Freshwater Eutrophication Potential Research Articles

Life cycle assessment on environmental feasibility of microalgae-based wastewater treatment for shrimp recirculating aquaculture systems

This life cycle assessment (LCA) study analyzed the environmental consequences of integrating microalgae-based wastewater treatment into a shrimp farm with recirculating aquaculture systems (RAS). Microalgae treatment produced <10 % of the system’s freshwater eutrophication potential (FEP), marine eutrophication potential (MEP) and global warming potential, which was dominantly contributed by electricity use. Microalgae treatment performed comparably to activated sludge treatment for FEP reduction, and was more effective in remediating marine eutrophication. Replacing coal in electricity mix, particularly with renewables, reduced the system’s impacts by up to 90–99 %. Performing the LCA based on system expansion generally obtained higher impacts compared to allocation. Utilizing algal biomass for biogas production reduced the MEP; however, production of feed ingredient and biodiesel were not environmentally beneficial. This study proved the use of microalgae for aquaculture wastewater treatment to be environmentally feasible, the results can guide more sustainable RAS operations and design of full-scale microalgae treatment.

Life cycle and environmental impact assessment of vegetation-activated sludge process (V-ASP) for decentralized wastewater treatment

The integrated Vegetation-Activated Sludge Process (V-ASP) has emerged as a promising solution for decentralized wastewater treatment, offering a unique combination of landscape vegetation with the traditional Anaerobic-Anoxic-Oxic process (AAO). The experiments displayed that V-ASP consistently demonstrated remarkable treatment performance, maintaining stable removal efficiency exceeding 90 % for COD, NH4+-N, and TP. The vegetation growth is helpful for the removal of pollutants and the microbial community in the allocated vegetation root, while the bulk suspended sludge was changed significantly by using PCR test. To comprehensively evaluate the environmental footprint of V-ASP, a Life Cycle Assessment (LCA) was conducted. The mass balance calculation containing wastewater treatment performance, energy consumption, vegetation growth behavior, greenhouse gas (GHG) emissions, treated water, and sludge discharge was carried out to establish the life cycle inventories (LCI). SimaPro 9.0 software and the ReCiPe (H) midpoint impact assessment method were employed, which revealed that the V-ASP system boasts low GHG emissions and freshwater eutrophication potential compared to the traditional AAO process. In essence, this study provides a comprehensive understanding of the V-ASP system, especially the environmental impacts, guiding its potential for sustainable decentralized sewage treatment applications.

Environmental impact of grass-based cattle farms: A life cycle assessment of nature-based diversification scenarios

Diversification is widely considered to positively influence the environmental sustainability of livestock farming. Multiple options exist to diversify cattle farms, but few have been examined at a systems level for grass-based livestock farms. Three nature-based diversification options recommended for livestock farms were examined in this study: mixed grass–white clover swards (GWC), organic farming (OFS) and agroforestry (AGF). They were applied on dairy and suckler calf-to-beef farming systems common in the Republic of Ireland. Both of these bovine systems were evaluated over a 3-year period (2017–2019) and were nationally representative. The environmental impact and resource use of dairy and suckler calf-to-beef systems were modelled using life cycle assessment (LCA). The system boundary of the LCA model extended from the extraction of raw materials to the sale of milk and cattle from the farm, i.e. cradle to farm-gate. Six of the major environmental impacts of cattle farming were simulated; global warming potential (GWP), non-renewable energy (NRE) depletion, land occupation (LO), acidification potential (ACP), freshwater and marine eutrophication potential (FEP and MEP). Impacts were scaled to the following functional units: land area, fat and protein corrected milk (FPCM) for dairy and carcass weight (CW) for beef. The result illustrated that GWC swards reduced the GWP of milk production by 9% and cut the GWP of beef LW by 3%. Per unit of product, this strategy decreased ACP by 4%–5%, NRE depletion by 13%–19% and LO by 6%–7%. However, it increased MEP by 5%–12% due to clover fixing more N than it replaced. Cattle farms based on GWC were more productive than conventional farms, but tended to increase impacts per hectare. Organic farming had the lowest environmental impacts per unit of land and reduced GWP and NRE depletion. Without carbon sequestration, organic farming had the opposite effect on GWP of FPCM and increased ACP and MEP per product unit. Declines in productivity in organic systems led to the rise in these impacts per unit of product and increases in LO relative to conventional systems. Partial conversion (10%–20%) of grassland to silvopasture decreased milk and beef output, and slightly improved environmental performance. Carbon sequestration was greater in silvopasture than in grassland, albeit LCA models struggle to accurately quantify the influence of management change on this process. This issue can be overcome through more field and modelling research on sequestration. Further research is also required on combining diversification options to optimise the environmental sustainability of cattle farming.

