185 research outputs found

    Circular economy and closing nutrient cycles:planning sustainable bio-waste management system for Puolanka municipality

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    Abstract. The government of Finland has set five-year National waste plan (2018–2023) with the theme “From recycling to circular economy” and the plan aims to sustainable waste management and waste prevention. Adapting circular economy shall bring three positives: economic growth, social development and lower environmental impact, when progressing towards sustainable development. The theory part defines and details the terms circular economy and how it is better than linear system; industrial ecology; cradle to cradle; low-carbon economy; nutrient cycle and the significance on closing the cycle; then defining fertiliser and the types of fertilisers and why to choose natural fertilizers over chemical fertilizers? Also, there is a mention of relevant EU regulations and directives for maintaining the quality and providing best living environment for all. Lastly the technologies that are used for managing the municipal bio-waste and the comparative advantages of anaerobic digestion (AD) over composting on the basis of sustainability are defined. In the experimental part, the current situation of separately collected bio-waste in Puolanka municipality in Kainuu (Status quo: transported to Kajaani for composting in Majasaari waste center) was compared with the other possible scenarios: — Scenario I: If separately collected bio-waste were transported to Oulu to be treated in existing biogas plant — Scenario II: If separately collected bio-waste were treated in Puolanka locally in new biogas plant The aim was to recommend best suitable management-option for long-term sustainability of source separated bio-waste in Puolanka municipality based on closing the nutrient cycle and boosting circular economy. The data were collected and appropriate calculations for sizing and feasibility studies were made. The Sustainability Assessment tests were performed using RECENT project’s sustainability assessment templates based on calculations and collected information. It was observed from sustainability outcomes that Status quo would be the least preferred option even though it was economical than Scenario I because the use of composting technology caused greenhouse gas emissions and didn’t have long-term socio-economic benefits. Also, Scenario II had an advantage over Scenario I for an impact on environment and community since creating an own anaerobic digester provides community a privilege of clean renewable energy (biogas) and its energy output was possible to replace our dependency on fossil fuel consumption. It was found that Scenario II is totally attainable, with only 3,22 years of payback period. The calculative biogas energy output for a year with 165,478 t of bio-waste/year was 144,8 MWh that would be enough to replace the annual fuel demand of 10,9 petrol-based cars and 15,4 diesel-based cars. The value of annual digestate (sanitized co-product of biogas process) sales was 1 556,3 €; annual district heating revenue was 13 694 €; and reduction of 40,37 t of CO₂e per year. The economic boost with reduction of gate fee and transportation charges and increase in job or business opportunities at Puolanka itself makes it more evident that Scenario II, the proposed AD plant in Puolanka is the best solution for the source separated bio-waste management for closing nutrient cycle as well as in achieving circular economy through circulation of the waste as an input to convert into energy in maintaining long term benefits. Thus, this thesis is an intensive consolidation of theory and experiment to understand that circulation of resources boosts circular economy and closing the nutrient cycle in biosphere is important. The future recommendations would be a detailed study on the feasibility (in terms of investments) for Scenario II (maximum use of local bio-refineries). Also, co-digestion (adding two or more substrates) as feed-inputs would boost in