Anticipatory life cycle analysis framework for sustainable management of end-of-life crystalline silicon photovoltaic panels

In this research, a framework for performing Anticipatory Life Cycle Analysis (a-LCA) has been developed to identify the sustainable end of life (EoL) management option for crystalline silicon photovoltaic (PV) panels. a-LCA can be used to stimulate proactive and sustainable decision making for emerging technologies through stakeholder participation. In this research, stakeholders related to EoL management of PV panels participated through a survey to identify and prioritize economic, environmental, and social indicators for PV EoL management. Several EoL strategies like bulk material recycling (centralized and decentralized), high value material recycling, and landfilling were chosen and assessed for the prioritised sustainability indicators. The EoL strategies were then ranked through a multi-criteria decision analysis tool for their level of sustainability. High value material recycling (close to 100% material recovery) was identified as the most sustainable option followed by bulk recycling of PV panels that recover only the major constituents, such as aluminium, glass, and e-waste. Landfilling remained the least preferred option, although it currently has an economic advantage over other recycling options, highlighting the need to shift the user preferences. The developed a-LCA framework is iterative and can be applied by decision makers for different EoL management strategies in the future.This research was supported by the by R2MIT project (ref. CTM2017-85346-R) financed by the Spanish Ministry of Economy and Competitiveness (MINECO) and the Catalan Government (ref. 2017-SGR-312) the Open Innovation - Research Translation and Applied Knowledge Exchange in Practice through University-In- dustry Cooperation (OpenInnoTrain), Grant agreement number (GAN): 823971, H2020-MSCA-RISE-2018-823971. The authors would also like to thank the various stakeholders who had partic- ipated in the survey to provide their valuable inputs. Special thanks Fig. 8. Sensitivity Analysis based on changes in Economic, Environmental, and Social impact criteria (Red vertical line indicating the overall weightage of the selected criteria). K. Ganesan and C. Valderrama Energy 245 (2022) 123207 12 to Sofies Sustainability Leaders Pvt Ltd and Poseidon Solar Pvt Ltd for supporting this work and for providing insights from their Solar Waste Action Plan project.Peer ReviewedPostprint (published version

Multicriteria evaluation of novel technologies for organic micropollutants removal in advanced water reclamation schemes for indirect potable reuse

Postprint (author's final draft

Towards a sustainability-based society: an analysis of fundamental values from the perspective of economics and philosophy

Sustainable development faces numerous challenges when applied in the real-world global economic model of capitalism. The prevailing trend of the economic pillar, in the implementation of sustainability planning based on the triple bottom line (TBL), compromises both the environment and society. This paper aims to address such challenges by proposing a new vision of strong sustainability that is characterised by: i) considering the global economic model in a real-world approach; and ii) having strong core values of sustainability. To evaluate the first characteristic, a review of the literature regarding capitalism and TBL-sustainability has been conducted. For the second characteristic, a historical-philosophical discussion around the role of society and the economy has been conducted. The results suggest that an actual sustainable society requires a fixed and sustained focus on environmental and social pillars together with a flexible organisation of society (including its economic model).Peer ReviewedObjectius de Desenvolupament Sostenible::2 - Fam zeroObjectius de Desenvolupament Sostenible::3 - Salut i BenestarObjectius de Desenvolupament Sostenible::1 - Fi de la PobresaObjectius de Desenvolupament Sostenible::4 - Educació de QualitatObjectius de Desenvolupament Sostenible::15 - Vida d'Ecosistemes TerrestresObjectius de Desenvolupament Sostenible::17 - Aliança per a Aconseguir els ObjetiusObjectius de Desenvolupament Sostenible::16 - Pau, Justícia i Institucions SòlidesObjectius de Desenvolupament Sostenible::5 - Igualtat de GènereObjectius de Desenvolupament Sostenible::6 - Aigua Neta i SanejamentObjectius de Desenvolupament Sostenible::7 - Energia Assequible i No ContaminantObjectius de Desenvolupament Sostenible::9 - Indústria, Innovació i InfraestructuraObjectius de Desenvolupament Sostenible::10 - Reducció de les DesigualtatsObjectius de Desenvolupament Sostenible::11 - Ciutats i Comunitats SosteniblesObjectius de Desenvolupament Sostenible::12 - Producció i Consum ResponsablesObjectius de Desenvolupament Sostenible::13 - Acció per al ClimaObjectius de Desenvolupament Sostenible::14 - Vida SubmarinaPostprint (published version

Selectrodialysis and bipolar membrane electrodialysis combination for industrial process brines treatment: Monovalent-divalent ions separation and acid and base production

