Marine 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.

A comparison of environmental performance of electronic and bound-thesis using life cycle assessment

Dematerialization through information technology aids in advancing environmental sustainability. Replacing a bound thesis with an e-thesis for a university dissertation will be a complementary paradigm shift for higher environmental performance. Hence, the study intended to determine and compare the environmental performance parameters of conventional paper-based bound-thesis and e-thesis. Moreover, the study aimed to identify the activities causing higher environmental burdens during the production of bound and e-thesis. Open LCA 1.11 was employed for a conventional bound thesis with its e-version submitted by the undergraduates of the Faculty of Agriculture, University of Ruhuna, Sri Lanka. The study utilized U.S. EPA life-cycle inventory data. The analysis demonstrated that the overall global warming potential of a 40-page hard cover thesis was 4,839,000.00 kg CO2-eq to which paper and cover import and paper manufacturing stages contributed more than 99% (4,830,000.0 kg CO2-eq). In comparison, a 0.084 MB soft copy of an e-thesis reported a negligible (0.09936 kg CO2-eq) global warming potential value. Ozone formation-human health, ozone formation-terrestrial ecosystems, terrestrial acidification, fine particulate matter formation, and marine eutrophication potential were 265,584.31 kg NOx eq, 265,583.21 kg NOx eq, 177,451.5 kg SO2 eq, 52,948 kg PM2.5 eq, and 29,041.0 kg N-eq for bound thesis production system. Except for the stratospheric ozone depletion impact and water consumption, environmental performance indicators of e-thesis were superior to the conventional-bound thesis. The study recommends the preparation of e-thesis as an environmentally sound approach. Switching to renewables, extended lifespan, and material recycling of devices at the end of use, sustainable forestry practices, process optimization, and cleaner production technologies can further enhance the environmental performance of e-thesis.

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.

Life cycle assessment of SBS modified bitumen waterproofing membrane

Building waterproofing membranes constitute essential components of construction materials. This study utilizes the life cycle assessment (LCA) methodology to develop a comprehensive life cycle inventory and conduct an environmental impact assessment of typical styrene-butadiene-styrene (SBS) modified bitumen waterproofing membrane products. The main research objective of this paper is to identify the key factors influencing the environmental impact of products and to provide data for the selection of green materials in the construction industry. The results reveal that the production of raw materials for SBS-modified bitumen waterproofing membranes contributes the most to all environmental impact categories, followed by the transportation and energy production stages, while the production stage of the membranes exhibits a relatively smaller contribution. Within the raw material production stage, the bitumen production process exhibits the highest contribution to fossil fuel depletion (FFP) environmental impact, surpassing 50%. The production process of polyester tire cloth demonstrates the greatest influence on human toxicity potential (HTPc), global warming potential (GWP), freshwater eutrophication (FEP), marine eutrophication potential (MEP), and mineral resource scarcity potential (SOP), accounting for 54.63%, 32.86%, 68.55%, 72.41%, and 61.69%, respectively. Additionally, the production process of base oil exhibits the most significant contribution to fine particulate matter formation (PMFP) and terrestrial acidification potential (AP) among the environmental impact indicators. Variations in the quantities of polyester tire cloth and base oil exhibit the most notable influence on the environmental indicators of the product. Specifically, the sensitivity analysis reveals that polyester tire cloth has the greatest impact on mineral resource scarcity potential (SOP); base oil exhibits the highest sensitivity to fossil fuel depletion (FFP).

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.

Life cycle assessment of pasture-based dairy production systems: Current and future performance