the production of biogas contributing to high clean renewable energy output.Tiivistelmä. Suomen hallitus on tehnyt viiden vuoden (2018–2023) jätesuunnitelman ”Kierrätyksestä kiertotalouteen”, jonka tavoitteena on kestävä jätehuolto ja jätteiden synnyn ehkäiseminen. Kiertotalouden omaksuminen tuo mukanaan kolme positiivista asiaa: talouskasvun, sosiaalisen kehityksen ja ympäristövaikutusten pienenemisen, edeten samalla kohti kestävää kehitystä. Teoreettinen osa määrittelee ja täsmentää kiertotalouden termejä ja kuvaa sitä, miten kiertotalous on parempi kuin lineaarinen järjestelmä; kuvaa, mitä ovat teollinen ekologia, vähähiilinen talous, ravinnekierto ja ravinteiden kierron sulkemisen tärkeys, tarkastelee erilaisia lannoitetyyppejä ja syitä miksi valita luonnonlannoitteet keinolannoitteiden sijaan. Myös asiankuuluvat EU:n säännökset ja direktiivit laadun ylläpitämiseksi ja hyvän elinympäristön turvaamiseksi kerrotaan. Lopuksi selvitetään biojätteiden käsittelyyn käytetyt tekniikat ja anaerobisen mädätyksen edut kompostointiin verrattuna kestävyyden kannalta tarkasteltuna. Kokeellisessa osassa Kainuussa sijaitsevan Puolangan kunnan nykyistä erilliskerätyn biojätteen käsittelyä (kuljetus ja kompostointi Kajaanin Majasaaren jätekeskuksessa) verrattiin muihin mahdollisiin skenaarioihin: — Skenaario I: Erilliskerätyt biojätteet kuljetetaan Ouluun käsiteltäväksi nykyisessä biokaasulaitoksessa — Skenaario II: Erilliskerätyt biojätteet käsitellään Puolangassa paikallisesti uudessa biokaasulaitoksessa Tavoitteena oli suositella parasta ja sopivinta vaihtoehtoa näiden kolmen vaihtoehdon väliltä yleisen kestävyyden kannalta tarkasteltuna sekä ravinnekierron sulkemisen ja kiertotalouden edistämiseksi. Tiedot kerättiin ja tehtiin asianmukaiset laskelmat biokaasureaktorin mitoittamiseen ja biokaasulaitoksen taloudelliseen kannattavuuteen liittyen. Kestävyysarviointi suoritettiin käyttäen RECENT-projektin kestävyydenarviointitemplaatteja tehtyihin laskelmiin ja kerättyyn tietoon perustuen. Kestävyysarvioinnin tulosten perusteella todettiin, että nykytilanne olisi vähiten suositeltava vaihtoehto, vaikka se olisi ollut skenaarioon I verrattuna taloudellisempaa, koska kompostointiteknologian käyttö aiheutti päästöjä eikä sillä ollut pitkäaikaisia sosioekonomisia hyötyjä. Skenaariossa II oli myös etu skenaarioon I verrattuna, sillä skenaario II vaikutti ympäristöön ja yhteisöön, koska oman biokaasulaitoksen hankkiminen tarjoaa yhteisölle etuoikeuden puhtaaseen uusiutuvaan energiaan (biokaasu) ja sen energiantuotannolla olisi mahdollista vähentää riippuvuutta fossiilisista polttoaineista. Todettiin, että skenaario II on täysin saavutettavissa, ja sen takaisinmaksuaika on vain 3,22 vuotta. Biokaasun laskennallinen energiantuotanto 165,478 tonnille biojätettä vuodessa vuodessa oli 144,8 MWh, joka riittää korvaamaan 10,9 bensiiniauton ja 15,4 dieselauton vuosittaisen polttoaineenkulutuksen. Biokaasuprosessista saatavan mädätteen vuosittainen arvo oli 1 556,3 €; vuosittainen kaukolämmön tuoton arvo 13 694 euroa; ja hiilidioksidipäästöjen väheneminen 40,37 t CO₂e vuodessa. Puolangan saamat taloudelliset edut porttimaksujen ja kuljetuskustannusten alenemisen sekä työpaikkojen tai liiketoimintamahdollisuuksien lisääntymisen myötä lisää selvyyttä siitä, että Skenaario II, Puolangan uusi biokaasulaitos, on paras vaihtoehto jätteenkäsittelylle Puolangan kunnassa ravinnekierron sulkemiseksi ja kiertotalouden aikaansaamiseksi jätteiden kierrätyksen kautta jätteen ollessa syötteenä energiantuotannossa pitkän aikavälin hyötyjen ylläpitämiseksi. Tämä diplomityö on intensiivinen teorian ja käytännön yhdistely sen ymmärtämiseksi, että resurssien kierrättäminen vahvistaa kiertotaloutta ja ravinnekierron sulkeminen biosfäärissä on tärkeää. Suosituksia jatkotutkimuksille ovat yksityiskohtainen selvitys (investointien osalta) skenaarion II toteutettavuudesta (paikallisten biojalostamojen mahdollisimman suuri käyttö). Myös yhteismädätys (kaksi tai useampi syötettä samalla laitoksella) lisäisi biokaasun tuotantoa, mikä puolestaan lisäisi puhtaan uusiutuvan energian tuotantoa