Chemical industries generate large amounts of wastewater rich in different chemical constituents. Amongst these, salts at high concentrations are of major concern, making necessary the treatment of saline effluents before discharge. Because most of these rejected streams comprise a combination of more than one salt at high concentration, it is reasonable to try to separate and revalorize them to promote circular economy at industry site level. For this reason, ion-exchange membranes based technologies were integrated in this study: selectrodialysis (SED) and electrodialysis with bipolar membranes (EDBM). Different process brines composed by Na2SO4 and NaCl at different concentrations were treated first by SED to separate each salt, and then by EDBM to produce base (NaOH) and acids (HCl and H2SO4) from each salt. The optimum of both electrolyte nature and concentration of the SED stack streams was evaluated. Results indicated that it was possible to separate Cl- and SO42- depending on the anionic membrane, initial electrolytes and concentrations of each stream. Pure NaOH and a mixture of HCl and H2SO4 with different purities could be obtained. Energy consumption evolutions were plotted and an optimal zone work was found where the consumption values were acceptable.Peer ReviewedPostprint (author's final draft

Nutrients recovery from treated secondary mainstream in an urban wastewater treatment plant: a financial assessment case study

This study presents the financial assessment for implementing an ammonium and phosphate simultaneous recovery process based on the use of calcium activated synthetic zeolites in a large urban Waste Water Treatment Plant (WWTP) located in the Metropolitan Area of Barcelona. A calcium activated synthetic zeolites was selected, after a benchmarking analysis, as it reported capability for simultaneously recover ammonium and phosphate by a combined mechanism of ion exchange for ammonium and formation of insoluble mineral phase for phosphate. The loaded sorbent, rich in ammonium and phosphate, can be used as slow-release fertilizer. Financial indexes such as the net present value, the internal return rate, the return of investment and the payback period were calculated concluding that the integration of a zeolite-based sorption treatment stage in the main stream is economically feasible, with a reasonable payback period. The need, to achieve low-levels of P and N on the discharged waters and the need to develop more sustainable WWTP facilities indicate that the deployment of nutrient recovery solutions will be encouraged. The sensitivity analysis carried out to define the critical parameters of the economic performance of the technology allows concluding that the main variable in the viability of the nutrient recovery unit is related to the nutrients sorbent, both in the cost of purchase and in the market for the sorbent loaded with nutrients.Peer ReviewedPostprint (author's final draft

A phosphorous flow analysis in Spain

Phosphorus (P) is a vital macronutrient required to improve the agricultural yields but its excessive use as a fertilizer has resulted in pollution of water bodies leading to eutrophication. With no reserves of phosphorus source in Spain, increased dependence on phosphorus in agriculture have not only increased dependence on imports but also has raised concerns on its future availability as a resource. A Phosphorous Flow Analysis (PFA) was conducted for Spain for the year 2012 focusing on the food production and consumption systems. The results obtained were finally compared with PFA at both country level and continent level (EU-27). To quantify food and non-food flows systems, country specific data were considered. The sectors covered were crop production (CP), animal production (AP), food processing (FP), non-food production (NF) and consumption (HC). The findings reveal that a total of 325 kt P was imported by Spain in 2012; 66% of which was accumulated in markets stock of food and feed, fertilizers and non-food (91 kt P) while 33% was lost to the environment through land-fill, losses to water bodies, land accumulation and incineration. The largest proportion of losses is associated with water bodies (44.7 kt P) followed by agriculture and land accumulation (42.1 kt P). Wastewater treatment plants (WWTPs) received around 79.5 kt P within wastewater, with 60% being removed in sewage sludge. The 31.7 kt P discharged within final effluent represented the 71% of the total losses to water bodies. Around 69% of the sewage sludge was recycled to agriculture and 27% was sent directly to landfill including the ashes from incineration. Net accumulation was 1.84 kg P/cap which was similar to values reported for the EU-27 average (2.5 kg P/cap).Peer ReviewedPreprin

Integration of monopolar and bipolar electrodialysis for valorization of seawater reverse osmosis desalination brines: Production of strong acid and base

Water scarcity in the Mediterranean basin has been solved by using seawater desalination reverse osmosis technology (SWD-RO). This technology produces brine which is discharged back into the sea resulting in an environmental impact on marine ecosystems. Under the circular economy approach, the aim of this work is to recover resources from NaCl-rich brine (~60-70 g/L), e.g. in the form of NaOH and HCl, by integration of two ion exchange-based membrane technologies and quantify the electrical energy consumption. Electrodialysis (ED) incorporating monovalent selective cation exchange membranes as divalent ions purification and concentration of the NaCl present in the SWD-RO brine, was integrated with bipolar membrane ED (EDBM) to produce NaOH and HCl. Current densities of 0.30–0.40 kA/m2 at two temperature ranges simulating different seawater temperature regimes (15-18 ºC and 22-28ºC) were tested and a pure NaCl solution was used as starting concentrate stream. NaCl-rich brines with 100 or 200 gNaCl/L were obtained by ED and then introduced in the EDBM stack producing HCl and NaOH up to 2 M, depending on the initial concentrations. A minimum energy consumption of 1.7 kWh/kgNaOH was calculated when working by EDBM with initial concentrations of 104 g NaCl/L and 0.24 M HCl and NaOH.Peer ReviewedPostprint (author's final draft

Effect of Mn2+/Zn2+/Fe3+ Oxy(Hydroxide) nanoparticles doping onto Mg-Al-LDH on the phosphate removal capacity from simulated wastewater

