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In the context of global warming and low water and fertilizer utilization efficiency in vineyards, identifying the driving factors of global warming potential (GWP) and proper irrigation and fertilization management strategies are crucial for high grape yields and emission reduction. In this experiment, drip fertigation technology was used, including three irrigation levels (W3 (100% M, where M is the irrigation quota), W2 (75% M) and W1 (50% M)) and four fertilization levels (F3 (648 kg hm-2), F2 (486 kg hm-2), F1 (324 kg hm-2) and F0 (0 kg hm-2)). Traditional furrow irrigation and fertilization (CG) and rainfed (CK) treatments were used as control treatments. The results indicated that under the drip fertigation system, fertilization significantly increased the grape leaf chlorophyll relative content (SPAD) and leaf area index (LAI) within a fertilizer application of 0-486 kg hm-2. Irrigation primarily had a direct positive effect on the water-filled pore space (WFPS) in the 0-60 cm soil layer, and the residual soil nutrient content was mainly affected by fertilization. The vital stage for reducing greenhouse gas emissions was the fruit-inflating and fruit-rendering stages. The CG treatment not only failed to ensure high grape yield but also adversely affected the soil environment and the reduction of greenhouse gas emissions in the vineyard. Fertilization had a direct positive effect on the grape SPAD, LAI, yield, and soil residual nutrient content. GWP was primarily directly driven by SPAD, WFPS, and soil residual nutrient content, while grape yield was primarily directly driven by fertilization and SPAD. In conclusion, the W2F2 treatment (25 % reduced irrigation and 486 kg hm-2 of fertilization) of drip fertigation in the vineyard was the preferred irrigation and fertilizer management strategy for maintaining good vine vigor and balancing grape yield and environmental benefits.

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Biochar application is an effective strategy to address Agro-climatic challenges. However, the agro-environmental impacts of different biochar technology models are lacking of systematic summaries and reviews. Therefore, this paper comprehensively reviews recent developments derived from published literature, delving into the economic implications and environmental benefits of three distinct process namely technologies-pyrolysis, gasification, and hydrothermal carbonization. This paper specifically focuses on the agricultural life cycle assessment (LCA) methodology, and the influence of biochar preparation technologies and products on energy consumption and agricultural carbon emissions. LCA analysis shows that process and feedstock pose a predominant role on the properties and production rate of biochar, while gasification technology exhibits excellent economic attributes compared to the other two technologies. Biochar applications in agricultural has the beneficial effect of sequestering carbon and reducing emissions, especially in the area of mitigating the carbon footprint of farmland. However, the complexity of the composition of the prepared feedstock and the mismatch between the biochar properties and the application scenarios are considered as potential sources of risks. Notably, mechanism of carbon sequestration and emission reduction by soil microorganisms and agro-environmental sequestration by biochar application remains unclear, calling for in-depth studies. We review novel aspects that have not been covered by previous reviews by comparing the technical, economic, and environmental benefits of pyrolysis, gasification, and hydrothermal carbonization systematically. Overall, this study will provide a valuable framework to environmental implications of biochar preparation, application, and life cycle assessments.

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This work aimed to synthesize and characterize the calcium acetate monohydrate (Ca(CH3COO)2·H2O) from the exothermic reaction between CaCO3 powder derived from cockle shells with three different acetic acids (8, 10, and 12 mol L-1) concentrations by the rapid and easy process without pH and temperature control to lead to cheap chemical production. The physicochemical characteristics of all synthesized Ca(CH3COO)2·H2O samples are investigated based on the chemical compositions, crystal structures, vibrational characteristics, morphologies, and thermal behavior to confirm the target compound. A suitable concentration of 10 mol L-1 CH3COOH was chosen to produce Ca(CH3COO)2·H2O with the highest yield (96.30 %), maximum calcium content (96.2 % CaO) with lower impurities, and time consumption of 17 h. The calcium acetate product obtained from cockle shells in this work shows differences in thermal stability, morphological structure purity, %yield, and metal contamination with those reported obtained from other sources and another shell type in the previous work. This research investigates the transformation of cockle shell waste into CaCO3 for the production of calcium acetate, aiming to address environmental sustainability concerns by reducing the use of calcium ore resources and greenhouse gas emissions.

