Eutrophication Potential Research Articles

Enhancing environmental sustainability in eastern Canada's corn agroecosystem with controlled drainage and subsurface irrigation

Abstract Water table management through controlled tile drainage and subsurface irrigation (CDSI), retrofitting to conventional tile drainage, has been developed to abate the environmental impacts of irrigation and drainage meanwhile supporting agroecosystems and crop productivity. Since the environmental profile of new technologies is a prerequisite to understanding their socio-economic benefits, a life cycle assessment was conducted to assess the environmental impacts of CDSI on corn production for the 2014 and 2015 growing seasons at St-Emmanuel, south-western Quebec in eastern Canada, compared to the free drainage (FD). Inventory flows of corn production with CDSI and FD were developed using biophysical data from field experiments and public databases. Then, environmental impacts were compared for corn production with CDSI and FD, including climate change, eutrophication potential, acidification potential, and toxicity. The assessment results show the environmental benefits of implementing CDSI, particularly in improving water quality. However, potential synergy and trade-offs of climate change, eutrophication, and acidification impacts from the implementation of CDSI, especially under different climatic conditions, should be further monitored to improve the performance of the technology. Nevertheless, CDSI and associated practices can be adopted as adaptation measures in agricultural water management to support agroecosystems and address the challenges posed by environmental impacts.

Effect of external carbon source type on effluent dissolved organic nitrogen characteristics in postdenitrifying moving bed biofilm reactors: Chemical molecular and microbial insights

Despite the higher potential for eutrophication of dissolved organic nitrogen (DON) than dissolved inorganic nitrogen, the influence of the types of external carbon sources on DON remains largely unknown. This study investigated the effect of external carbon source type (acetate, glucose, methanol, and ethanol) on effluent DON characteristics in postdenitrifying moving bed biofilm reactors (MBBRs) from chemical molecular and microbial insights. The results showed that the effluent DON concentration in postdenitrifying MBBRs fed different carbon source types followed the order of ethanol > glucose > methanol > acetate. Interestingly, the acetate-fed postdenitrifying MBBR effluent DON contained a less labile molecular composition (5.03%), indicating that these effluent DON are not prone to stimulate algae production in receiving waters. Principal component analysis demonstrated that the produced DON instead of removed and/or resisted DON during the denitrification process mainly contributed to the differences in DON molecular composition and bioavailability in effluent. The key microbes, including Proteobacteria, Chloroflexi, etc. and amino acid metabolism were potentially responsible for the produced DON. Overall, this study demonstrated that MBBRs used for postdenitrification could be optimized to minimize eutrophication effects by accounting for optimal carbon sources and that acetate is recommended as the preferred external carbon source in wastewater treatment using postdenitrifying MBBRs.

Estimating the Ecological Performance of Water and Wastewater Treatment in Africa: A Meta‐Analysis

AbstractThis article is the result of a systematic review of published life cycle assessment (LCA) studies on water and wastewater treatment in Africa. After applying the search and selection criteria, 32 observations for energy use were included and 20 for the global warming potential (GWP) and the eutrophication potential (EP). The dependent variables were categorized by technical, method, and typology factors. The meta‐regression model aligned with the descriptive statistics on the variation of the dependent variables due to water source but not location. Regarding energy use, GWP, and EP, the water source and the study location had the most significant influence in contrast to the life cycle impact assessment method. There is a need for more such LCA studies in Central and Western parts of Africa.

Comparative life cycle assessment of whiteleg shrimp (Penaeus vannamei) cultured in recirculating aquaculture systems (RAS), biofloc technology (BFT) and higher-place ponds (HPP) farming systems in China

