: forest activities (SS1), sawmill (SS2), biofoams production (SS3) and bioenergy production (SS4). Wherever possible, primary data from pilot plants were managed. Since two main co-products are obtained, three different approaches were considered and discussed: total allocation of environmental burdens to the electricity (main product), exergy based allocation and system expansion.According to the results, SS3 was identified as the environmental hotspot regardless the impact category considered for assessment. The large requirements of electricity in the tannin extraction unit as well as the production of chemicals required for the biofoam formulation were the responsible factors of these notable contributions. Special attention should also be paid to the uncontrolled pentane emissions associated to the biofoam formulation, specifically in terms of photochemicals oxidant formation.Remarkable environmental benefits were obtained in terms of climate change, fossil fuels depletion as well as in some toxicity related impact categories in comparison with the petroleum based foams, mainly based on the use of an abundant renewable source as raw material to produce the foams. Improvement actions should look at the reduction (or even recovery) of chemicals used, the control of diffuse emissions (e.g. pentane from evaporation unit and CHP unit) as well as the installation of a cogeneration unit to produce the electricity requirements to reduce dependence on fossil fuels.

Comparison of solidification/stabilization of fly ash and air pollution control residues from municipal solid waste incinerators with and without cement addition

Solidification/stabilization (S/S) of fly ash and air pollution control residues from MSWI was studied, with and without the use of cement. It appeared that metal and oxyanion leaching from these stabilised residues was comparable after 75 days of curing. Leaching of chloride and sulfate did not decrease by the addition of cement during S/S treatment. In an LCA perspective the environmental impact of the S/S treated mixtures with cement in the toxicity related impact categories was higher than the impact of the S/S treated mixtures without cement. Moreover, the production of cement for application in S/S also causes an impact in the impact categories climate change and terrestrial acidification. For environmental considerations in an LCA perspective S/S without cement should be preferred.

Comparative life cycle assessment of wastewater treatment in Denmark including sensitivity and uncertainty analysis

Abstract Wastewater treatment has nowadays multiple functions and produces both clean effluents and sludge, which is increasingly seen as a resource rather than a waste product. Technological as well as management choices influence the performance of wastewater treatment plants (WWTPs) on the multiple functions. In this context, Life Cycle Assessment (LCA) can determine what choices provide the best environmental performance. However, the assessment is not straightforward due to the intrinsic space and time-related variability of the wastewater treatment process. These challenges were addressed in a comparative LCA of four types of WWTPs, representative of mainstream treatment options in Denmark. The four plant types differ regarding size and treatment technology: aerobic versus anaerobic, chemical vs. combined chemical and biological. Trade-offs in their environmental performance were identified considering system expansion to model the avoided impacts achievable in different end-of-life scenarios for sludge: combustion with energy production versus agricultural application. To account for the variability in quality of effluents and sludge, and to address the related uncertainties, Monte Carlo simulation and sensitivity analysis were applied. Uncertainties related to the choice of Life Cycle Impact Assessment (LCIA) method and to the use of different data sources were also discussed. The results showed that, for the climate change and fossil depletion impact categories, recycling phosphorus to agricultural soils appear as a more sustainable alternative compared to the incineration of sludge. However, the uncertainty and sensitivity analysis showed that robust conclusions could not be drawn on the eutrophication and toxicity-related impact categories.

Life cycle assessment of waste incineration in Denmark and Italy using two LCA models

In Europe, about 20% of municipal solid waste is incinerated. Large differences can be found between northern and southern Europe regarding energy recovery efficiencies, flue gas cleaning technologies and residue management. Life-cycle assessment (LCA) of waste incineration often provides contradictory results if these local conditions are not properly accounted for. The importance of regional differences and site-specific data, and choice of LCA model itself, was evaluated by assessment of two waste incinerators representing northern and southern Europe (Denmark and Italy) based on two different LCA models (SimaPro and EASEWASTE). The results showed that assumptions and modelling approaches regarding energy recovery/substitution and direct air emissions were most critical. Differences in model design and model databases mainly had consequences for the toxicity-related impact categories. The overall environmental performance of the Danish system was better than the Italian, mainly because of higher heat recovery at the Danish plant. Flue gas cleaning at the Italian plant was, however, preferable to the Danish, indicating that efficient flue gas cleaning may provide significant benefits. Differences in waste composition between the two countries mainly affected global warming and human toxicity via water. Overall, SimaPro and EASEWASTE provided consistent ranking of the individual scenarios. However, important differences in results from the two models were related to differences in the databases and modelling approaches, in particular the possibility for modelling of waste-specific emissions affected the toxicity-related impact categories. The results clearly showed that the use of site-specific data was essential for the results.

