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Records with Subject: Environment
Showing records 2907 to 2931 of 3422. [First] Page: 1 114 115 116 117 118 119 120 121 122 Last
Study of a Pilot Scale Microbial Electrosynthesis Reactor for Organic Waste Biorefinery
Jiang-Hao Tian, Rémy Lacroix, Asim Ali Yaqoob, Chrystelle Bureau, Cédric Midoux, Elie Desmond-Le Quéméner, Théodore Bouchez
February 23, 2023 (v1)
Subject: Environment
Keywords: carbon storage, environmental biorefinery, microbial electrolysis, microbial electrosynthesis, upscaling
Microbial electrochemical technologies now enable microbial electrosynthesis (MES) of organic compounds using microbial electrolysis cells handling waste organic materials. An electrolytic cell with an MES cathode may generate soluble organic molecules at a higher market price than biomethane, thereby satisfying both economic and environmental goals. However, the long-term viability of bioanode activity might become a major concern. In this work, a 15-L MES reactor was designed with specific electrode configurations. An electrochemical model was established to assess the feasibility and possible performance of the design, considering the aging of the bioanode. The reactor was then constructed and tested for performance as well as a bioanode regeneration assay. Biowaste from an industrial deconditioning platform was used as a substrate for bioanode. The chemical oxygen demand (COD) removal rate in the anodic chamber reached 0.83 g day−1 L−1 of anolyte. Acetate was produced with a rate o... [more]
Optimal Power Flow Solution for Bipolar DC Networks Using a Recursive Quadratic Approximation
Oscar Danilo Montoya, Walter Gil-González, Jesus C. Hernández
February 23, 2023 (v1)
Subject: Environment
Keywords: bipolar DC networks, power loss minimization, recursive optimal power flow solution, sequential quadratic programming, unbalanced loads
The problem regarding of optimal power flow in bipolar DC networks is addressed in this paper from the recursive programming stand of view. A hyperbolic relationship between constant power terminals and voltage profiles is used to resolve the optimal power flow in bipolar DC networks. The proposed approximation is based on the Taylors’ Taylor series expansion. In addition, nonlinear relationships between dispersed generators and voltage profiles are relaxed based on the small voltage voltage-magnitude variations in contrast with power output. The resulting optimization model transforms the exact nonlinear non-convex formulation into a quadratic convex approximation. The main advantage of the quadratic convex reformulation lies in finding the optimum global via recursive programming, which adjusts the point until the desired convergence is reached. Two test feeders composed of 21 and 33 buses are employed for all the numerical validations. The effectiveness of the proposed recursive con... [more]
Life Cycle Analysis of Innovative Technologies: Cold Formed Steel System and Cross Laminated Timber
Ornella Iuorio, Antonio Gigante, Rosa Francesca De Masi
February 23, 2023 (v1)
Subject: Environment
Keywords: cold formed steel, cross laminate timber, embodied carbon, greenhouse gases, Life Cycle Analysis, net zero
Reducing the embodied and operational energy of buildings is a key priority for construction and real estate sectors. It is essential to prioritize materials and construction technologies with low carbon footprints for the design of new buildings. Off-site constructions systems are claimed to have the potential to deliver a low carbon build environment, but at present there are a lack of data about their real environmental impacts. This paper sheds lights on the environmental performance of two offsite technologies: cold formed steel and cross laminated timber. Specifically, the environmental impacts of a CFS technology are discussed according to six standard impact categories, which includes the global warming potential and the total use of primary energy. The study is based on a detailed cradle to gate life cycle analysis of a real case study, and discusses the impacts of both structural and non-structural components of CFS constructions. As a useful frame of reference, this work com... [more]
Energy Indicators for Enabling Energy Transition in Industry
Alessandro Franco, Lorenzo Miserocchi, Daniele Testi
February 23, 2023 (v1)
Subject: Environment
Keywords: energy indicators, energy transition, industry
Energy transition is a fundamental process in the move towards sustainable development, but in industry, it is complicated by the remarkable sectoral heterogeneity. Fostering the realization of energy transition in the industrial sector requires the characterization of its energy dimension, in terms of energy mixes and end-uses as the determinants of transition pathways, and energy solutions and tools as the enablers of this transition paradigm. We observe that the suitability of tools for energy analysis depend on trade-offs between comprehensiveness, ease of use, robustness, and generalization ability. In this regard, we discuss the appropriateness of energy indicators and provide an overview of indicator typologies, methodological issues, and applications for energy performance evaluation and improvement. With reference to the dairy processing industry, selected as a representative industrial branch, we outline current and desirable energy benchmarking applications and exemplify the... [more]
