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Sustainability of Renewable Fuel Infrastructure: A Screening LCA Case Study of Anti-Corrosive, Graphene Oxide Epoxy Liners in Steel Tanks for Storage of Biodiesel and its Blends
Abstract
Biodiesel is a widely used fuel that meets the renewable fuel standards developed under the Energy Policy Act of 2005. However, biodiesel is known to pose a series of abiotic and biotic corrosion risks to storage tanks. A typical practice (incumbent system) used to protect the tanks from these risks include (i) coating the interior surface of the tank with a solvent-free epoxy (SFE) liner, and (ii) adding a biocide to the tank. Herein, we present a screening-level life-cycle assessment study to compare the environmental performance of a graphene oxide (GO)-epoxy (GOE) liner with the incumbent system. TRACI was used as an impact assessment tool to model the midpoint environmental impacts in ten categories: global warming potential (GWP, kg CO2 eq.); acidification potential (AP, kg SO2 eq.); potential human health damage impacts due to carcinogens (HH-CP, CTUh) and non-carcinogens (HH-NCP, CTUh); potential respiratory effects (REP, kg PM2.5 eq.); eutrophication potential (EP, kg N eq.); ozone depletion potential (ODP kg CFC-11 eq.); ecotoxicity potential (ETXP, CTUe); smog formation potential (SFP kg O3 eq.) and fossil fuel depletion potential (FFDP MJ surplus). The equivalent functional unit of the LCA study was designed to protect 30 m(2) of the interior surface (unalloyed steel sheet) of a 10 000 liter biodiesel tank against abiotic and biotic corrosion during its service life of 20 years. Overall, this LCA study highlights the improved environmental performance for the GOE liner compared to the incumbent system, whereby the GOE liner showed 91% lower impacts in ODP impact category, 59% smaller in REP, 62% smaller in AP, 67-69% smaller in GWP and HH-CP, 72-76% smaller in EP, SFP, and FFDP, and 81-83% smaller ETXP and HH-NCP category results. The scenario analysis study revealed that these potential impacts change by less than 15% when the GOE liners are functionalized with silanized-GO nanosheets or GO-reinforced polyvinyl carbazole to improve the antimicrobial properties. The results from an uncertainty analysis indicated that the impacts for the incumbent system were more sensitive to changes in the key modeling parameters compared to that for the GOE liner system.
... Comparing life cycle impacts of an emerging product with its benchmarked products and suggesting environmental benefits or impacts offered by the new product launched into market (Chilkoor et al., 2017;Hervy et al., 2015;Pourzahedi and Eckelman, 2015;Upadhyayula et al., 2014;Upadhyayula et al., 2017). Understanding the broader environmental implications of adopting an emerging technology that complements the LCA scenarios mentioned earlier (e.g., energy and greenhouse gases impacts of various light weighted materials, quantifying their energy implications at a national level etc.,) (Joshua et al., 2015;Kelly et al., 2015;Moawad et al., 2011). ...
... V.K.K. Upadhyayula et al. Resources, Conservation & Recycling 133 (2018) 404-416 corrosion biodiesel storage tanks is published by our group recently (Chilkoor et al., 2017). Biodiesel is an attractive biofuel with many sustainable benefits. ...
... Currently to control MIC, the typical Corrosion Protection Practice (CPP) is used to protect biofuel infrastructure from corrosion, this includes two components: (i) epoxy liners on interior surface of storage Fig. 6. A. Summary of LCA case study considered as example (Chilkoor et al., 2017) B. Presenting LCA results of a GCI to investors. A case study of GO-Epoxy coatings. ...
Many Game Changing Innovations (GCIs) from the academic institutions struggle in the Technology Valley of Death (TVD) and they fail to reach commercialization. The academic researchers often lack motivation to seek entrepreneurial opportunities for their GCIs. They are often discouraged after considering the burden required to convince private investors to finance their GCIs beyond technology readiness level 4. Further, many academic institutions lack a structured framework to bridge the divide between a basic research and viable product. Here we propose a four-pronged approach for developing sustainability performance metrics that can be used by early investors to understand the commercialization prospects of the GCIs: (1) conduct a screening-level LCA of the GCI and simultaneously reduce uncertainties of underlying data and technological readiness; (2) compare the LCA performance of the GCI with similar commercial products in the target market; (3) factor the LCA results into investment evaluation methods; and (4) transform LCA results into indicators that reflect sustainability performance of the innovation. Finally, we present a case study that highlights the use of this approach for developing commercial opportunities for the emerging graphene-composites as corrosion resistant coatings for civil infrastructure applications. The paper also suggests an approach for promoting a sustainability driven innovation culture in academia.
... Different formulations of graphene oxide (GO)/epoxy nanocomposites were tested to prepare steel tanks for the storage of biodiesel and GO blends, with improved anticorrosive properties (due to antifouling and antimicrobial properties) being investigated. An LCA study was carried out to optimize the procedure for GO/epoxy nanocomposites preparation in agreement with the Energy Policy Act of 2005 [91]. The influence of oxygencontaining functional groups in epoxy/reduced graphene oxide composite coatings on corrosion and antimicrobial properties was investigated. ...
The main purpose of this work is to provide a comprehensive overview on the preparation of multifunctional epoxies, with improved antimicrobial activity and enhanced mechanical properties through nanomodification. In the first section, we focus on the approaches to achieve antimicrobial activity, as well as on the methods used to evaluate their efficacy against bacteria and fungi. Relevant application examples are also discussed, with particular reference to antifouling and anticorrosion coatings for marine environments, dental applications, antimicrobial fibers and fabrics, and others. Subsequently, we discuss the mechanical behaviors of nanomodified epoxies with improved antimicrobial properties, analyzing the typical damage mechanisms leading to the significant toughening effect of nanomodification. Some examples of mechanical properties of nanomodified polymers are provided. Eventually, the possibility of achieving, at the same time, antimicrobial and mechanical improvement capabilities by nanomodification with nanoclay is discussed, with reference to both nanomodified epoxies and glass/epoxy composite laminates. According to the literature, a nanomodified epoxy can successfully exhibit antibacterial properties, while increasing its fracture toughness, even though its tensile strength may decrease. As for laminates—obtaining antibacterial properties is not followed by improved interlaminar properties.
... The scenario analysis method could make up for this defect. In the case of complicated and changeable influence factors, scenario analysis (Chilkoor et al. 2017;Gutiérrez et al. 2018) exhibited an outstanding advantage, because it could take into account the variation of diverse conditions and focus on long-term planning. ...
