Environmental and energy assessment of the substitution of chemical fertilizers for industrial wastes of ethanol production in sugarcane cultivation in Brazil

Purpose

Vinasse and filter cake are residues of bioethanol processing that are used to be recycled as fertilizers in sugarcane plantation. Studies related to the environmental dimension on this practice are concerned only with the effects on water and soil. The present study examines the systemic effects of replacing chemical fertilizers with vinasse and filter cake on the environmental performance of ethanol, via life cycle assessment (LCA).

Methods

The analysis was carried out by comparing various scenarios structured from two control variables: crop management techniques (manual and mechanized harvesting) and source of nutrients (for supplying the nutritional needs of sugarcane crops): chemical fertilizers, chemical fertilizers + vinasse, and chemical fertilizer + vinasse + filter cake. Impact assessment was carried out in terms of primary energy demand, climate change, terrestrial acidification, freshwater eutrophication, human toxicity, and terrestrial ecotoxicity. LCA has been applied according to both attributional and consequential perspectives. Moreover, a sensitivity analysis was performed in order to verify the effects of the varying amounts of nitrogen (N), phosphorus (P), and potassium (K) in the composition of vinasse on the results obtained for the impact profile.

Results and discussion

From the attributional LCA perspective, the most expressive contributions regarding primary energy demand occurred in terms of depletion of non-renewable fossils. Replacing chemical fertilizers with vinasse and filter cake was beneficial for the environmental performance of ethanol as it reduces climate change, terrestrial acidification, and human toxicity impacts and sustains freshwater eutrophication and terrestrial ecotoxicity unaltered in relation to scenarios using only fertilizers. In terms of consequential LCA, ethanol’s environmental performance is influenced by the inclusion of the production of calcium fluorite to compensate the hexafluorosilicic acid deficit occurring in conjunction to the decrease of phosphate fertilizer and is compensated by the benefits provided by the general reduced consumption of chemical fertilizers for most of the impact categories. The exception occurred for primary energy demand.

Conclusions

The reuse of residues from bioethanol production—vinasse and filter cake—as primary nutrient suppliers for the cultivation of sugarcane instead of chemical fertilizers is a valid practice that improves the environmental performance of ethanol, even if it is analyzed under a consequential LCA perspective. The transport of these inputs to the field must be managed, however, in order to minimize primary energy demand and climate change impacts.

     

An environmental comparison of biocomposite film based on orange peel-derived pectin jelly-corn starch and LDPE film: LCA and biodegradability

Purpose

A new biodegradable film, based on orange peel-derived pectin jelly and corn starch developed in our labs, was environmentally compared with a low-density polyethylene (LDPE) film. An environmental assessment was realized in two stages to individually determine the environmental impact resulting from production-shaping processes and the biodegradation performance of the films.

Methods

Firstly, a prospective cradle-to-gate life cycle assessment (LCA) was performed using a CML-IA method implemented in SimaPro 8.0.1. Secondly, an aerobic biodegradation was simulated as directly disposing of the films in soil according to ASTM D 5988–03. The functional unit considered in this study was 1 m² of packaging film. The films were compared for impact categories of abiotic depletion (elements and fossil fuel), global warming potential, ozone layer depletion, human toxicity, fresh water aquatic ecotoxicity, marine aquatic ecotoxicity, terrestrial ecotoxicity, photochemical oxidation, acidification, and eutrophication. A Monte Carlo simulation was realized to determine the uncertainty levels. According to impact assessment results and major sources of uncertainties, two predictive improvement scenarios were performed for commercial scale production and compared with biocomposite film at the laboratory scale.

Results and discussion

LCA results show that biocomposite film has a slightly higher impact than LDPE film for all categories with probabilities ranging between 50 and 100 % except for acidification. The categories that have uncertainty (terrestrial ecotoxicity, abiotic depletion (element), photochemical oxidation, human toxicity, and fresh water aquatic ecotoxicity) were mainly resulted from electricity consumption for extrusion and film forming and modified starch addition. These two processes are mainly responsible for the environmental impact of the biocomposite film.