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Quercus gilva, an evergreen tree species in Quercus section Cyclobalanopsis, is an ecologically and economically valuable species in subtropical regions of East Asia. Predicting the impact of climate change on potential distribution of Q. gilva can provide a scientific basis for the conservation and utilization of its genetic resources, as well as for afforestation. In this study, 74 distribution records of Q. gilva and nine climate variables were obtained after data collection and processing. Current climate data downloaded from WorldClim and future climate data predicted by four future climate scenarios (2040s SSP1-2.6, 2040s SSP5-8.5, 2060s SSP1-2.6, and 2060s SSP5-8.5) mainly based on greenhouse gases emissions of distribution sites were used in MaxEnt model with optimized parameters to predict distribution dynamics of Q. gilva and its response to climate change. The results showed that the predicted current distribution was consistent with natural distribution of Q. gilva, which was mainly located in Hunan, Jiangxi, Zhejiang, Fujian, Guizhou, and Taiwan provinces of China, as well as Japan and Jeju Island of South Korea. Under current climate conditions, precipitation factors played a more significant role than temperature factors on distribution of Q. gilva, and precipitation of driest quarter (BIO17) is the most important restriction factor for its current distribution (contribution rate of 57.35%). Under future climate conditions, mean temperature of driest quarter (BIO9) was the essential climate factor affecting future change in potential distribution of Q. gilva. As the degree of climatic anomaly increased in the future, the total area of predicted distribution of Q. gilva showed a shrinking trend (decreased by 12.24%-45.21%) and Q. gilva would migrate to high altitudes and latitudes. The research results illustrated potential distribution range and suitable climate conditions of Q. gilva, which can provide essential theoretical references for the conservation, development, and utilization of Q. gilva and other related species.

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Biochar as agricultural soil amendment has been extensively investigated for its potential to sequester carbon, to mitigate greenhouse gases (GHGs) emissions, to enhance soil fertility and enhance crop yields. In this study, we investigated the impact of varying N fertilization rates in conjunction with biochar on soil properties, crop yield, and GHGs emissions in a rapeseed (Brassica napus L.)-soybean (Glycine max (L.) Merrill) rotation system for one year. Biochar and N fertilizer were applied following a factorial combination design of three biochar (B0: 0 t hm-2, B1: 15 t hm-2, and B2: 60 t hm-2) and three N fertilizer application rates (H: 100%, M: 75%, and L: 50% of the conventional application rates). In general, there was no significant effect of N fertilizer and its interaction with biochar application on soil water content, pH, and total carbon content, but the addition of biochar significantly increased these parameters (P < 0.05). The yield of both crops were significantly augmented by biochar up to 75% compared to using N fertilization alone, potentially due to enhanced N use efficiency. However, biochar significantly increased the cumulative N2O and CH4 emissions by as much as 2.2 times and 19 times, respectively, during the rapeseed season, thereby elevating the global warming potential (GWP) and the yield-scaled GWP. Nevertheless, the significantly increased soil carbon content following biochar addition might boost soil carbon sequestration, which could counterbalance the escalating GWP induced by GHGs. Therefore, we recommend a comprehensive and long-term evaluation of biochar's impact by considering crop yield, GHGs emissions, and carbon sequestration in agricultural systems to ensure sustainable agricultural management.

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The rise of plasticulture as mulching material in farming systems has raised concerns about microplastics (MPs) in the agricultural landscape. MPs are emerging pollutants in croplands and water systems with significant ecological risks, particularly over the long term. In the soil systems, MPs polymer type, thinness, shape, and size induces numerous effects on soil aggregates, dissolved organic carbon (C), rapidly oxidized organic C, microbial biomass C, microbial biomass nitrogen (N), microbial immobilization, degradation of organic matter, N cycling, and production of greenhouse gas emissions (GHGs), thereby posing a significant risk of impairing soil physical and biochemical properties over time. Further, toxic chemicals released from polyethylene mulching (PMs) might indirectly harm plant growth by affecting soil wetting-drying cycles, releasing toxic substances that interact with soil matrix, and suppressing soil microbial activity. In the environment, accumulation of MPs poses a risk to human health by accelerating emissions of GHGs, e.g., methane and carbon dioxide, or directly releasing toxic substances such as phthalic acid esters (PAEs) into the soils. Also, larger sizes MPs can adhere to root surface and block stomata could significantly change the shape of root epidermal cells resulting in arrest plant growth and development by restricting water-nutrient uptake, and gene expression and altering the biodiversity of the soil pollutants. In this review, we systematically analyzed the potential risks of MPs to the soil-plant and human body, their occurrence, abundance, and migration in agroecosystems. Further, the impacts of MPs on soil microbial function, nutrient cycling, soil C, and GHGs are mechanistically reviewed, with emphasis on potential green solutions such as organic materials amendments along with future research directions for more eco-friendly and sustainable plastic management in agroecosystems.