Recirculating aquaculture systems (RAS), biofloc technology (BFT), and higher-place ponds (HPP) are considered as alternative technologies in addressing major environmental challenges linked to conventional Whiteleg shrimp farming systems. Global concern about energy consumption and carbon emission in aquaculture industries, especially in countries like China. The application of life cycle assessment (LCA) in shrimp aquaculture, especially in comparing different shrimp production systems, is being used. In our study, surveys on three RAS, three BFT and nine HPP farms have been conducted, and the data inputs were used to establish a cradle to farm-gate LCA by means of software SimaPro 9.3.0.2 and CML-IA methods to evaluate the environmental performance. The methods are well suited to this LCA, as it focuses mainly on energy consumption input, pollution output, and ecological damage. A ton of live weight shrimp production did generate 4424.2, 4657.2, and 4965.6 kg CO2 eq; 21.8, 25.9, 36.2 kg PO4 eq; 38.7, 40.6 and 43.5 kg SO2 eq in RAS, BFT and HPP systems, respectively. Regarding the characterization and normalization results, eleven categories (abiotic depletion, acidification, eutrophication, etc.) were considered. In most impact categories, the results showed that HPP had the highest environmental impact per unit production when compared to RAS and BFT. Acidification potential (AP) and eutrophication potential (EP) were the top two contributing factors to RAS, BFT and HPP. And AP and EP is closely related to the production of electricity. Electricity was identified as primary contributors in all farming processes. Results indicate that BFT and RAS could be used in combination to reduce environmental impacts. In order to improve the environmental performance of these farming systems, feed ingredients substitution; feeding management and effluent treatment are among the suggested measures. In order to enhanced aquaculture LCI databases and support aquaculture LCA research, the life cycle inventory for shrimp farming were established.

Optimizing SCND with carbon-rich hydrolysates from typical organic wastes: Material composition, augmentation performance, microbiome response, and life cycle impact

The rapid growth of production and consumption has led to severe environmental pollution, creating a major challenge to achieving the United Nations' sustainable development goals (SDGs). To address it, recycling of organic wastes into value-added products is a possible solution. In this work, four typical organic wastes including sewage sludge (SS), chicken manure (CM), food waste (FW), and corn straw (CS) were employed to produce hydrolysates augmenting shortcut nitrification-denitrification (SCND) for nitrogen depletion in wastewater. The hydrolysates were carbon-rich, with total COD (TCOD), soluble COD (SCOD), and volatile fatty acids (VFA) concentrations ranging from 32.5 to 102.7, 5.7 to 48.4, and 2.0–16.5 mg/L, respectively. The most effective nitrogen depletion was obtained in units supplemented with CM and FW hydrolysates, which had reduced average NH3–N concentrations and near-zero TN removal failure rates under legal requirements. The microbial community analysis demonstrated that various functional bacteria from phylum to genus level were detected in all scenarios, which was corroborated by abundant genetic functions involved in nitrogen metabolism. Further, life cycle assessment revealed negative environmental impact on all categories, with an exception of eutrophication potential (EP) with negative values (∼−0.04 kg Phosphate eq.), allowing positive net environmental benefit (NEB). Operational cost analysis revealed that CM and FW are more effective but costlier than SS and CS. Together, these results indicate that, after hydrolysis, organic wastes can be efficient stimulant augmenting SCND performance for nitrogen depletion in wastewater, benefiting the overall environmental impact.

Refining life cycle nutrient modeling in organic pig production. An analysis focusing on feeding strategies in organic Danish pig farming

Organic pig farming systems are associated with considerable ammonia losses, nitrate leaching in sow pasture concepts, and dependency on imported protein feed components, such as soybean cake. Furthermore, in environmental nutrient modeling approaches, there is a lack of data on emission factors and models that account for nutrient balances concerning organic production systems. Therefore, the present study aimed to analyze feeding strategies in organic pig farming by using refined nutrient modeling approaches.A cradle-to-farm-gate life cycle approach was used to analyze six feeding scenarios: reduced crude protein content in feed rations for sows (S1) and sows and fattening pigs (S3), alternative protein sources and reduced protein in feed rations for sows (S2) and sows and fattening pigs (S4), and reduced compound feed intake for sows (S5) and sows and fattening pigs (S6). Danish average production data were collected and specific data regarding organic production (N content in manure, emission factors for ammonia for the paddock and housing) were identified. Six sub-systems (paddocks with sows and piglets on grass-clover, weaners, fattening pigs, feed, manure, and manufacturing of inputs) were considered and balanced out. Five environmental impact categories, climate change (including soil carbon changes), eutrophication potential, acidification potential, abiotic depletion of fossil fuels, and land occupation, were assessed.It was found that the feeding strategies had considerably higher effects when including both sows and fattening pigs compared to only including sows. The highest reductions for most of the analyzed environmental impacts (13% for eutrophication and acidification, 11% for climate change, and 8% for land occupation) were estimated due to reduced amount of compound feed to both sows and fattening pigs (S6). For abiotic depletion of fossil fuels, a decrease of 33% was determined by the use of locally grown protein sources (S4), which decreased the contribution of transportation. In terms of methodological refinements, an approach for nutrient modeling at the paddock level, where crop rotation and associated effects were also considered, was identified. Furthermore, adapted emission factors for indoor housing with access to outdoor runs were suggested.