A Doubly Green Separation Process: Merging Aqueous Two-Phase Extraction and Supercritical Fluid Extraction
Andrey Voshkin, Vitaliy Solov’ev, Mikhail Kostenko, Yulia Zakhodyaeva, Oleg Pokrovskiy
February 23, 2023 (v1)
Subject: Environment
Keywords: aqueous two-phase extraction, green separation processes, supercritical fluid extraction
Aqueous two-phase extraction (ATPE) is a green separation technique which uses mixtures of water and environmentally benign polymers such as polyethylene glycol (PEG) as solvents. One of the challenges in implementing this extraction on an industrial scale is finding a suitable method for the isolation of target compounds from water-polymer solutions after the extraction, without diminishing ecological benefits of the method. In this paper, we propose using another green separation technique, supercritical fluid extraction (SFE), for the back-extraction of low molecular weight medium polarity compounds from ATPE solutions. Experiments with two model compounds, caffeine and benzoic acid, showed principal applicability of SFE for this task. Pressure (100−300 bar) and temperature (35−75 °C) of supercritical carbon dioxide play a major role in defining extraction capability. Extraction ratios of 35% for caffeine and 42% for benzoic acid were obtained at high fluid pressure and moderate tem... [more]
Sustainable Removal of Contaminants by Biopolymers: A Novel Approach for Wastewater Treatment. Current State and Future Perspectives
Teresa Russo, Pierpaolo Fucile, Rosa Giacometti, Filomena Sannino
February 23, 2023 (v1)
Subject: Environment
Keywords: biopolymers, contaminants, sustainable and renewable approach, wastewater treatment
Naturally occurring substances or polymeric biomolecules synthesized by living organisms during their entire life cycle are commonly defined as biopolymers. Different classifications of biopolymers have been proposed, focusing on their monomeric units, thus allowing them to be distinguished into three different classes with a huge diversity of secondary structures. Due to their ability to be easily manipulated and modified, their versatility, and their sustainability, biopolymers have been proposed in different fields of interest, starting from food, pharmaceutical, and biomedical industries, (i.e., as excipients, gelling agents, stabilizers, or thickeners). Furthermore, due to their sustainable and renewable features, their biodegradability, and their non-toxicity, biopolymers have also been proposed in wastewater treatment, in combination with different reinforcing materials (natural fibers, inorganic micro- or nano-sized fillers, antioxidants, and pigments) toward the development of... [more]
Acute and Chronic Effects of a Glyphosate and a Cypermethrin-Based Pesticide on a Non-Target Species Eucypris sp. Vavra, 1891 (Crustacea, Ostracoda)
Arsène Mathieu Houssou, Daniel Cocan, Camelia Maria Răducu, Eric Joslin Daguégué, Vioara Miresan, Elie Montchowui
February 23, 2023 (v1)
Subject: Environment
Keywords: chronic effects, cypermethrin, Eucypris sp., glyphosate, lethal doses
Ostracoda species are indicators of their current and past environment (paleoenvironment). The study aims to evaluate the acute and chronic sensitivities of a freshwater ostracod species (Eucypris sp.) to agricultural pesticides (a cypermethrin-based insecticide and a glyphosate herbicide-based formulation). Lethal concentrations (LC50) of each pesticide for the species at 24 and 48 h were determined. The chronic exposure allowed assessing the effects of low concentrations of both pesticides; firstly, on the parthenogenetic reproduction of Eucypris sp., and, secondly, on its population growth. Then, individuals of Eucypris sp. were exposed to 0.536 ppb and 1.072 ppb of cypermethrin and 4.51 ppm and 9.03 ppm of glyphosate. These concentrations are respectively the 10%, and the 20% of the 48-h LC50 (median lethal concentration) of both pesticides for the species. The estimated 24-h LC50 of cypermethrin was 7.287 ppb. At 48-h, it was 5.361 ppb. For glyphosate, the 24-h LC50 was 50.521 ppm... [more]
Comparison of Potential Environmental Impacts and Waste-to-Energy Efficiency for Kitchen Waste Treatment Scenarios in Central Taiwan
Meng-Fen Shih, Chiu-Yue Lin, Chyi-How Lay
February 23, 2023 (v1)
Subject: Environment
Keywords: anaerobic digestion, energy recovery, environmental impacts, kitchen waste, life cycle assessment, waste-to-energy