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Nitrogen-rich materials such as poultry litter (PL) contributes to substantial N and C loss in the form of ammonia (NH3) and carbon dioxide (CO2) during composting. Biochar can act as a sorbent of ammonia (NH3) and CO2 emission released during co-composting. Thus, co-composting poultry litter with rice husk biochar as a bulking agent is a good technique to mitigate NH3 volatilization and CO2 emission. A study was conducted to evaluate the effects of composting the mixtures of poultry litter with rice husk biochar at different ratios on NH3 and CO2 emissions. Four mixtures of poultry litter and rice husk biochar at different rate were composted at 0:1, 0.5:1, 1.3:1 and 2.3:1 ratio of rice husk biochar (RHB): poultry litter (PL) on a dry weight basis to achieve a suitable C/N ratio of 15, 20, 25, and 30, respectively. The results show that composting poultry litter with rice husk biochar can accelerate the breakdown of organic matter, thereby shortening the thermophilic phase compared to composting using poultry litter alone. There was a significant reduction in the cumulative NH3 emissions, which accounted for 78.38%, 94.60%, and 97.30%, for each C/N ratio of 20, 25, and 30. The total nitrogen (TN) retained relative was 75.96%, 85.61%, 90.24%, and 87.89% for each C/N ratio of 15, 20, 25, and 30 at the completion of composting. Total carbon dioxide lost was 5.64%, 6.62%, 8.91%, and 14.54%, for each C/N ratio of 15, 20, 21, and 30. In addition, the total carbon (TC) retained were 66.60%, 72.56%, 77.39%, and 85.29% for 15, 20, 25, and 30 C/N ratios and shows significant difference as compared with the initial reading of TC of the compost mixtures. In conclusion, mixing and composting rice husk biochar in poultry litter with C/N ratio of 25 helps in reducing the NH3 volatilization and CO2 emissions, while reducing the overall operational costs of waste disposal by shortening the composting time alongside nitrogen conservation and carbon sequestration. In formulating the compost mixture with rice husk biochar, the contribution of C and N from the biochar can be neglected in the determination of C/N ratio to predict the rate of mineralization in the compost because biochar has characteristic of being quite inert and recalcitrant in nature.

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Constructed wetlands (CWs) are widely used for non-point source pollution control and water environmental quality improvement. Though it is effective in water quality improvement under most conditions, the overall impacts on the ecological environment in terms of greenhouse gases (GHGs) emissions is a growing concern. Besides, large area requirement has limited further applications of the technology in urban areas. A novel assessment tool of integrating grey water footprint into the ecological footprint framework is established for the assessment of pilot-scale CWs. Findings are compared with a natural riparian wetland adjacent to the researched CWs which were monitored simultaneously. Results demonstrated the CWs had relatively good water quality polishing performance, especially for nitrogen removal. Nonetheless, a large amount of CO2 and some CH4 and N2O emissions were recorded. Meanwhile, a substantial amount of CO2 was also sequestrated by wetland plants via photosynthesis. The strong reducing environment of the CWs inhibited CO2 and N2O generation to a great extent. Calculation of all gaseous emissions and sequestration in CO2 equivalents demonstrated that CWs are an efficient carbon sink. By contrast, the natural wetland was a carbon source because of the high emission of CO2 and N2O under its weak reducing environment conditions and low gross primary production. The carbon footprints of the constructed and natural wetlands were -24.24 and 12.99 gha respectively. Modified ecological footprint values were determined by integrating the carbon footprint, water footprint and build-up lands footprint, and a value of -24.36 gha was obtained for the CWs and 12.99 gha for the natural wetlands. The results indicated that the CWs had substantial beneficial impacts on the ecological environment. On account of the multifunctional service values provided by the CWs, a typical paradigm for water pollution remediation and carbon sequestration was presented for ecological and environmental governance, especially for riparian areas.