Comparative life cycle assessment of marine microalgae, Nannochloropsis sp. and fishmeal for sustainable protein ingredients in aquaculture feeds

Fishmeal from small marine pelagic fishes reduces their availability for marine wildlife forage and artisanal fishing catches that support food security in lower income coastal nations. Fishmeal is primarily used in feeds for aquaculture, the world’s fastest-growing food sector. Replacing fishmeal in aquafeeds with more environmentally responsible alternative ingredients can help feed aquaculture transition to more sustainable production methods. Protein from defatted marine microalga, Nannochloropsis sp., produced alongside polyunsaturated fatty acids (PUFAs) for the nutraceutical market lacks a comprehensive open-access analysis of environmental impacts of producing these products from biorefineries. This study compared life cycle impacts (global warming potential, water use, land use, marine eutrophication potential, freshwater eutrophication potential, and biotic resource use) of protein from fishmeal produced in a small pelagic fish biorefinery to protein from defatted Nannochloropsis meal. We conducted an attributional life cycle assessment using primary data provided by Cellana LLC to model biomass cultivation and harvesting at the Kona Demonstration Facility (Hawaii, USA) and literature data to model the downstream processing of biomass into a high-protein fishmeal replacement for the aquafeed market and concentrated PUFAs for the nutraceutical market. Material and energy inputs from a Nannochloropsis biorefinery included 2 harvesting scenarios (wet and dry biomass) and 2 scenarios for oil extraction and processing (i.e., oil fractionation and concentration of PUFAs): solvents or supercritical carbon dioxide. Results for aquafeed protein from defatted Nannochloropsis were that cultivation processes had the largest overall effect for all scenarios; urea and pure liquid carbon dioxide were environmental hot spots; and the processing scenario involving dry biomass followed by oil extraction and oil processing with solvent had significantly lower environmental impacts than protein from fishmeal from a small pelagic fish biorefinery for global warming potential, water use, marine eutrophication potential, freshwater eutrophication potential, and biotic resource use, but not for land use. These results suggest that aquafeed from marine microalgae can be an environmentally sustainable replacement for fishmeal if high-value metabolites are coproduced in a biorefinery.

Environmental assessment of road transport fueled by ammonia from a life cycle perspective

Renewable energy penetration into the electricity market has been increasing over the last decades; however, it is a different story in the transport sector. Fossil fuels are still predominant; therefore, several alternatives are being studied to attain a low-carbon, more sustainable transport and, consequently, a sustainable society. Ammonia has the potential to be a viable option, and it is critical to study its environmental profile in this early phase to appraise its sustainability as a fuel for passenger road transportation. This work aimed to develop a life cycle assessment of an ammonia-fueled internal combustion engine passenger car from the cradle to the grave, considering 1 km traveled as the basis for comparison. The product system under study included four stages: (i) vehicle, (ii) infrastructure, (iii) energy production, and (iv) operation. Life cycle inventory data related to vehicle operation, specifically ammonia combustion, resulted from various simulations of a model that considered the effect of different operation modes and vehicle emission control strategies, which resulted in nine configurations. The results show that rich mixtures (with an equivalence ratio of 1.1) help to reduce both nitrogen oxides (NOX) and nitrous oxide (N2O) emissions. As for unburnt ammonia (NH3), the after-treatment system drastically diminishes these and NOX emissions. Data on infrastructure and other upstream processes was taken from the Ecoinvent 3.7.1 database, and the ammonia production was based on the life cycle inventory from previous research. The life cycle impact assessment was performed on OpenLCA software implementing the ReCiPe2016 Midpoint (H) v1.13 methodology. On average, per 1 km traveled in an ammonia-based ICEV represents 0.098 kg CO2-eq for global warming potential (GWP100), 30.755 g oil-eq for fossil depletion potential (FDP), 38.974 mg P-eq for freshwater eutrophication potential (FEP), 8.907 μg CFC-11-eq for ozone depletion potential (ODP), 0.906 g NMVOC-eq for photochemical oxidant formation potential (POFP), and 1.029 g SO2-eq for terrestrial acidification potential (TAP). These results show a significant reduction, above −70%, for GWP100, FDP, and ODP compared with the same vehicle fueled on gasoline.