Sustainable management of dyeing industry is of paramount importance in order to minimize resource consumption and reduce related environmental impacts. Herein, an environmental study is conducted wherein life cycle assessment (LCA) is applied to a two-scenario process for Disperse blue 60 production with short and long processing chains with different (a) material types, (b) consumptions, (c) processes, and (d) functional units with yields of 300 t/a. The most important influenced substances of the two scenarios were sodium cyanide and electricity next. Results proved that the largest damage of the dye production was attributed to resources and reached 46 and 62 kPt in the two scenarios. Compared with the conventional coal-fired power generation, damaged values of electricity from nature gas (NG) could reduce from 102 to 86 kPt in scenarios 1 and from 123 to 104 kPt in scenarios 2, respectively. When the electricity switched from NG to solar power, the values of the two scenarios could further decrease by 17 and 27 kPt, respectively. Therefore, the process of scenario 1 with the short process chain was more environmentally friendly for the production of Disperse blue 60 owing to the more efficient process and lower resource consumption.
Graphic abstract
... The MAGE coatings could prevent abiotic corrosion as well as MIC, without the need for biocides used to control growth of SRB cells . Such coatings can be expected to offer life cycle analysis (LCA) sustainability benefits [25]. Our earlier study demonstrated that graphene-polymer coatings that obviate the use of biocides could reduce the negative impacts (e.g., global warming, carcinogenicity and eutrophication potential) [26]. ...
Iron-based alloys that are ubiquitously used in industrialized societies are prone to corrosion which results in large maintenance and repair costs. Here we design maleic-anhydride-functionalized graphene nanofillers to enhance corrosion resistance of epoxy coating (MAGE) on steel surfaces, with a corrosion protection efficiency of 99.9%. A mechanochemical approach based on Diels-Alder reaction was used to synthesize graphene nanofillers and functionalize them with difunctional bisphenol A/epichlorohydrin epoxy. The MAGE coating increased corrosion resistance of steel by 9–10 orders of magnitude compared to bare metal in both abiotic (3.5% NaCl) and aggressive microbial (sulfate-reducing bacteria, SRB) environments. Compared to unfunctionalized graphene nanoplatelets, the MAGE coating offered four orders of magnitude lower corrosion resistance against planktonic SRB cells, 80% lower against sessile SRB cells, and 19-fold lower against 3.5% NaCl. The unique functional groups in maleic-anhydride-graphene adducts enabled their dispersion in epoxy coating and enhanced its mechanical properties. The high corrosion resistance of MAGE in diverse environments is attributed its outstanding ability to block the intercalation of corrosive species.
... The MAGE coatings could prevent abiotic corrosion as well as MIC, without the need for biocides used to control growth of SRB cells . Such coatings can be expected to offer life cycle analysis (LCA) sustainability benefits [25]. Our earlier study demonstrated that graphene-polymer coatings that obviate the use of biocides could reduce the negative impacts (e.g., global warming, carcinogenicity and eutrophication potential) [26]. ...
... The MAGE coatings could prevent abiotic corrosion as well as MIC, without the need for biocides used to control growth of SRB cells . Such coatings can be expected to offer life cycle analysis (LCA) sustainability benefits [25]. Our earlier study demonstrated that graphene-polymer coatings that obviate the use of biocides could reduce the negative impacts (e.g., global warming, carcinogenicity and eutrophication potential) [26]. ...
Iron-based alloys that are ubiquitously used in industrialized societies are prone to corrosion which results in large maintenance and repair costs. Here we design maleic-anhydride-functionalized graphene nanofillers to enhance corrosion resistance of epoxy coating (MAGE) on steel surfaces, with a corrosion protection efficiency of 99.9%. A mechanochemical approach based on Diels-Alder reaction was used to synthesize graphene nanofillers and functionalize them with difunctional bisphenol A/epichlorohydrin epoxy. The MAGE coating increased corrosion resistance of steel by 9–10 orders of magnitude compared to bare metal in both abiotic (3.5% NaCl) and aggressive microbial (sulfate-reducing bacteria, SRB) environments. Compared to unfunctionalized graphene nanoplatelets, the MAGE coating offered four orders of magnitude lower corrosion resistance against planktonic SRB cells, 80% lower against sessile SRB cells, and 19-fold lower against 3.5% NaCl. The unique functional groups in maleic-anhydride-graphene adducts enabled their dispersion in epoxy coating and enhanced its mechanical properties. The high corrosion resistance of MAGE in diverse environments is attributed its outstanding ability to block the intercalation of corrosive species.
... Similar to reported concerns for other nanomaterials, 31−38 graphene coatings should be scrutinized with this regard to understand their potential trade-offs. 39 The objective of this study is to evaluate and compare the environmental performance of a UFG-PEI coating with a commercial zinc coating used in the steel industry. Although a range of graphene composites have been demonstrated as corrosion-resistant coatings, the UFG-reinforced PEI coating was selected as the model graphene coating in this LCA study for the following reasons. ...
A major concern for exposed steel in structural applications is susceptibility to atmospheric corrosion. The International Organization for Standardization classifies atmospheric environments into six zones, C1-C5 and CX, based on factors such as humidity, airborne salinity, and acidic pollutants. The C5 and CX zones are characterized by aggressive atmospheric corrosivity that results in mass losses from steel structures. Hot dipped galvanized (HDG) zinc coatings are typically used to protect steel in C5 and CX environments. HDG coatings suffer from disadvantages related to shorter service lives and the need for frequent maintenance cycles. Graphene-reinforced polyetherimide (PEI) coatings have been proposed as suitable alternatives to address these issues. However, general concerns regarding the implications of nanomaterials make it necessary to understand the potential environmental impacts of these coatings. A screening-level cradle-to-grave life cycle assessment is conducted to evaluate the environmental performance of a graphene-PEI-steel structure when compared with a traditional HDG-zinc-steel structure. Impact assessment scores are calculated using the Tool for the Reduction and Assessment of Environmental and other Potential impacts v2.1 and SimaPro (v8.0.3). When considering inventory uncertainty, the graphene-PEI-steel structure yields smaller potential impacts in five of the ten categories assessed when assuming the graphene-based coating requires no maintenance during the service life of the structure. Scenario-based sensitivity studies reveal that the potential impacts are highly sensitive to the service life and maintenance needs of the coating, but insensitive to the use of thermally or chemically functionalized graphene to improve coating adhesion. Further research is needed to understand the long-term performance of the graphene-based coatings and reduce the uncertainty of the inventory.
Protective coatings are widely used to control microbially induced corrosion (MIC) of ferrous and nonferrous metals and maintain their aesthetic appeal and structural integrity. The use of ultrathin graphene films as protective coatings in biological environments is discussed in this article. The way the atomic scale surficial features of graphene coatings influence adherence, colonization, and biofilm growth aspects of bacteria responsible for MIC of underlying metals is discussed. A critical review of the literature is carried out to evaluate the microbial corrosion resistance of pristine graphene and its functionalized forms. The article is concluded with a discussion on environmental impacts, technical challenges and potential solutions, and commercialization prospects of graphene coatings.