Conclusions

Prospective LCA showed that improvement of the process in this manner would decrease the environmental impact. On the other hand, the maximum level of biodegradation achieved in the biocomposite film is 78.4 %, whereas that for the LDPE film is 40.4 % with CO₂ production rates of 1.97 and 1.17 mmol CO₂/day, respectively.

     

Life cycle impacts of topsoil erosion on aquatic biota: case study on <Emphasis Type="Italic">Eucalyptus globulus</Emphasis> forest

Purpose

This study illustrates the applicability of a framework to conduct a spatially distributed inventory of suspended solids (SS) delivery to freshwater streams combined with a method to derive site-specific characterisation factors for endpoint damage on aquatic ecosystem diversity. A case study on Eucalyptus globulus stands located in Portugal was selected as an example of a land-based system. The main goal was to assess the relevance of SS delivery to freshwater streams, providing a more comprehensive assessment of the SS impact from land use systems on aquatic environments.

Methods

The WaTEM/SEDEM model, which was used to perform the SS inventory, is a raster-based empirical erosion and deposition model. This model allowed to predict the amount of SS from E. globulus stands under study and route this amount through the landscape towards the drainage network. Combining the spatially explicit SS inventory with the derived site-specific endpoint characterisation factors of SS delivered to two different river sections, the potential damages of SS on macroinvertebrates, algae and macrophytes were assessed. In addition, this damage was compared with the damage obtained with the commonly used ecosystem impact categories of the ReCiPe method.

Results and discussion

The relevance of the impact from SS delivery to freshwater streams is shown, providing a more comprehensive assessment of the SS impact from land use systems on aquatic environments. The SS impacts ranged from 15.5 to 1234.9 PDF m³.yr.ha^?1.revolution^?1 for macroinvertebrates, and from 5.2 to 411.9 PDF.m³.yr.ha^?1.revolution^?1 for algae and macrophytes.For some stands, SS potential impacts on macroinvertebrates have the same order of magnitude than freshwater eutrophication, freshwater ecotoxicity, terrestrial ecotoxicity and terrestrial acidification impacts. For algae and macrophytes, most of the stands present SS impacts of the same order of magnitude as terrestrial ecotoxicity, one order of magnitude higher than freshwater eutrophication and two orders of magnitude lower than freshwater ecotoxicity and terrestrial acidification.

Conclusions

The SS impact results allow concluding that the increase of SS in the water column can cause biodiversity damage and that the calculated impacts can have a similar or even higher contribution to the total environmental impact than the commonly used ecosystem impact categories of the ReCiPe method. A wide application of the framework and method developed at a local scale will enable the establishment of a regionalised SS inventory database and a deep characterisation of the potential environmental impacts of SS on local aquatic environments.

     

Life cycle assessment of European anchovy (<Emphasis Type="Italic">Engraulis encrasicolus</Emphasis>) landed by purse seine vessels in northern Spain

Purpose

The main purpose of this article is to assess the environmental impacts associated with the fishing operations related to European anchovy fishing in Cantabria (northern Spain) under a life cycle approach.

Methods

The life cycle assessment (LCA) methodology was applied for this case study including construction, maintenance, use, and end of life of the vessels. The functional unit used was 1 kg of landed round anchovy at port. Inventory data were collected for the main inputs and outputs of 32 vessels, representing a majority of vessels in the fleet.