Taiwan has a sound solid waste recycling system, and waste-to-energy is attractive under the encouragement policy and economic feasibility, especially in central and southern regions with vast agricultural wastes. The four scenarios evaluated in this study relating to current use or under consideration for kitchen waste treatment strategy in Taiwan were incineration, landfill, composting, and anaerobic digestion. These scenarios were compared through life cycle assessment to obtain the most preferable treatment solution. The analysis was based on a functional unit, i.e., 1 metric ton of kitchen waste treated, and considered all impact categories through the CML_IA baseline 2000 method. It has shown that energy recovery had enormous effects on all scenarios with the anaerobic digestion having the highest environmental performance change. A comparison between actual electricity consumption and estimated electricity generation by kitchen waste treatment through anaerobic digestion indicat... [more]
Anaerobic Degradation of Individual Components from 5-Hydroxymethylfurfural Process-Wastewater in Continuously Operated Fixed Bed Reactors
Muhammad Tahir Khan, Johannes Krümpel, Dominik Wüst, Andreas Lemmer
February 23, 2023 (v1)
Subject: Environment
Keywords: biogas, biorefinery, hydrothermal carbonization, inhibition, methane, Wastewater
Production of bio-based materials in biorefineries is coupled with the generation of organic-rich process-wastewater that requires further management. Anaerobic technologies can be employed as a tool for the rectification of such hazardous by-products. Therefore, 5-hydroxymethylfurfural process-wastewater and its components were investigated for their biodegradability in a continuous anaerobic process. The test components included 5-hydroxymethylfurfural, furfural, levulinic acid, and the full process-wastewater. Each component was injected individually into a continuously operating anaerobic filter at a concentration of 0.5 gCOD. On the basis of large discrepancies within the replicates for each component, we classified their degradation into the categories of “delayed”, “retarded”, and “inhibitory”. Inhibitory represented the replicates for all the test components that hampered the process. For the retarded degradation, their mean methane yield per 0.5 gCOD was between 21.31 ± 13.04... [more]
Hyperthermophilic Composting Technology for Organic Solid Waste Treatment: Recent Research Advances and Trends
Shaofeng Wang, Yuqi Wu
February 23, 2023 (v1)
Subject: Environment
Keywords: composts, humification, hyperthermophilic composting, hyperthermophilic microbes, organic solid waste
Organic solid waste is considered a renewable resource that can be converted by various technologies into valuable products. Conventional thermophilic composting (TC), a well-studied and mature technology, can be applied to organic solid waste treatment to achieve waste reduction, mineralization, and humification simultaneously. However, poor efficiency, a long processing period, as well as low compost quality have always limited its wide application. In order to overcome these shortages, hyperthermophilic composting (HTC) has been recently put forward. This paper reviews the basic principle, process flow, operation parameters, research advances, and application status of HTC. Compared with the TC process, the shorter composting period and higher temperature and treatment efficiency, as well as more desirable compost quality, can be achieved during HTC by inoculating the waste with hyperthermophilic microbes. Additionally, HTC can reduce greenhouse gas emission, increase the removal ra... [more]
Experimental Study on a Closed-Cycle Humidification and Dehumidification System for Treating Wastewater Containing High Concentrations of Inorganic Salts and Organic Matter
Jun Liu, Yong Sun, Sanjiang Yv, Jiaquan Wang, Kaixuan Hu
February 23, 2023 (v1)
Subject: Environment
Keywords: COD, EC, humidification and dehumidification, industrial wastewater, NH4-N, removal efficiency, TN
Industrial wastewater contains high concentrations of inorganic salts and organic matter. This experiment studied a system for treating wastewater containing high concentrations of inorganic salts and organic matter. The setup consists of a closed-cycle humidification and dehumidification system and a filter press. Chemical wastewater was used as the treatment solution, and the treatment performance of the system was tested and analyzed. The system effectively reduced the chemical oxygen demand (COD), electric conductivity (EC), total nitrogen (TN), and ammonia nitrogen (NH4-N) in the wastewater and, at the same time, dehydrated sludge was obtained through a filter press. The system maintains a stable removal rate of each index (COD, EC, TN, and NH4-N) in wastewater and can remove inorganic salts and organic matter from wastewater. The system can successfully treat industrial wastewater containing high concentrations of inorganic salts and organic matter.
