Terrestrial Acidification Research Articles

Environmental effect of improved forage fertilization practices in the beef production chain

Feeding is one of the most important factors influencing production efficiency and the environmental impact of livestock production. This study evaluates the possibility of reducing the impact of beef cattle production by optimizing the fertilization management of home-grown forage on the same farms. To this end, two scenarios were compared on two beef cattle farms in northern Italy, a baseline scenario (BS) and a scenario with optimized management (OMS) in terms of nitrogen fertilizer use. The cradle-to-gate LCA (Life Cycle Assessment) approach was used to compare the environmental performances in the different scenarios. Two different functional units (1 t dry matter of forage self-produced and 1 kg live weight of beef cattle produced) were used to express the results in relation to different stages of the supply chain. Inventory data were translated into indicators to reflect environmental pressures as well as resource scarcity by means of the ReCiPe 2016 Midpoint (H) method.The reduction of synthetic nitrogen fertilization, particularly during top fertilization, maintain yields at satisfactory levels while substantially reducing most of the evaluated impacts (e.g., Climate change from 17 % to 23 %). On the other hand, trade-offs among the different impact categories can be identified (e.g., terrestrial acidification grows up to 52 % for wheat silage).The optimization of the fertilization also involves a reduction in the impact of the feed as a whole and then of the beef cattle produced, even though the increasing number of external inputs, not affected by best fertilization practices, for each of these two phases leads to increasingly smaller reductions in impact. Ultimately, the optimization of internal crop production practices is important from an environmental point of view for farms but represents only one of the possible mitigation interventions necessary to mitigate the entire agricultural supply chain.

Environmental evaluation of family house materials impacts on climate change, land and water use, acidification and ecotoxicity

The construction industry plays a significant role in contributing to various environmental impacts, including climate change, acidification, and ecotoxicity, among others. This research paper presents a scientific analysis focused on the environmental evaluation of a masonry residential house by life cycle assessment (LCA) methodology. Specifically, it investigates the environmental impacts associated with the production phase of materials using the SimaPro software, which employs the Ecoinvent database. The ReCiPe method is utilized to calculate the comprehensive environmental impacts, with particular emphasis on climate change, terrestrial acidification, ecotoxicity, land use, and water use. To accurately determine the environmental impacts of the house materials, an allocation approach is employed, taking into account the function and location of the materials within individual structures. The calculated share of climate change per house materials amounted to 21.59 kg CO2 eq/m2/year, while the share on water scarcity was estimated at 15.87 m3/m2/year. The research findings reveal that vertical structures exhibit the highest environmental impacts across all impact categories, while horizontal structures demonstrate comparatively lower values.

An insight into environmental footprints of emerging air-conditioning systems towards sustainable cities

In this study, the environmental impacts of six conventional and modern air conditioning systems, including vapor-compression air conditioning (VAC), hybrid membrane-based air conditioning (HMBAC), desiccant enhanced evaporative air conditioning (DEVap), solar HMBAC, solar DEVap, and inverter VAC, are analyzed using a cradle-to-gate life cycle assessment (LCA) approach. The assessment is based on climate change, ozone depletion, terrestrial acidification, freshwater eutrophication, human toxicity, photochemical oxidant formation, ecotoxicity, water depletion, and fossil fuel depletion impacts. The LCA findings reveal that membrane-based systems (HMBAC and DEVap) are highly environmentally-friendly in comparison to the regular VAC systems (household split coolers), showing the capability of membranes in developing efficient air conditioning systems. In addition, solar-assisted systems reduce seven out of eleven environmental impacts, while they cause severe eutrophication, marine and freshwater ecotoxicity, and human toxicity consequences. Furthermore, it is unveiled that the inverter can reduce up to 38% of the environmental impacts of VAC systems which are the most common air conditioning system in buildings. Therefore, the manipulation of the inverter system in VACs can be considered as one of the short-term solutions in reducing the environmental footprints of air conditioning. Finally, the sensitivity analysis is applied to show the reliability of the outcomes.