Systematic Literature Review of Environmental Impacts of Canned Pineapple Production

A systematic literature review was conducted to assess the current state of knowledge on the environmental impacts of canned pineapple production. The review included studies published in peer-reviewed journals between 2000 and 2022, and focused on the assessment of greenhouse gas emissions, acidification, and eutrophication potential associated with the production of canned pineapple. The results of the review suggest that canned pineapple production has significant environmental impacts, particularly in terms of greenhouse gas emissions, which are mainly associated with energy use and transportation. However, the review also identified several strategies that can be implemented to reduce the environmental impacts of canned pineapple production, such as using renewable energy sources and optimizing transportation routes. The review concludes that further research is needed to fully understand the environmental impacts of canned pineapple production and to develop effective strategies for reducing these impacts.

Numerical modeling of aerobic bio-phosphorus removal by phosphorus accumulating organisms using coupled lattice Boltzmann method and cellular automata platform

The removal of phosphorus (P) from wastewater is important to reduce water pollution and potential eutrophication in surface waters. In previous studies, the multilateral interactions of biofilm growth and spatiotemporal concentrations of species were not considered or not affected by flow field and reaction rates. To fill some important parts of these gaps, an integrated platform of lattice Boltzmann method and cellular automata was developed to model the spatiotemporal nutrient transport and biofilm growth of an enhanced bio‑phosphorus removal process in a T-shaped bioreactor. The model was validated against the data available in the literature. The effects of different dissolved oxygen concentrations and fluid velocities were investigated. The results showed that increasing the velocity ratio decreased the biofilm growth, leading to a decrease in the polyphosphate concentrations in the bioreactor. There was a difference of up to 33.9 % between the lowest normalized biofilm concentration and the highest one. Increasing dissolved oxygen concentrations through the primary inlet produced more biofilm in the bioreactor, especially in its bottom zone, than that through the secondary inlet. It is also found that there is a specific biofilm concentration threshold. After the threshold, the biofilm growth and the biochemical reaction rates decreased, leading to a decrease in the phosphorus removal rate and an increase in phosphorus concentration. This study demonstrates the LBM-CA model could improve our understanding of biological P-removal and help to optimize and improve the efficiency of such operations.

Geographically-resolved evaluation of the economic and environmental services from renewable diesel derived from attached algae flow-ways across the United States

Harmful algal blooms (HABs) are becoming more invasive and ever more prevalent due to rises in nitrogen and phosphorus pollution in watersheds. Herein, we introduce a novel biorefinery that taps into the vast sources of nitrogen and phosphorus in watersheds. Contaminated water is diverted to flow over attached algae systems, feeding native, periphytic algal cultures and scrubbing excessive nutrients from the water with the produced biomass converted to fuels through hydrothermal liquefaction. The evaluation of the biorefinery concept is done with sustainability analysis that incorporates geographically-resolved growth modeling with nutrient resource availability based on all Hydrologic Unit Code-8 (HUC8) in the contiguous US. Life cycle analysis results demonstrate a global warming potential of 25 g CO2-eq MJ−1, a eutrophication potential of 1.3 ∗ 10−5 kg N eq. MJ−1, and a net energy ratio 0.33 of MJ MJ−1 in the Santa Monica Bay, CA subbasin. Techno-economic assessments found that renewable diesel can be produced for $1.20 per cubic decimeter (dm−3) or $4.56 per gallon of gasoline equivalent (GGE−1) under optimal conditions in the Santa Monica Bay, CA subbasin, with results dramatically varying across the US. Water quality trading was also incorporated into the analysis. Using modest nutrient credit values of $4.5 per kg of total nitrogen (kg-TN−1) and $4.5 per kg total phosphorus (kg-TP−1) removed enabled the renewable diesel to achieve parity with conventional diesel, $1.01 dm−3 ($3.84 GGE−1) in the Santa Monica Bay, CA subbasin. A more aggressive credit value of $45 kg-TN−1 and $45 kg-TP−1 made the price of the renewable diesel negative in Santa Monica Bay, CA, roughly $-4.45 dm−3 ($-16.8 GGE−1), and across the Midwest, the Gulf of Mexico, and major cities on the East and West Coast. These results highlight a path forward for mitigating eutrophication while also creating a sustainable fuel.