To overcome the environmental challenges faced by the global agricultural sector while also ensuring economic viability, dairy farmers must improve the efficiency of their systems. To improve system efficiency, the performance of an average production system must be determined, as it establishes a benchmark from which the efficacy of proposed management practices and mitigation strategies can be assessed. Identified management practices and mitigation strategies can then be compiled to create ambitious but realistic targets for the sector to strive toward. Therefore the objective of this study was to calculate the environmental performance of an average spring-calving pasture-based dairy system and an ambitious target dairy system. Life cycle assessment (LCA) of 2 pasture-based dairy systems were conducted: (1) current average spring-calving pasture-based dairy system (current), and (2) a spring-calving pasture-based dairy system that has achieved key performance targets set by the most efficient dairy systems (target). An existing dairy LCA model was updated with country-specific emission factors, life cycle inventory data, and recommended methodologies. The environmental impact categories assessed were global warming potential, nonrenewable energy depletion, acidification potential, and eutrophication potential (marine and freshwater). Two functional units were used: per kilogram of fat- and protein-corrected milk (FPCM), and per hectare. To assess the effects of the model updates, the current dairy system was simulated twice, once with the previous version of the dairy LCA model, and second with the updated LCA model. The addition of country-specific emission factors, updated inventory data, and implementation of recommended methods has resulted in global warming potential and nonrenewable energy depletion being reduced by 10.4% and 10.9%, respectively. The updates had negligible effects on acidification and eutrophication potential. The inclusion of assumptions around carbon sequestration in grassland further reduced global warming potential by 16.4%. Moving from the current dairy system to the target dairy system was reported to reduce the environmental impact per kilogram of FPCM across all impact categories investigated. When expressed per hectare, transitioning toward the target dairy system reduced acidification, freshwater eutrophication, and nonrenewable energy depletion by 2.0%, 8.8%, and 13.8%, respectively. In contrast, transitioning toward the target dairy system increased global warming per hectare and, to a lesser degree, marine eutrophication potential per hectare. The increase in global warming and marine eutrophication potential per hectare was attributed to the increase in stocking rate and subsequently milk production per hectare (9,950 vs. 14,100 kg of FPCM/ha). This study demonstrates that the adoption of management practices that improve system efficiency will reduce the environmental impact per kilogram of FPCM and can contribute to the future sustainability of pasture-based dairy systems. However, improved system efficiency can be offset by the associated increase in productivity, highlighting the importance of reporting multiple environmental impact categories and functional units to prevent pollution swapping. New research and mitigation strategies will be required to improve the environmental sustainability of dairy systems beyond the target system in the future.

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.

Tools for a circular economy: Assessing waste taxation in a CGE multi-pollutant framework

Economic theory states that incineration and landfill taxation can effectively diminish the environmental impacts of pollution and resource use by reducing their associated pollutants while stimulating the reuse and recycling of materials, and therefore, fostering a circular economy. The aim of this research is to assess the economic and environmental effects of these taxes in Spain in different scenarios with a detailed dynamic computable general equilibrium (CGE) model, as there are no studies analyzing this in detail. We focus on the economic impact on GDP and sectorial production and the environmental impact on different categories: global warming potential, marine eutrophication potential, photochemical ozone formation potential, particulate matter, human toxicity (cancer and noncancer), ecotoxicity, and depletion of fossil resources. We find in all scenarios that these taxes have a limited economic impact while reducing all of the environmental impact categories analyzed. The study reinforces the theory that policy makers need to impose taxes on landfill and incineration to reinforce the circularity of the economy and reduce environmental burdens, but also demonstrates that they can improve their design without additional costs.

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.

The First City Organizational LCA Case Study: Feasibility and Lessons Learned from Vienna

Cities are recognized as a major contributor to environmental pressures. Recently, organizational LCA (OLCA) has been found to align well with requirements for city-scale environmental decision support and a novel city-OLCA framework was introduced. City-OLCA combines two relevant aspects: It covers activities beyond public service provision (multi-stakeholder) and emissions beyond greenhouse gases (multi-impact). Its unique approach of acknowledging responsibility levels should help both city-managers and academia in performance tracking and to prioritize mitigation measures. The goal of this work is to test city-OLCA’s feasibility in a first case study with real city data from Vienna. The feasibility was confirmed, and results for 12 impact categories were obtained. As an example, Vienna’s global warming potential, ozone depletion potential, and marine eutrophication potential for 2016 were 14,686 kt CO2 eq., 6796 kg CFC-11 eq., and 310 t N eq., respectively. Our results indicate that current accounting practices may underestimate greenhouse gas emissions of the entire city by up to a factor of 3. This is mainly due to additional activities not covered by conventional standards (food and goods consumption). While the city itself only accounts for 25% of greenhouse gases, 75% are caused by activities beyond public service provision or beyond governmental responsibilities. Based on our results, we encourage city managers to include an organizational based LCA approach in defining reduction strategies. This will reveal environmental blind spots and avoids underestimating environmental burdens, which might lead to setting the wrong focus for mitigation.