Investigating the environmental and mechanical properties of sustainable asphalt mastic solutions for road flexible pavements

The circular economy is restorative in nature, and it aims to maintain the utility of products, components and materials for as long as possible while also retaining their value. It thus minimizes the need for new inputs of virgin materials and energy, while reducing environmental pressures linked to resource extraction, emissions and waste management. The research focus on the investigation of an innovative procedure for reusing the jet grouting waste (JGW) obtained from soil consolidation activities to produce high-performing sustainable road asphalt mastics (filler plus neat bitumen). The mastics under analysis were made at three different filler over bitumen ratios of 0.5, 1 and 1.5, in particular six were obtained with neat bitumen and other six at the same f/b ratios mixed with an aged bitumen after the RTFO procedure. The rheological properties of the mastics were investigated using a dynamic shear rheometer, and the performance of the innovative mastics was compared with that of the neat bitumen and traditional mastics made up of bitumen and limestone filler (LF). The main results of the initial step of the analysis showed that, at temperatures from 0 to 30°C, the shear moduli of the mastics containing JGW (MJGW) averaged 30% higher than the limestone mastic (ML) blended with an f/b ratio of 0.30. The life-cycle assessment impact category indicators were then calculated, highlighting the considerable environmental benefits of the innovative hot asphalt mastics in question. The primary outcomes showed that compared with the asphalt mastics containing LF, the asphalt mastic solution lowered terrestrial ecotoxicity by 53% and the freshwater eutrophication potential by up to 97%.

Environmental impact assessment of vegetable production in West Java, Indonesia

Indonesia is one of the world's economies contributing the most to greenhouse gas (GHG) emissions from the global food system. This study aimed to quantify the environmental impacts of Indonesian vegetable production and the relative contribution of different farm inputs. Data were collected from 322 vegetable farms in the Lembang sub-district in West Java. A Life Cycle Assessment (LCA) was carried out to estimate global warming potential (GWP), acidification potential (AP), freshwater eutrophication potential (EP), and abiotic resource depletion. Results of the LCA showed that GHG emissions were 14.1 t CO2eq ha−1 yr−1 (0.5 t CO2eq t−1), AP was 39.3 kg SO2eq ha−1 yr−1 (1.4 kg SO2eq t−1), EP was 45.3 kg PO4eq ha−1 yr−1 (1.7 kg PO4eq,), and depletion of phosphate, potash, and fossil fuel resources were 60.0 kg P2O5, 101 kg K2O, and 6299 MJ ha−1 yr−1, respectively (1.9 kg P2O5, 3.7 kg K2O, and 281 MJ t−1). Organic fertilizer use contributed the most to impact categories of global warming, freshwater eutrophication, and acidification, followed by synthetic fertilizer. The sensitivity analysis showed that yield and organic fertilizer use explained most of the variation in GHG emission per ton product. Therefore, it is recommended to include organic fertilizer use in the fertilizer advisory system for vegetable production in Indonesia.

