Clean Technologies and Recycling最新文献

{"title":"Effect of moisture absorption-desorption cycles, UV irradiation and coupling agent on the mechanical performance of pinewood waste/polyethylene composites","authors":"Javier Guillén-Mallette, Irma Flores-Cerón, Soledad Cecilia Pech-Cohuo, Edgar José López-Naranjo, Carlos Vidal Cupul-Manzano, Alex Valadez-González, Ricardo Herbé Cruz-Estrada","doi":"10.3934/ctr.2023013","DOIUrl":"https://doi.org/10.3934/ctr.2023013","url":null,"abstract":"<abstract> <p>The effects of UV radiation, a maleic anhydride grafted polyethylene (MAPE) coupling agent and moisture cycling exposure on wood plastic composites (WPC) made from pinewood waste (PW) and high-density polyethylene (HDPE) on their tensile and flex properties, were studied. First, the effect of UV radiation and the presence of anhydride grafted polyethylene on the absorption-desorption behavior of the compounds was evaluated and then its effect on the mechanical properties. Scanning electron microscopy (SEM) was used to analyze the surfaces of the samples subjected to these factors and their subsequent damage in fracture zones of the samples. The moisture absorption-desorption process exhibited a two-stage mechanism: the first is significant increases in the absorption values in the first five cycles, and a second stabilization stage that occurs from the sixth cycle onwards. The first stage includes several steps: initial absorption and delamination; capillary action and polymer-wood interaction; and swelling, fiber-matrix interaction and mechanical damage. The second stage involves the balance and stabilization step. Statistically, it was found that the changes in the humidity values in the absorption and desorption cycles show that UV radiation has a significant contribution with the effect of increasing the absorption and desorption values, while the presence of anhydride grafted polyethylene as a lesser effect with an effect of decreasing those values. The tensile and flexural properties of the compounds were significantly affected by UV radiation and moisture cycling. Taking the sample without anhydride grafted polyethylene and without treatments as a reference, only a slight increase of 5–12% in its tensile and flexural properties was observed, while treatments with UV radiation and absorption-desorption cycles reduced them by up to 45%. The SEM analysis confirmed the deterioration of the composites in the form of microcracks, delamination, interfacial voids and mechanical failures in both the wood filler and the polyethylene matrix, especially in the samples exposed to ultraviolet radiation, where this deterioration was lower in the samples containing anhydride grafted polyethylene.</p> </abstract>","PeriodicalId":500288,"journal":{"name":"Clean Technologies and Recycling","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135649366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Identification of marine micro algae in correlation with water quality assessment of coastal region of Maharashtra, India","authors":"Smita M. Pore, Vinayak P. Dhulap","doi":"10.3934/ctr.2023016","DOIUrl":"https://doi.org/10.3934/ctr.2023016","url":null,"abstract":"<abstract> <p>The recent marine algae study was carried out in the coastal region of Maharashtra, which is a district of Ratnagiri, Sindhudurg between 2021 and 2022. Water and algae samples were collected between September to October, mainly because to availability of algae is maximum in this period. The sampling locations were decided based on both previous work performed by researchers and on a literature review. The sampling sites were fixed based on the size of study area, sampling site accessibility, availability of algae on surface and substratum of the rock or wall. The microalgae were collected and preserved in plastic jar containing 3% to 4% formalin. The water samples were collected and specific physical and chemical parameters such as pH with pH meter, dissolved oxygen (mg/L) by DO meter, and temperature (Celsius) by digital thermometer were analyzed in situ. The remaining physical and chemical parameters were analyzed in the departmental research laboratory using standard methods outlined by the American Public Health Association (APHA). The collected micro algae were identified by a standard microscopy method using key references and with the help of algae experts. The main objective of the present research was to conduct extensive research on the collection and identification of diverse algal species in a coastal region to determine algal diversity, to determine the water quality standard and to measure the occurrence of algae in water.</p> </abstract>","PeriodicalId":500288,"journal":{"name":"Clean Technologies and Recycling","volume":"153 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135507962","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A possible direct recycling of dredged sediments from the Usumacinta River (Mexico) into fired bricks","authors":"Mazhar Hussain, Daniel Levacher, Nathalie Leblanc, Hafida Zmamou, Irini Djeran-Maigre, Andry Razakamanantsoa, Ali Hussan","doi":"10.3934/ctr.2023012","DOIUrl":"https://doi.org/10.3934/ctr.2023012","url":null,"abstract":"<abstract> <p>Reuse of dredged sediments is an effective approach to waste management. This study focuses on the reuse of Usumacinta River dredged sediments in fired bricks. Physico-chemical characteristics of sediments were investigated for their reuse. The grain size of sediments shows that Usumacinta sediments have a sandy texture with low organic matter. The presence of contaminants in these sediments is negligible. Suitability for bricks was observed with a clay workability