Emerging Technologies for Biorefining, Food and Environmental Applications
Roberto Castro-Muñoz
February 23, 2023 (v1)
Subject: Environment
Several emerging technologies, such as membrane technologies, biofermentation, oxidation processes, among others, are currently attracting interest in different areas of biotechnological and chemical engineering [...]
Implications of Entrepreneurial Intentions of Romanian Secondary Education Students, over the Romanian Business Market Development
Amalia Furdui, Lucian Lupu-Dima, Eduard Edelhauser
February 23, 2023 (v1)
Subject: Environment
Keywords: education for sustainable development, entrepreneurial intentions, entrepreneurship, innovation, resource efficiency, sustainable process
The study investigates the Romanian entrepreneurial education training program emphasizing the secondary education student entrepreneurial intents included in technical and professional Vocational Education Training (VET) programs, in order to identify its role in increasing student intention in the process of choosing a career as an entrepreneur among graduates of the vocational and technical Romanian education system. The study research methodology was based on the interpretation of two questionnaires consisting of 23 questions, which were applied to a population of 253 and 159 respondents. The survey period was conducted between 2019 and 2020. The respondents were students from the vocational and technical education system in Romania, mostly from the Central Region of Romania, but the results of the study could be extended to the entire Romanian education system. The data were processed using SPSS software, and the results of the study revealed direct, positive, and significant link... [more]
An Integrated Multicriteria Decision-Making Approach for Collection Modes Selection in Remanufacturing Reverse Logistics
Xumei Zhang, Zhizhao Li, Yan Wang, Wei Yan
February 23, 2023 (v1)
Subject: Environment
Keywords: circular economy, collection modes, multicriteria decision-making, remanufacturing, reverse logistics
Reverse logistics (RL) is closely related to remanufacturing and could have a profound impact on the remanufacturing industry. Different from sustainable development which is focused on economy, environment and society, circular economy (CE) puts forward more requirements on the circularity and resource efficiency of manufacturing industry. In order to select the best reverse logistics provider for remanufacturing, a multicriteria decision-making (MCDM) method considering the circular economy is proposed. In this article, a circularity dimension is included in the evaluation criteria. Then, analytic hierarchy process (AHP) is used to calculate the global weights of each criterion, which are used as the parameters in selecting RL providers. Finally, technique for order of preference by similarity to ideal solution (TOPSIS) is applied to rank reverse logistics providers with three different modes. A medium-sized engine manufacturer in China is taken as a case study to validate the applic... [more]
Achieving a Sustainable Development Process by Deployment of Solar PV Power in ASEAN: A SWOT Analysis
Hengtian Wang, Xiaolong Yang, Qihe Lou, Xinxin Xu
February 23, 2023 (v1)
Subject: Environment
Keywords: ASEAN, Renewable and Sustainable Energy, solar PV power, sustainable development, SWOT analysis
The Association of Southeast Asian Nations (ASEAN) has experienced rapid social and economic development in the past decades, while energy shortage, environmental pollution, and climate change are the factors that prevent a sustainable development process. Deployment of solar photovoltaic (PV) power is one of the effective alternatives to overcome the above barriers and assist ASEAN to achieve the aspirational target of 23% renewable energy (RE) in the total primary energy supply (TPES). In this study, SWOT analysis is adopted to analyze the internal strengths and weaknesses and the external threats and opportunities tightly related to the development of solar PV power in ASEAN countries. Through the SWOT analysis, great potential for the development of solar PV power in ASEAN is found. As long as appropriate policies are implemented and proper actions are taken, huge space for deployment of solar PV power can be expected. Based on the SWOT analysis, countermeasures that emphasize furt... [more]