Life Cycle Assessment of a Sustainable Prefabricated Housing System: A Cradle-to-Site Approach Based on a Small-Scale Experimental Model

India is in need of rapid construction technology with sustainability and environmentally friendly aspects. Prefabrication is a well-known technique that lowers carbon emissions and reduces environmental impacts. Life cycle assessment (LCA) evaluates these impacts of developed product/process. A new-age construction product was designed from a locally available agro-industrial waste called co-fired ash (CFA). Expanded polystyrene beads, fly ash, and crushed sand were also used in designing lightweight (LW) sustainable prefabricated panels. The effect of incorporating sustainable alternates into the mix designs is to be studied. An experimental small-scale model house was erected and LCA for the same was carried out with cradle-to-site approach. Based on the inventory, the environmental impact was assessed for four different indicators: acidification potential (AP), eutrophication potential (EP), global warming potential (GWP), and ozone depletion potential (ODP) were evaluated. Carbon emissions of the respective CFA-based concrete and LW prefabricated mix were found to be 0.162 kgCO2e/kg and 0.268 kgCO2e/kg, respectively. The impact of energy required during production, transport, and indirect emissions were found to contribute 3%, 3%, and 94%, respectively, to the proposed prefabricated system. Comprehensively, the phase involving mixing of LW mix contributed majorly towards all the impact indicators followed by mould preparation and material transport. The presented data helps the academia to quantify and recognise the possibilities to enhance their products’ performance.

Optimisation and environmental impact analysis of green dry mix mortar paving block incorporating high volume recycled waste glass and ground granulated blast furnace slag

This research incorporates sustainable materials such as ground granulated blast furnace slag (GGBS) and recycled waste glass (RWG) as cement and fine aggregate replacement respectively to produce green dry mix mortar paving blocks. The GGBS and RWG contents in the mortar paving block were optimised using the response surface methodology (RSM), considering the performances of the ultrasonic pulse velocity (UPV), flexural and compressive strengths, water absorption, and Cantabro loss. Life cycle assessment (LCA) was also conducted to evaluate the environmental impact of the optimised green mortar paving blocks. The RSM suggested that the paving block with optimum GGBS and RWG contents of 26.5% and 91.3%, respectively, could exhibit compressive strength of 36.5MPa, which complied with the requirement for concrete segmental paving units (MA20). Excluding the mixes not fulfilling the MA20 requirement, the mix with 40% GGBS and 100% RWG exhibited the lowest values for the acidification potential (AP), global warming potential (GWP), photochemical oxidation (POCP), abiotic depletion potential for fossil fuel (ADPF), and water scarcity/strength ratio. Whereas, for eutrophication potential (EP) and abiotic depletion for elements (ADP (elements))/strength ratio, the mix with 100% RWG exhibited the lowest value. The optimised mix from RSM showed a similar performance as the two mixes.

Optimizing Agronomic, Environmental, Health and Economic Performances in Summer Maize Production through Fertilizer Nitrogen Management Strategies.

