Browse
Subjects
Records with Subject: Environment
Showing records 170 to 194 of 3422. [First] Page: 1 4 5 6 7 8 9 10 11 12 Last
Acetylcellulose Recovery from Waste Residual for Attenuating Reactive Dye from Aquaculture Waste as a Fascinating Synergistic Ecology Effect
Hossam A. Nabwey, Maha A. Tony, Manasik M. Nour
February 10, 2024 (v1)
Subject: Environment
Keywords: acetylcellulose waste, Adsorption, isotherm models, levafix dye, wastewater treatment
Waste valorization is attracting not only the scientific world but also the world. Acetylcellulose wastes from cigarette filter residuals are signified as the largest global impact of solid waste. Acetylcellulose recycling for desired products is a promising way for environmental management. In this regard, the current investigation is dealing with the immersion of residual filters sequentially into aqueous solutions of alkali and ethanol before water washing, which converts them into a superhydrophobic acetylcellulose adsorbent material. The morphology and characteristics of the acetylcellulose fiber were characterized using a Scanning Electron Microscope (SEM) and Fourier-Transform infrared spectroscopy (FTIR). The adsorption tendency was checked for Levafix Blue dye compromised in an aqueous stream as a model textile polluted effluent. The experimental results exposed that the acetylcellulose fiber displayed a sensible textile dye elimination from the dying stream. Langmuir isotherm... [more]
Can subsea shuttles be a cost-competitive solution for CO2 transport?
Simon Roussanaly, Sigmund Holm, Avinash Subramanian
February 1, 2024 (v1)
Subject: Environment
Keywords: Carbon Capture and Storage, CO2 transport, Offshore storage, subsea shuttle, Technoeconomic Analysis
Considering the role that offshore CO2 storage is expected to play in deploying carbon capture and storage, enabling cost-efficient and flexible solutions for transporting CO2 to relevant storage locations. While several pipeline and ship-based approaches have been proposed to do so, subsea shuttles are a new concept that has also been proposed in the past couple of years. The present study seeks to understand if this new approach could be cost-efficient compared to current and upcoming ship-based transport concepts.
The result shows that the shuttle concept could be cost-competitive to currently mature 15 barg-based shipping, especially if the subsea shuttle connects to a CO2 pipeline infrastructure rather than to the reservoir directly, although cost-competitiveness is achieved only for a limited range of volumes and distances. However, it is unlikely that this concept would be cost-attractive compared to the upcoming 7 barg-based shipping, and sensitivity analyses highlight that th... [more]
An Experimental Study on Temperature, Relative Humidity, and Concentrations of CO and CO2 during Different Cooking Procedures
Xi Chen, Yahui Gao, Liu Yang, Yang Liu, Miaomiao Qin, Jialing Xia, Peng Wang
January 12, 2024 (v1)
Subject: Environment
Keywords: CO concentration, CO2 concentration, cooking procedure, relative humidity, temperature
In order to explore the indoor air quality during different cooking procedures, a very common kitchen in China is selected for experimental research. An indoor air quality meter is used to measure the temperature, relative humidity, and CO and CO2 concentrations of the indoor air above the stove when people cook four different dishes under different ventilation patterns in the kitchen. The results indicate that the heat and gas consumed during cooking are closely related to the temperature and concentrations of CO and CO2. Some cooking procedures such as boiling water are related to the indoor air temperature and relative humidity in the kitchen. In addition, in kitchens without mechanical ventilation, natural ventilation shows a more significant positive effect on controlling temperature, relative humidity, and concentrations of CO and CO2 during cooking procedures.