Enhancing Microplastics Removal from Wastewater Using Electro-Coagulation and Granule-Activated Carbon with Thermal Regeneration
Keug Tae Kim, Sanghwa Park
February 23, 2023 (v1)
Subject: Environment
Keywords: electro coagulation, granule activated carbon, microplastics, pyrolysis
Discharge from sewage treatment plants (STPs) is a significant pathway of entry for microplastics (MPs) to the environment. Therefore, STPs should be considered as an important barrier to the distribution and circulation of MPs in the aquatic environment. In this study, the fate and material-specific properties of MPs were investigated in an STP-equipped and granule-activated carbon (GAC) tower with a thermal regeneration system. This system functioned with a tertiary treatment unit. The GAC with thermal regeneration removed 92.8% of MPs and was useful for removing MPs with a specific gravity less than that of water and with a size of 20−50 µm, which had negligible removal in the conventional STP process. In addition, a lab-scale electric-coagulation experiment was conducted to examine its potential utility as a pretreatment process for further enhancing the removal efficiency of MPs by GAC. After 30 min of electro-coagulation using aluminum electrodes, 90% of MPs were converted into s... [more]
Application of Alum Sludge in Wastewater Treatment Processes: “Science” of Reuse and Reclamation Pathways
Wei Zhao, Huina Xie, Jie Li, Lihong Zhang, Yaqian Zhao
February 23, 2023 (v1)
Subject: Environment
Keywords: Adsorption, alum sludge, phosphorus, reuse, waste disposal
Alum sludge (AlS) refers to the inevitable by-product generated during the drinking water purification process, where Al-salt is used as a coagulant in the water industry. It has long been treated as “waste”, while landfill is its major final disposal destination. In fact, AlS is an underutilized material with huge potential for beneficial reuse as a raw material in various wastewater treatment processes. In the last two decades, intensive studies have been conducted worldwide to explore the “science” and practical application of AlS. This paper focuses on the recent developments in the use of AlS that show its strong potential for reuse in wastewater treatment processes. In particular, the review covers the key “science” of the nature and mechanisms of AlS, revealing why AlS has the potential to be a value-added material. In addition, the future focus of research towards the widespread application of AlS as a raw material/product in commercial markets is suggested, which expands the s... [more]
Recent Advances in the Synthesis of Nanocellulose Functionalized−Hybrid Membranes and Application in Water Quality Improvement
Sandrine Mbakop, Lebea N. Nthunya, Maurice S. Onyango
February 23, 2023 (v1)
Subject: Environment
Keywords: membrane technology, nanocelluloses, nanocomposite membranes, water pollution
The increasing discharge of voluminous non or partially treated wastewaters characterized by complex contaminants poses significant ecological and health risks. Particularly, this practice impacts negatively on socio-economic, technological, industrial, and agricultural development. Therefore, effective control of water pollution is imperative. Over the past decade, membrane filtration has been established as an effective and commercially attractive technology for the separation and purification of water. The performance of membrane-based technologies relies on the intrinsic properties of the membrane barrier itself. As a result, the development of innovative techniques for the preparation of highly efficient membranes has received remarkable attention. Moreover, growing concerns related to cost-effective and greener technologies have induced the need for eco-friendly, renewable, biodegradable, and sustainable source materials for membrane fabrication. Recently, advances in nanotechnol... [more]
A Systematic Model for Process Development Activities to Support Process Intelligence
Edrisi Muñoz, Elisabet Capon-Garcia, Enrique Martinez Muñoz, Luis Puigjaner
February 23, 2023 (v1)
Subject: Environment
Keywords: enterprise process architecture, new technologies integration, process intelligence
