108 research outputs found

    Biotalousstrategioiden vertailu

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    World Bioeconomy Forum teki biotalousstrategioiden vertailun huhti–toukokuussa 2023 työ- ja elinkeinoministeriön toimeksiannosta. Vertailussa analysoitiin valittujen alueiden (Brasilia, Yhdysvallat, Kanada, EU, Ruotsi, Suomi, Intia ja Kiina) viimeisimpiä biotalousohjelmia. Vaikka kaikilla alueilla ei ole julkistettua biotalousstrategiaa, niillä on kiinnostusta biotalouden kehittämiseen. Maailmantalouden mahdit ovat selkeästi aktivoituneet biotaloudessa viime aikoina. Myös kansainvälisessä yhteistyössä biotalous on noussut entistä enemmän esille ja biotalous nähdäänkin yhtenä työkaluna globaalien haasteiden ratkaisemisessa. Biotalous ei ole yksiselitteinen käsite ja sen sisältö ja taloudellinen arvo eivät ole vertailukelpoisia eri alueiden suhteen. Tässä työssä eri alueiden biotalouden profiili ja arvo arvioitiin alueiden omien esitysten pohjalta. Eri alueiden biotalouksien vertailussa hyödynnettiin biotalouden visio -jaottelua, jonka mukaan biotalous voidaan jakaa biotekniseen, bioresurssi- tai bioekologiseen lähestymistapaan. Biotekniikan merkitys kasvaa. Bioresurssien käytön suhteen on eroavaisuuksia. Yhdysvallat on lisäämässä omien biomassojen käyttöä, kun EU:ssa suuntaus on ollut vähentää omien biomassojen käyttöä. Kiina haluaa tehostaa omien biomassojen hallintaa. Brasilia näkee mahdollisuuksia lisätä biomassojen käyttöä ja samalla se hakee korkeamman arvonlisän tuotteita

    Phytoremediation for heavy metal‐contaminated soils combined with bioenergy production