Effects of feed formula and farming system on the environmental performance of shrimp production chain from a life cycle perspective

AbstractShrimp is the most popular seafood in the United States; its production plays an important role in the aquaculture industry. However, shrimp farming causes various environment impacts that must be mitigated to ensure the sustainability of shrimp production. This study performed a life cycle assessment (LCA) on two US‐based and one Vietnam‐based shrimp production chains from cradle to US market covering three farming systems and eight shrimp feed formulae. Midpoint environmental impacts including terrestrial acidification, freshwater eutrophication, and global warming were determined. For the intensive production chain (IPC), feed production was identified as the main contributor to the terrestrial acidification potential (TAP) and global warming potential (GWP), and its freshwater eutrophication potential (FEP) was dominated by shrimp farming. Poultry by‐product and fish meals were the feed ingredients contributing high TAP and GWP. However, soybean, wheat, and corn gluten meals produced higher FEP; hence, substituting plant‐based proteins for animal‐based ones in shrimp feeds did not all have positive environmental consequences. Shrimp farming was the hotspot of all the environmental impacts of the semi‐intensive production chain (SPC) and extensive production chain (EPC), except for the TAP of the EPC. Among the three production chains, the IPC had the highest FEP due to the on‐farm discharge of phosphorus‐containing wastewater, and the SPC caused the highest TAP because of the intensive uses of electricity and fertilizers for pond cultivation. Although the EPC was most sustainable in terms of TAP and FEP, open farming in mangrove areas produced the highest GWP owing to land transformation. This LCA study is expected to serve as US shrimp farmers’ decision‐making guidelines to adapt farming practices with lower environmental footprint.

Comparison of environmental impacts of individual meals - Does it really make a difference to choose plant-based meals instead of meat-based ones?

More than one third of global greenhouse gas emissions (GHG) can be attributed to our food system. Limiting global warming to 1.5° or 2 °C will not be possible without reducing GHG emissions from the food system. Dietary change at the meal level is of great importance as day-to-day consumption patterns drive the global food production system. The aim of this paper was to assess the life cycle environmental impact of a sample of meals from different cuisines (chilli, lasagne, curry and teriyaki meals) and their meat-based, vegetarian, vegan, and whole-food vegan recipe variations. The environmental impacts (global warming, freshwater eutrophication, terrestrial acidification and water depletion potential) of 13 meals, made with 33 different ingredients, were estimated from cradle to plate using Life Cycle Assessment (LCA). Results showed that irrespective of the type of cuisine, the plant-based version of meals (vegan and whole-food vegan) had substantially lower environmental impacts across all impact categories than their vegetarian and meat-based versions. On average, meat-based meals had 14 times higher environmental impact, while vegetarian meals had 3 times higher environmental impact than vegan meals. Substantial reductions in the environmental impacts of meals can be achieved when animal-based ingredients (e.g., beef, cheese, pork, chicken) are replaced with whole or minimally processed plant-based ingredients (i.e., vegetables, legumes) in recipes. Swapping animal-based meals for plant-based versions, and preferably transitioning to plant-based diets, present important opportunities for mitigating climate change and safeguarding environmental sustainability.

Environmental life cycle impact assessment of fresh California strawberries: A full supply chain perspective

A cradle-to-grave life cycle assessment (LCA) study was conducted for an open-field strawberry (strb) produced in California. The evaluation covered the full supply chain of strawberry, which also included the impacts of food waste generated at each phase of the life cycle. The supply chain included farming, retail, consumption, and end-of-life treatments of waste generated. Data on strawberry farming (included cultivation, harvest and packaging) were collected from the selected farms, with an average strawberry acreage of 138 acres. The defined functional unit (FU) was 1 kg-strb, consumed at the consumer stage, including food waste. Life cycle inventory (LCI) data for post-farm (retail and consumer stage) were based on the available literature and engineering estimates. The ReCiPe 2016 method was used to calculate the potential environmental impacts. The total GHG emissions calculated per FU was 1.45 kg CO 2eq ; freshwater eutrophication potential was 4.43*10 −4 kg P eq /FU, fossil resource scarcity was 0.46 kg oil eq /FU. Transportation contributed to about 32% of the total GHG emissions, the use of all forms of plastics (including packaging PET, labels, and field plastics) contributed 18% of the total GHG emissions, while their treatments contributed ∼1% (including the credits from the related recycling process). The use of corrugated boxes contributed 15% of the GHG emissions, while end-of-life treatment provided credits by –7% of the total impact. Food waste treatment contributed ∼15% to the total GHG emissions. For fossil resource scarcity, cultivation along with packaging contributed 71% of the total impact, followed by retail and consumer (25% and 11%, respectively), which was mainly due to transportation. Results showed that the use of recycled packaging materials and the adoption of a suitable recycling process are effective strategies to lower the environmental impacts. The study also showed that with changes in crop yields by ±10%, as compared to the reported yields, most of the selected environmental impacts could change by ± 3–4%, while water consumption would vary by −9% (with +10% yield increase) and increase by 11% (with −10% yield). Reducing food waste by 10% could lower the total GHG emissions by around 1%. • Cradle-to-grave environmental performance of open-field strawberry analyzed. • Farm based life cycle inventory utilized the data collected from California-based farms. • Environmental impacts and hotspot evaluations are discussed for the supply chain. • Packaging and transportation were the top contributors to the supply chain impacts.