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Estuaries, considered as the important carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4) sources to the atmosphere, are increasingly affected by near-bottom hypoxia. However, the impact of estuarine hypoxic zone development on GHGs production and discharge remains poorly understood due to the seasonal and spatially distributed heterogeneity of estuarine hypoxia occurrence and the lack of simultaneous monitoring of the distribution of bottom hypoxic waters and the vertical distribution of GHGs. Here, we conducted high spatial resolution vertical stratification sampling and analysis of water column GHGs in the Pearl River Estuary (PRE), a large estuary with frequent hypoxia in recent years. Our results showed that Pearl River runoff is the main source of GHGs in the PRE. Strong nitrification is an important N2O production mechanism in the PRE. In situ generation of water and resuspension of surface sediments were the main sources of CH4 in bottom water, while massive organic matter (OM) mineralization is the main driver of CO2 in bottom water. The development of a hypoxic zone in the PRE significantly increased the concentration of N2O and CH4 in the bottom water and thus increased air-water fluxes. The air-water fluxes of N2O, CH4 and CO2 of PRE in summer were 31.9 ± 7.5 µmol m-2 d-1, 192.5 ± 229.4 µmol m-2 d-1 and 51.9 ± 14.1 mmol m-2 d-1, respectively. This study reveals that GHGs fluxes from estuarine waters to the atmosphere will increase significantly with increasing eutrophication caused by human activities and the expansion of hypoxic zones in estuarine waters.

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This study aimed to explore the roles of selenite (Se) on nitrogen conservation and greenhouse gases (GHGs) mitigation during the composting process. Six levels of Se(IV) dosages (i.e. 0, 2, 4, 6, 8 and 10 mg/kg) were examined for 80-day composting of goat manure and wheat straw mixtures, where the different blending proportions were marked as T1 (Control), T2, T3, T4, T5 and T6, respectively. The results showed that adding Se(IV) was beneficial for reducing NH3 by 3.50-42.41% by buffering pH and promoting nitrification. For N2O, it showed different responses to different Se(IV) dosages, and it was increased by 29.62-71.29% in T2-T4 but reduced by 30.45-69.54% in T5-T6. Methane (CH4), another main component of GHGs, was increased by 1.35-107.42% by adding 2-10 mg/kg Se(IV). To further evaluate the effect of Se(IV) on GHGs, global warming potential value was calculated, which was 103.32-499.80 and minimum value was in T5. Furthermore, the physicochemical indexes, especially temperature and OM, had vital effects on microbial community. Overall, the results obtained from this study demonstrated that the application of Se (IV) in composting was reasonable to generate Se-rich organic fertilizer, and the 8 mg/kg was suggested from perspectives of nitrogen conservation and GHGs reduction.

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In situ coal fires significantly pollute the environment in many countries of the world. Monitoring these pollutants is challenging due to extensive area coverage and spatial variations. Thus, the present study demonstrates the method of deriving the spatial and temporal profiles of columnar density of three major greenhouse gases (carbon monoxide (CO), sulfur dioxide (SO2), and nitrogen dioxide (NO2)) in an in situ coal fire region (Jharia coalfield (JCF), India) using high-resolution satellite data (TROPOMI) of the European Space Agency (ESA). The study also demonstrates a new methodology for estimating greenhouse gas emissions from in situ coal burning. JCF is one of the significant polluted mining regions with multiple in situ coal fire pockets. The columnar density of the gaseous pollutants in the mining region was compared with the same in the rural, urban, and forest regions to identify the major emission inventories. The study results indicated that coal fire is the major source of CO emission in the region, as the CO was high in the fire regions compared to that of the non-fire regions. But, the major source of NO2 is the traffic, as the NO2 was high in the city area as compared to other regions. The spatial profile of SO2 does not reveal the specific emission sources. The study results indicated that TROPOMI onboard satellite sensors could be effectively used for deriving the spatial profiles of greenhouse gaseous in coal fire regions, which further assist in identifying the emission inventories. Furthermore, the satellite-based Earth observations offer information to understand and manage the greenhouse gas emissions over a large area.