Life-cycle assessment of selected management options for air pollution control residues from waste incineration

Based on available technology and emission data seven selected management options for air-pollution-control (APC) residues from waste incineration were evaluated by life-cycle assessment (LCA) using the EASEWASTE model. Scenarios were evaluated with respect to both non-toxicity impact categories (e.g. global warming) and toxicity related impact categories (e.g. ecotoxicity and human toxicity). The assessment addressed treatment and final placement of 1 tonne of APC residue in seven scenarios: 1) direct landfilling without treatment (baseline), 2) backfilling in salt mines, 3) neutralization of waste acid, 4) filler material in asphalt, 5) Ferrox stabilization, 6) vitrification, and 7) melting with automobile shredder residues (ASR). The management scenarios were selected as examples of the wide range of different technologies available worldwide while at the same time using realistic technology data. Results from the LCA were discussed with respect to importance of: energy consumption/substitution, material substitution, leaching, air emissions, time horizon aspects for the assessment, and transportation distances. The LCA modeling showed that thermal processes were associated with the highest loads in the non-toxicity categories (energy consumption), while differences between the remaining alternatives were small and generally considered insignificant. In the toxicity categories, all treatment/utilization options were significantly better than direct landfilling without treatment (lower leaching), although the thermal processes had somewhat higher impacts than the others options (air emissions). Transportation distances did not affect the overall ranking of the management alternatives.

Environmental assessment of Ämmässuo Landfill (Finland) by means of LCA-modelling (EASEWASTE)

The Old Ammässuo Landfill (Espoo, Finland) covers an area of 52 hectares and contains about 10 million tonnes of waste that was landfilled between 1987 and 2007. The majority of this waste was mixed, of which about 57% originated from households. This paper aims at describing the management of the Old Ammässuo Landfill throughout its operational lifetime (1987-2007), and at developing an environmental evaluation based on life-cycle assessment (LCA) using the EASEWASTE-model. The assessment criteria evaluate specific categories of impact, including standard impact categories, toxicity-related impact categories and an impact categorized as spoiled groundwater resources (SGR). With respect to standard and toxicity-related impact categories, the LCA results show that substantial impact potentials are estimated for global warming (GW), ozone depletion (OD), human toxicity via soil (HTs) and ecotoxicity in water chronic (ETwc). The largest impact potential was found for SGR and amounted to 57.6 person equivalent (PE) per tonne of landfilled waste. However, the SGR impact may not be viewed as a significant issue in Finland as the drinking water is mostly supplied from surface water bodies. Overall, the results demonstrate that gas management has great importance to the environmental performance of the Old Ammässuo Landfill. However, several chemicals related to gas composition (especially trace compounds) and specific emissions from on-site operations were not available or were not measured and were therefore taken from the literature. Measurement campaigns and field investigations should be undertaken in order to obtain a more robust and comprehensive dataset that can be used in the LCA-modelling, before major improvements regarding landfill management are finalized.

Environmental assessment of gas management options at the Old Ämmässuo landfill (Finland) by means of LCA-modeling (EASEWASTE)

The current landfill gas (LFG) management (based on flaring and utilization for heat generation of the collected gas) and three potential future gas management options (LFG flaring, heat generation and combined heat and power generation) for the Old Ammässuo landfill (Espoo, Finland) were evaluated by life-cycle assessment modeling. The evaluation accounts for all resource utilization and emissions to the environment related to the gas generation and management for a life-cycle time horizon of 100 yr. The assessment criteria comprise standard impact categories (global warming, photo-chemical ozone formation, stratospheric ozone depletion, acidification and nutrient enrichment) and toxicity-related impact categories (human toxicity via soil, via water and via air, eco-toxicity in soil and in water chronic). The results of the life-cycle impact assessment show that disperse emissions of LFG from the landfill surface determine the highest potential impacts in terms of global warming, stratospheric ozone depletion, and human toxicity via soil. Conversely, the impact potentials estimated for other categories are numerically-negative when the collected LFG is utilized for energy generation, demonstrating that net environmental savings can be obtained. Such savings are proportional to the amount of gas utilized for energy generation and the gas energy recovery efficiency achieved, which thus have to be regarded as key parameters. As a result, the overall best performance is found for the heat generation option - as it has the highest LFG utilization/energy recovery rates - whereas the worst performance is estimated for the LFG flaring option, as no LFG is here utilized for energy generation. Therefore, to reduce the environmental burdens caused by the current gas management strategy, more LFG should be used for energy generation. This inherently requires a superior LFG capture rate that, in addition, would reduce fugitive emissions of LFG from the landfill surface, bringing further environmental benefits.

Life Cycle Assessment of urban wastewater reuse with ozonation as tertiary treatment: A focus on toxicity-related impacts

Life Cycle Assessment has been used to compare different scenarios involving wastewater reuse, with special focus on toxicity-related impact categories. The study is based on bench-scale experiments applying ozone and ozone in combination with hydrogen peroxide to a wastewater effluent from a Spanish sewage treatment plant. Two alternative characterisation models have been used to account for toxicity of chemical substances, namely USES-LCA and EDIP97. Four alternative scenarios have been assessed: wastewater discharge plus desalination supply, wastewater reuse without tertiary treatment, wastewater reuse after applying a tertiary treatment consisting on ozonation, and wastewater reuse after applying ozonation in combination with hydrogen peroxide. The results highlight the importance of including wastewater pollutants in LCA of wastewater systems assessing toxicity, since the contribution of wastewater pollutants to the overall toxicity scores in this case study can be above 90%. Key pollutants here are not only heavy metals and other priority pollutants, but also non-regulated pollutants such as pharmaceuticals and personal care products. Wastewater reuse after applying any of the tertiary treatments considered appears as the best choice from an ecotoxicity perspective. As for human toxicity, differences between scenarios are smaller, and taking into account the experimental and modelling uncertainty, the benefits of tertiary treatment are not so clear. From a global warming potential perspective, tertiary treatments involve a potential 85% reduction of greenhouse gas emissions when compared with desalination.