The First City Organizational LCA Case Study: Feasibility and Lessons Learned from Vienna

Cities are recognized as a major contributor to environmental pressures. Recently, organizational LCA (OLCA) has been found to align well with requirements for city-scale environmental decision support and a novel city-OLCA framework was introduced. City-OLCA combines two relevant aspects: It covers activities beyond public service provision (multi-stakeholder) and emissions beyond greenhouse gases (multi-impact). Its unique approach of acknowledging responsibility levels should help both city-managers and academia in performance tracking and to prioritize mitigation measures. The goal of this work is to test city-OLCA’s feasibility in a first case study with real city data from Vienna. The feasibility was confirmed, and results for 12 impact categories were obtained. As an example, Vienna’s global warming potential, ozone depletion potential, and marine eutrophication potential for 2016 were 14,686 kt CO2 eq., 6796 kg CFC-11 eq., and 310 t N eq., respectively. Our results indicate that current accounting practices may underestimate greenhouse gas emissions of the entire city by up to a factor of 3. This is mainly due to additional activities not covered by conventional standards (food and goods consumption). While the city itself only accounts for 25% of greenhouse gases, 75% are caused by activities beyond public service provision or beyond governmental responsibilities. Based on our results, we encourage city managers to include an organizational based LCA approach in defining reduction strategies. This will reveal environmental blind spots and avoids underestimating environmental burdens, which might lead to setting the wrong focus for mitigation.

The simulated environmental impact of incorporating white clover into pasture-based dairy production systems

White clover (WC) offers an alternative source of nitrogen (N) for pasture-based systems. Substituting energy- and carbon-intensive synthetic N fertilizers with N derived from biological fixation by WC has been highlighted as a promising environmental mitigation strategy through the omission of emissions, pollutants, and energy usage during the production and application of synthetic fertilizer. Therefore, the objective was to investigate the effect of the inclusion of WC in perennial ryegrass (PRG) swards on the environmental impact of pasture-based dairy systems. Cradle-to-farm gate life cycle assessment of 3 pasture-based dairy systems were conducted: (1) a PRG-WC sward receiving 150 kg of N/ha per year (CL150), (2) a PRG-WC sward receiving 250 kg of N/ha per year (CL250), and (3) a PRG-only sward receiving 250 kg of N/ha per year (GR250). A dairy environmental model was updated with country-specific N excretion equations and recently developed N2O, NH3, and NO3- emission factors. The environmental impact categories assessed were global warming potential, nonrenewable energy, acidification potential, and eutrophication potential (marine and freshwater). Impact categories were expressed using 2 functional units: per hectare and per metric tonne of fat- and protein-corrected milk. The GR250 system had the lowest milk production and highest global warming potential, nonrenewable energy, and acidification potential per tonne of fat- and protein-corrected milk for all systems. The CL250 system produced the most milk and had the highest environmental impact across all categories when expressed on an area basis. It also had the highest marine eutrophication potential for both functional units. The impact category freshwater eutrophication potential did not differ across the 3 systems. The CL150 system had the lowest environmental impact across all categories and functional units. This life cycle assessment study demonstrates that the substitution of synthetic N fertilizer with atmospheric N fixed by WC has potential to reduce the environmental impact of intensive pasture-based dairy systems in temperate regions, not only through improvement in animal performance but also through the reduction in total emissions and pollutants contributing to the environmental indicators assessed.

Resilience and life cycle assessment of ion exchange process for ammonium removal from municipal wastewater

This study was completed to understand the resilience of an ion exchange (IEX) process for its ability to remove variable ammonium (NH4+-N) loads) and to prove its environmental benefits through a life cycle assessment (LCA). The tertiary 10 m3/day demonstration scale IEX was fed with variable NH4+-N concentrations (<0.006–26 mg NH4+-N /L) naturally found in municipal wastewater. Zeolite-N was used as ion exchange media and regeneration was completed with 10% potassium chloride (KCl). The influent NH4+-N concentration impacted the ion exchange capacity, which ranged from 0.9–17.7 mg NH4+-N/g media. When the influent concentration was <2.5 mg NH4+-N/L, the Zeolite-N released NH4+-N (up to 12%). However, the exchange increased up to 62% when the influent NH4+-N load peaked, confirming the resilience of the process. A 94% regeneration efficiency was obtained with fresh regenerant, however, with the increase of the mass of NH4+-N on the media, the regeneration efficiency decreased. An optimisation of the volume of brine and regeneration contact time is suggested. To further measure the benefits of the IEX process, an LCA was conducted, for a 10,000 population equivalent reference scenario, and compared with traditional nitrification-denitrification WWTP. The LCA revealed that IEX with regenerant re-use and NH4+-N recovery through a membrane stripping process resulted in reductions of: 25% cumulative energy demand; 66% global warming potential and 62% marine eutrophication potential, when compared to traditional WWTP. This work demonstrated that the IEX process is an efficient and an environmentally benign technology that can be widely applied in WWTPs.