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Domestic wastewater and wastewater treatment plants (WWTPs) are key emitters of greenhouse gases (GHGs). Quantifying these emissions in the present and future is crucial to tackle global climate change issues. As a developing country with few rural and urban wastewater treatment facilities, Nepal may have a unique opportunity to reduce future GHGs emissions by a proper selection of wastewater treatment technology. In this paper, the authors used Python programming to estimate the GHGs emissions from the domestic wastewater sector in Nepal under various technological development scenarios for 2020 to 2040 using the refined 2019 estimation methodology developed by Inter-governmental Panel on Climate Change (IPCC). Results show total equivalent CO2 emission of 3829.43 and 4523.65 Gigagrams in 2020 and 2040, respectively. The 2020 value is seven times greater than Nepal's 2017 national estimates because this study considered rural population and updated methodology. Comparing the technology development scenarios with the Business as Usual scenario, the highest GHGs reduction could be achieved by hybrid constructed wetlands (69.20%) followed by a combined anaerobic and aerobic system with biogas recovery for energy generation (61.72%). Further accuracy may be attained only through the actual measurement of WWTPs emissions and country-specific emission factors. Thus, this paper proposes GHGs estimation of future scenarios portraying urban and rural populations may be invaluable to policymakers of GHGs mitigation for selection of feasible WWTPs, especially in developing countries with limited wastewater treatment facilities and wastewater activity data.

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Composting is very robust and efficient for the biodegradation of organic waste; however secondary pollutants, namely greenhouse gases (GHGs) and odorous emissions, are environmental concerns during this process. Biochar addition to compost has attracted the interest of scientists with a lot of publication in recent years because it has addressed this matter and enhanced the quality of compost mixture. This review aims to evaluate the role of biochar during organic waste composting and identify the gaps of knowledge in this field. Moreover, the research direction to fill knowledge gaps was proposed and highlighted. Results demonstrated the commonly referenced conditions during composting mixed biochar should be reached such as pH (6.5-7.5), moisture (50-60%), initial C/N ratio (20-25:1), biochar doses (1-20% w/w), improved oxygen content availability, enhanced the performance and humification, accelerating organic matter decomposition through faster microbial growth. Biochar significantly decreased GHGs and odorous emissions by adding a 5-10% dosage range due to its larger surface area and porosity. On the other hand, with high exchange capacity and interaction with organic matters, biochar enhanced the composting performance humification (e.g., formation humic and fulvic acid). Biochar could extend the thermophilic phase of composting, reduce the pH value, NH3 emission, and prevent nitrogen losses through positive effects to nitrifying bacteria. The surfaces of the biochar particles are partly attributed to the presence of functional groups such as Si-O-Si, OH, COOH, CO, C-O, N for high cation exchange capacity and adsorption. Adding biochars could decrease NH3 emissions in the highest range up to 98%, the removal efficiency of CH4 emissions has been reported with a wide range greater than 80%. Biochar could absorb volatile organic compounds (VOCs) more than 50% in the experiment based on distribution mechanisms and surface adsorption and efficient reduction in metal bioaccessibilities for Pb, Ni, Cu, Zn, As, Cr and Cd. By applicating biochar improved the compost maturity by promoting enzymatic activity and germination index (>80%). However, physico-chemical properties of biochar such as particle size, pore size, pore volume should be clarified and its influence on the composting process evaluated in further studies.