Contribution of citizens is a key factor in the success of urban development projects and the cornerstone of smart cities in general. The domain researchers have attempted to understand the attributes of a meaningful and effective collaboration with citizens and improve the quality of engagement accordingly. With this aim, a rich and extensive literature has been created, covering different aspects of citizen engagement. The subjective-ness and context-sensitivity of involved issues, however, do not allow for a ‘universal’ standard solution to be proposed, even to a similar problem, in different spatiotemporal contexts. In this paper, after an extensive analysis of a broadly inclusive range of existing literature through more than 1092 publications, a conceptual framework is proposed to contextualize citizen engagement in urban projects. Using this framework, a model is trained, with the aid of the fuzzy paradigm to provide fuzzy sets of most relevant keywords for a query regarding citizen engagement in urban projects, and a decision support system is developed to retrieve the most relevant publications, based on the fuzzy inference mechanism. The system provides the most relevant keywords for reviewing the literature, as well as the most related documents, through answering a set of simple questions. The solution is deployed through a user interface, linked to the well-known Elsevier online database Scopus. The developed system can assist researchers and practitioners with retrieving knowledge from the literature, for setting up new projects.
In the last couple of decades, carbon nanomaterials have been a hot topic in research, and while they start appearing in commercial products, their environmental impacts are still far from being understood. The life-cycle assessment (LCA) is one way of assessing the environmental burdens of a product throughout its lifecycle on the environment and human beings. This chapter starts with an introduction to the LCA technique, from its origins to the ideas behind its holistic approach that, by investigating the whole lifecycle, avoids shifting the environmental burden from one life stage to the others (e.g. from production to disposal). The chapter then focuses then on a review of the published LCA studies on carbon nanomaterials evaluating commonalities among studies and limitations. Findings suggest that carbon nanomaterials production is more energy demanding than their traditional counterparts, but they can have a lower environmental profile when their whole lifecycle is considered. The last part focuses on the limitations of the LCA in relation to nanomaterials, and the difficulties in understanding their toxicological impacts when released to the environment.
An intimate physical mixture of graphene oxide (GO) and semiconducting organic molecules like
bromophenathrene (BrPh) and bromopyrene (BrPy) was prepared by using a ball milling technique. The
structural, microstructural, physical and chemical properties of the mixtures (20 wt% of GO) were
analyzed by X-ray diffraction, SEM, FT-IR, TGA and TCSPC studies. Furthermore, the electrochemical
properties like AC electrical conductivity, transient photocurrent response (PCTR) and open circuit
voltage (OCVD) of the samples were analyzed. It has been observed from TCSPC and OCVD
measurements that 20 wt% of GO in the semiconductor composite leads to an enhanced life-time of
photo-generated charge carriers. The physical mixture composites exhibit a higher photocurrent than
pure BrPh and BrPy
We report the use of a single layer of two-dimensional hexagonal boron nitride (SL-hBN) as the thinnest insulating barrier to microbial corrosion induced by the sulfate-reducing bacteria Desulfovibrio alaskensis G20. We used electrochemical methods to assess the corrosion resistance of SL-hBN on copper against the effects of both the planktonic and sessile forms of the sulfate-reducing bacteria. Cyclic voltammetry results show that SL-hBN-Cu is effective in suppressing corrosion effects of the planktonic cells at potentials as high as 0.2 V (vs. Ag/AgCl). The peak anodic current for the SL-hBN coatings is ~36 times lower than that of bare Cu. Linear polarization resistance tests confirm that the SL-hBN coatings serve as a barrier against corrosive effects of the G20 biofilm when compared to bare Cu. The SL-hBN serves as an impermeable barrier to aggressive metabolites and offers ~91% corrosion inhibition efficiency, which is comparable to much thicker commercial coatings such as polyaniline. In addition to impermeability, the insulating nature of SL-hBN suppresses galvanic effects and improves its ability to combat microbial corrosion.
The incorporation of carbonaceous nanofillers into polymers can result in significant materials with improved physicochemical properties and novel composite functionalities. In this study, we have fabricated antibacterial, lightweight, transparent, and flexible graphene oxide (GO) reinforced polycarbonate thin films by a facile and low-cost methodology. Solution blending is employed to get a homogeneous mixture of PC-GO composites at various loading of GO, and the thin films are prepared by dry-wet phase inversion technique. Thermal studies and micrographs of the films revealed the incorporation of GO in PC matrix. Microstructure of the thin films showed the homogeneous dispersion of GO at micro- and nanoscales; however, at higher loading of GO (0.7%), significant agglomeration is observed. More importantly, PC-GO composite films exhibited excellent antibacterial activities against E. coli and S. aureus , owing to the antibacterial nature of GO nanoparticles.
Recent petroleum crises, increasing cost and unavailability of petroleum diesel gave impetus to the search for an alternative fuel. Among the renewable fuels, the ones that are produced from oilseeds and food waste as the sources are favored by the majority of researchers because of their ability to minimize air pollution and emission of greenhouse gases and also to achieve reduction of dependency on fuel import, which result in reducing the overall energy cost. Biodiesel can be considered as the optimum alternative fuel for diesel fuel in Turkey. The biodiesel production potential from oil seeds such as soybean, peanut, sunflower, sesame, safflower, canola, cottonseed, flaxseed, hempseed and poppyseed in Turkey was investigated. Purpose of this study is to examine the potential of biodiesel in Turkey in parallel with global developments and agricultural products used in biodiesel energy production. In the present study, data was received from Turkish Statistical Institute. Around Turkey, 1.17 million ha of land from 81 provinces are predicted to be suitable land for growing of oil seeds. There are approximately 3.31 million tons of oil seed crops in Turkey that can potentially produce 1.12 million tons every year. Furthermore, there are 4.15 million ha fallow land in Turkey. When the production of oil seed crops were realized in these area, approximately 11.74 million tons of seeds can be produced. In Turkey, water is a main problem for growing plants, so that drought-resistant oil seed crops will be produced such as safflower, and poppy seed etc. Based on the results, drought-resistant oil seed crops can be grown in Turkey and these oils can be used in biodiesel production industry.
A putatively novel basidiomycetous fungus termed Moniliella wahieum Y12T was isolated from a 20% biodiesel blend. The strain maximally degraded biodiesel at a rate of 3.56 × 10-2 mg/h during log phase growth. Induction of metal corrosion by the strain in a mass loss procedure using 1018 metal coupons showed total mass reduction exceeded that in controls by 70% through 30 days. Enhanced corrosion was observed at the pellicle and due to medium acidification. This is the first investigation of a Moniliella sp. and its impact on biodiesel stability and 1018 steel corrosion. (M. wahieum Y12T = ATCC MYA-4962).