chart, Winkler, and Augustinik diagram. Bricks were molded into cubic and prismatic brick specimens of size 20 × 20 × 20 mm³ and 15 × 15 × 60 mm³ for compressive and tensile strength. The molding moisture content of sediments was defined with the Sembenelli diagram. Bricks were dried at 60 ℃ and fired at a temperature of 700 to 1100 ℃. Linear shrinkage and density of Usumacinta sediments bricks increase with increasing temperature. Clayey sediments (T2 and J4) show higher shrinkage on drying. Testing of bricks shows their compressive strength varies between 0.10 to 19.38 MPa and the indirect tensile strength varies from 0.17 to 12.82 MPa. T2 sediment bricks have the lowest strength due higher percentage of sand. The compressive strength of bricks from T5 and J4 is comparatively higher and satisfies the strength requirements of bricks at a moderate temperature of 850 ℃.</p> </abstract>","PeriodicalId":500288,"journal":{"name":"Clean Technologies and Recycling","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135594737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Artificial intelligence for Circular Economy 2.0: Opportunities, challenges, and outlook","authors":"Babu George","doi":"10.3934/ctr.2023011","DOIUrl":"https://doi.org/10.3934/ctr.2023011","url":null,"abstract":"<jats:p xml:lang=\"fr\" />","PeriodicalId":500288,"journal":{"name":"Clean Technologies and Recycling","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135498116","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Challenges of existing grid codes and the call for enhanced standards","authors":"Anshu Murdan, Iqbal Jahmeerbacus, S Z Sayed Hassen","doi":"10.3934/ctr.2023015","DOIUrl":"https://doi.org/10.3934/ctr.2023015","url":null,"abstract":"<abstract> <p>The escalating penetration of renewable energy, notably wind and solar, introduces unique complexities into power systems, particularly in frequency and voltage regulation. Current grid codes are inadequate for these emerging dynamics, necessitating significant enhancements to cope with the evolving energy landscape. The paper highlights several pivotal areas of improvement, including increased flexibility within power systems, integration of energy storage systems, expansion of ancillary services, the inclusion of grid-forming inverters, and the international harmonization of grid codes. The research underscores that conventional power system methodologies, primarily reliant on traditional power plants, fail to manage the fluctuating supply-demand dynamics of renewable energy effectively. By proposing improvements in grid codes, the research contributes towards resolving this issue. Furthermore, the paper underlines the paramount importance of international harmonization of grid codes for system interoperability, efficient operation, and exchange of best practices across diverse regions. Through its exhaustive exploration and recommendations, the study empowers policymakers, grid operators, and energy producers to advance grid code frameworks. Consequently, this facilitates renewable energy integration, ensures grid stability, and paves the way for a more sustainable energy future.</p> </abstract>","PeriodicalId":500288,"journal":{"name":"Clean Technologies and Recycling","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135798897","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Glass fibre composites recycling using the fluidised bed: A study into the economic viability in the UK","authors":"Kyle Pender, Liu Yang","doi":"10.3934/ctr.2023014","DOIUrl":"https://doi.org/10.3934/ctr.2023014","url":null,"abstract":"<abstract> <p>As it stands, the UK has no commercialised process capable of recycling waste glass fibre reinforced thermosets, resulting in disposal via landfill or energy from waste facilities. Thermal recycling within a fluidised bed process has been demonstrated to successfully recover clean glass fibre from composite waste materials, such as wind turbine blades, and successfully reuse it as a reinforcement phase in second life composites. If brought to a commercial scale, this technology has the potential to divert up to 1200 kt of mixed glass fibre reinforced plastics (GRP) waste and an additional 240 kt of wind blade waste away from UK landfill sites over the next fifteen years, while offsetting the environmental impact and raw material consumption of virgin glass fibre production. Despite this, commercialisation and long-term success depend on economic viability and resilience of the recycling technology, ensuring that sufficient value is added to offset costs required to bring recyclate products to market. In this study, techno-economic analysis was used to analyse the economic outlook for at scale fluidised bed recycling plants within the context of the current and future UK glass fibre reinforced plastic waste landscape. It was found that fluidised bed recycling plants operating well within current UK waste volumes can maintain gate fees that are competitive with landfill while producing recycled glass fibre (rGF) at less than 50% of the prices of virgin counterparts. Plants processing single waste streams, such as wind blades, can maintain long term profitability despite irregular flow of waste feedstock availability. Despite higher transportation cost, total recycling costs are lower for national level plants. Therefore, it is recommended to accept composites from multiple waste streams to maximise operating capacity, profits and return on investment.</p> </abstract>","PeriodicalId":500288,"journal":{"name":"Clean Technologies and Recycling","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135798906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}