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Recently, the world has faced environmental disasters mainly due to global warming. One of the main reasons for global temperature imbalances is the greenhouse gases (GHG) that soar the atmosphere's heat. The major aim of the current study is to explore whether the livestock population is the main contributor to GHG emission through econometric estimations. In this study, we examine the impact of livestock population with other explanatory variables-GDP per capita, Economic Complexity Index (ECI), ecological balance, and total patent applications-over GHG emission of 25 countries responsible for 76% of GHG emission between 1990 and 2017. To investigate the relationship of variables, Fully modified ordinary least squares (FMOLS) and dynamic ordinary least squares (DOLS) are used, as well as panel causality. Also, the relationship is examined by using the responsiveness scores (RS) approach. The empirical results reveal that all variables have a causal relationship with GHG emission. GDP per capita, ECI, and livestock population enhance the GHG emission whereas square of GDP per capita and ecological balance decline the environmental degradation. The paper demonstrates that the environmental Kuznets curve is valid and supports the literature. Lastly, the RS estimation results reveal that the livestock population is causing higher GHG emissions for all countries in the analysis, contrary to other independent variables. Governments should promote carbon-neutral meat production facilities instead of traditional beef farms to live in a more sustainable world. In the future, countries that invest in research and development (R&D) for less emission meat production will have a comparative advantage in the sustainable international meat market.

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Three bioreactors were inoculated with Polar Arctic Circle-activated sludge, started-up and operated for 150 days at 8, 15 and 26 °C. Removal performances and granular conformation were similar at steady-state, but higher stability from start-up was found when operating at 8 °C. Important changes in the eukaryotic and prokaryotic populations caused by operational temperature were observed, being fungi dominant at 8 °C and 15 °C, while that ciliated organisms were found at 26 °C. The qPCR results showed higher copies of bacteria, and nitrifiers and denitrifying bacteria at cold temperature. The emission of nitrous oxide was linked directly with temperature and the involved microorganisms. This study represents a proof of concept in performance, greenhouse gas emission, granular formation and the role of the Polar Arctic Circle microbial population in AGS technology under different temperatures with the aim to understand the effect of seasonal o daily changes for implementation of AGS at full-scale.

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We developed a three-dimensional model to study the dynamics of carbon dioxide (CO2) emission from a subtropical drinking water reservoir. The quantitative effects of dissolved CO2 concentration on phytoplankton growth were coupled in an inorganic carbon module. Water quality monitoring was carried out to calibrate and validate the model. The simulated surface CO2 concentrations showed no significant difference between seasons (p>0.05). Regarding the spatial distribution, high CO2 concentrations were observed in the inflow and dam regions (p<0.05). Four scenarios of different atmospheric CO2 pressures and eutrophic levels were simulated to test the following hypotheses: (1) eutrophication will reverse the carbon budgets in reservoir systems and (2) rising CO2 levels will increase phytoplankton biomass. The results showed that water quality improvements will promote the emission of CO2 into the atmosphere. Simultaneously, the elevated CO2 in the air will stimulate algal biomass, especially in nutrient-rich systems. The systematic analysis of carbon cycling revealed the different internal transformation rates under different scenarios and showed that 32% of carbon was removed via CO2 emission and carbon burial. The interaction provides a novel direction to understand the feedback loops between aquatic ecosystems and increasing CO2 pressure in the future.

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Apart from industrial activities, our eating habits also have a significant environmental cost associated with crop cultivation, manufacturing processes, packaging, refrigeration, transport cooking and waste management. In a context of growing social awareness of the role of different dietary choices in the environment, the review of different alternatives on the road to a healthy and sustainable diet should integrate relevant information on the nutritional quality of different eating habits. Since dietary choices have an effect on environmental sustainability and human health, a literature review on different dietary choices has been conducted to determine the differences in carbon footprint and nutritional quality identifying the main hotspots trying to give advice towards the identification of sustainable diets. After applying a set of criteria for reference selection, 21 peer-reviewed studies have been analysed in detail, allowing the comparison of 66 dietary scenarios. We identified that the so-called Mediterranean and Atlantic diets present high nutritional scores and low carbon footprints. On the contrary, the dietary choices identified in northern and Western Europe, as well as in the United States, have the highest carbon footprints, highlighting the contribution of dairy products as a basic source of high-quality nutrients and protein. Broadly speaking, dietary choices rich in vegetables (e.g., vegan, vegetarian as well as Indian and Peruvian) have a better environmental profile than those rich in meat (mainly ruminant meat). In line with these findings, the shift in meat consumption habits from beef and veal to chicken, pork and poultry, the introduction of alternative foods to animal protein (e.g. quinoa) and the consumption of olive oil as a major source of vegetable oil may be compatible with a healthier and more environmentally friendly diet. However, the complete elimination of meat and dairy products from the daily diet may not be feasible in case the supply of some micronutrients (e.g., calcium and vitamin D) is not guaranteed. Limitations were identified in the consulted studies related to the consideration of the different system boundaries, as well as underlying uncertainties related to data sources. Therefore, efforts should be made to develop consistent and agreed-upon methods for estimating both the carbon footprint and nutritional quality scores.