Life Cycle Assessment of Craft Beer Brewing at Different Scales on a Unit Operation Basis

Beer brewing is a complex process that comprises many fundamental unit operations. Over the last few years, craft brewing has become very popular, and the number of small-scale commercial brewers has drastically increased. However, due to the use of traditional beer-making methods, energy utilization in craft breweries tends to be inefficient, resulting in poor sustainability. Therefore, there is a necessity for a holistic analysis on the energy profile of craft beer brewing to evaluate its environmental performance on a unit operation basis. In this study, a gate-to-gate life cycle assessment was conducted to analyze and compare the environmental profiles of craft beer brewing, including ale and lager, at commercial (microbrewery) and pilot scales. A process simulation model was developed to estimate the electricity and/or natural gas uses of each unit operation, including heating, mashing, boiling, whirlpool, cooling, fermentation, and maturation. The model accurately predicted the steam use for pilot-scale brewing and the electricity and gas bills of a microbrewery. The beers brewed at the microbrewery scale (21.5-barrel brewhouse) had 2–11-fold lower environmental impacts than those brewed at the pilot scale (1-barrel brewhouse), and lager beer generally produced 11–32% higher impacts than ale. The fermentation and maturation steps in brewing were the major contributors to global warming and terrestrial acidification, whereas the mashing step was predominantly responsible for marine eutrophication. This study provides craft brewers with a useful tool for identifying the hotspots of energy use in their processes and developing potential improvement strategies.

A comparative environmental analysis of conventional and organic rice farming in Thailand in a life cycle perspective using a stochastic modeling approach

System stochasticity is an inherent characteristic of agricultural systems. Many studies have been conducted in Thailand to analyze the rice production systems. However, most of the prior work just focused on deterministic approach to investigate the rice production systems while disregarding the system variability. In this study, the conventional and organic rice farming systems in Thailand were compared considering the uncertainties associated with parameters. The system variability was taken into account by employing a stochastic modeling approach. The considered impact categories include global warming, ozone formation (human health), freshwater ecotoxicity, terrestrial acidification, fine particulate matter formation, freshwater eutrophication, and fossil resource scarcity. The results showed that yield had considerable influence on the environmental profiles of the two systems; organic and conventional farming showed similar results in terms of global warming on a per hectare basis, but the considerable difference was observed on a per tonne basis. The field emissions due to farm inputs were the most significant contributor to most of the impact categories. The fuel used for irrigation, land preparation, and harvesting also contributed significantly to several impact categories. On the other hand, the impacts of inputs production and material transportation were modest. Uncertainty analysis outcomes indicated that there was a noticeable deviation from the deterministic results in terms of global warming and freshwater ecotoxicity. However, when considering the associated uncertainties, no significant difference was observed between the environmental profiles of the two systems.

Resource recovery of biological residues from the Brazilian poultry industry in mitigating environmental impacts: A life cycle assessment (LCA) approach

Poultry farming is often associated with negative environmental impacts, such as water quality degradation and greenhouse gas emissions. This study covers important gaps in the geographic scope of poultry farming using Life Cycle Assessment analysis. Data on animal feed, energy, packaging, and waste were collected from the poultry industry in Rondônia, Brazil. The life cycle inventory included all inflows and outflows of feed production, poultry housing, slaughter, processing, the retail market, and the functional unit of “1 kg chicken meat with 0.22 kg protein”. The ReCiPe Midpoint (H) method was used for seven categories of impact. The results showed that emissions of greenhouse gases (GHG, CO2, N2O and CH4) during the feed production phase was dominant, totaling 2.0 kg CO2-eq per kg of live weight produced. This stage was most relevant in six of seven categories of impacts assessed. During the poultry housing stage, terrestrial acidification was dominated by emissions of NH3, P and N2O from one-day-old chicks (hatching eggs, poultry house litter, and feed). The total environmental impact of producing broilers in Brazil amounted to 3.37 kg CO2-eq per kg of meat at the consumer market gate. The LPG gas and biological waste from slaughterhouses was dominant in this phase. The retail stage revealed contributions above 43% in all impact categories due to high consumption of electricity (0.11 kWh (0.39 MJ) per kg of meat). Three scenarios were proposed and demonstrated, using biological residues as a source of nutrients for feed composition. The results showed that using poultry viscera meal led to better environmental outcomes for all impacted categories.