CO2 e footprint and eco-impact of ultralow phosphorus removal by hydrous ferric oxide reactive filtration: A municipal wastewater LCA case study.

Dual upflow reactive filtration by a slowly moving sand bed with continuously renewed, hydrous ferric oxide‐coated sand is used for removing polluting substances and for meeting the ultralow 0.05 mg/l total phosphorus discharge permit limits at a 1.2 million liters per day (0.32 million gallons per day) water resource recovery facility in Plummer, Idaho, in the United States. A life cycle assessment (LCA) of this reactive filtration installation was carried out to assess the environmental hotspots in the system and analyze alternative system configurations with a focus on CO2 equivalent (CO2e) global warming potential, freshwater and marine eutrophication, and mineral resource scarcity. “What if” scenarios with alternative inputs for the energy, metal salts, and air compressor optimization show trade‐offs between the impact categories. Key results that show a comparative reduction of global warming potential include the use of Fe versus Al metal salts, the use of renewable energy, and the energy efficiency benefit of optimizing process inputs, such as compressor air pressure, to match operational demand. The LCA shows a 2 × 10−2 kg CO2e footprint per cubic meter of water, with 47% from housing concrete, and an overall freshwater eutrophication impact reduced by 99% versus no treatment. The use of renewable hydropower energy at this site isolates construction concrete as a target for lowering the CO2e footprint.Practitioner Points The main LCA eco‐impact hotspots in this dual reactive filtration tertiary treatment are construction concrete and the ferric sulfate used.Iron salts show smaller impact in global warming, freshwater eutrophication, and mineral resource scarcity than “what if scenario” aluminum salts.The energy mix for this site is predominantly hydropower; other energy mix “what if” scenarios show larger impacts.Operational energy efficiency and thermodynamic analysis show that fine tuning the air compressor helps reduce carbon footprint and energy use.LCA shows a favorable 2 x 10‐2 kg CO2e/m3 water impact with 99% reduction of freshwater eutrophication potential versus no treatment.

Environmental life cycle assessment of nano-cellulose and biogas production from manure

Due to its unique properties, nano fibrillated cellulose (NFC) has been a popular topic of research in recent years. Nevertheless, literature assessing environmental impacts of NFC production is scarce, especially for using other starting materials than wood pulp. Hence, in this study, a new approach of cascaded use of manure to produce biogas and subsequently use the cellulose containing digestate for NFC production (manure scenario) is compared to the production from Kraft pulp from hardwood chips (wood chips scenario) via life cycle assessment (LCA). To produce comparable outputs (NFC and biogas) in both scenarios a typical Austrian biogas plant with maize silage and pig slurry as input material is included in the wood chips scenario. A proxy approach is used to upscale the manure scenario from laboratory to an industrial scale (except for the pulp to NFC step) to ensure comparability of both scenarios. The impact categories global warming potential (GWP), fossil resource scarcity, freshwater eutrophication, human toxicity, terrestrial acidification (TAP) and terrestrial ecotoxicity potential are analysed referring to the functional unit of 1 kg NFC. Results show that the manure scenario has at least 45% lower impacts in all assessed categories. GWP is 4.41 kg CO2 eq./kg NFC in the manure and 9.74 kg CO2 eq./kg NFC in the wood chips scenario. The transformation step from pulp to NFC is identified as environmental hotspot due to the high electricity demand in both scenarios. Results are additionally assessed only for the industrial scale part (includes biogas and pulp production). In the latter the main difference can be found in the substrate production. While it plays a subordinate role in the manure scenario (up to 8%) as manure is seen as a waste stream with no upstream environmental impacts attached, the production of maize silage is one of the hotspots in the industrial part in the wood chips scenario. This difference is especially prominent in TAP, where the substrate production is responsible for 91% of the 0.06 kg SO2 eq. impact, which is tenfold the impact of the manure scenario. This underlines the issue of using energy crops as substrate in biogas plants. It also highlights the importance of further research of using waste streams as inputs for the electricity production and subsequent use in the pulp and paper industry. This LCA demonstrates that NFC production from manure is a sustainable alternative to the production from hardwood Kraft pulp.

