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Records with Subject: Environment
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Purification of Textile Effluents Containing C.I. Acid Violet 1: Adsorptive Removal versus Hydrogen Peroxide and Peracetic Acid Based Advanced Oxidation
Monika Wawrzkiewicz, Urszula Kotowska, Aneta Sokół
February 23, 2023 (v1)
Subject: Environment
Keywords: Adsorption, advanced oxidation, anion exchanger, dye, hydrogen peroxide, peracetic acid, textile effluents
Textile effluent containing azo dyes such as C.I. Acid Violet 1 (AV1) can be degraded to toxic aromatic amines in the environment. Thus, there is a legitimate need to treat such effluents before they are discharged to surface waters. Two methods were proposed to remove AV1 from aqueous solutions: adsorption and advanced oxidation processes (AOPs). The sorption capacity of the strongly basic anion exchanger Purolite A520E of the polystyrene matrix determined from the Langmuir isotherm model was found to be 835 mg/g, while that of Lewatit S5428 of the polyacrylamide matrix Freundlich model seems to be more appropriate for describing the experimental data. The pseudo-second-order kinetic model and external diffusion are the rate limiting steps of adsorption. The removal efficiency of AV1 by the anion exchangers was higher than 99% after 40 min of phase contact time. AOPs involved the usage of hydrogen peroxide and peracetic acid (PAA) as oxidizing agents, while Fe2+ and simulated sunlight... [more]
An Alternative Method for the Obtention of Ceramic Foams from Gold and Silver Tailings with High Pyrite Content
Cristian Salazar, Lina Uribe
February 23, 2023 (v1)
Subject: Environment
Keywords: ceramic foams, circular economy, flotation, sintering time, tailings
Mining extraction operations generate a large number of tailings that contain different mineral phases such as quartz (principally), complex silicates, metallic elements, etc. Tailings impose a serious concern as it is possible to have acid mine drainage potential, leaching, and percolation events of heavy metals into the environment under certain conditions. The objective of this work was to evaluate the technical feasibility of producing ceramic foams from gold and silver tailings with high sulfide gangue through a previous flotation process to eliminate impurities associated to this gangue, as it can produce SO2 in the foaming process, and to analyze the effect of the sintering time and the temperature on the characteristics of foams obtained with this type of waste. The results showed that the inverse flotation reduced the presence of impurities associated to sulfides. In addition, it was possible to observe that in the absence of a foaming agent, it was possible to obtain ceramic... [more]
Incorporating Environmental Perspective in Integrated Strategic-Tactical Economic Optimization Model of Biomass-to-Biofuel Supply Chain—A Real Case Study in Ethiopia
Brook Tesfamichael, Ludovic Montastruc, Stéphane Negny, Abubeker Yimam
February 23, 2023 (v1)
Subject: Environment
Keywords: economic and environmental dimensions, Ethiopia, integrated strategic-tactical model, life cycle assessment (LCA), multi-period supply chain design, semi-heuristic method
Several optimization models, which consider economic and environmental perspectives, have been developed recently to support the sustainable biomass-to-biofuel supply chain (BBSC) design. All of the economic-environmental optimization models rely on solving long-term planning problems with a conventional hierarchical approach, where tactical decisions are made based on the optimal strategic decisions from the strategic-level model, despite it arousing non-optimal solutions. Moreover, almost all of them have used non-monetary-based environmental indicators, which result in difficulties with clarity when comparing with economic objectives. Therefore, in this work, an effort is made to develop a more reliable planning strategy that offers optimal strategic and tactical decisions simultaneously and maximizes the economic and environmental benefits. Furthermore, the environmental performance of the BBSC has been assessed in terms of monetary value by adopting an ecocost approach after perfo... [more]
Biogas Production by Pilot-Scale Anaerobic Co-Digestion and Life Cycle Assessment Using a Real Scale Scenario: Independent Parameters and Co-Substrates Influence