    The structure of Lactobacillus brevis surface layer reassembled on liposomes differs from native structure as revealed by SAXS

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    AbstractThe reassembly of the S-layer protein SlpA of Lactobacillus brevis ATCC 8287 on positively charged liposomes was studied by small angle X-ray scattering (SAXS) and zeta potential measurements. SlpA was reassembled on unilamellar liposomes consisting of 1-palmitoyl-2-oleyl-sn-glycero-3-phosphocholine and 1,2-dioleoyl-3-trimethylammonium-propane, prepared by extrusion through membranes with pore sizes of 50nm and 100nm. Similarly extruded samples without SlpA were used as a reference. The SlpA-containing samples showed clear diffraction peaks in their SAXS intensities. The lattice constants were calculated from the diffraction pattern and compared to those determined for SlpA on native cell wall fragments. Lattice constants for SlpA reassembled on liposomes (a=9.29nm, b=8.03nm, and γ=84.9°) showed a marked change in the lattice constants b and γ when compared to those determined for SlpA on native cell wall fragments (a=9.41nm, b=6.48nm, and γ=77.0°). The latter are in good agreement with values previously determined by electron microscopy. This indicates that the structure formed by SlpA is stable on the bacterial cell wall, but SlpA reassembles into a different structure on cationic liposomes. From the (10) reflection, the lower limit of crystallite size of SlpA on liposomes was determined to be 92nm, corresponding to approximately ten aligned lattice planes

    Nanosilver-Silica Composite : Prolonged Antibacterial Effects and Bacterial Interaction Mechanisms for Wound Dressings

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    Infected superficial wounds were traditionally controlled by topical antibiotics until the emergence of antibiotic-resistant bacteria. Silver (Ag) is a kernel for alternative antibacterial agents to fight this resistance quandary. The present study demonstrates a method for immobilizing small-sized (similar to 5 nm) silver nanoparticles on silica matrix to form a nanosilver-silica (Ag-SiO2) composite and shows the prolonged antibacterial effects of the composite in vitro. The composite exhibited a rapid initial Ag release after 24 h and a slower leaching after 48 and 72 h and was effective against both methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli (E. coli). Ultraviolet (UV)-irradiation was superior to filter-sterilization in retaining the antibacterial effects of the composite, through the higher remaining Ag concentration. A gauze, impregnated with the Ag-SiO2 composite, showed higher antibacterial effects against MRSA and E. coli than a commercial Ag-containing dressing, indicating a potential for the management and infection control of superficial wounds. Transmission and scanning transmission electron microscope analyses of the composite-treated MRSA revealed an interaction of the released silver ions with the bacterial cytoplasmic constituents, causing ultimately the loss of bacterial membranes. The present results indicate that the Ag-SiO2 composite, with prolonged antibacterial effects, is a promising candidate for wound dressing applications.Peer reviewe

    Silica-gentamicin nanohybrids : combating antibiotic resistance, bacterial biofilms, and in vivo toxicity

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    Introduction: Antibiotic resistance is a growing concern in health care. Methicillin-resistant Staphylococcus aureus (MRSA), forming biofilms, is a common cause of resistant orthopedic implant infections. Gentamicin is a crucial antibiotic preventing orthopedic infections. Silica-gentamicin (SiO2-G) delivery systems have attracted significant interest in preventing the formation of biofilms. However, compelling scientific evidence addressing their efficacy against planktonic MRSA and MRSA biofilms is still lacking, and their safety has not extensively been studied. Materials and methods: In this work, we have investigated the effects of SiO2-G nanohybrids against planktonic MRSA as well as MRSA and Escherichia coli biofilms and then evaluated their toxicity in zebrafish embryos, which are an excellent model for assessing the toxicity of nanotherapeutics. Results: SiO2-G nanohybrids inhibited the growth and killed planktonic MRSA at a minimum concentration of 500 mu g/mL. SiO2-G nanohybrids entirely eradicated E. coli cells in biofilms at a minimum concentration of 250 mu g/mL and utterly deformed their ultrastructure through the deterioration of bacterial shapes and wrinkling of their cell walls. Zebrafish embryos exposed to SiO2-G nanohybrids (500 and 1,000 mu g/mL) showed a nonsignificant increase in mortality rates, 13.4 +/- 9.4 and 15%+/- 7.1%, respectively, mainly detected 24 hours post fertilization (hpf). Frequencies of malformations were significantly different from the control group only 24 hpf at the higher exposure concentration. Conclusion: Collectively, this work provides the first comprehensive in vivo assessment of SiO2-G nanohybrids as a biocompatible drug delivery system and describes the efficacy of SiO2-G nanohybrids in combating planktonic MRSA cells and eradicating E. coli biofilms.Peer reviewe

