The electrochemistry of a gelatin modified gold electrode

This paper discusses the electrochemical behaviour of gelatin coated gold electrodes in physiological pH conditions in a potential window -1.5 till 1.0 V vs SCE by performing cyclic voltammetry. A comparison is made between gelatin A and gelatin B, which have respectively a positive and a negative net charge at physiological pH. The deposition of gelatin onto the gold surface is confirmed by means of attenuated total reflection-infrared (ATR-IR) spectroscopic analyses

Трендсеттінг як ключовий фактор управління інноваційними ризиками індустрії моди

Індустрія моди нового тисячоріччя перетворилася в багатомільйонний сектор економіки, у котрому інноваційна діяльність грає ключову роль. Інновації в дизайні сучасного костюма з інструмента вдосконалювання характеристик об’єкта перетворюються в одну з основних його характеристик, тому фешн-проекти є інноваційними за своєю природою [2]

Phytoremediation for heavy metal‐contaminated soils combined with bioenergy production

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

Synergistic Degradation of Linuron by a Bacterial Consortium and Isolation of a Single Linuron-Degrading Variovorax Strain

The bacterial community composition of a linuron-degrading enrichment culture and the role of the individual strains in linuron degradation have been determined by a combination of methods, such as denaturing gradient gel electrophoresis of the total 16S rRNA gene pool, isolation and identification of strains, and biodegradation assays. Three strains, Variovorax sp. strain WDL1, Delftia acidovorans WDL34, and Pseudomonas sp. strain WDL5, were isolated directly from the linuron-degrading culture. In addition, subculture of this enrichment culture on potential intermediates in the degradation pathway of linuron (i.e., N,O-dimethylhydroxylamine and 3-chloroaniline) resulted in the isolation of, respectively, Hyphomicrobium sulfonivorans WDL6 and Comamonas testosteroni WDL7. Of these five strains, only Variovorax sp. strain WDL1 was able to use linuron as the sole source of C, N, and energy. WDL1 first converted linuron to 3,4-dichloroaniline (3,4-DCA), which transiently accumulated in the medium but was subsequently degraded. To the best of our knowledge, this is the first report of a strain that degrades linuron further than the aromatic intermediates. Interestingly, the rate of linuron degradation by strain WDL1 was lower than that for the consortium, but was clearly increased when WDL1 was coinoculated with each of the other four strains. D. acidovorans WDL34 and C. testosteroni WDL7 were found to be responsible for degradation of the intermediate 3,4-DCA, and H. sulfonivorans WDL6 was the only strain able to degrade N,O-dimethylhydroxylamine. The role of Pseudomonas sp. strain WDL5 needs to be further elucidated. The degradation of linuron can thus be performed by a single isolate, Variovorax sp. strain WDL1, but is stimulated by a synergistic interaction with the other strains isolated from the same linuron-degrading culture

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}

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

Impact of a wastewater treatment plant on microbial community composition and function in a hyporheic zone of a eutrophic river

The impact of the installation of a technologically advanced wastewater treatment plant (WWTP) on the benthic microbial community of a vinyl chloride (VC) impacted eutrophic river was examined two years before, and three and four years after installation of the WWTP. Reduced dissolved organic carbon and increased dissolved oxygen concentrations in surface water and reduced total organic carbon and total nitrogen content in the sediment were recorded in the post-WWTP samples. Pyrosequencing of bacterial 16S rRNA gene fragments in sediment cores showed reduced relative abundance of heterotrophs and fermenters such as Chloroflexi and Firmicutes in more oxic and nutrient poor post-WWTP sediments. Similarly, quantitative PCR analysis showed 1-3 orders of magnitude reduction in phylogenetic and functional genes of sulphate reducers, denitrifiers, ammonium oxidizers, methanogens and VC-respiring Dehalococcoides mccartyi. In contrast, members of Proteobacteria adapted to nutrient-poor conditions were enriched in post-WWTP samples. This transition in the trophic state of the hyporheic sediments reduced but did not abolish the VC respiration potential in the post-WWTP sediments as an important hyporheic sediment function. Our results highlight effective nutrient load reduction and parallel microbial ecological state restoration of a human-stressed urban river as a result of installation of a WWTP.Peer reviewe

Impact of chemical oxidants on the heavy metals and the microbial population in sediments

In this study, chemical oxidation was applied to treat three contaminated sediments. All the sediments were contaminated with mineral oil, polycyclic aromatic hydrocarbons and heavy metals and had an organic matter content ranging from 2.4 to 7.6 %. The natural oxidant demand of the sediments was determined during treatment with two different types of oxidants (potassium permanganate and sodium persulfate), and the effect of these oxidants on the heavy metal release and on the microbial community was investigated. The natural oxidant demands of the sediments under persulfate treatment were lower (30-100 g kg(-1)) than the ones treated with permanganate (50-450 g kg(-1)). Cr was released during the application of permanganate whereas Zn and Pb were released under persulfate treatment. qPCR results showed that permanganate and persulfate, both at a concentration of 150 g kg(-1), caused a decrease (2 log units) in the number of 16S rRNA gene of total bacteria in the sediment having the lowest organic matter content. However, the total ATP, considered as a biomarker for microbial activity, was below detection limit in all sediments in the presence of at least 150 g kg(-1) oxidant. Only permanganate induced a shift in the structure of the microbial community