Can free-floating electric bike sharing promote more sustainable urban mobility? Evidence from a life cycle environmental impact assessment

Electric shared micromobility has been popularized and developed worldwide in recent years. However, its environmental impact remains unclear. Based on user travel behavior and actual operational data, a life cycle assessment (LCA) study quantitatively estimates the environmental impacts of China's free-floating e-bike sharing (FFEBS) promotion, including human health, ecosystems, and resources. The results show that the low utilization makes FFEBS not an environmentally friendly mode of transportation. Taking into account the travel mode shift towards FFEBS, under the current operating efficiency of FFEBS, the substitution rate of car travel needs to reach about 40% to obtain environmental benefits. However, FFEBS can barely obtain environmental benefits on fine particulate matter formation, Human toxicity, Ozone formation, Freshwater and Marine eutrophication, Terrestrial acidification, and Terrestrial ecotoxicity, which is largely attributed to the negative effects of batteries and electronic components and the required rebalancing and recharging activities. As utilization continues to increase, it is estimated that each kilometer of FFEBS trips could reduce the impact of fossil resource scarcity and global warming by up to about 11.87 g oil eq and 32.06 g CO2-eq, respectively. This empirical study can not only help authorities, operators and the public better understand the environmental impact of FFEBS, but also provide a valuable reference for formulating effective measures to improve the sustainability of the FFEBS and urban transportation systems.

On the relevance of site specificity and temporal variability in agricultural LCA: a case study on mandarin in North Uruguay

PurposeMandarin is a relevant citrus crop in Uruguay both in terms of yield and area. This study is aimed at assessing the environmental impacts of mandarin cultivation in the country to identify the environmental hotspots. Temporal variability is assessed by considering six harvest seasons and site specificity by developing a regionalized inventory using a Tier 3 to estimate nitrogen on-field emissions. Also, the effect of regionalizing specific impact categories is analyzed.MethodsA cradle-to-farm gate assessment was carried out based on mass and area functional units. Primary data was gathered from a representative orchard of the region for the seasons 2016 to 2022. Nitrogen on-field emissions were modeled using LEACHN, a Tier 3 model that considers site-specific climatic and soil parameters as well as water and fertilizer applications at a daily scale. In addition, other modeling approaches were tested following the Environmental Product Declarations (EPD), Product Environmental Footprint (PEF), World Food LCA Database guidelines (WFLDB), and the updated IPCC and EMEP/EEA guidelines. The EN 15804 + A2 standard was followed to assess the environmental impacts, except for the categories concerning acidification, where IMPACT 2002 + v2.1 was used. In addition, to analyze the variations in the results when regionalizing impacts of on-field emissions, IMPACT World + was used.ResultsThe main hotspots detected are on-field emissions, machinery operations, pesticides, and fertilizer production. Irrigation is the main hotspot in blue water scarcity. As for the models tested to estimate nitrogen emissions, significant differences were detected in marine eutrophication between LEACHN and WFLDB, regardless of the functional unit, and in terrestrial acidification, terrestrial eutrophication, and aquatic acidification per ha between LEACHN and PEF. Significant reductions in the results were observed by regionalizing the environmental impacts caused by the on-field emissions.ConclusionsThe development of site-specific inventories and impact assessment methods with spatial resolution is encouraged, although more research is needed to draw general conclusions about the convenience of mechanistic models to estimate nitrogen emissions in Uruguayan citriculture. The high variation coefficients obtained reaffirm the importance of considering temporal variability. Moreover, the relevance of considering different functional units is highlighted since different influencing variables are observed throughout the seasons depending on the functional unit used.