Transitioning towards Net-Zero Emissions in Chemical and Process Industries: A Holistic Perspective
Peter Glavič, Zorka Novak Pintarič, Helena Levičnik, Vesna Dragojlović, Miloš Bogataj
January 12, 2024 (v1)
Subject: Environment
Keywords: Biomass, cement, chemicals, climate, emissions, Energy, metals, net zero, process industries, waste
Given the urgency to combat climate change and ensure environmental sustainability, this review examines the transition to net-zero emissions in chemical and process industries. It addresses the core areas of carbon emissions reduction, efficient energy use, and sustainable practices. What is new, however, is that it focuses on cutting-edge technologies such as biomass utilization, biotechnology applications, and waste management strategies that are key drivers of this transition. In particular, the study addresses the unique challenges faced by industries such as cement manufacturing and highlights the need for innovative solutions to effectively reduce their carbon footprint. In particular, the role of hydrogen as a clean fuel is at the heart of revolutionizing the chemical and process sectors, pointing the way to cleaner and greener operations. In addition, the manuscript explores the immense importance of the European Green Deal and the Sustainable Development Goals (SDGs) for the... [more]
Investigation of the Adsorption Process of Triclosan from an Aqueous Solution, Using Nanoporous Carbon Adsorbents, Obtained after Treatment of Organic Household and Vegetable Waste
Ivanka Stoycheva, Bilyana Petrova, Boyko Tsyntsarski, Pavlina Dolashka, Angelina Kosateva, Nartzislav Petrov
January 12, 2024 (v1)
Subject: Environment
Keywords: Adsorption, environmental protection, nanoporous carbon adsorbents, organic waste, triclosan
The absorption of triclosan on the surface of four different carbon adsorbents, obtained on the base of plant and household waste (RDF), provided by Sofia Waste Plant, was investigated. The obtained results indicate that the most important parameters, which determine the process of triclosan adsorption by adsorbent surface are pore texture, the size of the accessible surface for the molecules of triclosan, and the chemical nature of the adsorbent surface. It was found that the obtained adsorbents can be successfully applied for the extraction of triclosan from waste and drinking water. The possibilities for solid products, obtained by thermal treatment of household and vegetable waste, to be applied successfully in a water purification technique are discussed.
Geological Features, Paleosedimentary Environment, and Organic Matter Accumulation Mechanisms of the Lacustrine Shale Oil System: A Case Study of the Jurassic Dongyuemiao Member in the Sichuan Basin
Enze Wang, Yang Li, Tonglou Guo, Liang Xiong, Xiaoxia Dong, Tong Wang, Kaibo Shi
January 12, 2024 (v1)
Subject: Environment
Keywords: Dongyuemiao member, lacustrine shale, organic matter accumulation mechanism, sedimentary environment
Lacustrine shale has garnered significant attention due to its significant resource potential. The Jurassic shale in the Sichuan Basin is an important target for lacustrine shale exploration in China. However, previous studies have predominantly focused on the Da’anzhai member of the Ziliujing Formation, and little attention has been paid to the shale of other strata. This paper aims to address this gap by investigating the Jurassic Dongyuemiao member in the Sichuan Basin. The study systematically characterizes the geological properties of the Dongyuemiao shale system, reconstructs the paleosedimentary environment, identifies the key factors influencing organic matter (OM) enrichment and physical properties, and assesses its resource potential through comparative analysis. Our results show that the Dongyuemiao shale was deposited in an oxic and semi-humid sedimentary environment characterized by intense weathering conditions. The enrichment of OM in the shale is primarily controlled by... [more]
Performance of Regenerated Activated Carbons on Pesticides Removal from the Aqueous Phase
Isabel Pestana da Paixão Cansado, Paulo Alexandre Mira Mourão, José Eduardo dos Santos Félix Castanheiro
January 5, 2024 (v1)
Subject: Environment
Keywords: activated carbon regeneration, circular economy, pesticide removal, reuse
Adsorbents presenting high adsorption capacity, fast adsorption rate, easy regeneration, and a good possibility for reusability are ideal for removing 4-chloro-2-methyl-phenoxyacetic acid (MCPA) or other pesticides from wastewater. Here, the effects of regeneration treatments on adsorption−desorption cycles are examined using two commercial activated carbons (ACs) (Merck and Norit 1240 X). MCPA adsorption was fast on Merck and Norit ACs in powder form (6 h) but on Norit AC, in granular form, adsorption was too slow, and the equilibrium time was reached only after 288 h. MCPA adsorption kinetic data were analyzed by applying pseudo-first-order, pseudo-second-order, and Weber−Morris models. The pseudo-second-order model fit better to all data, and the Weber−Morris representation allows confirming that on Norit 1240 X, in granular form, the pore diffusion was the limiting factor concerning the MCPA adsorption. Merck and Norit 1240 X (in powder and granular form) ACs loaded with MCPA were... [more]