Results and discussion

Results indicated, in a similar line to what is reported in the literature, that the production, transportation, and use of diesel were the main environmental hot spots in conventional impact categories. Moreover, in this case, the production and transportation of seine nets was also relevant. Impacts linked to greenhouse gas (GHG) emissions suggest that emissions were in the upper range for fishing species captured with seine nets and the value of global warming potential (GWP) was 1.44 kg CO₂ eq per functional unit. The ecotoxicity impacts were mainly due to the emissions of antifouling substances to the ocean. Regarding fishery-specific categories, many were discarded given the lack of detailed stock assessments for this fishery. Hence, only the biotic resource use category was computed, demonstrating that the ecosystems’ effort to sustain the fishery is relatively low.

Conclusions

The use of the LCA methodology allowed identifying the main environmental hot spots of the purse seining fleet targeting European anchovy in Cantabria. Individualized results per port or per vessel suggested that there are significant differences in GHG emissions between groups. In addition, fuel use is high when compared to similar fisheries. Therefore, research needs to be undertaken to identify why fuel use is so high, particularly if it is related to biomass and fisheries management or if skipper decisions could play a role.

     

Life cycle assessment of copper production: a case study in China

Purpose

China is the world’s largest producer and consumer of refined and reclaimed copper because of the rapid economic and industrial development of this country. However, only a few studies have analyzed the environmental impact of China’s copper industry. The current study analyzes the life cycle environmental impact of copper production in China.

Methods

A life cycle impact assessment using the ReCiPe method was conducted to estimate the environmental impact of refined and reclaimed copper production in China. Uncertainty analysis was also performed based on the Monte-Carlo simulation.

Results and discussion

The environmental impact of refined copper was higher than that of reclaimed copper in almost all categories except for human toxicity because of the direct atmospheric arsenic emission during the copper recycling stage. The overall environmental impact for the refined copper production was mainly attributed to metal depletion, freshwater ecotoxicity, marine ecotoxicity, and water depletion potential impact. By contrast, that for the reclaimed copper production was mainly caused by human toxicity impact.

Conclusions

Results show that the reclaimed copper scenario had approximately 59 to 99% more environmental benefits than those of the refined copper scenario in most key categories except for human toxicity, in which a similar environmental burden was observed between both scenarios. The key factors that reduce the overall environmental impact for China’s copper industry include decreasing direct heavy metal emissions in air and water, increasing the national recycling rate of copper, improving electricity consumption efficiency, replacing coal with clean energy sources for electricity production, and optimizing the efficiency of copper ore mining and consumption.

     

Testing environmental and social indicators for biorefineries: bioethanol and biochemical production

Purpose

The article aims to test indicators for assessing the environmental and social impacts of biorefineries. Testing environmental and social impact categories and indicators, and selecting the most suitable ones, will simultaneously contribute to the further development of social life cycle assessment (S-LCA) methodologies while assessing several dimensions of sustainability at biorefineries.

Methods

The work applies two methodologies, environmental LCA (E-LCA) and social LCA (S-LCA), to two hypothetical production processes of second-generation bioethanol and biochemical in two alternative locations (Norway and the USA). Five impact categories were chosen for the E-LCA. The S-LCA was performed in two stages: a generic assessment (top-down approach) using the social hotspot database (SHDB 2013) to screen for potential social issues in the stakeholder group Worker in Norway and the USA and a specific assessment (bottom-up approach) for collecting data and confirming or refuting the SHDB results in the Norwegian case only.

Results and discussion

Bioethanol produced in the Norwegian biorefinery would perform relatively well in relation to climate change targets, with emissions of approximately 11 g CO₂-eq/MJ. The same production process located in the USA would produce emissions of approximately 29 g CO₂-eq/MJ. Other biorefinery products are difficult to compare because of a lack of clear alternatives. Bioethanol and biochemicals produced in the hypothetical USA production process have higher burdens than those from the Norwegian production process in all environmental categories assessed. For both production processes, the main social risks were in the category Health and safety followed by Labor rights and decent work. More detailed investigations in an existing Norwegian biorefinery value chain confirmed some of the risk issues but discarded others, demonstrating the necessity of providing specific data and results for the social dimension.