Remanufacturing cleaning can lay foundation for testing, painting and assembling waste products and components in remanufacturing procedure. Currently, high temperature decomposition and shot blasting cleaning are conventional industrial cleaning technologies for remanufacturing while supercritical CO2 cleaning and liquid blasting cleaning are the relatively new ones. This study completed by the method of simplified life cycle assessment aims at comparing the environmental impacts of the cleaning process of these two types of cleaning technologies. Most of the data were collected from a remanufacturing company directly and some laboratorial data were used to speculate about the industrial data for the difficulties of collection. The results indicate that, compared with conventional cleaning technologies, the new cleaning technologies are relatively environmental friendly since they are more favorable in terms of several environmental impact indicators such as GPW, AP, EP, ODP, POCP and most of emissions have been reduced dramatically.
Although the documentation of fuel biodeterioration dates back to the late 19th century, general recognition of the value of microbial contamination control evolved slowly until the 1980s. Since the early 1980s a number of factors have converged to stimulate greater interest in fuel and fuel system biodeterioration. This, in turn, has stimulated applied research in the ecology of biodeteriogenic processes and biodeterioration control. This presentation reviews progress in both of these areas since 1980. The aforementioned factors that have provided the impetus for improved microbial control, the evolution of our understanding of the nature of the biodeteriogenic processes will be discussed. Activities of consensus organizations to develop guidelines and practices will also be reviewed.
Oxidation and corrosion resistant hydrophobic graphene oxide-polymer composite (GOPC) coating was fabricated on the copper by electrophoretic deposition (EPD). The GOPC coatings were characterized by scanning, and transmission electron microscope (SEM, TEM), thermogravimetric (TGA) and electrochemical impedance spectroscopy (EIS). At optimal EPD conditions of operating voltage 10 V and deposition time 30s, uniform crack free deposit with thickness 45 nm was achieved. Potentiodynamic polarization and EIS investigation demonstrated the efficacy of GOPC coating in shielding copper from corrosion under stringent environment condition. The electrochemical degradation of GOPC coating is more than three orders of magnitude lower than the bare copper substrate. This was due to the impermeability of GOPC coatings to ion diffusion of oxidizing gas and corrosive liquid solution. The procedure employed is fairly facile, inexpensive and less time consuming.
Understanding how nanomaterials interact with cell membranes is related to how they cause cytotoxicity and is therefore critical for designing safer biomedical applications. Recently, graphene (a two-dimensional nanomaterial) was shown to have antibacterial activity on Escherichia coli, but its underlying molecular mechanisms remain unknown. Here we show experimentally and theoretically that pristine graphene and graphene oxide nanosheets can induce the degradation of the inner and outer cell membranes of Escherichia coli, and reduce their viability. Transmission electron microscopy shows three rough stages, and molecular dynamics simulations reveal the atomic details of the process. Graphene nanosheets can penetrate into and extract large amounts of phospholipids from the cell membranes because of the strong dispersion interactions between graphene and lipid molecules. This destructive extraction offers a novel mechanism for the molecular basis of graphene's cytotoxicity and antibacterial activity.
Materials possessing excellent bacterial toxicity, while presenting low cytotoxicity to human cells, are strong candidates for biomaterials applications. In this study, we present the fabrication of a nanocomposite containing poly(N-vinylcarbazole) (PVK) and graphene (G) in solutions and thin films. Highly dispersed PVK-G (97-3 w/w%) solutions in various organic and aqueous solvents were prepared by solution mixing and sonication methods. The thermal properties and morphology of the new composite were analyzed using thermal gravimetry analysis (TGA) and atomic force microscopy (AFM), respectively. PVK-G films were immobilized onto indium tin oxide (ITO) substrates via electrodeposition. AFM was used to characterize the resulting topography of the nanocomposite thin films, while cyclic voltammetry and UV-vis were used to monitor their successful electrodeposition. The antimicrobial properties of the electrodeposited PVK-G films and solution-based PVK-G were investigated against Escherichia coli (E. coli) and Bacillus subtilis (B. subtilis). Microbial growth after exposure to the nanocomposite, metabolic assay and live-dead assay of the bacterial solutions exposed to PVK-G presented fewer viable and active bacteria than those exposed to pure PVK or pure graphene solutions. The PVK-G film inhibited about 80% of biofilm surface coverage whereas the PVK- and G-modified surfaces allowed biofilm formation over almost the whole coated surface (i.e. > 80%). The biocompatibility of the prepared PVK-G solutions on NIH 3T3 cells was evaluated using the MTS cell proliferation assay. A 24 h exposure of the PVK-G nanocomposite to the NIH 3T3 cells presented ∼80% cell survival.
It is critical to develop highly effective antimicrobial agents that are not harmful to humans and do not present adverse effects on the environment. Although antimicrobial studies of graphene-based nanomaterials are still quite limited, some researchers have paid particular attention to such nanocomposites as promising candidates for the next generation of antimicrobial agents. The polyvinyl-N-carbazole (PVK)-graphene oxide (GO) nanocomposite (PVK-GO), which contains only 3 wt% of GO well-dispersed in a 97 wt% PVK matrix, presents excellent antibacterial properties without significant cytotoxicity to mammalian cells. The high polymer content in this nanocomposite makes future large-scale material manufacturing possible in a high-yield process of adiabatic bulk polymerization. In this study, the toxicity of PVK-GO was assessed with planktonic microbial cells, biofilms, and NIH 3T3 fibroblast cells. The antibacterial effects were evaluated against two Gram-negative bacteria: Escherichia coli and Cupriavidus metallidurans; and two Gram-positive bacteria: Bacillus subtilis and Rhodococcus opacus. The results show that the PVK-GO nanocomposite presents higher antimicrobial effects than the pristine GO. The effectiveness of the PVK-GO in solution was demonstrated as the nanocomposite "encapsulated" the bacterial cells, which led to reduced microbial metabolic activity and cell death. The fact that the PVK-GO did not present significant cytotoxicity to fibroblast cells offers a great opportunity for potential applications in important biomedical and industrial fields.
Most high intensity or power ultrasound applications involve a special transmission mode of sound waves in a medium that is
composed of consecutive compressions and rarefactions. Since the propagation of such longitudinal waves is normally associated
with a liquid medium, the use of power ultrasound is often termed as sonication. When the negative pressure in the rarefaction
phase surpasses the tensile stress of the liquid, the liquid will be torn apart and cavities will be formed (Leighton, 1994).
The inception of cavitation and the subsequent mechanical and chemical effects rising from the cavitation activity enable
interactions between the acoustic energy and food and biological systems being processed. Such interactions take place at
microscopic levels as the average diameters of cavitation bubbles are at 150–170 μm, for bubbles generated in water by 20kHz
ultrasound transducers (Awad, 1996; Vago, 1992).