Although nitrogen (N) fertilizer application plays an essential role in improving crop productivity, an inappropriate management can result in negative impacts on environment and human health. To break this dilemma, a 12-year field experiment (2008-2019) with five N application rates was conducted on the North China Plain (NCP) to evaluate the integrated impacts of optimizing N management (Opt. N, 160 kg N ha-1 on average) on agronomic, environmental, health, and economic performances of summer maize production. Over the 12-year study, the Opt. N treatment achieved the maximal average grain yield (10.6 Mg ha-1) and grain protein yield (793 kg ha-1) among five N treatments. The life cycle assessment methodology was applied to determine the negative impacts on environmental and human health, and both of them increased with the N rate. Compared with the farmers' conventional N rate (250 kg N ha-1), the Opt. N treatment reduced acidification, eutrophication, global warming, and energy depletion potentials by 29%, 42%, 35%, and 18%, respectively, and reduced the health impact by 32% per Mg of grain yield or grain protein yield produced. Both the Opt. N and Opt. N*50-70% treatments resulted in high private profitability (2038 USD ha-1), ecosystem economic benefit (1811 USD ha-1), and integrated compensation benefit (17,548 USD ha-1). This study demonstrates the potential benefits of long-term optimizing of N management to maintain high maize yields and grain quality, to reduce various environmental impacts and health impacts, and to enhance economic benefits. These benefits can be further enhanced when Opt. N was combined with advanced agronomic management practices. The results also suggest that reducing the optimal N rate from 160 to 145 kg N ha-1 is achievable to further reduce the negative impacts while maintaining high crop productivity. In conclusion, optimizing the N management is essential to promote sustainable summer maize production on the NCP.

Engineered Biomaterials for Reducing Phosphorus and Nitrogen Levels from Downstream Water of Aquaculture Facilities

The United States (U.S.) has a nearly USD 17 billion seafood trade deficit annually. However, the U.S. aquaculture industry faces strict micronutrient (e.g., phosphorus and nitrogen) level mandates that negatively impact fish production, especially for the state of Idaho, which produces 70–75% of the nation’s rainbow trout. This study investigates the sustainability benefits of producing engineered biomaterials from lignocellulosic-based feedstocks near collection sites via portable biorefineries for use by fish farms to reduce eutrophication (oversupply of micronutrients) impacts. In this study, sustainability assessments are performed on a case study in southern Idaho, the largest U.S. commercial producer of rainbow trout. The results show that 20 and 60 min of water treatment, using small particle size biomaterial from lodgepole pine, has the highest total phosphorus removal rate, at 150–180 g of phosphorus per 1 metric ton of engineered biomaterials. The results of techno-economic and environmental impacts studies indicate that pinewood-based biomaterials production cost ranges from USD 213 USD 242 per ton and reduces the eutrophication potential by 5–17 kg PO4eq/ton. Additionally, the environmental impact results show that the total greenhouse gas emission for biomaterial production is 47–54 kg CO2eq/ton; however, the used biomaterials after water treatment can be sold for around USD 850 per ton as nutrient-rich soil conditioners. This study concluded that engineered biomaterials from lignocellulosic-based feedstocks could be a sustainable solution to the challenge that aquaculture faces, particularly capturing micronutrients from eutrophic water and reusing them as fertilizers.

Exploring a sustainable rice-cropping system to balance grain yield, environmental footprint and economic benefits in the middle and lower reaches of the Yangtze River in China

Environmental degradation and resource scarcity are serious challenges faced by global rice production. Although rice production is crucial to ensure global food security, it is also one of the principal sources of greenhouse gas (GHG) and reactive nitrogen (Nr) emissions. Exploring rice-cropping systems with a low environmental footprint and high grain yield and economic benefits is a crucial strategy to improve the sustainability of rice production. Here, life cycle assessment was used to compare the performance of middle-season rice (MR), double-season rice (DR) and ratoon rice systems (RR) based on farmer-reported data in the middle and lower reaches of the Yangtze River of China. The average annual grain yields of DR, MR, and RR were 13.68, 8.96 and 11.97 t ha−1, respectively. Although RR produced 12.5% lower grain yield, it had 41.2% lower global warming potential (GWP) and 33.8% smaller eutrophication potential (EP) than DR, which resulted in lower greenhouse gas intensity (GHGI) and reactive nitrogen intensity (NrI). The lower GWP and EP in RR were mainly attributed to lower agricultural inputs, smaller CH4 and N2O emissions and less Nr losses. Compared with MR, RR had higher GWP and EP, but significantly higher grain yield (33.6%) in RR contributed to lower GHGI and similar NrI. In all three cropping systems, CH4 emissions and NH3 volatilization had the highest contributions to GWP and EP, respectively. Compared with the other two cropping systems, RR exhibited the highest net economic income (NEI), benefit-cost ratio and eco-efficiency. Overall, our results suggested that RR is a sustainable rice-cropping system that can coordinate grain yield, environmental footprint and economic benefits.