Conclusions

E-LCA and S-LCA make it possible to highlight the main environmental and social challenges when producing biochemicals. The SHDB has potential as a social screening tool although social indicators are not yet well established. Hence, specific assessment is necessary for validating the results in the social dimension. S-LCA is still in its infancy and needs to be applied in order to develop the best practice. The two methodologies addressed bioethanol and biochemical production performance in two different dimensions (environmental and social), and their combination makes it possible to achieve results that integrate the product-oriented approach with the more location-specific approach.

     

Engineering of an endogenous hexose transporter into a specific D-xylose transporter facilitates glucose-xylose co-consumption in <Emphasis Type="Italic">Saccharomyces cerevisiae</Emphasis>

Background

Engineering of Saccharomyces cerevisiae for the simultaneous utilization of hexose and pentose sugars is vital for cost-efficient cellulosic bioethanol production. This yeast lacks specific pentose transporters and depends on endogenous hexose transporters for low affinity pentose uptake. Consequently, engineered xylose-fermenting yeast strains first utilize D-glucose before D-xylose can be transported and metabolized.

Results

We have used an evolutionary engineering approach that depends on a quadruple hexokinase deletion xylose-fermenting S. cerevisiae strain to select for growth on D-xylose in the presence of high D-glucose concentrations. This resulted in D-glucose-tolerant growth of the yeast of D-xylose. This could be attributed to mutations at N367 in the endogenous chimeric Hxt36 transporter, causing a defect in D-glucose transport while still allowing specific uptake of D-xylose. The Hxt36-N367A variant transports D-xylose with a high rate and improved affinity, enabling the efficient co-consumption of D-glucose and D-xylose.

Conclusions

Engineering of yeast endogenous hexose transporters provides an effective strategy to construct glucose-insensitive xylose transporters that are well integrated in the carbon metabolism regulatory network, and that can be used for efficient lignocellulosic bioethanol production.

     

High-resolution mass spectrometry metabolomics of grape chemical markers to reveal use of not-allowed varieties in the production of Amarone and Recioto wines

Introduction

Grape varieties allowed to produce Amarone della Valpolicella and Recioto DOCG wines are strictly regulated by their disciplinary of production. These are Corvina Veronese and Corvinone grapes, to a lesser extent also Rondinella can be used. The use of other varieties, is not allowed.

Objectives

To identify chemical markers suitable to reveal addition of two not allowed grape varieties to the Corvina/Corvinone blend, such as Primitivo or Negro Amaro.

Methods

The identification of the secondary metabolites of the four grape varieties was conducted by high-resolution mass spectrometry (HRMS) metabolomics. By using the signals of these metabolites the indexes able to identify the presence of Primitivo or Negro Amaro grapes in the Corvina/Corvinone 1:1 blend were calculated.

Results

Indexes of laricitrin (Lr), delphinidin (Dp), and petunidin (Pt) signals were effective to identify the use of 10% Primitivo, while α-terpineol pentosyl-hexoside and linalool pentosyl-hexoside reveal the presence of Negro Amaro in the grape blend.

Conclusions

Varietal markers useful to detect the presence of Primitivo and Negro Amaro in the grape blend were identified by HRMS metabolomics, a method suitable to check the identity of grapes on arrival at the winery, as well as the fermenting musts. The effectiveness of the identified markers in the final wines have to be confirmed. Potentially, a similar approach can be used to reveal analogous frauds performed on other high-quality wines.

     

Life cycle environmental and economic assessment of lead refining in China

Purpose

Lead is one of the most commonly used metals in the past millennium because of its various properties. Moreover, lead is easy to extract and handle. However, the lead industry often encounters strong public opposition because of lead poisoning. This study analyzes the economic and environmental impacts of lead in China, which is the world’s largest producer and consumer of lead.