A parent Mg-Al-LDH was upgraded in its adsorption properties due to the incorporation of tri-metal species oxy(hydroxide) nanoparticles obtaining Mn2+/Zn2+/Fe3+/Mg-Al-LDH composite for the phosphate recovery from simulated urban treated wastewater. The physicochemical properties of the synthesized Mn2+/Zn2+/Fe3+/Mg-Al-LDH make promising for real application without being environmentally harmful. The performance of Mn2+/Zn2+/Fe3+/Mg-Al-LDH composite was evaluated through batch adsorption assays. The support of iron, manganese, and zinc (oxy)hydroxide nanoparticles onto the parent Mg-Al-LDH structure was performed by precipitation, isomorphic substitution, and complexation reactions. The main improvement of the Mn2+/Zn2+/Fe3+/Mg-Al-LDH composite was the highest phosphate adsorption capacity (82.3 mg·g-1) in comparison to the parent Mg-Al-LDH (65.3 mg·g-1), in a broad range of concentrations and the effective phosphate adsorption at neutral pH (7.5) near to the real wastewater effluents conditions in comparison to the conventional limitations of other adsorbents. The effectiveness of Mn2+/Zn2+/Fe3+/Mg-Al-LDH composite was higher than the conventional metal LDHs materials synthesized in a single co-precipitation step. The phosphate adsorption onto Mn2+/Zn2+/Fe3+/Mg-Al-LDH composite was described to be governed by both physical and chemical interactions. The support of Mn2+/Zn2+/Fe3+ oxy(hydroxide) nanoparticles over the parent Mg-Al-LDH was a determinant for the improvement of the phosphate adsorption that was governed by complexation, hydrogen bonding, precipitation, and anion exchange. The intra-particular diffusion also described well the phosphate adsorption onto the Mn2+/Zn2+/Fe3+/Mg-Al-LDH composite. Three specific stages of adsorption were determined during the phosphate immobilization with an initial fast rate, followed by the diffusion through the internal pores and the final equilibrium stage, reaching 80% of removal and the equilibrium within 1 h. The Mn2+/Zn2+/Fe3+/Mg-Al-LDH was strongly selective towards phosphate adsorption in presence of competing ions reducing the adsorption capacity at 20%. The Mn2+/Zn2+/Fe3+/Mg-Al-LDH has limited reusability, only 51% of the adsorbed phosphate could be recovered in the second cycle of the adsorption-desorption process. Around 14% of phosphate was loosely-bond to Mn2+/Zn2+/Fe3+/Mg-Al-LDH which brings the opportunity to be a new source of phosphorus. The use of eluted concentrates and the final disposal of the exhausted adsorbent for soil amendment applications can be an integral nutrient system (P, Mn, Zn, Fe) for agriculture purposes.Peer ReviewedPostprint (published version

Stability analysis of an industrial salinity gradient solar pond

In this study, an assessment of salinity gradient stability of an industrial solar pond during two operation seasons (2014 and 2105) is presented. An industrial solar pond was constructed to supply a low-temperature heat (up to 60¿°C) to achieve the temperature requirements of the flotation stage in a mineral processing plant (Solvay Minerales in Granada (Spain)). Along the first season, the salinity gradient was considered technically destroyed in April 2015 as the height to the upper convective zone increases from 0.3¿m in July 2014 to 0.8¿m. Two different methodologies based on the stratification principle were adapted and used in order to evaluate the salinity gradient stability. The boundaries of the salinity gradient appeared as the main source of instability. In the upper zone it is associated with the environmental parameters (e.g., rain and wind) that affect the upper convective zone and the upper layers of the non-convective zone that subsequently transmit the instability to the lower layers. In the bottom zone it is caused by operation parameters, such as the heat extraction or the addition of salt. Both methodologies provided similar predictive capability of stability results. However, the results provided by the stability analysis using the thermal and salinity expansion coefficients are a more useful tool in the control of the salinity gradient for solar pond technology.Peer ReviewedPostprint (published version

Life cycle assessment and economic analysis of the electric motorcycle in the city of Barcelona and the impact on air pollution

In this work, the evaluation of the life cycle of the service provided by a medium-power motorcycle in a Spanish urban environment was carried out, comparing two motorcycles, a battery electric vehicle (BEV) is compared with an internal combustion engine vehicle (ICEV). The economic study of the total costs of ownership is also carried out considering the environmental costs associated with each type of vehicle. A comprehensive inventory is compiled for both vehicles (motorcycles) that describes the most relevant components and includes two types of batteries for the BEV. A sensitivity analysis of the most impactful parameters is also considered. The results indicate that the ICEV contributes approximately 5 times more in the global warming potential impact category mainly due to the consumption of fossil fuels. The BEV also impacts some categories in the manufacturing stage, a fact that is strongly related to the battery. Sensitivity analysis indicates that the total distance travelled plays an important role, but the electricity mix is probably the most relevant factor in terms of climate change impact category. The economic analysis reported lower environmental externality costs for the BEV, making it more affordable than the ICEV and highlighting the benefit in terms of air pollution. The BEV is presented as a suitable option vehicle from environmental and economic point of view and one of the actors to accelerate the transition towards a more sustainable urban mobility model.Peer ReviewedPostprint (published version