Assessment of eutrophication potential from fertiliser application in agricultural systems in Thailand

Releases of excess nitrogen and phosphorus from fertilisers applied in agricultural production cause eutrophication in the aquatic ecosystem. This study assessed the marine and freshwater eutrophication potentials associated with the fertiliser application in rice, maize, cassava, sugar cane and oil palm, cultivation in Thailand using a life cycle assessment characterisation model at midpoint and endpoint levels. The total marine eutrophication potential was 209,632,298 kg N eq while the total freshwater eutrophication potential was 2,044,136 kg PO4 eq. The associated ecosystem damage was 2,643,706,874 PDF.m2.year. Marine eutrophication potential was the major contributor to the ecosystem damage, accounting for 99.1% of the total. Sugarcane cultivation was the main contributor (28.5%) to eutrophication impacts, followed by rice (28.0%), cassava (16.0%), oil palm (14.8%) and maize (12.7%). Nitrate was the major contributor to marine eutrophication (92.7%), far more than ammonia (6.7%) and nitrogen oxide (0.6%). Seventeen scenarios were developed and analysed in view of mitigating the ecosystem damage through emission reduction. Applications of a nitrification inhibitor (Dicyandiamide) with fertilisers, 4R nutrient management practices (right source, right rate, right time and right place) and the integrated scenario of these two scenarios depicted substantial decreases in ecosystem damage by 46%, 40% and 68%, respectively compared to the damage from existing fertiliser application rates. Therefore, the integrated approach would be recommended as the most effective way to reduce the eutrophication impacts from fertilisers. Existing studies have significantly focused on ammonia mitigation with less attention on nitrate reduction. This assessment revealed that nitrate reduction plays a crucial role in reducing the eutrophication impacts and new policy focuses should include the nitrate reduction. Future studies could consider threshold values for the impacts of freshwater and marine eutrophication to discover the risk level of eutrophication.

Comparative study of the environmental impacts of used cooking oil valorization options in Thailand

Used cooking oil (UCO) is a valuable resource that can be utilized in different ways. Appropriate management of UCO waste can provide environmental and economic benefits, compared to improper disposal practices. This study assessed the environmental impacts of potential UCO valorization options in Thailand. Altogether, 14 scenarios, including 10 for alternative energy recovering processes (S1-10) and other options such as soap production (S11), use in dry pig feed (DPF) production (S12), synthesis of plastics (S13) and polyol (S14), were considered. The defined system boundaries for each scenario include pretreatment, material and energy consumption, and waste treatment stages for the treatment of 1000 kg UCO. Environmental impacts in terms of global warming potential (GWP), freshwater eutrophication potential (FEP), fossil resource scarcity (FRS), and freshwater, terrestrial, and marine eco-toxicity (FE, TE, and ME, respectively) were analyzed using the ReCiPe Midpoint (H) method. The results revealed that all the current waste valorization options create an environmental burden and contribute towards GWP. Scenarios 7 and 10 showed environmental credits for FEP, FE, and ME indicators while scenario 9 did so for FRS. The processes direct energy consumption resulted in the highest contribution to GWP in Scenarios 1, 5–8, 10, 12, and 13. Environmental effects of material consumption and waste treatments were found to be the highest in bio-oil and DPF production, respectively. However, co-products produced could not offset the burden created by energy and material consumption. Overall, the results showed better environmental performance from energy recovery-based UCO management options compared to alternative processes.