Methods

Life cycle assessment coupled with life cycle costing was conducted to estimate the environmental and economic impacts of primary and secondary lead refining in China. The internal cost (i.e., raw materials and energy consumption, labor, tax, interest, transport, infrastructure, depreciation, and maintenance) and external market price (i.e., carbon, ammonia, arsenic, COD, lead, mercury, nitrogen oxides, particulates, sulfur dioxide, and land eco-remediation) are considered.

Results and discussion

The overall environmental burden was mainly generated from the human toxicity and marine ecotoxicity categories for both primary and secondary lead refining scenarios because of the direct lead emission in the air and water. For the primary lead refining, the effect on metal depletion represented an additional dominant contribution to the overall environmental burden. The overall economic impact was mainly attributed to lead ore or waste lead, tax, labor fee, and emission cost of ammonia and chromium. In 2013, approximately 5.61 Mt CO₂ eq, 5.81 Mt 1,4-DB eq, 6.59 kt 1,4-DB eq, 7.86 kt 1,4-DB eq, 1.82 Mt·kg Fe eq, 2.37 Mt·kg oil eq, and $9.9 billion were recorded from the lead industry in China in the climate change, human toxicity, freshwater ecotoxicity, marine ecotoxicity, metal depletion, fossil depletion, and economic impact categories, respectively. Additionally, approximately 0.4 kt lead, 18.4 kt sulfur dioxide, 15.6 kt nitrogen oxide, and 6.4 kt particulate emissions in the same year were released from the lead industry in China.

Conclusions

Approximately 57 to 96 % environmental benefits through waste lead recycling in all key categories were observed, whereas its economic benefit was low. The key factors that contribute in reducing the overall environmental and economic impacts include reducing direct lead emissions in air and water, increasing the national recycling rate of lead, replacing coal with clean energy sources for electricity production, improving heavy metal-removing technologies from mining wastewater, and optimizing the efficiency of electricity, lead ore, coal, oxygen, natural gas, and sodium carbonate consumption.

     

Anaerobic microplate assay for direct microbial conversion of switchgrass and Avicel using <Emphasis Type="Italic">Clostridium thermocellum</Emphasis>

Objective

To develop and prototype a high-throughput microplate assay to assess anaerobic microorganisms and lignocellulosic biomasses in a rapid, cost-effective screen for consolidated bioprocessing potential.

Results

Clostridium thermocellum parent Δhpt strain deconstructed Avicel to cellobiose, glucose, and generated lactic acid, formic acid, acetic acid and ethanol as fermentation products in titers and ratios similar to larger scale fermentations confirming the suitability of a plate-based method for C. thermocellum growth studies. C. thermocellum strain LL1210, with gene deletions in the key central metabolic pathways, produced higher ethanol titers in the Consolidated Bioprocessing (CBP) plate assay for both Avicel and switchgrass fermentations when compared to the Δhpt strain.

Conclusion

A prototype microplate assay system is developed that will facilitate high-throughput bioprospecting for new lignocellulosic biomass types, genetic variants and new microbial strains for bioethanol production.

     

Life cycle assessment of Chinese radial passenger vehicle tire

Purpose

We evaluated and quantified the environmental impact of a radial tire product for passenger vehicles throughout the product’s life cycle to identify key stages that contribute to the overall environmental burden and to find ways to reduce these burdens effectively. The study covers all relevant life cycle stages, from the acquisition of raw materials to the production, use, and end of life.

Methods

Data collected onsite in 2014 by one of the largest Chinese tire companies were used in the assessment. The evaluation is presented in terms of individual impact category according to the CML model. Five impact categories (i.e., global warming potential (GWP), acidification potential (AP), photochemical oxidant creation potential (POCP), eutrophication potential (EP), and human toxicity potential (HTP)) were considered. The research was conducted in accordance with the ISO 14040/14044 standards.