    Environmental awareness gained during a citizen science project in touristic resorts is maintained after 3 years since participation

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    The research leading to these results has received funding from Project AWARE Foundation, ASTOI Association, Milano, Ministry of Tourism of the Arab Republic of Egypt, Settemari S. p. A Tour Operator, Scuba Nitrox Safety International, Viaggio nel Blu Diving Center.Tourism is one of the largest economic sectors in the world. It has a positive effect on the economy of many countries, but it can also lead to negative impacts on local ecosystems. Informal environmental education through Citizen Science (CS) projects can be effective in increasing citizen environmental knowledge and awareness in the short-term. A change of awareness could bring to a behavioral change in the long-term, making tourism more sustainable. However, the long-term effects of participating in CS projects are still unknown. This is the first follow-up study concerning the effects of participating in a CS project on cognitive and psychological aspects at the basis of pro-environmental behavior. An environmental education program was developed, between 2012 and 2013, in a resort in Marsa Alam, Egypt. The study directly evaluated, through paper questionnaires, the short-term (after 1 week or 10 days) retention of knowledge and awareness of volunteers that had participated in the activities proposed by the program. After three years, participants were re-contacted via email to fill in the same questionnaire as in the short-term study, plus a new section with psychological variables. 40.5% of the re-contacted participants completed the follow-up questionnaires with a final sample size of fifty-five people for this study. Notwithstanding the limited sample size, positive trends in volunteer awareness, personal satisfaction regarding the CS project, and motivation to engage in pro-environmental behavior in the long-term were observed.Publisher PDFPeer reviewe

    Gene expression and metabolite profiling of Populus euphratica growing in the Negev desert

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    BACKGROUND: Plants growing in their natural habitat represent a valuable resource for elucidating mechanisms of acclimation to environmental constraints. Populus euphratica is a salt-tolerant tree species growing in saline semi-arid areas. To identify genes involved in abiotic stress responses under natural conditions we constructed several normalized and subtracted cDNA libraries from control, stress-exposed and desert-grown P. euphratica trees. In addition, we identified several metabolites in desert-grown P. euphratica trees. RESULTS: About 14,000 expressed sequence tag (EST) sequences were obtained with a good representation of genes putatively involved in resistance and tolerance to salt and other abiotic stresses. A P. euphratica DNA microarray with a uni-gene set of ESTs representing approximately 6,340 different genes was constructed. The microarray was used to study gene expression in adult P. euphratica trees growing in the desert canyon of Ein Avdat in Israel. In parallel, 22 selected metabolites were profiled in the same trees. CONCLUSION: Of the obtained ESTs, 98% were found in the sequenced P. trichocarpa genome and 74% in other Populus EST collections. This implies that the P. euphratica genome does not contain different genes per se, but that regulation of gene expression might be different and that P. euphratica expresses a different set of genes that contribute to adaptation to saline growth conditions. Also, all of the five measured amino acids show increased levels in trees growing in the more saline soil

    Biochemical classification of tauopathies by immunoblot, protein sequence and mass spectrometric analyses of sarkosyl-insoluble and trypsin-resistant tau

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    Intracellular filamentous tau pathology is the defining feature of tauopathies, which form a subset of neurodegenerative diseases. We have analyzed pathological tau in Alzheimer’s disease, and in frontotemporal lobar degeneration associated with tauopathy to include cases with Pick bodies, corticobasal degeneration, progressive supranuclear palsy, and ones due to intronic mutations in MAPT. We found that the C-terminal band pattern of the pathological tau species is distinct for each disease. Immunoblot analysis of trypsin-resistant tau indicated that the different band patterns of the 7–18 kDa fragments in these diseases likely reflect different conformations of tau molecular species. Protein sequence and mass spectrometric analyses revealed the carboxyl-terminal region (residues 243–406) of tau comprises the protease-resistant core units of the tau aggregates, and the sequence lengths and precise regions involved are different among the diseases. These unique assembled tau cores may be used to classify and diagnose disease strains. Based on these results, we propose a new clinicopathological classification of tauopathies based on the biochemical properties of tau
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