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    In June 2007, a project started in Flanders (Belgium) in which we will apply phytoremediation to clean soils that are diffusely polluted with heavy metals. Uptake ranges of heavy metals by rape seed, maize and wheat will be enhanced by increasing the bioavailability of these heavy metals by the addition of biodegradable physico‐chemical agents and by stimulating the heavy‐metal uptake capacity of the microbial community in and around the plant. In addition, the harvested biomass crops will be converted into bioenergy by using different energy‐recovery‐techniques. The energy and heavy metal mass balances will be compared for four different energy‐recovery techniques (anaerobic digestion, incineration, gasification and production of biodiesel). The overall information obtained will result in an economic evaluation of the use of phytoremediation combined with bioenergy production for the remediation of sites which are diffusely polluted with heavy metals. In the present review we will first explain the most important research steps investigated in our phytoremediation project. Secondly, an overview of literature discussing the phytoremediation capacity of rape seed to clean soils that are contaminated with heavy metals and the possibilities to produce biodiesel from this (heavy metal polluted) rape seed will be discussed in more detail. Fitoremediacijos taikymas sunkiaisiais metalais užterštame dirvožemyje derinant su bioenergijos gamyba Santrauka. 2007 m. birželį Flandrijoje (Belgija) pradėtas vykdyti projektas, kuriame mes pritaikysime fitoremediaciją siekdami išvalyti sunkiuosius metalus iš dirvožemio. Sunkiųjų metalų patekimas į rapsus, kukurūzus ir kviečius bus suintensyvintas didinant šių sunkiųjų metalų biopriimamumą dėl pridedamų biodegraduojančių fizikinių-cheminių priedų bei stimuliuojant mikrobiologinių bendrijų pajėgumą augale ir aplink jį sugerti sunkiuosius metalus. Be to, nuimta javų biomasė bus perdirbta į bioenergiją, taikant įvairias energijos gavybos technologijas. Energijos ir sunkiųjų metalų masės balansas bus palygintas pagal keturias skirtingas energijos gavybos technologijas (anaerobinis kompostavimas, deginimas, dujofikavimas ir biodyzelio gamyba). Visa gauta informacija leis ekonominiu požiūriu įvertinti fitoremediacijos, derinamos su bioenergijos gamyba, taikymą valant sunkiaisiais metalais nevienodai užterštus plotus. Pateikiamoje apžvalgoje pirma aptarsime svarbiausius fitoremediacijos projekto etapus. Antra, detaliau apžvelgsime literatūrą apie rapsų pajėgumą išvalyti dirvožemį, užterštą sunkiaisiais metalais, ir galimybes gaminti biodyzelį iš (sunkiaisiais metalais užterštų) rapsų sėklų. Reikšminiai žodžiai: fitoremediacija, sunkieji metalai, biomasė, energijos gamyba, rapsai, biodyzelis. Применение фиторемедиации в почве, загрязненной тяжелыми металлами и приспосабливаемой для производства биоэнергии Резюме. В июне 2007 г. во Фландере (Бельгия) была начата работа над проектом по фиторемедиации с целью очищения почвы от тяжелых металлов. Процесс поглощения тяжелых металлов рапсом, кукурузой и пшеницей будет более интенсивным благодаря введению биодеградирующих физико-химических добавок и стимуляции способности микробиологических сообществ в растении и вокруг него впитывать тяжелые металлы. Снятая биомасса зерновых с помощью различных технологий по производству энергии будет конвертирована в биоэнергию. Баланс энергии и массы тяжелых металлов будет сравнен с помощью четырех разных технологий по производству энергии (анаэробического компостирования, сжигания, газофикации, производства биотоплива). Полученная информация позволит с экономической точки зрения оценить применение фиторемедиации как для очищения площадей, в разной степени загрязненных тяжелыми металлами, так и для производства биоэнергии. В статье прежде всего проанализированы важнейшие этапы проекта по фиторемедиации. Затем произведен обзор литературы о способности рапса благодаря фиторемедиации очищать почву, загрязненную тяжелыми металлами, и возможностях производства биотоплива из семян рапса, загрязненных тяжелыми металлами. Ключевые слова: фиторемедиация, тяжелые металлы, биомасса, производство энергии, семена рапса, биотопливо. First Published Online: 14 Oct 201

    The novel method to reduce the silica content in lignin recovered from black liquor originating from rice straw

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    Difficulties in the production of lignin from rice straw because of high silica content in the recovered lignin reduce its recovery yield and applications as bio-fuel and aromatic chemicals. Therefore, the objective of this study is to develop a novel method to reduce the silica content in lignin from rice straw more effectively and selectively. The method is established by monitoring the precipitation behavior as well as the chemical structure of precipitate by single-stage acidification at different pH values of black liquor collected from the alkaline treatment of rice straw. The result illustrates the significant influence of pH on the physical and chemical properties of the precipitate and the supernatant. The simple two-step acidification of the black liquor at pilot-scale by sulfuric acid 20w/v% is applied to recover lignin at pH 9 and pH 3 and gives a percentage of silica removal as high as 94.38%. Following the developed process, the high-quality lignin could be produced from abundant rice straw at the industrial-scale

    Dynamics of an Oligotrophic Bacterial Aquifer Community during Contact with a Groundwater Plume Contaminated with Benzene, Toluene, Ethylbenzene, and Xylenes: an In Situ Mesocosm Study{dagger}