Process, manufacturing, and service industries currently face a large number of non-trivial challenges ranging from product conception, going through design, development, commercialization, and delivering in a customized market’s environment. Thus, industries can benefit by integrating new technologies in their day-by-day tasks gaining profitability. This work presents a model for enterprise process development activities called the wide intelligent management architecture model to integrate new technologies for services, processes, and manufacturing companies who strive to find the most efficient way towards enterprise and process intelligence. The model comprises and structures three critical systems: process system, knowledge system, and transactional system. As a result, analytical tools belonging to process activities and transactional data system are guided by a systematic development framework consolidated with formal knowledge models. Thus, the model improves the interaction am... [more]
Metal Accumulation Profile of Catharanthus roseus (L.) G.Don and Celosia argentea L. with EDTA Co-Application
Muneeba Qurban, Cyrus Raza Mirza, Aqib Hassan Ali Khan, Walid Khalifa, Mustapha Boukendakdji, Belkacem Achour, Sohail Yousaf, Ismat Nawaz, Tayyab Ashfaq Butt, Mazhar Iqbal
February 23, 2023 (v1)
Subject: Environment
Keywords: Catharanthus roseus, Celosia argentea, hydroponics, metals, ornamental plants
The problem of metal-induced toxicity is proliferating with an increase in industrialization and urbanization. The buildup of metals results in severe environmental deterioration and harmful impacts on plant growth. In this study, we investigated the potential of two ornamental plants, Catharanthus roseus (L.) G.Don and Celosia argentea L., to tolerate and accumulate Ni, Cr, Cd, Pb, and Cu. These ornamental plants were grown in Hoagland’s nutrient solution containing metal loads (50 µM and 100 µM) alone and in combination with a synthetic chelator, ethylenediaminetetraacetic acid (EDTA) (2.5 mM). Plant growth and metal tolerance varied in both plant species for Ni, Cr, Cd, Pb, and Cu. C. roseus growth was better in treatments without EDTA, particularly in Ni, Cr, and Pb treatments, and Pb content increased in all parts of the plant. In contrast, Cd content decreased with EDTA addition. In C. argentea, the addition of EDTA resulted in improved plant biomass at both doses of Cu. In contr... [more]
Corrosion and Corrosion Fatigue of Steels in Downhole CCS Environment—A Summary
Anja Pfennig, Marcus Wolf, Axel Kranzmann
February 23, 2023 (v1)
Subject: Environment
Keywords: carbon capture and storage, CCS, corrosion, corrosion fatigue, high alloyed steel, Steel
Static immersion tests of potential injection pipe steels 42CrMo4, X20Cr13, X46Cr13, X35CrMo4, and X5CrNiCuNb16-4 at T = 60 °C and ambient pressure, as well as p = 100 bar were performed for 700−8000 h in a CO2-saturated synthetic aquifer environment similar to CCS sites in the Northern German Basin (NGB). Corrosion rates at 100 bar are generally lower than at ambient pressure. The main corrosion products are FeCO3 and FeOOH with surface and local corrosion phenomena directly related to the alloy composition and microstructure. The appropriate heat treatment enhances corrosion resistance. The lifetime reduction of X46Cr13, X5CrNiCuNb16-4, and duplex stainless steel X2CrNiMoN22-5-3 in a CCS environment is demonstrated in the in situ corrosion fatigue CF experiments (axial push-pull and rotation bending load, 60 °C, brine: Stuttgart Aquifer and NGB, flowing CO2: 30 L/h, +/− applied potential). Insulating the test setup is necessary to gain reliable data. S-N plots, micrographic-, phase-,... [more]
Evaluation of the Engineering Properties of Powdered Activated Carbon Amendments in Porous Asphalt Pavement
Shengyi Huang, Chenju Liang
February 23, 2023 (v1)
Subject: Environment
Keywords: asphalt concrete, porous asphalt pavement (PAP), remediation, surface runoff, volatile organic compounds (VOCs)
Porous asphalt pavement (PAP) with a high drainage capacity was modified with powdered activated carbon (PAC) addition to produce permeable reactive pavement (PRP), which may exhibit the potential to reduce environmental non-point source (NPS) pollution. The experimental design mixtures used to produce and test the PRP incorporated with PAC (named PRP-PACs) were conducted as follows: first, the PACs were initially tested to determine their feasibility as an additive in PAP; second, different amounts of PAC were added during the preparation of PAP to produce PRP-PAC, and the unregulated and regulated physical characteristics for the mechanical performance of PRP-PACs were examined to ensure that they meet the regulatory specifications. Third, the aqueous contaminants, namely benzene, toluene, ethyl-benzene, and xylene (BTEX), column adsorption tests were preliminarily conducted to demonstrate their adsorption capacities compared to traditional PAP. The compositions of 0.8% and 1.5% PAC... [more]