Environmental issues, the growing demand for energy, political concerns and the medium-term depletion of petroleum has created the need for development of sustainable technologies based on renewable raw materials. Biofuels might help to meet the future energy supply demands as well as contributing to a reduction of green house gas emissions. Although this topic is highly controversial and many investigations are currently ongoing, this review is intended to give a brief overview about certain aspects of the complex biofuel issue, providing the latest update of the production and potential of biofuels in the transport sector including types of biofuel, feedstocks and technologies and some of the possible socio-economic, environmental and political implications of the widespread use of biofuels in our society.
The first report on the fabrication and application of a nanocomposite containing poly-N-vinyl carbazole (PVK) polymer and graphene oxide (GO) as an antimicrobial film was demonstrated. The antimicrobial film was 90% more effective in preventing bacterial colonization relative to the unmodified surface. More importantly, the nanocomposite thin film showed higher bacterial toxicity than pure GO-modified surface.
Background, aim and scope In 2005, a comprehensive comparison of life cycle impact assessment toxicity characterisation models was initiated by the United Nations Environment Program (UNEP)-Society for Environmental Toxicology and Chemistry (SETAC) Life Cycle Initiative, directly involving the model developers of CalTOX, IMPACT 2002, USES-LCA, BETR, EDIP, WATSON and EcoSense. In this paper, we describe this model comparison process and its results-in particular the scientific consensus model developed by the model developers. The main objectives of this effort were (1) to identify specific sources of differences between the models' results and structure, (2) to detect the indispensable model components and (3) to build a scientific consensus model from them, representing recommended practice.
The present study enlightens the role of Bacillus cereus ACE4 on biodegradation of commercial corrosion inhibitors (CCI) and the corrosion process on API 5LX steel. Bacillus cereus ACE4, a dominant facultative aerobic species was identified by 16S rDNA sequence analysis, which was isolated from the corrosion products of refined diesel-transporting pipeline in North West India. The effect of CCI on the growth of bacterium and its corrosion inhibition efficiency were investigated. Corrosion inhibition efficiency was studied by rotating cage test and the nature of biodegradation of corrosion inhibitors was also analyzed. This isolate has the capacity to degrade the aromatic and aliphatic hydrocarbon present in the corrosion inhibitors. The degraded products of corrosion inhibitors and bacterial activity determine the electrochemical behavior of API 5LX steel.
Silanized graphene oxide (SGO) reinforced organofunctional silane composite coatings were fabricated on galvanized steel substrates. A mixture of silane precursors were employed to prepare the composite matrix. The graphene oxide surfaces were functionalized by tetraethoxysilane molecules to improve its compatibility with the silane matrix. The protective properties of the composite coatings were significantly improved compared with the neat silane coatings. The composite coatings exhibited the highest protective properties with the addition of 0.2 wt% of SGO. Silanized graphene provided a physical barrier to the corrosive molecules.
Graphene oxide (GO) is extensively proposed as an effective antibacterial agent in commercial product packaging and for various biomedical applications. However, the antibacterial mode of action of GO is yet hypothetical and unclear. Here we developed a new and sensitive fingerprint approach to study the antibacterial activity of GO and underlying mechanism, using Raman spectroscopy. Spectroscopic signatures obtained from biomolecules such as Adenine and proteins from bacterial cultures with different concentrations of GO, allowed us to probe the antibacterial activity of GO with its mechanism at the molecular level. Escherichia coli (E. coli) and Enterococcus faecalis (E. faecalis) were used as model micro-organisms for all the experiments performed. The observation of higher intensity Raman peaks from Adenine and proteins in GO treated E. coli and E. faecalis; correlated with induced death, confirmed by Scanning electron Microscopy (SEM) and Biological Atomic Force Microscopy (Bio-AFM). Our findings open the way for future investigations of the antibacterial properties of different nanomaterial/GO composites using Raman spectroscopy.
Silane coating has been used as a steel surface treatment for the promotion of adhesion between a substrate and an organic coating. However, the corrosion protection properties of this coating are not sufficient. Incorporation of various additives and nano-fillers into the coating is a promising way to improve the coating barrier action. In this paper a new nano-filler based on graphene oxide is recommended for this type of coating. The graphene oxide is silanized in the first step through a sol-gel route by using aminopropyl triethoxysilane (ATPES). Then, it is employed in a hybrid silane coating based on the mixture of aminopropyl triethoxysilane and tetraethyl orthosilicate (TEOS). The graphene oxide functionalization was characterized by Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The silane coatings filled with silanized and untreated graphene oxide were also characterized by FT-IR, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results obtained from different characterizations showed successful silanization and dispersion of graphene oxide in the silane hybrid coating. The silane coating containing silanized graphene oxide showed superior corrosion protective performance compared to the unfilled silane coating in electrochemical impedance spectroscopy (EIS) and polarization measurements, indicating the considerable corrosion barrier effect of this nano-filler.
Forward osmosis (FO) is an emerging membrane process with potential applications in the treatment of highly fouling waters. However, biofouling, the adhesion of microorganisms to the membrane and the subsequent formation of biofilms, remains a major limitation since antifouling membrane modifications offer limited protection against biofouling. In this study, we evaluated the use of graphene oxide (GO) for biofouling mitigation in FO. GO functionalization of thin-film composite membranes (GO-TFC) increased the surface hydrophilicity and imparted antimicrobial activity to the membrane without altering its transport properties. After 1 h of contact time, deposition and viability of Pseudomonas aeruginosa cells on GO-TFC was reduced by 36% and 30%, respectively, compared to pristine membranes. When GO-TFC membranes were tested for treatment of an artificial secondary wastewater supplemented with P. aeruginosa, membrane biofouling is reduced by 50% after 24 hours of operation. This biofouling resistance is attributed to the reduced accumulation of microbial biomass on GO-TFC compared to pristine membranes. In addition, confocal microscopy demonstrated that cells deposited on the membrane surface are inactivated, resulting in a layer of dead cells on GO-TFC that limit biofilm formation. These findings highlight the potential of GO to be used for biofouling mitigation in FO membrane design.
We report an efficient and a simple synergistic antimicrobial therapy for lysing pathogenic E. coli K12 MG1655 using layer-by-layer (LbL) films of graphene oxide (GO) and poly(allylamine hydrochloride) (PAH). Two kinds of antimicrobial therapies have been tested in this study. The first therapy involves the inherent antimicrobial property of GO studied by incubating the bacteria with glass slides coated with GO/PAH films up to 16 h (varying number of layers from 20 to 80). The optical density (OD) measurements at 600 nm revealed that the antimicrobial activity of the films increased with an increase in the number of layers, which can be attributed to an increase in the roughness of the films and also the amount of GO in the films. The second therapy involves exploiting the photothermal property of GO by exposing the films to a near-infrared (NIR) laser at 1064 nm (Nd:YAG, 10 ns pulse, 10 Hz, 85 mW) for 15 min and incubation for 4 or 16 h. The photothermal therapy results revealed the enhanced antimicrobial activity compared to incubation of bacteria with films in the absence of a NIR-laser for 4 or 16 h. The enhanced antimicrobial activity of GO/PAH films is because of the synergistic effect resulting from membrane-stress induced on bacteria by GO sheets and photothermal heating in the presence of NIR-light. Further, we have also performed a fluorescence-based live/dead assay using confocal fluorescence microscopy to verify the viability of bacterial cells after incubating the bacteria and GO/PAH films with and without a NIR laser. All the results suggest that the synergistic antimicrobial effect of GO/PAH films causes increased lysis of E. coli compared to the individual effects.