Beneficial use of dredged sediments as a resource for mine reclamation: A case study of Lake Dianchi’s management in China

Dredging is one of the most effective methods for inhibiting the endogenous contamination of natural lakes. However, both the amount and the scope of dredging will be restricted if the disposal of the dredged sediment incurs considerable environmental and economic costs. The use of dredged sediments as a post-mining soil amendment for mine reclamation benefits both sustainable dredging and ecological restoration. This study incorporates a field planting experiment with a life cycle assessment to confirm the practical effectiveness of sediment disposal via mine reclamation, as well as its environmental and economic superiority over other alternative scenarios. The results show that the sediment offered plentiful organic matter and nitrogen for mine substrate, stimulating plant growth and increasing photosynthetic carbon fixation density, followed by enhanced plant root absorption and an improved soil immobilization effect on heavy metals. A 2:1 ratio of mine substrate to sediment is recommended to significantly promote the yield of ryegrass while reducing levels of groundwater pollution and soil contaminant accumulation. Due to the significant reduction in electricity and fuel, mine reclamation had minimal environmental impacts on global warming (2.63 × 10-2 kg CO2 eq./kg DS), fossil depletion (6.81 × 10-3 kg oil eq./DS), human toxicity (2.29 × 10-5 kg 1,4-DB eq/kg DS), photochemical oxidant formation (7.62 × 10-5 kg NOx eq./kg DS), and terrestrial acidification (6.69 × 10-5 kg SO2 eq./kg DS). Mine reclamation also had a lower cost (CNY 0.260/ kg DS) than cement production (CNY 0.965/kg DS) and unfired brick production (CNY 0.268/kg DS). The use of freshwater for irrigation and electricity for dehydration were the key factors in mine reclamation. Through this comprehensive evaluation, the disposal of dredged sediment for mine reclamation was verified to be both environmentally and economically feasible.

Conservation agriculture reduces climate change impact of a popcorn and wheat crop rotation.

Urgent action is needed to ensure humanity's future under climate change. Agriculture faces major challenges as it is both influenced by and contributes to climate change. Conservation agriculture sequesters carbon (C) in the soil due to practices such as reduced tillage and planting of cover crops. This study assessed effects of an innovative conservation agriculture popcorn (Zea mays) and wheat (Triticum aestivum) crop rotation in south-western France on soil C sequestration, GHG emissions and several environmental impacts. Two complementary approaches were used: i) a comparison based on field data and expert judgement to assess short-term effects and ii) modelling of three scenarios to quantify long-term outcomes. In both approaches Life cycle assessment (LCA) was used to compare popcorn and wheat rotations. The conventional rotation used ploughing, and its soil was bare between wheat harvest and popcorn sowing. Conservation agriculture used reduced tillage, cover crops, and compost of green waste. Impacts of compost production were allocated mainly to its waste treatment function, based on waste treatment cost and compost price. Simulation modelling of soil C was used to estimate the amount of C sequestered by the conservation and conventional crop rotations. LCA was combined with soil C modelling over 100 years to assess the long-term climate change impact of three scenarios for the popcorn and wheat rotation. These scenarios were 1) Conventional agriculture, 2) Conservation agriculture with cover crops only, 3) Conservation agriculture with cover crops + compost. Mean annual C sequestration and net climate change impact were -0.24 t/ha and 3867 kg CO2-eq./ha, respectively, for the conventional rotation and 0.91 t/ha and 434 kg CO2-eq./ha, respectively, for the conservation rotation. The climate change impact of the conservation rotation depended strongly on the allocation of composting impacts between the waste treatment and compost production functions. Compared to the conventional rotation, the conservation rotation had a lower marine eutrophication impact (-7%) but higher impacts for terrestrial acidification (+9%), land competition (+3%), and cumulative energy demand (+2%). Modelling over 100 years revealed that, at near soil C equilibrium, a conventional scenario lost 9% of soil C, whereas conservation agriculture scenarios gained 14% (only cover crop) and 26% of soil C (cover crop + compost). Conservation agriculture resulted in soil C sequestration over several decades, until a new soil C equilibrium was reached.