Jhessica Mosquera, Carol Rangel, Jogy Thomas, Angelica Santis, Paola Acevedo, Ivan Cabeza
February 23, 2023 (v1)
Subject: Environment
Keywords: anaerobic co-digestion, biogas production potential, Box–Behnken design, life cycle assessment, residual biomass
This study evaluates the performance of different agricultural by-products to identify the potential effect of independent variables, using as the dependent variable the biogas production. A Box−Behnken experimental design was carried out in a pilot-scale plant of four stirred stainless-steel digesters under mesophilic semi-continuous digestion. The results obtained support the creation of a technical framework to scale up the process and further evaluation of the potential environmental impacts through life cycle assessment (LCA) methodology. A stable behaviour was achieved in 12 of the 13 experiments proposed. The highest value of daily biogas production was 2200.15 mL day−1 with a stabilization time of 14 days, an organic loading rate of 4 g VS feed daily, low C/N ratio and a 1:1 relation of nitrogen providers. The concentrations of CH4 remained stable after the production stabilization and an average biogas composition of 60.6% CH4, 40.1% CO2 and 0.3% O2 was obtained for the condit... [more]
The Dark Side of Platinum Based Cytostatic Drugs: From Detection to Removal
Yessica Roque-Diaz, Martina Sanadar, Dong Han, Montserrat López-Mesas, Manuel Valiente, Marilena Tolazzi, Andrea Melchior, Daniele Veclani
February 23, 2023 (v1)
Subject: Environment
Keywords: cytostatic drugs, emerging pollutants, environmental remediation, water treatment
The uncontrolled release of pharmaceutical drugs into the environment raised serious concerns in the last decades as they can potentially exert adverse effects on living organisms even at the low concentrations at which they are typically found. Among them, platinum based cytostatic drugs (Pt CDs) are among the most used drugs in cancer treatments which are administered via intravenous infusion and released partially intact or as transformation products. In this review, the studies on environmental occurrence, transformation, potential ecotoxicity, and possible treatment for the removal of platinum cytostatic compounds are revised. The analysis of the literature highlighted the generally low total platinum concentration values (from a few tens of ng L−1 to a few hundred μg L−1) found in hospital effluents. Additionally, several studies highlighted how hospitals are sources of a minor fraction of the total Pt CDs found in the environment due to the slow excretion rate which is longer th... [more]
Salicylate or Phthalate: The Main Intermediates in the Bacterial Degradation of Naphthalene
Vasili M. Travkin, Inna P. Solyanikova
February 23, 2023 (v1)
Subject: Environment
Keywords: bacteria, biodegradation pathway, degradation, genes, naphthalene, phthalate, salicylate
Polycyclic aromatic hydrocarbons (PAHs) are widely presented in the environment and pose a serious environmental threat due to their toxicity. Among PAHs, naphthalene is the simplest compound. Nevertheless, due to its high toxicity and presence in the waste of chemical and oil processing industries, naphthalene is one of the most critical pollutants. Similar to other PAHs, naphthalene is released into the environment via the incomplete combustion of organic compounds, pyrolysis, oil spills, oil processing, household waste disposal, and use of fumigants and deodorants. One of the main ways to detoxify such compounds in the natural environment is through their microbial degradation. For the first time, the pathway of naphthalene degradation was investigated in pseudomonades. The salicylate was found to be a key intermediate. For some time, this pathway was considered the main, if not the only one, in the bacterial destruction of naphthalene. However, later, data emerged which indicated t... [more]
Research on Measurement and Application of China’s Regional Logistics Development Level under Low Carbon Environment
Zixue Guo, Yu Tian, Xinmei Guo, Zefang He
February 22, 2023 (v1)
Subject: Environment
Keywords: Beijing-Tianjin-Hebei region, cloud model, comprehensive evaluation, low-carbon economy, regional logistics