The deterioration of coatings by microbiological attack takes place directly or indirectly as a result of metabolic activity of microorganisms. The most severe bacterial corrosion occurs due to presence of sulphate reducing bacteria (SRB), as these produce hydrogen sulphide, leading to formation of metal sulphides and sulphates. Such type of microbiological corrosion can be controlled by incorporating suitable biocide in the coating. The objective of this study was to simulate such microbiological corrosion phenomena in the laboratory and observe its effect on the coating performance. In the present work, experiments were conducted to assess the antibacterial property of epoxy based anticorrosive coatings, with and without of biocide, by exposing them to SRB culture under anaerobic condition. Coal tar epoxy (CTE)-polyamide coating system which is known for superior antibacterial properties was selected as benchmark. The SRB effectiveness was evaluated by the formation of zone of inhibition in nutrient agar and visual observation. The surface morphology of coatings before and after exposure was analysed by scanning electron microscopy (SEM). The anticorrosive property of these coatings under SRB exposure was also monitored by measuring impedance of the coating by electrochemical impedance spectroscopy (EIS). The loss in adhesion after exposure was also measured for all the coatings.
To improve the dispersion and the strength of filler-matrix interface in acrylic resin, the functional graphene oxide (FGO) was obtained by surface modification of graphene oxide (GO) by γ-methacryloxypropyl trimethoxysilane (KH-570) and then the acrylic nanocomposites containing different loadings of GO and FGO were prepared. The structure, morphology and dispersion/exfoliation of the FGO were characterized by XRD, FT-IR, Raman, XPS, SEM and TEM. The results demonstrated that the KH-570 was successfully grafted onto the surface of GO sheets. Furthermore, the corresponding thermal, mechanical and chemical resistance properties of the acrylic nanocomposites filled with the FGO were studied and compared with those of neat acrylic and GO/acrylic nanocomposites. The results revealed that the loading of FGO effectively enhanced various properties of acrylic resin. These findings confirmed that the dispersion and interfacial interaction were greatly improved by incorporation of FGO, which might be the result of covalent bonds between the FGO and the acrylic matrix. This work demonstrates an in situ polymerization method to construct a flexible interphase structure, strong interfacial interaction and good dispersion of FGO in acrylic nanocomposites, which can reinforce the polymer properties and be applied in research and industrial areas.
In studies of epoxy/graphene oxide (GO) nanocomposites, organic solvents are commonly used to disperse GO, and vigorous mechanical processes and complicated modification of GO are usually required, increasing the cost and hindering the development and application of epoxy nanocomposites. Here, we report a green, facile, and efficient method of preparing epoxy/GO nanocomposites. When triglycidyl para-aminophenol (TGPAP), a commercially available glycidyl amine epoxy resin with one tertiary amine group per molecule, is used as both the surface modifier and phase transfer agent of GO, GO can be directly and rapidly transferred from water to diglycidyl ether of bisphenol A and other types of epoxy resins by manual stirring under ambient conditions, whereas GO cannot be transferred to these epoxy resins in the absence of TGPAP. The interaction between TGPAP and GO and the effect of the TGPAP content on the dispersion of GO in the epoxy matrix were investigated systematically. Superior dispersion and exfoliation of GO nanosheets and remarkably improved mechanical properties, including tensile and flexural properties, toughness, storage modulus and micro-hardness, of the epoxy/GO nanocomposites with a suitable amount of TGPAP were demonstrated. This method is organic-solvent-free and technically feasible for large-scale preparation of high-performance nanocomposites; it opens up new opportunities for exploiting the unique properties of graphene or even other nanofillers for a wide range of applications.
The use of biodiesel as alternative to fossil fuel for light duty CI engines to reduce greenhouse gas emissions was widely investigated. However, poor stability of biodiesel-diesel mixture limits the use of biodiesel to low volume concentrations. This paper presents the results concerning the use of a novel fuel additive package containing antioxidant (AS), pour-point depressant (D) and biocide (Bi) with the aim to increase the quality and amount of biodiesel in the diesel-biodiesel blends. Some of the goals are linked to the degradative effects due to free radicals oxidation, contamination by water and microorganisms. The interaction between two different additive packages and two biodiesel (soybean and rapeseed)-diesel blends at 20% in volume was investigated. Optical studies have been performed to characterize the spatial and temporal spray evolution both in a high pressure quiescent vessel and in an optically-accessible single-cylinder 2-stroke CI engine. Soot and NOx emissions were measured at the exhaust. Physicochemical tests showed that the stability of diesel-biodiesel blends was strongly influenced by the use of the two packages of additives. The mixture containing the biocide "P" (B20SMEASDP) was approximately 87.33% more stable than the same sample containing the biocide "C" (B20SMEASDC). Furthermore, no significant changes were observed in term of engine efficiency, fuel injection rate and spray penetration. Hence, it was demonstrated that use of additive package increased the durability of the blends without exhaust emission and performance penalties.
Graphene and its derivatives are new materials with unique properties. In recent years, various studies about the nanocomposites based on graphene oxide (GO) have been carried out. However, the electrochemical properties of nanocomposite coatings based on GO materials have not been widely studied. In this study, GO/epoxy nanocomposite coatings were prepared by incorporation of different amounts of GO nanosheets into the epoxy matrix via mechanical agitation and sonication process. The dispersion of GO nanosheets in matrix was analysed by optical microscopy, transmission electron microscopy and Fourier transform infrared. The anticorrosive properties of these nanocomposite coatings were investigated by electrochemical impedance spectroscopy tests. Results showed that the corrosion protection of coatings was improved by addition of GO into the coatings material. Furthermore, the best corrosion resistance was achieved in 0·25 wt-%GO/epoxy nanocomposite coatings.
In this article, advancement in epoxy/graphene oxide composites is presented. These materials are comprised of graphene oxide (GO) as filler (carbon-based material, thermodynamically stable, two-dimensional, planar and layered structure). Owing to improved properties (mechanical response, low density, electrical resistance, and thermal stability), epoxy resins are used in variety of applications. Graphene oxide proposes unique properties to epoxy composites as high surface area, thermal and electrical conductivity as well as mechanical and barrier properties, relative to neat matrix. The corresponding significance of epoxy/GO-based materials, related challenges, and potential exploitation regarding technical applications (aerospace, gas sensor, electronic devices, etc.) have been overviewed.