Investigating the Impact of Shifting the Brick Kiln Industry from Conventional to Zigzag Technology for a Sustainable Environment

The brick kiln industry is one of the largest and most highly unregulated industrial sectors in developing countries. Most of the kilns use low-quality coal as primary fuel along with small quantities of bagasse, rice husk, and wooden chips. As a result of inefficient methods of combustion in conventional brick kilns, such as fixed chimney Bull’s trench kilns (FCBTKs), harmful pollutants are emitted in high quantities, which ultimately deteriorate the environment and are widely in operation in Pakistan. The most prominent harmful pollutants include carbon dioxide (CO2), carbon monoxide (CO), sulphur dioxide (SO2), black carbon (BC), and particulate matter less than 2.5 microns (PM2.5). Over the years, new technologies have been adopted by developed countries for the reduction of environmental burdens. One of these technologies is induced draught zigzag kilns (IDZKs), or zigzag kilns (ZZKs), technology, which effectively improves the combustion across the path of bricks stacked in a zigzag pattern. For the mass adoption of this technology, environmental assessment and comparison of both technologies is a crucial step. Both types of kiln sites are investigated for the analysis of their emissions and their environmental impact in this work. Carbon mass balance equations are used for the calculation of emission factors. Collected inventory data is then used for the life cycle assessment of both types of kilns using open LCA (version 1.10.3) and the Eco-invent database. According to the study, ZZK technology outperforms FCBTK in all aspects. The analysis of the specific energy consumption (SEC) of fired bricks for each kiln type reveals that ZZKs require 30% less energy than the conventional FCBTK. This implies that ZZKs demand lesser fuel than FCBTKs. The zigzag technology adoption scenario, in particular, can lead to approximately 30% lower CO2 emissions, which can be further reduced by up to 80% when taking into account black carbon (BC) emissions. Additionally, the adoption of zigzag technology can result in a 35% decrease in PM2.5 emissions. The study shows that adopting ZZK technology significantly reduces impact categories, such as particulate matter formation (PMF), photochemical oxidant formation (POF), and terrestrial acidification (TA) by 63%, 93%, and 95%, respectively.

Life cycle assessment of injection moulding tools and multicomponent plastic cap production

Long-term product improvement requires detailed analysis that includes information from the entire product life cycle. Life cycle assessment according to the standards ISO 14040 and ISO 14044 provides information on the environmental impact of products throughout their life cycle. The aim of the study is to analyze the environmental impact of a multicomponent plastic product in two variants and the associated customized tools using life cycle assessment. The subject of this analysis is the previous and the improved design of a multicomponent plastic cap for 19 l water bottles and the associated custom-manufactured tools. The main improvements of the custom-made tools are in the larger number of cores, and the new cap design was improved with fewer components and mass. The results show that the production and packaging of the improved multicomponent plastic cap has more than two times lower environmental impacts in the categories of global warming potential, freshwater eutrophication, terrestrial acidification ozone formation, human health and non reneweable, fossil. The environmental impact of custom injection moulding tools is strongly influenced by the capacity of the injection moulding machine and the number of cores or number of products that can be produced in a batch. In addition, the results of the improved 19 l multicomponent plastic cap showed a lower environmental impact compared to previous studie of the 5 l plastic cap.

Life cycle analyses of SOFC/gas turbine hybrid power plants accounting for long-term degradation effects

In this study, cradle-to-product life cycle analyses were conducted for a variety of natural-gas-based and coal-based SOFC power plant conceptual designs, while also accounting for long-term SOFC degradation. For each type of plant, four base case designs were considered: a standalone SOFC plant, a standalone SOFC plant with a steam cycle, an SOFC/GT hybrid plant, and an SOFC/GT hybrid plant with a steam cycle. The boundary of each base case was subsequently expanded to include either wet cooling or dry cooling options and DC to AC conversion, and was subjected to additional cradle-to-product life cycle analyses. The environmental impact results were computed using ReCiPe 2016 (H) and TRACI 2.1 V1.05 in SimaPro. The main factors affecting the midpoint impacts between cases were the plant efficiency and total SOFC manufacturing required over the plant's lifetime, which were both strongly connected to long-term degradation effects. The findings also showed that the standalone SOFC plant with a steam cycle (which featured higher plant efficiency) had lower midpoint impacts with respect to global warming potential and fossil resource scarcity, which were largely the product of plant operation. The case with the longer SOFC stack lifetime (e.g., a SOFC/GT hybrid power plant with a steam cycle) had lower midpoint impacts with respect to fine particulate matter formation, terrestrial acidification, terrestrial ecotoxicity, and mineral resource scarcity due to the large proportion of midpoint contributed by SOFC manufacturing. Ultimately, the SOFC/GT hybrid plant with a steam cycle was found to be the best option, as it had the lowest ReCiPe endpoint impact (4.5%–42% lower than the other cases)among both the natural gas-based and coal-based cases.