To solve the problem of fuzziness and randomness in regional logistics decarbonization evaluation and accurately assess regional logistics decarbonization development, an evaluation model of regional logistics decarbonization development is established. First, the evaluation index of regional logistics decarbonization development is constructed from three dimensions: low-carbon logistics environment support, low-carbon logistics strength and low-carbon logistics potential. Second, the evaluation indexes are used as cloud model variables, and the cloud numerical characteristic values and cloud affiliation degrees are determined according to the cloud model theory. The entropy weight method is used to determine the index weights, and the comprehensive determination degree of the research object affiliated to the logistics decarbonization level is calculated comprehensively. Finally, Beijing-Tianjin-Hebei region is used as an example for empirical evidence, analyzing the development logis... [more]
Evaluation of Landsat 8-like Land Surface Temperature by Fusing Landsat 8 and MODIS Land Surface Temperature Product
Shenglin Li, Jinglei Wang, Dacheng Li, Zhongxin Ran, Bo Yang
February 22, 2023 (v1)
Subject: Environment
Keywords: Landsat 8 LST product, MODIS, spatiotemporal fusion, validation
High-spatiotemporal-resolution land surface temperature (LST) is a crucial parameter in various environmental monitoring. However, due to the limitation of sensor trade-off between the spatial and temporal resolutions, such data are still unavailable. Therefore, the generation and verification of such data are of great value. The spatiotemporal fusion algorithm, which can be used to improve the spatiotemporal resolution, is widely used in Landsat and MODIS data to generate Landsat-like images, but there is less exploration of combining long-time series MODIS LST and Landsat 8 LST product to generate Landsat 8-like LST. The purpose of this study is to evaluate the accuracy of the long-time series Landsat 8 LST product and the Landsat 8-like LST generated by spatiotemporal fusion. In this study, based on the Landsat 8 LST product and MODIS LST product, Landsat 8-like LST is generated using Spatial and Temporal Adaptive Reflectance Fusion Model (STARFM), Enhanced STARFM (ESTARFM), and the... [more]
Environmental and Energetic Evaluation of Refuse-Derived Fuel Gasification for Electricity Generation
Taís Eliane Marques, York Castillo Santiago, Maria Luiza Grillo Renó, Diego Mauricio Yepes Maya, Leandro Alcoforado Sphaier, Yunye Shi, Albert Ratner
February 22, 2023 (v1)
Subject: Environment
Keywords: electricity generation, energy use, gasification, life cycle assessment, refuse-derived fuel (RDF)
In this work, an energetic and environmental evaluation of the electricity generation process through refuse-derived fuel (RDF) gasification coupled to a gas microturbine (GM) was performed. Two scenarios are considered with different gasification agents in RDF gasification modeling: air and air enriched with oxygen. A thermodynamic chemical equilibrium approach was used to analyze the gasification parameters. The results of RDF gasification indicate a maximum value of syngas low heating value (LHV) equal to 8.0 MJ/Nm3, obtained for an equivalence ratio of 0.3. The use of these syngas in the gas microturbine produces 79.6 kW of electrical power. For the environmental evaluation of gasification and electricity generation systems, the Life Cycle Assessment methodology was employed. The calculated environmental impacts indicate that the emission of contaminants from fossil fuel combustion (in the stage of transport by heavy load vehicles) and that the electricity consumption for equipment... [more]
A Multi-Criteria Decision-Making Approach to Evaluate Different UVC/H2O2 Systems in Wastewater Treatment
Isadora Luiza Climaco Cunha, Jose Geraldo Vidal Vieira, Luiz Kulay
February 22, 2023 (v1)
Subject: Environment
Keywords: life cycle assessment, multi-criteria decision making, pesticides, UVC/H2O2, wastewater treatment
High azoxystrobin (AZO), difenoconazole (DFZ), and imidacloprid (IMD) pesticide removal rates in sixteen bench-scale experiments concerning tomato washing water treatment were obtained through a UVC/H2O2 advanced oxidative process. Experimental conditions ([H2O2]0) and irradiance (EUVC) were optimized for higher degradation rates (pseudo-first-order reaction). To consider both economic aspects and environmental impacts when defining the treatment technology, as well as technological requirements, this study applied a multi-criteria decision-making method (MCDM) to assess and differentiate similar UVC/H2O2 process configurations. This allowed for the identification of the cheapest experimental arrangement with the lowest associated environmental impacts, coupled to the highest degradation rate (kIMD). After consulting experts to determine the importance of the applied criteria and measuring alternative performances, experiment E7 ([H2O2]0 = 43.5 mg L−1; EUVC = 15.0 W m−2; kIMD = 0.236 s... [more]