Potential mitigation of environmental impacts of intensive plum production in southeast China with maintenance of high yields: Evaluation using life cycle assessment.

Intensive plum production usually involves high yields but also high environmental costs due to excessive fertilizer inputs. Quantitative analysis of the environmental effects of plum production is thereby required in the development of optimum strategies to promote sustainable fruit production. We collected survey questionnaires from 254 plum production farms in Zhao'an county, Fujian province, southeast China to assess the environmental impacts by life cycle assessment (LCA) methodology. The farms were categorized into four groups based on yield and environmental impacts, i.e., LL (low yield and low environmental impact), LH (low yield but high environmental impact), HL (high yield but low environmental impact), and HH (high yield and high environmental impact). The environmental impacts, i.e., average energy depletion, global warming, acidification, and eutrophication potential in plum production were 18.17 GJ ha-1, 3.63t CO2 eq ha-1, 42.18kg SO2 eq ha-1, and 25.06kg PO4 eq ha-1, respectively. Only 19.7% of farmers were in the HL group, with 13.3% in the HH group, 39.0% in LL, and 28.0% LH. Plum yields of the HL group were 109-114% higher than the mean value of all 254 farms. Additionally, the HL group had a lower environmental impact per unit area compared to the overall mean value, with a reduction ranging from 31.9% to 36.7%. Furthermore, on a per tonne of plum production basis, the energy depletion, global warming potential, acidification potential, and eutrophication potential of HL farms were lower by 75.4%, 75.0%, 75.6%, and 75.8%, respectively. Overall, the total environmental impact index of LL, LH, HL, and HH groups were 0.26, 0.42, 0.06, and 0.21, respectively. Excessive fertilizer N application was the main source of the environmental impacts, the potential to reduce fertilizer N rate can be achieved without compromising plum yield by studying the HH group. The results provide an important foundation for enhancing the management of plum production, in order to promote 'green' agricultural development by reducing environmental impacts.

Environmental Impact Assessment of Apple Production under Different Production Modes and in Different Regions in China

The full-fruit period in apple orchards has the greatest environmental impact during the whole apple life cycle, and the characteristics of apple planting and high investment in agricultural materials in China aggravate the impact of this stage on the environment. The life cycle assessment (LCA) method was used to study the resource use (RU), global warming potential (GWP), environmental acidification potential (AP), and eutrophication potential (EP) of apple orchards in the full-fruit period. These apple orchards are, smallholder orchards (SO) in the Bohai Bay area (BH), commercial orchards (CO) in the Bohai Bay area, smallholder orchards in the Loess Plateau area (LP), and commercial orchards in the Loess Plateau area. The results showed that the RU of commercial orchards was 23.87% higher than that of smallholder orchards, the EP of smallholder orchards was 72.36% higher than that of commercial orchards, the RU of the Bohai Bay was 19.70% higher than that of the Loess Plateau, the EP in the Loess Plateau was 35.93% higher than that in Bohai Bay.

Single Score Environmental Performances of Roof Coverings

Buildings and constructions are responsible for a great amount of global energy and energy-related carbon dioxide emissions. Because of these negative impacts, there is an increase in Life cycle assessment research in the construction sector to measure these effects and evaluate the sustainability performances. Life cycle assessment is a tool that can facilitate the decision-making process in the construction sector for material selection, or for the selection of the best environmentally friendly option in the building component level or building level. In this study, a comparative life cycle assessment analysis is conducted among 12 roof coverings of 1 square meter in the 60-year lifetime of a building. Impact categories that are available in environmental product declarations and included in this study are the global warming potential, ozone depletion potential, acidification potential, eutrophication potential, photochemical ozone creation potential, abiotic depletion potential of non-fossils and abiotic depletion potential of fossils resources. To facilitate the decision-making process, panel and monetary weightings are applied to convert environmental product declaration data of seven impact categories into one single-score. Monetary weightings applied in the study are in Euro 2019, differentiating itself from other comparative life cycle assessment studies. The single-score results are ranked and compared. R04 has the best performance for all panel weightings, while for monetary weightings, R03, R07 and R08 have the best performance for EPS, MMG and EVR, respectively. As a result, for 12 roof coverings, the weighted results could not address one single roof-covering material for numerous reasons. Among the weighting methods, panel weighting sets show more similarity in ranking results, while monetary-weighting sets results are more diverse.