A scenario-specific nexus modelling toolkit to identify trade-offs in the promotion of sustainable irrigated agriculture in Ecuador, a Belt and Road country

Increased demand for food due to development and population growth has prompted irrigated agriculture expansion, posing enhanced global challenges to water, energy, and food security. To confront these challenges, an approach that considers the water-energy-food-environment nexus can address multidimensional trade-offs that complicate the efficient use of resources and the achievement of Sustainable Development Goals. In order to provide insights into solutions to these challenges for a specific case, this study develops a modelling toolkit that integrates biophysical and socioeconomic aspects of nexus components in the context of agro-export and irrigation expansion in Ecuador, a Belt and Road Country. The nexus toolkit is applied to agricultural-development scenarios defined in participatory workshops and incorporates a water resources model, a lifecycle environmental assessment, and a socioeconomic analysis. The modelling exercise is constructed around specific scenario-determined land use patterns in the Santa Elena peninsula of Ecuador. Agriculture in the peninsula is water-limited, relying on delivery infrastructure and transfers from a neighbouring catchment. Impacts on nexus components are analysed for ten crops under two potential land-use scenarios: a substantial increase in irrigated area due to investment in irrigation infrastructure; and a substantial shift in land use towards export crops. The two have distinct impact on water and energy use, global warming potential, freshwater eutrophication, terrestrial acidification, and fine particulate matter formation. The results provide insights into future water and energy resource challenges and environmental and socioeconomic trade-offs associated with likely changes in irrigation expansion. The results for scenarios show that, for example, banana production has the greatest environmental impacts (e.g. a 519% increase in global warming potential and 452% increase in fine particulate matter form for scenario 2), primarily due to water and energy requirements, despite the crop being mainly produced organically. In addition, total net income and labour demand increase (net income increases by 43% and 217% under scenarios 1 and 2, respectively) due to a larger crop area and crop intensification. Scale effects on labour demand are mainly due to labour intensity of maize in Ecuador, which is disadvantaged in the crop export scenario (an unexpected result). However, expanding irrigated areas would also increase total water and energy demand for irrigation, global warming potential, and freshwater eutrophication. This type of information enables stakeholders and decision-makers to design policies that achieve equitable and sustainable agricultural production, water use, and economic growth.

Reducing the environmental impacts of Brazilian chicken meat production using different waste recovery strategies

Chicken meat has achieved significant index rates worldwide, with Brazil leading production and exports. The agribusiness significance has led to strengthening attention to the environmental burdens produced by the poultry industry. This research considered reducing the environmental impacts in the life cycle of Brazilian chicken meat regarding strategies for recycling waste from the production process. An attributional cradle-to-gate life cycle assessment was performed, with the functional unit of 1 kg of slaughtered and unpacked chicken meat. The two suggested scenarios used: i) chicken bedding for biogas production and ii) chicken carcass waste as meat meals in feed production. Handling poultry litter for biogas production avoided methane and ammonia emissions, reducing over 50% of the environmental indicators of Climate Change, Terrestrial Acidification, and Freshwater Eutrophication. Reuse poultry waste to produce meat meals reduced from 12% to 55% in all impact categories, decreasing emissions from carcasses destined for decomposition in landfills and using less raw materials from bovine sources. Investigating the environmental performance of the chicken meat production chain encouraged the circularity of natural resources and waste recovery strategies in the system boundary, thus helping to accomplish Sustainable Development Goals 7, 9, 12, and 13 of the UN Agenda 2030