The Learning Path to Neural Network Industrial Application in Distributed Environments
Lenka Landryová, Jan Sikora, Renata Wagnerová
February 22, 2023 (v1)
Subject: Environment
Keywords: algorithm, Big Data, clustering, data visualization, distributed systems, Machine Learning, predictions, process control
Industrial companies focus on efficiency and cost reduction, which is very closely related to production process safety and secured environments enabling production with reduced risks and minimized cost on machines maintenance. Legacy systems are being replaced with new systems built into distributed production environments and equipped with machine learning algorithms that help to make this change more effective and efficient. A distributed control system consists of several subsystems distributed across areas and sites requiring application interfaces built across a control network. Data acquisition and data processing are challenging processes. This contribution aims to present an approach for the data collection based on features standardized in industry and for data classification processed with an applied machine learning algorithm for distinguishing exceptions in a dataset. Files with classified exceptions can be used to train prediction models to make forecasts in a large amoun... [more]
Dining Lampblack Treatment Processes in China
Wanpeng Hu, Jumei Ye, Xiaozhen Chen, Guoying Wang, Sen Li, Hui Wang, Hong Li, Haiping Zhang
February 22, 2023 (v1)
Subject: Environment
Keywords: air pollution, dining lampblack, PM2.5, purification technology, technological development, VOCs
The PM2.5 and other small particles produced by cooking oil fumes have contributed up to 25% to the urban atmospheric PM2.5, which has a bad impact on air quality and seriously threatens human health. Aiming at the pollution problem caused by catering oil fume, this article analyzes the threats of air pollution to human health based on the compositions and characteristics of catering oil fume, illustrates the development trend of China′s food and beverage lampblack control policy, and summarizes and points out the current situation and development trend of catering oil fume treatment. In order to provide ideas for the design of more efficient and energy-saving treatment processes in the future, the advantages and disadvantages were reviewed, and the improvement direction of the treatment technology was discussed.
Value Configurations for Data and Connectivity Solutions in Digitalized Future Factories
Solmaz Mansoori, Iqra Sadaf Khan, Petri Ahokangas, Marja Matinmikko-Blue, Harri Haapasalo, Seppo Yrjölä
February 22, 2023 (v1)
Subject: Environment
Keywords: 5G, business ecosystem, digitalization, future factories, Industry 4.0, local operator, value configuration
The ongoing Industry 4.0 transformation places significant pressures on how businesses create and capture value. Technological advancements such as next-generation mobile communications are reshaping the business ecosystem of Industry 4.0, resulting in emerging business opportunities for new players, such as local operators, to collaborate and compete with mobile communications companies that are implementing I4.0. These changes raise the need to explore emerging business opportunities concerning the digitalization of future factories. New data and connectivity services are introduced to serve the needs of rapidly increasing machine-type communications that rely on connectivity, primarily through the fifth generation (5G) mobile solutions provided by local operators. Thus, this paper outlines the potential value configurations for data and connectivity solutions by identifying, matching, and bridging the utilizable resources and addressable needs within the factory processes. The resea... [more]
Industrial Symbiosis for Optimal Bio-Waste Management and Production of a Higher Value-Added Product
Edgaras Stunžėnas, Irina Kliopova, Daina Kliaugaitė, Rimas Pranas Budrys
February 22, 2023 (v1)
Subject: Environment