The effect of biodiesel fuel made from Jatropha curcus L. seed oil and methanol on the corrosion rates of mild carbon steel (MCS) and aluminium (Al) was investigated and compared with those of the conventional petroleum diesel and its blend. Static immersion tests in diesel (B0), biodiesel-diesel blend (B50) and biodiesel (B100) fuels were carried out at room temperature for 18 weeks. Corrosion rates of MCS and Al in these fuels were determined at an interval of 3 weeks by the weight loss method. Also, during the period of investigation, the fuels were analysed by measuring the total acid number (TAN). It was observed from the results that the corrosion rates for these metals were higher in B100 compared to the corrosion rates in B50 and B0. The corrosion rates for MCS were found to be higher than corrosion rates for Al in these fuels. The corrosion rate for MCS at the end of our investigation were 0.026, 0.022 and 0.011 mpy in B100, B50 and B0 respectively, while that for aluminium were 0.016, 0.0099 and 0.0025 mpy in B100, B50 and B0 respectively. There was an increase in the TAN during the period of investigation. Maximum TAN of 3.53 mg KOH/g was observed in the B100 fuel in which MCS was immersed, while the lowest TAN of 0.69 mg KOH/g was measured in B0 containing aluminium.
The demand for biodiesel and biodiesel blends as a fuel source has increased exponentially in the last decade. Water is the most significant contaminant in biodiesel-handling facilities (pipeline, storage tanks on the land, and fuel storage tanks on ships). Corrosion performance of materials in these facilities in biodiesel needs to be understood well to ascertain the facility integrity. The highly resistive nature of biodiesel imposes a great challenge in using the conventional electrochemical techniques for corrosion evaluation, even in the presence of water. Multielectrode array technique was demonstrated to be useful in evaluating the corrosion of steel in both the biodiesel phase and the water phase that is overlaid by the biodiesel phase. This work demonstrated that the corrosion rate in biodiesel phase is low. However, the biodiesel does influence the corrosion rate in the water phase when it is in contact. Appreciable corrosion was observed on the steel exposed to the water phase below a biodiesel layer, likely because of the diffusion of corrosive species (e.g., chloride) from the biodiesel phase into the water phase.
The synthesis of chemically reduced graphene oxide nanosheets (RGO) from graphite oxide commonly involves some harmful chemical reductants that are undesirable for most practical applications of graphene. An easy and environment friendly approach has been developed to reduce graphene oxide (GO) by using sodium acetate trihydrate as a reductant The as-prepared RGO was characterized by X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), field emission transmission electron microscopy (FETEM), atomic force microscopy (AFM) and thermogravimetric analysis (TGA). Results show that GO was reduced to fewlayers level with poor dispersion in water. A mechanism for removing of epoxy and hydroxyl groups from GO with sodium acetate trihydrate has been proposed. Considering that all the raw materials used are low cost, nontoxic and widely available, this approach may open up the new possibility for cost-effective, environment friendly and large-scale production of graphene.
One promising future bulk application of graphene is as composite additive. Therefore, we compare two production routes for in-solution graphene using a cradle-to-gate lifecycle assessment focusing on potential differences in energy use, blue water footprint, human toxicity, and ecotoxicity. The data used for the assessment is based on information in scientific papers and patents. Considering the prospective nature of this study, environmental impacts from background systems such as energy production were not included. The production routes are either based on ultrasonication or chemical reduction. The results show that the ultrasonication route has lower energy and water use, but higher human and ecotoxicity impacts, compared to the chemical reduction route. However, a sensitivity analysis showed that solvent recovery in the ultrasonication process gives lower impacts for all included impact categories. The sensitivity analysis also showed that solvent recovery is important to lower the blue water footprint of the chemical reduction route as well. The results demonstrate the possibility to conduct a life cycle assessment study based mainly on information from patents and scientific articles, enabling prospective life cycle assessment studies of products at early stages of technological development.
Functionalized graphene oxide (f-GO) was synthesized by a simple covalent functionalization with 3-aminopropyltriethoxysilane (APTS). The hybrid polyvinylidene fluoride (PVDF) ultrafiltration membranes were then prepared by adding different ratios of graphene oxide (GO) and f-GO via phase inversion induced by immersion precipitation technique. Zeta potential demonstrated that covalent functionalization of GO with APTS was favorable for their homogeneous dispersion in organic solvents. SEM images showed that very large channel appeared in top-layer by the addition of additives. Furthermore, the PVDF/f-GO membranes exhibited superior hydrophilicity, water flux, BSA flux and rejection rate than nascent PVDF membranes and PVDF/GO membranes. Filtration results indicated that the fouling resistance parameters were significantly declined due to higher hydrophilicity of hybrid membranes. An atomic force microscope (AFM) analysis with a BSA-immobilized tip revealed that the adhesion forces between membrane and foulants increased in the following order: PVDF/f-GO<PVDF/GO<PVDF. After a ternary cycle BSA solution inner fouling process, PVDF/f-GO membranes exhibited higher water flux recovery ratio (FRR) value than that of PVDF/GO. Meanwhile, tensile strength and elongation-at-break of PVDF/f-GO membranes were increased by 69.01% and 48.38% compared with those of PVDF/GO membranes, which is believed to be attributed to the strong interfacial interaction between f-GO and matrix by covalent functionalization of GO. As a result, GO functionalization will provide a promising method to fabricate graphene-based hybrid membranes with effective reinforced permeation, antifouling and mechanical performance.
Microbial corrosion limits the use of metallic structures in a variety of technological processes and applications. Here, we report the first demonstration of graphene as a passive layer that retards microbially-induced galvanic corrosion (MIC) of metals for extended periods of time (∼2700 h). The effectiveness of the MIC-resistant graphene coating was evaluated under realistic operating conditions by testing baseline Ni foams and graphene-coated Ni foams as anodes in a microbial fuel cell. The rates of Ni dissolution in the graphene-coated Ni anode were at least an order of magnitude lower than the baseline (uncoated) Ni electrode. Electrochemical impedance spectroscopy characterization revealed that the MIC of Ni was impeded by over 40-fold when coated with graphene.
Biodiesel has the characteristic of absorbing more moisture than petroleum diesel. High moisture content in biodiesel can cause problems such as water accumulation and microbial growth in fuel handling, storage, and transportation equipment. Currently, there is a lack of information on moisture absorbance in biodiesel and biodiesel/diesel blends. Experiments were conducted to determine the water absorbance in biodiesel of different feedstocks (three vegetable oils and two primary alcohols) at three temperatures. The effects of temperature and blending levels were explored through a central composite experimental design. Dynamic moisture absorption was studied at three constant relative humidities. Petroleum diesel was used as a reference. It was found that there were no significant differences in moisture absorbence among the biodiesel samples of different origins at given temperatures. Saturation moisture in biodiesel ranged from 0.10 to 0.17%wt in the temperature range of 4C to 35C, which was 15 to 25 times higher than that of diesel. Results also showed that in biodiesel/diesel blends, both temperature and level of blending affected the moisture absorbence. Moisture content of the blends was not a simple addition of the two moisture contents of biodiesel and petro-diesel. Blending created a mixture that had a lower capacity for moisture absorption.