Results and discussion

Fuel (gasoline) consumption represents an important contribution to most impact categories, including the GWP, AP, POCP, and EP, during the use stage. The largest contributor to the HTP category is raw material acquisition, mainly because of the impact of the production of organic chemicals. In the end-of-life stage, assuming that 100 % of used tires are collected and recycled to produce reclaimed rubber, the GWP, EP, and HTP contributions are negative, whereas those to the AP and POCP are positive. During the raw material acquisition stage, natural rubber, synthetic rubber, carbon black, and organic chemicals represent the largest contribution to the environmental impact categories. During the production stage, the compound blending process is the largest contributor to the AP and POCP, whereas vulcanizing and testing contribute most to the GWP, EP, and HTP.

Conclusions

Vehicle fuel consumption and its proportion consumed by the tires during the use stage are key factors that contribute to environmental impact during tire life. Further investigations should be conducted to decrease the impact of these factors and improve the environmental performance of tire products.

     

Synthesis of rosmarinic acid analogues in <Emphasis Type="Italic">Escherichia coli</Emphasis>

Objectives

To produce rosmarinic acid analogues in the recombinant Escherichia coli BLRA1, harboring a 4-coumarate: CoA ligase from Arabidopsis thaliana (At4CL) and a rosmarinic acid synthase from Coleus blumei (CbRAS).

Results

Incubation of the recombinant E. coli strain BLRA1 with exogenously supplied phenyllactic acid (PL) and analogues as acceptor substrates, and coumaric acid and analogues as donor substrates led to production of 18 compounds, including 13 unnatural RA analogues.

Conclusion

This work demonstrates the viability of synthesizing a broad range of rosmarinic acid analogues in E. coli, and sheds new light on the substrate specificity of CbRAS.

     

Metabolic response of porcine colon explants to in vitro infection by <Emphasis Type="Italic">Brachyspira hyodysenteriae</Emphasis>: a leap into disease pathophysiology

Introduction

Swine dysentery caused by Brachyspira hyodysenteriae is a production limiting disease in pig farming. Currently antimicrobial therapy is the only treatment and control method available.

Objective

The aim of this study was to characterize the metabolic response of porcine colon explants to infection by B. hyodysenteriae.

Methods

Porcine colon explants exposed to B. hyodysenteriae were analyzed for histopathological, metabolic and pro-inflammatory gene expression changes.

Results

Significant epithelial necrosis, increased levels of l-citrulline and IL-1α were observed on explants infected with B. hyodysenteriae.

Conclusions

The spirochete induces necrosis in vitro likely through an inflammatory process mediated by IL-1α and NO.

     

Production of caffeoylmalic acid from glucose in engineered <Emphasis Type="Italic">Escherichia coli</Emphasis>

Objectives

To achieve biosynthesis of caffeoylmalic acid from glucose in engineered Escherichia coli.

Results

We constructed the biosynthetic pathway of caffeoylmalic acid in E. coli by co-expression of heterologous genes RgTAL, HpaBC, At4CL2 and HCT2. To enhance the production of caffeoylmalic acid, we optimized the tyrosine metabolic pathway of E. coli to increase the supply of the substrate caffeic acid. Consequently, an E. coli–E. coli co-culture system was used for the efficient production of caffeoylmalic acid. The final titer of caffeoylmalic acid reached 570.1 mg/L.

Conclusions

Microbial production of caffeoylmalic acid using glucose has application potential. In addition, microbial co-culture is an efficient tool for producing caffeic acid esters.

     

Extraction of natural products from bark of <Emphasis Type="Italic">Betula pendula</Emphasis> using ionic liquids

Introduction

Aqueous–methanol mixtures have successfully been applied to extract a broad range of metabolites from plant tissue. However, a certain amount of material remains insoluble.

Objectives

To enlarge the metabolic compendium, two ionic liquids were selected to extract the methanol insoluble part of trunk from Betula pendula.

Methods

The extracted compounds were analyzed by LC/MS and GC/MS.