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    An in situ mesocosm system was designed to monitor the in situ dynamics of the microbial community in polluted aquifers. The mesocosm system consists of a permeable membrane pocket filled with aquifer material and placed within a polypropylene holder, which is inserted below groundwater level in a monitoring well. After a specific time period, the microcosm is recovered from the well and its bacterial community is analyzed. Using this system, we examined the effect of benzene, toluene, ethylbenzene, and xylene (BTEX) contamination on the response of an aquifer bacterial community by denaturing gradient gel electrophoresis analysis of PCR-amplified 16S rRNA genes and PCR detection of BTEX degradation genes. Mesocosms were filled with nonsterile or sterile aquifer material derived from an uncontaminated area and positioned in a well located in either the uncontaminated area or a nearby contaminated area. In the contaminated area, the bacterial community in the microcosms rapidly evolved into a stable community identical to that in the adjacent aquifer but different from that in the uncontaminated area. At the contaminated location, bacteria with tmoA- and xylM/xylE1-like BTEX catabolic genotypes colonized the aquifer, while at the uncontaminated location only tmoA-like genotypes were detected. The communities in the mesocosms and in the aquifer adjacent to the wells in the contaminated area consisted mainly of Proteobacteria. At the uncontaminated location, Actinobacteria and Proteobacteria were found. Our results indicate that communities with long-term stability in their structures follow the contamination plume and rapidly colonize downstream areas upon contaminatio

    Hydrodynamic characterisation of a groundwater - surface water system and evaluation of BTEX, PAHs decay and heavy metals fate

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    Most contaminated sites related to past industrial activities in Europe are adjacent to rivers and urbanized areas. These sites pose a major problem for water authorities and policy makers in terms of contaminants mobility, natural attenuation (or degradation) and risk assessment for environment and humans. Natural attenuation in groundwater is only effective if hydrogeochemical conditions of the system are favourable and contaminant degrading microorganisms are present. To evaluate this effectiveness, many site specific factors have to be considered, among which the dynamics of groundwater fluxes and groundwater – surface water interactions and biogeochemical processes. The site of concern in this study is a brownfield located in the north bank of the Meuse River, upstream of the city of Liège, Belgium. The soil, the unsaturated zone and the gravel aquifer are heavily contaminated by organic pollutants (BTEX and PAHs) and metals due to past industrial activities of coke production in the XXth Century. Various point sources of contaminants were delineated in the site. Benzene and Toluene concentrations in groundwater were found up to 50.000 μg l-1 and 23.000 μg l-1 respectively in source areas, while pollution due to metals was less important, with presence of Fe (> 6400 μg l-1), Zn (40 μg l-1), Co (18 μg l-1), Cu (>9 μg l-1), Pb (>100 μg l-1) and Cr (2 μg l-1) mainly with higher concentrations in some hot spots. The Meuse River level is established at around 59.5 meters a.s.l. by dams. However, river water levels fluctuate continuously with amplitude varying between a few centimetres up to 2 meters during winter and spring seasons. The main objectives of the research investigations were 1) to evaluate whether an interaction exists, at the level of the mentioned brownfield, between groundwater and the neighbouring river; 2) to assess the dynamics of such interactions and to quantify groundwater fluxes as the main potential vector of mobility of contaminants offsite; 3) to determine the potential of bacterial degradation of organic compounds and fate of metals contaminants in the specific environment of the site; and 4) to integrate groundwater – surface water dynamics with potential degradation of contaminants in order to evaluate further evolutions of contaminants in the aquifer. A detailed monitoring of groundwater and surface water levels, together with a series of field tests like pumping and tracer tests, contributed to a good knowledge in hydrodynamics of the contaminated aquifer. Groundwater and surface water monitoring datasets were analyzed in order to characterize hydraulic dynamics of the groundwater – surface water system. Groundwater heads observed were strongly influenced by Meuse River stages, and groundwater flow in the transition zone (seepage) was oriented in the direction going from the aquifer to the river under normal conditions. The use of an analytical model, however, pointed out that small changes on water river level were enough for a groundwater flow inversion, so seepage going from the Meuse River into the aquifer. Organic compounds (mainly benzene and low weight PAHs) have been studied with respect to their intrinsic bacterial degradation potential. Two independent stable isotope-based approaches (laboratory and field) were used to determine in situ biodegradation rates for benzene, and for the two- and three-ring aromatic hydrocarbons naphthalene and acenaphthene. In the laboratory, microcosms were set up with 13C-labeled substrates as well as with groundwater and with sediments from the site. The increase in 13C-CO2 over time was monitored by GC-IRMS analysis and used to calculate biodegradation rates. Benzene, naphthalene and acenaphthene were found to be biodegradable by the intrinsic microbial community under in situ-like conditions. The respective biodegradation rates decreased with increasing number of aromatic rings and were significantly lower under anoxic conditions. Apart from the microcosm study, in situ-biodegradation rates could be retrieved in a field study from 13C/12C signatures of residual groundwater contaminants using first-order kinetics. Biodegradation rates of lab- and field-based approaches were found to be in good agreement. Batch tests revealed that the heavy metals could be precipitated under sulphate (present at the site) reducing conditions. This in situ bioprecipitation process can be induced by the presence of electron donors and plays an important role in the natural attenuation process. Other conditions as aerobic or nitrate reducing conditions, did not lead to heavy metal immobilization. This gives specific indications about future site management and land use. It was also proved that the present heavy metal concentration did not influence the PAH biodegradation. However, PAH biodegradation under aerobic conditions is very slow. Further investigations will be necessary to evaluate the effect of aerobic biodegradation (addition of air) on the mobilization of the heavy metals, bound to the aquifer. The continuous changes of the groundwater flow direction observed in the studied site, lead to surface water flowing into the aquifer. This is likely to be an additional source of oxygen for the aquifer. This influx of oxygen-saturate water could enhance the degradation of BTEX and PAHs in the regions of the aquifer which are affected. Further investigations are needed to come to a qualitative evaluation to what extent oxygen from river water contributes to the removal of BTEX and PAHs at the site