Experimental, economic and life cycle assessments of recycling end-of-life monocrystalline silicon photovoltaic modules

The utilization of solar technology for clean energy generation has seen a dramatic increase over the past decade. Eyeing the ever-growing solar capacity and the subsequent inevitable deluge of solar panel wastes, the ideal approach to handle End-of-Life (EoL) solar photovoltaic (PV) panels is to recycle their materials for reuse. This present study explores an optimal recycling process with a high resource recovery efficiency on a laboratory scale, which comprises of three main steps: module delamination, acid etching and sequential electrodeposition. High recoveries of 86, 95 and 97% were achieved for silver, lead and aluminum, respectively. The acquired results are further applied in a life cycle assessment. The process was scaled up to simulate an industrial process and its human and environmental impacts were compared to those of the landfilling disposal method, with six main impact categories analyzed and described: global warming potential, human toxicity potential, freshwater ecotoxicity potential, acidification potential, eutrophication potential and ozone depletion potential. Mitigation strategies are also proposed. Lastly, economic analysis demonstrated that at a treatment capacity of 892.5 kg/h, the process is feasible with an internal revenue rate of 28.2% and a payback time of less than a year, provided the waste collection is subsidized.

Rice-crayfish coculture delivers more nutrition at a lower environmental cost

A growing demand for food products from limited arable land has meant that paddy fields have been developed to provide both grain and aquatic products. China has the world's largest aquaculture area of crayfish, of which ∼86% is in the form of rice-crayfish coculture. Here, we use a life cycle assessment to evaluate and compare the environmental impacts of three farming systems: rice monoculture, crayfish monoculture, and rice-crayfish coculture. Two functional units were used: one hectare of land occupied, and one Nutrient Density Unit (NDU) – i.e., the combined nutrition delivered in rice and/or crayfish products. Rice-crayfish coculture has a larger environmental footprint than rice monoculture per hectare occupied across at least 7 of the 8 impact categories studied, though performs better than crayfish monoculture. However, rice-crayfish coculture yields 1.12 to 2.21 times more nutrition per hectare than rice monoculture and crayfish monoculture, respectively. Hence, rice-crayfish coculture was found to have lower impact per NDU across all 8 impact categories studied, compared with the monoculture systems. Application of urea, crayfish feed inputs, and electricity consumption dominated most environmental burdens for rice-crayfish coculture, while field emissions (e.g., CH 4 and NH 3 ) strongly influenced global warming potential, terrestrial acidification potential and freshwater eutrophication potential, respectively. Environmental burdens of rice-crayfish coculture could be further reduced by increasing productivity per hectare and/or improving fertilizer and feed use efficiency. Shifting from rice- and crayfish-monoculture to rice-crayfish coculture could deliver more nutrition at a lower environmental cost, as well as increasing farm profitability by 7−462%.

Life cycle assessment of plant cell cultures

A novel food such as plant cell culture (PCC) is an important complementary asset for traditional agriculture to tackle global food insecurity. To evaluate environmental impacts of PCC, a life cycle assessment was applied to tobacco bright yellow-2 and cloudberry PCCs. Global warming potential (GWP), freshwater eutrophication potential (FEUP), marine eutrophication potential, terrestrial acidification potential (TAP), stratospheric ozone depletion, water consumption and land use were assessed. The results showed particularly high contributions (82–93%) of electricity consumption to GWP, FEUP and TAP. Sensitivity analysis indicated that using wind energy instead of the average Finnish electricity mix reduced the environmental impacts by 34–81%. Enhancement in the energy efficiency of bioreactor mixing processes and reduction in cultivation time also effectively improved the environmental performance (4–47% reduction of impacts). In comparison with other novel foods, the environmental impacts of the PCC products studied were mostly comparable to those of microalgae products but higher than those of microbial protein products produced by autotrophic hydrogen-oxidizing bacteria. Assayed fresh PCC products were similar or close to GWP of conventionally grown food products and, with technological advancements, can be highly competitive.