TRACI 2.0, the Tool for the Reduction and Assessment of Chemical and other environmental Impacts 2.0, has been expanded and
developed for sustainability metrics, life cycle impact assessment, industrial ecology, and process design impact assessment
for developing increasingly sustainable products, processes, facilities, companies, and communities. TRACI 2.0 allows the
quantification of stressors that have potential effects, including ozone depletion, global warming, acidification, eutrophication,
tropospheric ozone (smog) formation, human health criteria-related effects, human health cancer, human health noncancer, ecotoxicity,
and fossil fuel depletion effects. Research is going on to quantify the use of land and water in a future version of TRACI.
The original version of TRACI released in August 2002 (Bare et al. J Ind Ecol 6:49–78, 2003) has been used in many prestigious applications including: the US Green Building Council’s LEED Certification (US Green Building
Council, Welcome to US Green Building Council, 2008), the National Institute of Standards and Technology’s BEES (Building for Environment and Economic Sustainability) (Lippiatt,
BEES 4.0: building for environmental and economic sustainability technical manual and user guide, 2007) which is used by US EPA for Environmentally Preferable Purchasing (US Environmental Protection Agency, Environmentally Preferable
Purchasing (EPP), 2008d), the US Marine Corps’ EKAT (Environmental Knowledge and Assessment Tool) for military and nonmilitary uses (US Marine Corps,
Environmental knowledge and assessment tool (EKAT): first time user’s guide, 2007), and within numerous college curriculums in engineering and design departments.
KeywordsLife cycle impact assessment–Life cycle assessment–Methodology development
Fatty acid profiles of seed oils of 75 plant species having 30% or more fixed oil in their seed/kernel were examined. Saponification number (SN), iodine value (IV) and cetane number (CN) of fatty acid methyl esters of oils were empirically determined and they varied from 169.2 to 312.5, 4.8 to 212 and 20.56 to 67.47, respectively. Fatty acid compositions, IV and CN were used to predict the quality of fatty acid methyl esters of oil for use as biodiesel. Fatty acid methyl ester of oils of 26 species including Azadirachta indica, Calophyllum inophyllum, Jatropha curcas and Pongamia pinnata were found most suitable for use as biodiesel and they meet the major specification of biodiesel standards of USA, Germany and European Standard Organization. The fatty acid methyl esters of another 11 species meet the specification of biodiesel standard of USA only. These selected plants have great potential for biodiesel.
Although biofilms are often associated with hospital infection problems owing to their high resistance to antimicrobial agents, in recent years biofilms have also been studied in the industrial sector, mainly because they are a major cause of contamination outbreaks in facilities and products. The aim of this study was to investigate whether different materials commonly found in the metalworking industries have different biofilm formation characteristics when in contact with contaminated cutting fluid as well as to establish an optimal concentration of a triazine-based antimicrobial agent to protect the oil/water emulsion and also to delay or interrupt the development of biofilms. Biofilms grown on the surface of carbon steel, stainless steel, aluminum, polyvinyl chloride, and glass were analyzed in terms of cell growth and susceptibility to the tested biocide. The results showed that the type of material used had little influence on cell adhesion or on the microbicide concentration required to control and eradicate microorganisms suspended in the emulsion and in the biofilms.
Introduction of biofuels to the fuel matrix poses new questions and challenges. The present study investigates the microbiological stability of biodiesel blends in small scale microcosms. The study presents results from incubations of diesel-biodiesel blends with contaminated inoculation water collected from diesel storage tanks to ensure the presence of relevant fuel degrading bacteria. DAPI and qPCR analyses has subsequently shown an increased bacterial growth and activity in the microcosms containing biodiesel blends as the carbon source compared to those microcosms where neat fossil diesel made up the carbon source. Several anaerobic microorganisms have been identified after incubation. Presence of methanogens, sulfate-reducing bacteria and nitrate reducing bacteria has furthermore been confirmed by chemical analyses, supplemented by observations of methane formation in biodiesel incubations. The findings will contribute to the knowledge base for a safer introduction of biodiesel in the fuel matrix by employment of proper house-keeping and monitoring methods.
The ability of carbon nanotubes (CNTs) to undergo surface modification allows them to form nanocomposites (NCs) with materials such as polymers, metal nanoparticles, biomolecules, and metal oxides. The biocidal nature, protein fouling resistance, and fouling release properties of CNT-NCs render them the perfect material for biofouling prevention. At the same time, the cytotoxicity of CNT-NCs can be reduced before applying them as substrates to promote biofilm formation in environmental biotechnology applications. This paper reviews the potential prospects of CNT-NCs to accomplish two widely varying objectives in environmental engineering applications: (i) preventing biofouling, and (ii) promoting the formation of desirable biofilms on materials surface. This paper addresses practical issues such as costs, risks to human health, and ecological impacts that are associated with the application, development and commercialization of CNT-NC technology.
Recognizing the value of different modeling approaches helped to build consensus when developing a recommended model for assessing the impacts of chemical emissions from a product's life cycle.
Nanofillers modification of epocast-50-A1/946 epoxy for 231 bonded joints
- U A Kashaba
- A A Aljinaidi
- M A Hamed
Kashaba, U. A.; Aljinaidi, A. A.; Hamed, M. A., Nanofillers modification of epocast-50-A1/946 epoxy for
231 bonded joints. Chinese Journal of Aeronautics 2014, 27, (5), 1288-1300.
Application of graphene oxide nanomaterials on surfaces
- D F Rodigues
- Rodigues
Rodigues, D. F. Application of graphene oxide nanomaterials on surfaces; Sustainable Nanotechnology
240 Organization Houston, TX, USA, 2013; pp 1-21.
Corrosion costs and preventive strategies in the United States: supplement to materials performance
- G H Koch
- M P H Bronger
- N G Thompson
- Y P Virmani
- J H Payer
- Koch
Microbiologically influenced corrosion in ship ballast tanks
- A Heyer
- Heyer
Life cycle assessment handbook: a guide for environmentally sustainable products
- M A Curran
- Curran
Ullmann's energy: resources, processes and products
- B Elvers
- Elvers
Life cycle assessment of the use of marine biocides in antifouling paint: A comparison of the environmental profiles between conventional copper based and innovative selektope paint
- S Lin
- D Usino
- Lin
Microbial influenced corrosion of materials: scientific and engineering aspects
- E Heitz
- H C Flemming
- W Sand
- Heitz