Environmental and economic assessment of the construction, operation, and demolition of a decentralized composting facility

Decentralized waste treatment facilities are recently highlighted for the treatment of solid waste in rural areas for being cheap, flexible, and reliable. Among them, decentralized composting is most commonly used. Many forms of decentralized composting facilities also develop and apply in developing countries, but the environmental and economical performances remain unknown. Therefore, this study analyzed the environmental impacts and cost of a decentralized composting facility through life cycle assessment and life cycle cost. The functional unit was the construction, operation, and demolition the composting facility. Contribution and sensitivity analysis were also performed to find out the most influential processes and parameters. The facility had a 10-year designed life span and could treat about 5840 t organic waste in its life cycle. The life cycle environmental impacts were 646,700 kg CO2-eq, 8980 kg SO2-eq, −28 kg P-eq, 7.09 × 10−3 CTUh, 0.13 CTUh, and 16,754 kg oil-eq for climate change, terrestrial acidification, freshwater eutrophication, human toxicity cancer effects, human toxicity non-cancer effects, and fossil resources scarce, respectively. The life cycle cost was 1080.925 k CNY. When scaling to treating 1 t organic waste, the environmental impacts were close to those of similar decentralized and centralized composting facilities and the cost was lower than those of centralized biological treatment plants when excluding revenues from compost. According to the contribution and sensitivity analysis, the operation stage had the largest environmental impacts. The composting and compost substitution processes in the operation stage were the most sensitive processes. This study proved quantitatively that the decentralized facility was feasible both environmentally and economically and enriched the study cases for decentralized composting facilities.

Life cycle assessment: Sustainability of biodiesel production from black soldier fly larvae feeding on thermally pre-treated sewage sludge under a tropical country setting

More energy is needed nowadays due to global population growth. Concurrently, sewage sludge generation has also increased steadily stemming from the inevitable urbanization. As such, black soldier fly larvae (BSFL) can be potentially deployed to solve both issues. This paper investigates the environmental sustainability of biodiesel production derived from sludge-fed BSFL feedstock. A cradle-to-gate life cycle assessment (LCA) was performed through SimaPro software utilizing the ReCiPe 2016 Midpoint (H) and Endpoint (H) methods. The entire LCA covered 3 main stages, including the thermal pre-treatment of sludge, BSFL rearing and processing, and lastly lipid extraction and biodiesel production. LCA showed that the sludge pre-treatment stage had the highest environmental impact, while BSFL rearing and processing had the least due to the suitable geographical climate. Electricity usage during the pre-treatment stage was the main contributing component, followed by chemical usage during biodiesel production. After normalizing, it was observed that land occupation, marine ecotoxicity, freshwater ecotoxicity and freshwater eutrophication were more impactful than the commonly studied global warming potential (GWP). Lipid content and biodiesel conversion efficiency were determined as the sensitive factors which could influence the LCA outcome. In comparison with other types of biodiesel, BSFL biodiesel had a milder impact in terms of climate change, land occupation, terrestrial acidification, marine and freshwater eutrophication. Furthermore, this biological reduction of sludge through BSFL valorization avoided sludge landfilling, which reduced up to 100 times GWP. Therefore, sludge-fed BSFL biodiesel production is an environmentally-sound and highly potential solution that should be investigated comprehensively.

Environmental impacts and optimization simulation of aerobic anaerobic combination treatment technology for food waste with life cycle assessment