Keywords: animal by-products, catering, compost quality parameters, hospitality, industrial symbiosis, intensive composting, life cycle assessment, life cycle inventory
A considerable amount of food waste ends up in centralized treatment plants due to the lack of preventive measures, resulting in significant environmental impacts. Hospitality food waste management is even more resource-intensive because of animal by-products regulation. According to this regulation, companies must store and then consign waste to specific waste managers. The extensive need for transportation of high-moisture-content materials is the leading cause of the impact. Moreover, the management of category III animal by-products is costly for companies. A previous study has shown the economic benefits of decentralized animal by-product treatment by intensive composting in catering companies. Although the produced compost was characterized by exceptional quality parameters, it was phytotoxic. The investigation of hospitality waste management is scarcely discussed among scholars, and waste management on a regional scale is nearly absent. This study examines the regional managemen... [more]
Application of Green Technology in Gelatin Extraction: A Review
Nor Qhairul Izzreen Mohd Noor, Rina Syafinaz Razali, Nur Khairina Ismail, Rabiatul Amirah Ramli, Umi Hartina Mohamad Razali, Ahmad Riduan Bahauddin, Nazikussabah Zaharudin, Ashari Rozzamri, Jamilah Bakar, Sharifudin Md. Shaarani
February 22, 2023 (v1)
Subject: Environment
Keywords: high-pressure processing, microwave extraction, novel technology, subcritical water extraction, ultrasound extraction
Growing demands for green and sustainable processing that eliminates the utilization of toxic chemicals and increases efficiency has encouraged the application of novel extraction technologies for the food industry. This review discusses the principles and potential application of several green technology for gelatin extraction. Several novel technologies and their processing efficiency are discussed in this review. Furthermore, factors that affect the quality of the gelatin produced from different sources are also highlighted. The potential application of ultrasound-assisted extraction (UAE), subcritical water extraction, high-pressure processing, and microwave-assisted extraction (MAE) to improve gelatin extraction are addressed. These technologies have the potential to become an efficient extraction method compared to the conventional extraction technologies. Several combinations of green and conventional technologies have been reported to yield promising results. These combinations... [more]
Effects of Seasonal Thermal Stratification on Ammonia Nitrogen Transformation in a Source Water Reservoir
Jianchao Shi, Lianxiang Wang, Yongrui Yang, Tinglin Huang
February 22, 2023 (v1)
Subject: Environment
Keywords: ammonia nitrogen, sediments, source water reservoir, thermal stratification
Seasonal thermal stratification has a significant impact on water quality. In this paper, the variation of vertical distribution of ammonia nitrogen in a source water reservoir was studied, on the base of field monitoring data. The dominant factor of the variation in ammonia nitrogen is the anaerobic environment caused by the seasonal thermal stratification, which leads to the degradation of nitrogen-containing organic compounds in the sediments. To determine the rates of ammonia accumulation, an in situ experimental chamber was used. The results showed that, before the formation of thermal stratification in the reservoir, sediments in the bottom of the water have a high tendency to release ammonia; the rates of ammonia accumulation in the overlying water are 40.31−111.41 mg·m−2·d−1. However, thermal stratification causes changes in the physical and chemical properties of the sediment and reduction in the degradability of the nitrogen-containing compound in the sediment. The rates of a... [more]
Overview of Vehicle Exhaust Particle Number Regulations
Barouch Giechaskiel, Anastasios Melas, Giorgio Martini, Panagiota Dilara
February 22, 2023 (v1)
Subject: Environment
Keywords: air pollution, catalytic stripper, emission regulations, Particle Measurement Programme (PMP), particle number, particulate matter, portable emissions measurement system (PEMS), real-driving emissions (RDE), vehicle exhaust emissions