    DNA Probe-Mediated Detection of Resistant Bacteria from Soils Highly Polluted by Heavy Metals

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    Alcaligenes eutrophus CH34 DNA fragments encoding resistance to Cd(2+), Co(2+), Zn(2+) (czc), or Hg(2+) (merA) were cloned and used as probes in colony hybridization procedures with bacteria isolated from polluted environments such as a zinc factory area (desertified because of the toxic effects of zinc contamination) and from sediments from factories of nonferrous metallurgy in Belgium and mine areas in Zaire. From the different soil samples, strains could be isolated and hybridized with the czc probe (resistance to Cd(2+), Co(2+), and Zn(2+) from plasmid pMOL30). Percentages of CFU isolated on nonselective plates which hybridized with the czc and the mercury resistance probes were, respectively, 25 and 0% for the zinc desert, 15 to 20 and 10 to 20% for the two Belgian factories, and 40 and 40% for the Likasi mine area. Most of these strains also carried two large plasmids of about the same size as those of A. eutrophus CH34 and shared many phenotypic traits with this strain. These findings indicated a certain correlation between the heavy-metal content in contaminated soils and the presence of heavy-metal-resistant megaplasmid-bearing A. eutrophus strains

    Synergistic effects of sulfate reducing bacteria and zero valent iron on zinc removal and stability in aquifer sediment

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    International audienceWe conducted a series of flow-through column experiments using aquifer sediment treated with zero valent iron (Fe-0) with or without active microbial sulfate reduction. The aim of this study was to investigate the stability of Zn removed by Fe-0 and impact of sulfate reducing bacteria (SRB). The leaching of Zn was assessed by flushing the aquifer in vertical glass columns with groundwater that was pre-treated with mixture of gases to simulate natural changes (pH and ORP) in subsurface environment (N-2 + CO2 for pH and N-2 + O-2 for ORP) along with a control (N-2 flushed). Zinc removed synergistically by Fe and SRBs was found to be more stable and did not leach from the aquifer sediment with pH or redox changes. We also observed that the Zn leaching in the aquifer treated only with Fe was more influenced by change in redox than by pH changes. These results were also confirmed by sequential metal extractions and scanning electron microscopy observations in the aquifer sediments. Mineral phases were predicted using geochemical modeling tool CHESS confirming that the metal removed in Fe-o + SRB conditions formed more stable precipitates and did not show any signs of leaching back to groundwater upon change in pH and redox conditions. (C) 2014 Elsevier B.V. All rights reserved
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