Environmental impact evaluation of decentralized sewage treatment technologies: A life cycle assessment approach

AbstractA life cycle assessment study on decentralized sewage (DS) treatment technologies is conducted using Gabi software and ReCiPe midpoint method, focusing on three DS treatment technologies: extended aeration (EA), imhoff (IF) and activated sludge (AS). The three most significant environmental impacts identified by the analysis are climate change (CC), freshwater eutrophication potential (FEP) and marine eutrophication potential (MEP). In this study, none of the DS systems could reduce all three indicators assessed. In terms of CC, IF has the lowest impact, with a value of 2.78 kg CO2 eq/m3, while EA has the lowest FEP impact of 0.030 kg P eq/m3. As regards MEP, AS has the lowest value of 0.043 kg N eq/m3. The findings offer investors with relevant information on the effects of the three DS treatment technologies used to treat domestic wastewater in Malaysia.

Environmental life cycle assessment of yellow mealworm (Tenebrio molitor) production for human consumption in Austria \u2013 a comparison of mealworm and broiler as protein source

PurposeGlobal food production needs to increase to provide enough food for over 9 billion people living by 2050. Traditional animal production is among the leading causes for climate change and occupation of land. Edible insects might be a sustainable protein supply to humans, but environmental life cycle assessment (LCA) studies on them are scarce. This study performs an LCA of a small-scale production system of yellow mealworms (Tenebrio molitor) in Central Europe that are supplied with organic feedstuff.MethodsA combined ReCiPe midpoint (H) and CED method is used to estimate the potential environmental impacts from cradle-to-gate. Impact categories include global warming potential (GWP), non-renewable energy use (NREU), agricultural land occupation (ALOP), terrestrial acidification potential (TAP) and freshwater eutrophication potential (FEP). The robustness of the results is tested via sensitivity analyses and Monte Carlo simulations.Results and discussionImpacts related to the production of 1 kg of edible mealworm protein amount to 20.4 kg CO2-eq (GWP), 213.66 MJ-eq (NREU), 22.38 m2 (ALOP), 159.52 g SO2-eq (TAP) and 12.41 g P-eq (FEP). Upstream feed production and on-farm energy demand related to the heating of the facilities are identified as environmental hot-spots: Depending on the impact category, feed supply contributes up to 90% and on-farm heating accounts for up to 65% of overall impacts. The organic mealworm production system is contrasted with a selected Austrian organic broiler production system, to which it compares favourably (18–72% lower impacts per category), with the exception of freshwater eutrophication (6% higher impacts).ConclusionsThis case study shows that the Austrian mealworm production system compares favourably to traditional livestock systems. Compared to LCAs from large-scale T. molitor rearing facilities in France and in the Netherlands, however, the Austrian production system cannot compete for the reasons of production scale, feed conversion efficiency and type of production system. Nevertheless, the investigated mealworms represent a sustainable protein alternative that should be added to the Western diet.

Estimation of Eco-Efficiency of Wastewater Management Plants Using the Life Cycle Assessment (LCA) Method

An eco-cost measurement was carried out to see the LCA process stages' efficiency in this study. The LCA process used in the wastewater treatment plant will carry out the steps in the LCA method. The four phases must be carried out correctly to provide good results when making decisions for improvements in each process unit carried out. When carrying out goals and scope, the process determines the goals to be achieved in wastewater management. Environmental impact calculations are carried out using SimaPro software. The nine types defined by the abbreviation are climate change or global warming potential (GWP), freshwater eco-toxicity potential (FETP), freshwater eutrophication potential (FEP), human toxicity potential (HTP), metal depletion potential (MDP), depletion ozone potential (ODP), particulate matter formation (PMF), terrestrial eco-toxicity potential (TETP), and water depletion potential (WDP). The value of the Eco-Efficiency Index (EEI) in the wastewater management installation is 0.183. Meanwhile, the Eco-Efficiency Ratio (EER Rate) value in the installation is -445.81% The total damage assessment resulting from the process is human health (DALY) of 0.00339, ecosystem quality (PDF m2yr) of 874,123 and resources (MJ Surplus) of 5,8234. Then the eco cost value for human health is IDR 4,293,393.642; ecosystem quality is IDR 20,944,494.07; land resources is IDR 409,629. Then the Eco- Efficiency Index (EEI) value in the wastewater management installation is 0.178. Thus the installation can be affordable (financially affordable) and not sustainable (not environmentally friendly) because the eco cost value is greater than the net value of the WWTP.