Vehicle emissions are a significant source of air pollution in cities. Particulate matter (PM) is a pollutant with adverse health effects. Regulations worldwide determine the PM exhaust emissions of vehicles by gravimetric quantification of the mass deposited on a filter over a test cycle. The introduction of particulate filters as vehicle exhaust gas aftertreatment devices led to low PM emissions. A particle number methodology (counting solid particles > 23 nm), complementary to the PM mass measurement, was developed by the PMP (Particle Measurement Programme) group of the GRPE (Working Party on Pollution and Energy) of the UNECE (United Nations Economic Commission for Europe) during the first decade of the 21st century. The methodology was then introduced in the EU (European Union) regulations for light-duty (2011), heavy-duty (2013), and non-road mobile machinery (2019). In parallel, during the last 15 years, UN (United Nations) regulations and GTRs (Global Technical Regulations) in... [more]
Removal of Emerging Pollutants in Horizontal Subsurface Flow and Vertical Flow Pilot-Scale Constructed Wetlands
Georgios D. Gikas, Vassiliki A. Papaevangelou, Vassilios A. Tsihrintzis, Maria Antonopoulou, Ioannis K. Konstantinou
February 22, 2023 (v1)
Subject: Environment
Keywords: caffeine, flame retardant (TCPP), horizontal subsurface flow constructed wetlands, phthalate esters, vertical flow constructed wetlands
We assessed constructed wetland (CW) performance in the removal of six emerging pollutants (EPs) from university campus wastewater. The EPs considered were: diethyl phthalate (DEP), di-isobutyl phthalate (DIBP), di-n-octyl phthalate (DNOP), bis(2-ehtylxexyl) phthalate (DEHP), tris(1-chloro-2-propyl) phosphate (TCPP) and caffeine (CAF). Six pilot-scale CWs, i.e., three horizontal subsurface flow (HSF) and three vertical flow (VF), with different design configurations were used: two types of plants and one unplanted for both the HSF and the VF, two hydraulic retention times (HRT) for the HSF, and two wastewater feeding strategies for the VF units. The results showed that the median removals in the three HSF-CWs ranged between 84.3 and 99.9%, 79.0 and 95.7%, 91.4 and 99.7%, 72.2 and 81.0%, 99.1 and 99.6%, and 99.3 and 99.6% for DEP, DIBP, DNOP, DEHP, TCPP, and CAF, respectively. In the three VF-CWs, the median removal efficiencies range was 98.6−99.4%, 63.6−98.0%, 96.6−97.8%, 73.6−94.5%,... [more]
Special Issue “Sustainable Remediation Processes Based on Zeolites”
Claudia Belviso
February 22, 2023 (v1)
Subject: Environment
Zeolites are microporous tectosilicates characterized by a three-dimensional network of tetrahedral (Si, Al)O4 units with the general formula: Mx+Ly2+[Al(x+2y)Si1−(x+2y)O2n]·mH2O where M+ and L2+ are monovalent and divalent cations [...]
Bioaccumulation of Fluoride in Plants and Its Microbially Assisted Remediation: A Review of Biological Processes and Technological Performance
Rakesh Kumar, Rama Sinha, Pushpa Kumari Sharma, Nishita Ivy, Pawan Kumar, Nishi Kant, Aprajita Jha, Prakash Kumar Jha, Pankaj Kumar Gupta, Prabhakar Sharma, Rakesh Kumar Singh, Rajeev Pratap Singh, Ashok Ghosh, P. V. Vara Prasad
February 22, 2023 (v1)
Subject: Environment
Keywords: bioremediation, fluoride, microbes, mycoremediation, phytoremediation, remediation
Fluoride is widely found in soil−water systems due to anthropogenic and geogenic activities that affect millions worldwide. Fluoride ingestion results in chronic and acute toxicity, including skeletal and dental fluorosis, neurological damage, and bone softening in humans. Therefore, this review paper summarizes biological processes for fluoride remediation, i.e., bioaccumulation in plants and microbially assisted systems. Bioremediation approaches for fluoride removal have recently gained prominence in removing fluoride ions. Plants are vulnerable to fluoride accumulation in soil, and their growth and development can be negatively affected, even with low fluoride content in the soil. The microbial bioremediation processes involve bioaccumulation, biotransformation, and biosorption. Bacterial, fungal, and algal biomass are ecologically efficient bioremediators. Most bioremediation techniques are laboratory-scale based on contaminated solutions; however, treatment of fluoride-contaminat... [more]
Recycling of Waste Oils: Technology and Application
Alberto Mannu, Sebastiano Garroni
February 22, 2023 (v1)
Subject: Environment
Reducing the impact of human activity on the environment and, in general, on Earth, represents the most challenging target of the next years [...]