Life Cycle Assessment of Post-Combustion CO2 Capture and Recovery by Hydrophobic Polypropylene Cross-Flow Hollow Fiber Membrane Contactors with Activated Methyldiethanolamine

The present study evaluated the environmental impacts of post-combustion CO2 capture and recovery via membrane–gas absorption processes. We have used SimaPro v.9 packages with the Ecoinvent v3.5 database employing two different methods, ReCiPe 2016 Endpoint (H) and Midpoint (H), considering a fundamental methodological framework to determine the most environmentally friendly experimental condition. Life cycle impact categories were examined and assessed supposing a functional unit of 1 kgCO2/h recovered. Fourteen environmental impact categories including global warming, ozone depletion, eutrophication, and toxicity potentials have been evaluated within the context of a gate-to-gate approach focusing on only the process stage. Simulation results showed that the maximum liquid flow rate, sweep helium flow rate together with the minimum solvent concentration demonstrated the highest impact on human health, ecosystem, and resources. The usage of pure methyldiethanolamine (MDEA) activated by piperazine as a reactive absorbent provided the lowest environmental impact due to the elimination of the energy needed to heat and evaporate water present in aqueous absorbent solutions and the prevention of the excess water consumption depending on meeting the water needed for reactive absorption of CO2 in tertiary amine MDEA from simulated humidified flue gas stream. The study highlights the importance of LCA in the determination of an environmentally more sustainable condition during the capture and recovery of post-combustion CO2 by gas absorption and stripping using membrane contactors in tertiary amine MDEA.

Spatiotemporal analysis of water quality indicators in a watershed in Brazilian Cerrado

Abstract Tools for monitoring and evaluating water quality are necessary for the measurement of environmental impacts arising from diverse activities in hydrographic basins. Here, the water quality of the Verdinho River, an important hydrographic basin of Brazilian Cerrado, was evaluated using 16 physical–chemical parameters. The indicators with major interference with water quality were identified by principal component analysis (PCA), in order to suggest less laborious and less expensive assessments. The water quality index (WQI) was applied considering seasonal changes and the analysis of eutrophication potential was determined using the trophic state index (TSI). The concentrations of chemical water quality indicators (e.g., nitrate, total phosphorus, total nitrogen) increased mainly in the rainy season. The PCA explained 73.69% of the variance among the data. Total solids, temperature, turbidity, alkalinity, biochemical oxygen demand, hardness, total phosphorus, nitrite, nitrate and ammonia showed strong correlations. The water quality was classified in the ‘good’ category in most of the evaluations. The TSI presented conditions between mesotrophic and eutrophic. The indicators that are analyzed seasonally and spatially are associated with natural and anthropic factors. The future implementation of a water catchment project water depends on environmental planning strategies to reduce the impacts on the water quality of this hydrographic basin.

Compression of input to total output index and environmental impacts of dryland and irrigated wheat production systems

Today, reducing costs, energy, and environmental impacts, in addition to increasing technical performance, are important goals of agriculture and industry sectors. The present study was conducted with the aim of evaluating the status of environmental indicators of the dryland and irrigated wheat production systems. The required information was obtained from 100 wheat production farms through questionnaire method. After calculating the input and outputs, environmental indicators were calculated by life cycle assessment method. A novel index as “input to total output” was formulated to evaluate the efficiency of using/consuming each input in production systems. In average, the values of input to total output index for all inputs in dryland wheat production system were 1.45 times higher than those of the irrigated system. In average, the environmental indicators of the dryland wheat production systems had 1.85 times higher values than those of the irrigated systems. Marine water ecotoxicity was the indicator with highest value for both production systems as 12.33 × 104 and 8.22 × 104 kg 1.4 DB eq and the indicator with lowest value was ozone layer depletion as 3.54 × 10−5 and 1.90 × 10−5 kg CFC −11 eq for dryland and irrigated wheat production systems, respectively. In both production systems, nitrogen had the greeted share in all environmental indicators from 15 to 80 %, except for eutrophication and acidification potential which were mostly affected by emissions of wheat farms.