Multi-Step Subcritical Water Extracts of Fucus vesiculosus L. and Codium tomentosum Stackhouse: Composition, Health-Benefits and Safety
Cristina Soares, Paula Paíga, Marta Marques, Tânia Neto, Ana Paula Carvalho, Alexandre Paiva, Pedro Simões, Leonor Costa, Ana Bernardo, Naiara Fernández, Edgar Pinto, Agostinho Almeida, Maria Rosário Bronze, Cristina Delerue-Matos, Clara Grosso
February 23, 2023 (v1)
Subject: Environment
Keywords: bioactivities, environmental contaminants, iodine, neuroprotection, reactive nitrogen species, reactive oxygen species, seaweeds
Mental health and active aging are two of the main concerns in the 21st century. To search for new neuroprotective compounds, extracts of Codium tomentosum Stackhouse and Fucus vesiculosus L. were obtained through multi-step (four step) subcritical water extraction using a temperature gradient. The safety assessment of the extracts was performed by screening pharmaceutical compounds and pesticides by UHPLC-MS/MS, and iodine and arsenic levels by ICP-MS. Although the extracts were free of pharmaceutical compounds and pesticides, the presence of arsenic and high iodine contents were found in the first two extraction steps. Thus, the health-benefits were only evaluated for the fractions obtained in steps 3 and 4 from the extraction process. These fractions were tested against five brain enzymes implicated in Alzheimer’s, Parkinson’s, and major depression etiology as well as against reactive oxygen and nitrogen species, having been observed a strong enzyme inhibition and radical scavenging... [more]
Efficient Removal of Cr (VI) with Biochar and Optimized Parameters by Response Surface Methodology
Hao Peng, Jing Guo, Hongzhi Qiu, Caiqiong Wang, Chenyu Zhang, Zhihui Hao, Yating Rao, Yanhong Gong
February 23, 2023 (v1)
Subject: Environment
Keywords: biochar, chromium, reduction, response surface methodology
A highly efficient reduction process of Cr (VI) with biochar was conducted in this paper. The results showed that nearly 100% Cr (VI) was reduced at selected reaction conditions: Dosage of biochar at m (C)/m(Cr) = 3.0, reaction temperature of 90 °C, reaction time of60 min, and concentration of H2SO4 of 20 g/L. The reduction kinetics analysis demonstrated that the reduction of Cr (VI) fitted well with the pseudo-first-order model and the apparent activation energy was calculated to be 40.24 kJ/mol. Response surface methodology confirmed that all of the experimental parameters had a positive effect on the reduction of Cr (VI). The influence of each parameter on the reduction process followed the order: Dosage of biochar>concentration of H2SO4>reaction temperature >reaction time. This paper provides a versatile strategy for the treatment of wastewater containing Cr (VI) and shows a bright tomorrow for wastewater treatment.
Intergenerational Externalities Influence for Exploitation Process of Rare Metal Minerals
Shijie Ding, Mengxian Wang, Hongwei Zhang
February 23, 2023 (v1)
Subject: Environment
Keywords: development game, intergenerational externalities, rare metal minerals, sustainable exploitation process
Rare metal minerals are important strategic resources. Promoting the sustainable development of their mining process is not only related to energy and environmental issues, but also directly affects the sustainable development of the entire supply chain. Considering the influence of intergenerational externalities on the equilibrium in the rare metal mineral exploitation process is of critical significance to maintaining the sustainable development of rare metal minerals and securing a sustainable resource exploitation process. This paper develops a sustainability analysis model based on an intergenerational externalities influence and examines the influence of the shift in comprehensive production cost burden through the whole supply chain, which aims at the sustainable development of the exploitation process of rare metal minerals. The results indicate that in a vertically linked industrial chain, the upstream and downstream structure of the supply chain and the type of production co... [more]
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