After the implementation of waste sorting policy in Shanghai, the amount of food waste (FW) separation and treatment demand has increased significantly. It is necessary to establish the life cycle assessment (LCA) to assess the environmental impacts of various treatment technologies comprehensively, thus provide support for sorting, recycling, treatment and disposal strategies of FW. In this study, a local FW treatment plant in Shanghai, using typically aerobic anaerobic combination treatment technology was selected to analyze the environmental impacts with LCA. The process mainly included pretreatment, power, aerobic composting, anaerobic digestion, and further process systems. LCA results showed that the environmental impacts mainly came from the power and aerobic composting systems on the fine particulate matter formation and eutrophication, and freshwater ecotoxicity and terrestrial acidification, respectively. Considering the carbon footprint, the aerobic composting system contributed 3.61E + 02 kg CO2 eq and represented the largest source of carbon emission. The soil conditioner yielded both environmental benefits on eutrophication and terrestrial ecotoxicity, and ecological benefits of 75.33 million CNY per year being the major revenue for the treatment plant. It also suggested that the biogas generation capacity of anaerobic digestion could be increased to achieve electricity self-sufficiency, thus save about 7.12 million CNY per year in electricity costs, and avoid corresponding environmental impacts caused by coal-fired. In summary, the aerobic anaerobic combination treatment could be further optimized and applied in FW treatment to reduce the environmental impacts, and enhance resource recovery and secondary pollution control.

Adherence to the EAT-Lancet Healthy Reference Diet in Relation to Risk of Cardiovascular Events and Environmental Impact: Results From the EPIC-NL Cohort.

Background The Healthy Reference Diet (HRD) was created to formulate dietary guidelines that would be healthy and sustainable. We aimed to construct a diet score measuring adherence to the HRD and to explore its association with cardiovascular events and environmental impact. Methods and Results We included 35 496 participants from the population-based EPIC-NL (European Prospective Investigation into Cancer and Nutrition-Netherlands) study. HRD scores were calculated using data from food frequency questionnaires (0-140). Data on morbidity and mortality were retrieved through linkage with national and death registries. Data on environmental impact indicators were obtained from life cycle assessments. Associations between adherence to the HRD and cardiovascular events were estimated with Cox proportional hazard models. Linear regression analysis was conducted for the adherence to the HRD and each environmental indicator. High adherence to the HRD was associated with 14%, 12%, and 11% lower risks of cardiovascular disease (hazard ratio [HR]Q4vsQ1, 0.86 [95% CI, 0.78-0.94]), coronary heart disease (HRQ4vsQ1, 0.88 [95% CI, 0.78-1.00]), and total stroke (HRQ4vsQ1, 0.89 [95% CI, 0.72-1.10]), respectively. High HRD adherence was associated with 2.4% (95% CI, -5.0 to 0.2) lower greenhouse gas emissions, 3.9% (95% CI, -5.2 to -2.6) less land use, 0.5% (95% CI, -2.6 to 1.6), less freshwater eutrophication, 3.3% (95% CI, -5.8 to -0.8), less marine eutrophication, 7.7% (95% CI, -10.8 to -4.6), less terrestrial acidification, and 32.1 % (95% CI, 28.5-35.7) higher blue water use. Conclusions High adherence to the HRD was associated with lower risk of cardiovascular disease, coronary heart disease, and modestly lower levels of most environmental indicators but a higher level of blue water use.

Evaluation of the Sustainability of a Prototype for Atmospheric Ammonia Capture from Swine Farms Using Gas-Permeable Membrane Technology

Ammonia (NH3) emissions from animal wastes are directly related to serious environmental problems and can be reduced by using gas-permeable membranes (GPMs) in animal housings, but not many studies have been conducted on the environmental impact of the entire system. Thus, the aim of this work was to analyze the environmental impacts caused by the implementation of GPM technology in a 920-animal swine farm with a closed cycle (i.e., birth, breeding, transition, and fattening take place on the same site), using life-cycle analysis (LCA). Two scenarios were studied: a reference scenario in which there was no NH3 reduction from the air captured in the sheds and a treatment scenario that used the GPM technology. The LCA results were evaluated by using the ReCiPe 2016 Midpoint (H) V1.04 method, showing that using the GPM technology had beneficial environmental impacts. Terrestrial acidification (TA) showed a reduction of 14.68 kg SO2 eq compared with the reference scenario, whilst human carcinogenic toxicity (HCT), human non-carcinogenic toxicity (HnCT), and land use (LU) showed reductions of 1.52 kg 1,4-DCB, 66.26 kg 1,4-DCB, and 44.55 m2a crop eq, respectively.