Efficiency in Ofloxacin Antibiotic Water Remediation by Magnetic Zeolites Formed Combining Pure Sources and Wastes
Claudia Belviso, Giulia Guerra, Maryam Abdolrahimi, Davide Peddis, Federica Maraschi, Francesco Cavalcante, Maurizio Ferretti, Annalisa Martucci, Michela Sturini
February 22, 2023 (v1)
Subject: Environment
Keywords: magnetic properties, nano-magnetite, ofloxacin antibiotic, wastes, water depollution, zeolites
In this work, red mud (RM) and spinel iron oxide nanoparticles (SPIONs) were added to pure silica/alumina sources (SAs) and fly ash (FA) with the aim of synthesizing and investigating the magnetic behavior of different zeolites. SAs were used to synthesize zeolite with LTA topology (zeolite A) with the addition of both red mud and spinel iron oxide nanoparticles. FA and RM were mixed to synthesize sodalite whereas only FA with the addition of SPIONs was used to form zeolite with FAU-topology (zeolite X). All the synthetic products showed magnetic properties. However, zeolites with spinel iron oxide nanoparticles (zeolites A and X) showed ferromagnetic-like behavior. Sodalite was characterized by a reduction in saturation magnetization, whereas zeolite A with red mud displayed antiferromagnetic behavior. For the first time, all the synthetic products were tested for polluted water remediation by a persistent emerging contaminant, ofloxacin (OFL) antibiotic. The four zeolite types showed... [more]
Adaptive Visual Servoing for Obstacle Avoidance of Micro Unmanned Aerial Vehicle with Optical Flow and Switched System Model
Ming-Li Chiang, Shun-Hung Tsai, Cheng-Ming Huang, Kuang-Tin Tao
February 22, 2023 (v1)
Subject: Environment
Keywords: MUAV, optical flow, switched systems, visual servoing
A vision-based adaptive switching controller that uses optical flow information to avoid obstacles for micro unmanned aerial vehicles (MUAV) is proposed in this paper. To use the optical flow to indicate the distance between the MUAV and the environment, we propose an algorithm with multi-thread processing such that the optical flow information is obtained reliably and continuously in the entire camera field of view. The flying behavior of considered MUAV is regarded as a switching system when considering different flying modes during the mission of obstacle avoidance. By the required flight direction for obstacle avoidance specified by the detected optical flow, an adaptive control scheme is designed to track the required trajectory in switching modes. The simulation result shows the tracking performances of the adaptive control with the switching system. The experiment of the whole system is completed to verify the obstacle avoidance capability of our system.
Life Cycle Assessment of Functional Food: Improving Sustainability in the Biotechnology Industry through Transparency
Alisha Lee, Yini Wang, Shih-Fang Lo
February 22, 2023 (v1)
Subject: Environment
Keywords: biotechnology, carbon footprint, functional food, greenhouse gas emissions, life cycle assessment LCA
With the advancement of biotechnology, consumers are demanding more scientifically advanced products as well as being more concerned with the environmental impact of products. A life cycle carbon footprint assessment is an important tool in reaching net-zero carbon production goals. This paper presents the greenhouse gas emissions of functional foods by highlighting TCI Co., Ltd. as a case study. TCI conducted life cycle assessments (LCAs) on two mainstream products that utilize common manufacturing processes to examine their carbon footprint and gain a better understanding of their environmental impact. The main finding shows that while the manufacturing stage accounts for around 20−30% of emissions, the raw material stage accounts for 70−80% for both products. This suggests that TCI needs to work closely with its suppliers to ensure a low emissions supply chain and to achieve its net-zero target. Not only do these LCAs allow TCI to increase the products’ transparency, but they can al... [more]
Removal of Heavy Metals from Wastewater Using Novel Polydopamine-Modified CNTs-Based Composite Membranes
Faizah Altaf, Shakeel Ahmed, Muhammad Usman, Tahira Batool, Jaweria Shamshad, Patrizia Bocchetta, Rida Batool
February 22, 2023 (v1)
Subject: Environment
Keywords: Adsorption, CNTs, heavy metals, polydopamine, removal percentage
The presence of major heavy metals including Pb2+, Cu2+, Co2+, Ni2+, Hg2+, Cr6+, Cd2+, and Zn2+ in water is of great concern because they cannot degrade or be destroyed. They are toxic even at very low concentrations. Therefore, it is necessary to remove such toxicants from water. In the current study, polydopamine carbon nanotubes (PD-CNTs) and polysulfone (PS) composite membranes were prepared. The structural and morphological features of the prepared PDCN composite membranes were studied using FTIR, XRD, SEM, and EDS. The potential application of PDCNs for heavy metal removal was studied for the removal of Pb2+, Cr6+, and Cd2+ from wastewater. The maximum removal efficiency of 96.1% was obtained for Cr6+ at 2.6 pH using a composite membrane containing 1.0% PD-CNTs. The removal efficiencies decreased by 64.1 and 73.4, respectively, by enhancing the pressure from 0.50 up to 0.85 MPa. Under the same circumstances, the percentages of Pb+2 removal at 0.49 bar by the PDCNS membranes conta... [more]
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