Results

The results show that 1-butyl-3-methylimidazolium acetate (IL-Ac) predominantly resulted in fatty acids, whereas 1-ethyl-3-methylimidazolium tosylate (IL-Tos) mostly yielded phenolic structures. Interestingly, bark yielded more ionic liquid soluble metabolites compared to interior wood.

Conclusion

From this one can conclude that the application of ionic liquids may expand the metabolic snapshot.

     

Quantitative analysis of tetrahydrofolate metabolites from <Emphasis Type="Italic">clostridium autoethanogenum</Emphasis>

Introduction

Quantification of tetrahydrofolates (THFs), important metabolites in the Wood–Ljungdahl pathway (WLP) of acetogens, is challenging given their sensitivity to oxygen.

Objective

To develop a simple anaerobic protocol to enable reliable THFs quantification from bioreactors.

Methods

Anaerobic cultures were mixed with anaerobic acetonitrile for extraction. Targeted LC–MS/MS was used for quantification.

Results

Tetrahydrofolates can only be quantified if sampled anaerobically. THF levels showed a strong correlation to acetyl-CoA, the end product of the WLP.

Conclusion

Our method is useful for relative quantification of THFs across different growth conditions. Absolute quantification of THFs requires the use of labelled standards.

     

Cradle to gate environmental impact assessment of acrylic fiber manufacturing

Purpose

The aim of the current study was to analyze the impacts of acrylic fiber manufacturing on the environment and to obtain information for assisting decision makers in improving relevant environmental protection measures for green field investments in developing countries especially in Africa and Middle East and North Africa (MENA) regions. The key research questions were as follows: what are the different impacts of acrylic fiber manufacturing on the environment and which base material has the highest impact?

Methods

The life cycle assessment (LCA) started from obtaining the raw material until the end of the production process (cradle to gate analysis). Focus was given on water consumption, energy utilization in acrylic fiber production, and generated waste from the industry. The input and output data for life cycle inventory was collected from an acrylic fiber manufacturing plant in Egypt. SimaPro software was used to calculate the inventory of twelve impact categories that were taken into consideration, including global warming potential (GWP), acidification potential (AP), eutrophication potential (EP), carcinogen potential (CP), ecotoxicity potential (ETP), respiratory inorganic formation potential (RIFP), respiratory organic formation potential (ROFP), radiation potential (RP), ozone layer depletion (OLD), mineral depletion (MD), land use (LU), and fossil fuel depletion (FFD).

Results and discussion

LCA results of acrylic fiber manufacturing on the environment show that 82.0 % of the impact is on fossil fuel depletion due to the high-energy requirement for acrylonitrile production, 15.9 % of the impact is on human health, and 2.1 % on ecosystem quality. No impacts were detected on radiation potential, ozone layer depletion, land use, mineral depletion, or human respiratory system due to organic substances.

Conclusions

Based on these study results, it is concluded that acrylic fiber manufacturing is a high-energy consumption industry with the highest impact to be found on fossil fuel depletion and human health. This study is based on modeling the environmental effects of the production of 1-kg acrylic fiber and can serve to estimate impacts of similar manufacturing facilities and accordingly use these results as an indicator for better decision-making.

     

Shale gas: a life-cycle perspective for UK production

Purpose

Following the boom of shale gas production in the USA and the decrease in the US gas prices, increasing interest in shale gas is developing in many countries holding shale reserves and exploration is already taking place in some EU countries, including the UK. Any commercial development of shale gas in Europe requires a broad environmental assessment, recognizing the different European conditions and legislations.

Methods

This study focuses on the UK situation and estimates the environmental impacts of shale gas using life-cycle assessment (LCA); the burdens of shale gas production in the UK are compared with the burdens of the current UK natural gas mix. The main focus is on the analysis of water impacts, but a broad range of other impact categories are also considered. A sensitivity analysis is performed on the most environmentally criticized operations in shale gas production, including flowback disposal and emission control, by considering a range of possible process options.