Enhancement of Food Waste Management and Its Environmental Consequences

This paper assesses the potential environmental effects of the optimization of the kitchen waste management in Opole. The separate collection of kitchen waste is improved by distribution of separate collection kits consisting of an in-home bin and 10 L biodegradable bags. The surplus of collected kitchen waste is diverted from treatment in a mechanical-biological pretreatment (MBP) along with the residual waste to anaerobic digestion (AD) with the biowaste. This has positive effects on European and Polish goals, ambitions, and targets, such as (i) increasing the level of renewables in the primary energy supply, (ii) decreasing the level of greenhouse gas (GHG) emissions, (iii) increasing the level of preparation for reuse and recycling of municipal waste. The environmental effects of 1 ton additionally separately collected and treated kitchen waste are determined by using life cycle assessment. It was shown that in all selected impact categories (global warming potential, marine eutrophication potential, acidification potential, and ozone depletion potential) a clear environmental benefit can be achieved. These benefits are mainly caused by the avoided emissions of electricity and heat from the Polish production mix, which are substituted by energy generation from biogas combustion. Optimization of the waste management system by diversion of kitchen waste from mechanical-biological pretreatment to anaerobic digestion can lead to considerable saving of 448 kg CO2-eq/t of waste diverted. With an estimated optimization potential for the demonstration site of 40 kg/inh·year for the city of Opole, this would lead to 680,000 t CO2-eq savings per year for the whole of Poland. The sensitivity analysis showed that with a choice for cleaner energy sources the results would, albeit lower, show a significant savings potential.

An attributional life cycle assessment of microbial protein production: A case study on using hydrogen-oxidizing bacteria

Novel food production technologies are being developed to address the challenges of securing sustainable and healthy nutrition for the growing global population. This study assessed the environmental impacts of microbial protein (MP) produced by autotrophic hydrogen-oxidizing bacteria (HOB). Data was collected from a company currently producing MP using HOB (hereafter simply referred to as MP) on a small-scale. Earlier studies have performed an environmental assessment of MP on a theoretical basis but no study yet has used empirical data. An attributional life cycle assessment (LCA) with a cradle-to-gate approach was used to quantify global warming potential (GWP), land use, freshwater and marine eutrophication potential, water scarcity, human (non-)carcinogenic toxicity, and the cumulative energy demand (CED) of MP production in Finland. A Monte Carlo analysis was performed to assess uncertainties while a sensitivity analysis was used to explore the impacts of alternative production options and locations. The results were compared with animal- and plant-based protein sources for human consumption as well as protein sources for feed. Electricity consumption had the highest contribution to environmental impacts. Therefore, the source of energy had a substantial impact on the results. MP production using hydropower as an energy source yielded 87.5% lower GWP compared to using the average Finnish electricity mix. In comparison with animal-based protein sources for food production, MP had 53–100% lower environmental impacts depending on the reference product and the source of energy assumed for MP production. When compared with plant-based protein sources for food production, MP had lower land and water use requirements, and eutrophication potential but GWP was reduced only if low-emission energy sources were used. Compared to protein sources for feed production, MP production often resulted in lower environmental impact for GWP (FHE), land use, and eutrophication and acidification potential, but generally caused high water scarcity and required more energy.

Assessing the environmental impact of the dairy processing industry in the Republic of Ireland.