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A pilot-scale upflow anaerobic sludge blanket (UASB)-downflow hanging sponge system (DHS) combined with an anaerobic baffled reactor (ABR) and a settling tank (ST) was installed in a natural rubber processing factory in South Vietnam and its process performance was evaluated for 267days. The UASB reactor achieved a total removal efficiency of 55.6±16.6% for chemical oxygen demand (COD) and 77.8±10.3% for biochemical oxygen demand (BOD) with an organic loading rate of 1.7±0.6kg-COD·m-3·day-1. The final effluent of the proposed system had 140±64mg·L-1 of total COD, 31±12mg·L-1 of total BOD, and 58±24mg-N·L-1 of total nitrogen. The system could significantly reduce 92% of greenhouse gas emissions and 80% of hydraulic retention times compared with current treatment systems.

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We used a three-dimensional model to assess the dynamics of diffusive carbon dioxide flux (F(CO2)) from a hydroelectric reservoir located at Amazon rainforest. Our results showed that for the studied periods (2013 summer/wet and winter/dry seasons) the surface averaged F(CO2) presented similar behaviors, with regular emissions peaks. The mean daily surface averaged F(CO2) showed no significant difference between the seasons (p>0.01), with values around -1338mg Cm-2day-1 (summer/wet) and -1395mg Cm-2day-1 (winter/dry). At diel scale, the F(CO2) was large during the night and morning and low during the afternoon in both seasons. Regarding its spatial distribution, the F(CO2) showed to be more heterogeneous during the summer/wet than during the winter/dry season. The highest F(CO2) were observed at transition zone (-300mg Cm-2h-1) during summer and at littoral zone (-55mg Cm-2h-1) during the winter. The total CO2 emitted by the reservoir along 2013 year was estimated to be 1.1Tg C year-1. By extrapolating our results we found that the total carbon emitted by all Amazonian reservoirs can be around 7Tg C year-1, which is 22% lower than the previous published estimate. This significant difference should not be neglected in the carbon inventories since the carbon emission is a key factor when comparing the environmental impacts of different sources of electricity generation and can influences decision makers in the selection of the more appropriate source of electricity and, in case of hydroelectricity, the geographical position of the reservoirs.

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Global warming is a worldwide issue with its evident impact across a wide range of systems and sectors. It is caused by a number of greenhouse gases (GHGs) emissions, in which food system has made up of a large part. Recently, reduction of GHG emissions has become an urgent issue to be resolved in the food system. Many governments and organizations are making great endeavors to alleviate the adverse effect of this phenomenon. In this review, methods to reduce the carbon footprint within the life cycle of a food system are presented from the technical, consumption behavior and environmental policies perspectives. The whole food system including raw material acquisition, processing, packaging, preservation, transportation, consumption, and disposal are covered. Improving management techniques, and adopting advanced technology and equipment are critical for every stage of a food system. Rational site selection is important to alleviate the influence of land use change. In addition, environmental choices of packaging stage, reduction in refrigeration dependence, and correct waste treatment are essential to reduce the total carbon footprint of the production. However, only technical methods cannot radically reverse the trend of climate change, as consumption behaviors present a great deal of influence over climate change. Appropriate purchase patterns and substitution within food product categories by low carbon products can reduce GHG emissions. Development of methods to calculate the carbon footprint of every kind of food and its processing technology enable people to make environmental choice. Policy can shape and cultivate the new code of consumption and influence the direction of emerging technology and science. From political perspectives, government intervention and carbon offset are common tools, especially for carbon tax and a real or implicit price of carbon. Finally, by mitigating the methodologies described above, the rate and magnitude of climate changes can be also reduced to some extent.

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