Results and discussion

Improper waste water management and direct disposal or spills of waste water to river can lead to high water and human ecotoxicity. Mining of the sand and withdrawal of the water used in fracking fluids determine the main impacts on water use and degradation. However, the water degradation of the conventional natural gas supply to the UK is shown to be even higher than that of shale gas. For the global warming potential (GWP), the handling methods of the emissions associated with the hydraulic fracturing influence the results only when emissions are vented. Finally, the estimated ultimate recovery of the well has the greatest impact on the results as well as the flowback ratio and flowback disposal method.

Conclusions

This paper provides insights to better understand the future development of shale gas in the UK. Adequate waste water management and emission handling significantly reduce the environmental impacts of shale gas production. Policy makers should consider that shale gas at the same time increases the water consumption and decreases the water degradation when compared with the gas mix supply. Furthermore, the environmental impacts of shale gas should be considered according to the low productivity that force the drilling and exploitation of a high number of wells.

     

Inclusion of uncertainty in the LCA comparison of different cherry tomato production scenarios

Purpose

Knowledge regarding environmental impacts of agricultural systems is required. Consideration of uncertainty in life cycle assessment (LCA) provides additional scientific information for decision making. The aims of this study were to compare the environmental impacts of different growing cherry tomato cultivation scenarios under Mediterranean conditions and to assess the uncertainty associated to the different agricultural production scenarios.

Materials and methods

The burdens associated to cherry tomato production were calculated and evaluated by the LCA methodology. The functional unit (FU) chosen for this study was the mass unit of 1 t of commercial loose cherry tomatoes. This study included the quantitative uncertainty analysis through Monte Carlo simulation. Three scenarios were considered: greenhouse (GH), screenhouse (SH), and open field (OF). The flows and processes of the product scenario were structured in several sections: structure, auxiliary equipment, fertilizers, crop management, pesticides, and waste management. Six midpoint impact categories were selected for their relevance: climate change, terrestrial acidification, marine eutrophication, metal depletion, and fossil depletion using the impact evaluation method Recipe Midpoint and ecotoxicity using USEtox.

Results and discussion

The structure, auxiliary equipment, and fertilizers produced the largest environmental impacts in cherry tomato production. The greatest impact in these stages was found in the manufacture and drawing of the steel structures, manufacture of perlite, the amount of HDPE plastics used, and the electricity consumed by the irrigation system and the manufacture and application of fertilizers. GH was the cropping scenario with the largest environmental impact in most categories (varying from 18 and 37% higher than SH and OF, respectively, in metal depletion, to 96% higher than SH and OF, in eutrophication). OF showed the highest uncertainty in ecotoxicity, with a bandwidth of 60 CTUe and a probability of 100 and 99.4% to be higher than GH and SH, respectively.

Conclusions

The LCA was used to improve the identification and evaluation of the environmental burdens for cherry tomato production in the Mediterranean area. This study demonstrates the significance of conducting uncertainty analyses for comparative LCAs used in comparative relative product environmental impacts.

     

Media optimization for extracellular amylase production by <Emphasis Type="Italic">Pseudomonas balearica</Emphasis> vitps19 using response surface methodology

Background

In this study, we optimized the process for enhancing amylase production from Pseudomonas balearica VITPS19 isolated from agricultural lands in Kolathur, India.

Methods

Process optimization for enhancing amylase production from the isolate was carried out by Response Surface Methodology (RSM) with optimized chemical and physical sources using Design expert v.7.0. A central composite design was used to evaluate the interaction between parameters. Interaction between four factors–maltose (C-source), malt extract (Nsource), pH, and CaCl₂ was studied.

Results

The factors pH and CaCl₂ concentration were found to affect amylase production. Validation of the experiment showed a nearly twofold increase in alpha amylase production.

Conclusion

Amylase production was thus optimized and increased yield was achieved.