This Research Communication describes the methodology used and the subsequent results obtained for an assessment of the environmental impact associated with the manufacture of dairy products in the Republic of Ireland. As the Irish dairy industry changes and grows, it is necessary to have a benchmark of the environmental performance of the sector if it is to remain sustainable in the future. In order to estimate the environmental impact, life cycle assessment has been implemented, which has been structured in accordance with the International Organisation for Standardisation guidelines. In this study, the environmental impact categories assessed are terrestrial acidification potential, cumulative energy demand, freshwater eutrophication potential, global warming potential, marine eutrophication potential and water depletion. The main Irish dairy products have been compared across these environmental impact categories in order to derive meaningful results. It is identified that packaging materials, particularly for infant formula, and energy usage, across each of the life cycle stages, should be targeted as these are the most significant contributors to the overall environmental impact.

Comparative environmental life cycle assessment of phosphorus recovery with different generations of the AirPrex® systems

Phosphorus (P) recovery through struvite is already both technically and economically feasible. This has been proved by more than 40 large-scale plants worldwide. However, when designing and implementing these P-recovery technologies, the environmental effects need to be considered. Therefore, a comparative environmental life cycle assessment of phosphorus recovery with different generations of the AirPrex® reactors at WWTP Wassmannsdorf and Amsterdam West was carried out in this study. Results show that both AirPrex® configurations with 1 reactor and 3 reactor have positive energy benefits and better environmental credits for the global warming potential (GWP), freshwater eutrophication potential, and marine eutrophication potential. The 3-reactor configuration shows better results in cumulative energy demand with 35% improvement of energy surplus, 36% reduction of GWP and less eutrophication potential. These improvements are mainly due to optimized struvite precipitation and harvesting and show that technology can be developed further, especially in plant operation and not only in the laboratory or pilot plant.

Comparative Farm-Gate Life Cycle Assessment of Oilseed Feedstocks in the Northern Great Plains

Second generation biofuel feedstocks such as carinata (Brassica carinata L. Braun) and camelina (Camelina sativa L. Crantz) offer unique advantages over traditional bioenergy alternatives, such as canola (Brassica napus L.) or soybean (Glycine max L. Merr). As the global demand for food and livestock feed continues grow, the utility of canola and soybeans as a bioenergy resource is uncertain. This work focused on two oilseed alternatives for use as biofuel feedstocks across the semi-arid region of the Northern Great Plains. This analysis compared the geographic distribution of current yields, assessed the environmental impacts, and evaluated the energetic benefit of oilseed production at aggregated crop management zone levels through a life cycle assessment (LCA) methodology. The average regional LCA results for environmental and energetic impacts for carinata and camelina compared favorably to canola and soybeans and were found to represent sustainable biofuel feedstock alternatives for the study region. The estimated climate change impact of carinata and camelina offered a substantial benefit over that of canola and soybeans. The regional results for freshwater and marine eutrophication potential and the net energy results of carinata and camelina also compared favorably to canola and soybeans. The most environmentally and energetically beneficial feedstock varied based on geographic location within the region. Soybeans tended to perform well in southeastern South Dakota, canola performed well in northeastern North Dakota, and camelina and carinata remained strong alternatives comparatively across the region.

Nitrogen and phosphorus losses and eutrophication potential associated with fertilizer application to cropland in China

Increased application of nitrogen (N) and phosphorus (P) fertilizer has significantly improved crop yields and food security in China over the past several decades. However, this has also led to serious problems of aquatic eutrophication in inland and coastal waters. This study analyzed N and P losses from major cropping systems across China using the China Pollution Source Census dataset. The associated eutrophication impacts, including freshwater eutrophication potential (FEP) and marine eutrophication potential (MEP), were then quantified using spatially-explicit characterization models. Large spatial and crop specific variations in N and P loss were identified. For example, net N leaching varied from 0.78 to 23.66 kg ha−1 for vegetable cropping in open fields and covered systems. Provinces with large cropping areas contributed the largest total nutrient loads. However, the application of spatially-explicit characterization factors (CFs) led to the identification of eutrophication hotspots that were not simply correlated with the inventory of nutrient emissions. Hainan, Yunnan, Guangdong, Guangxi and Fujian, with high global CFs for P, contributed the most (79.9%) to the total global FEP. China's breadbasket provinces with high losses and local CFs for both P and N, such as Hunan, Hubei and Sichuan, contributed significantly to both local FEP and MEP. Hunan, Hubei and Sichuan accounted for 10.1%, 9.8% and 9.2% to the total local FEP, respectively; and accounted for 7.7%, 8.4% and 9.0% to the total local MEP, respectively. Strategic actions in these hotspot regions would be most beneficial in addressing aquatic eutrophication challenges.