Paleo-Sedimentary Environments and Controlling Factors for Enrichment of Organic Matter in Alkaline Lake Sediments: A Case Study of the Lower Permian Fengcheng Formation in Well F7 at the Western Slope of Mahu Sag, Junggar Basin
Gangqiang Chen, Yuantao Tang, Yuhang Nan, Fan Yang, Dongyong Wang
January 5, 2024 (v1)
Subject: Environment
Keywords: depositional environment, Fengcheng formation, Junggar Basin, major elements, organic matter enrichment, trace elements
The Lower Permian Fengcheng formation is a significant source of rocks and a reservoir for the Mahu Sag in the Junggar Basin. Recently, the paleo-environment deposition factors of the P1f formation have become a popular research topic. This research was conducted using data from the F7 well of Mahu Sag, based on the geochemical analysis results of TOC (total organic carbon), REE (rare earth elements), and major and trace elements of 53 samples from P1f (Lower Permian Fengcheng formation), and some deposition factors are discussed. The P1f deposition process was classified into four stages based on paleo-environment elemental indicators. This research describes the deposition process of the evolution of alkaline lakes. The early and preliminary stages of alkali lake evolution are considered as late P1f1 to middle P1f2; the paleoclimate of this process was dry, the reduction conditions increased, and the paleo-productivity and lake salinity were enhanced. The terminal stage of alkali lak... [more]
A Hybrid Ultrasonic Membrane Anaerobic System (UMAS) Development for Palm Oil Mill Effluent (POME) Treatment
Nour Hamid Abdurahman, Yunus Mohd Rosli, Nour Hamid Azhari, Gasim Hayder, Ismail Norasyikin
January 5, 2024 (v1)
Subject: Environment
Keywords: anaerobic, COD removal, kinetics equations, membrane, POME, ultrasonic
The high chemical oxygen demand (COD) and biochemical oxygen demand (BOD) levels in palm oil mill effluent (POME) wastewater make it an environmental contaminant. Moreover, conventional POME wastewater treatment approaches pose economic and environmental risks. The present study employed an ultrasonic membrane anaerobic system (UMAS) to treat POME. Resultantly, six steady states were procured when a kinetic assessment involving 11,800−21,700 mg·L−1 of mixed liquor suspended solids (MLSS) and 9800−16,800 mg·L−1 of mixed liquor volatile suspended solids (MLVSS) was conducted. The POME treatment kinetics were explained with kinetic equations derived by Monod, Contois and Chen and Hashimoto for organic at loading rates within the 1−11 kg·COD·m−3·d−1 range. The UMAS proposed successfully removed 96.6−98.4% COD with a 7.5 day hydraulic retention time. The Y value was 0.67 g·VSS/g·COD, while the specific micro-organism decay rate, b was 0.24 day−1. Methane (CH4) gas production ranged from 0.2... [more]
Fenton: A Systematic Review of Its Application in Wastewater Treatment
Matheus Pimentel Prates, Suzana Maria de Oliveira Loures Marcionílio, Karine Borges Machado, Danyelle Medeiros de Araújo, Carlos A. Martínez-Huitle, Arizeu Luiz Leão Arantes, José Eduardo Ferreira da Silva Gadêlha
January 5, 2024 (v1)
Subject: Environment
Keywords: advanced oxidative processes, pollution, scientometrics, Wastewater
The use of new technologies for the removal of pollutants from wastewater has become globally necessary due to the complexity and facilities defined by conventional treatments. Advanced oxidative processes, specifically the Fenton process, have become widely applied given their low cost and ease of use. Therefore, this study aimed to evaluate the progression of the scientific publications on the implementation of Fenton process, investigating their space−time evolution. Additionally, useful solutions, trends, and gaps in the applications for the removal of pollutants with this methodology were identified, and also different remediation strategies and the design of new treatments for wastewaters were identified within this scientometric analysis. Bibliometric research was conducted in two scientific databases, Web of Science and Scopus, from 2011 to 2022, and we identified 932 and 1263 studies with the word “Fenton,” respectively. When these publications are associated with the treatmen... [more]
Improving the Process of Product Design in a Phase of Life Cycle Assessment (LCA)
Andrzej Pacana, Dominika Siwiec, Lucia Bednárová, Ján Petrovský
November 30, 2023 (v1)
Subject: Environment
Keywords: design, impact on environment, LCA, life cycle assessment, photovoltaic panel, product, production engineering, quality, relative state scale, weighted sum model
The early phases of product development effect fundamental changes in products throughout their life cycle. Therefore, the objective of the investigation was to develop a simplified model that supports the process of product design simultaneously in terms of qualitative and environmental factors. The model is dedicated to the design phase in the life cycle assessment of the product (LCA). The originality of the model consists in: (i) analysis of customers’ satisfaction from qualitative alternatives of products; (ii) assessments of the environmental impact of these alternatives; (iii) definition of the importance of qualitative and environmental attributes of products; and (iv) prediction of favourable changes in products according to qualitative−environmental levels. The model was tested for photovoltaic panels (PVs). The model is mainly dedicated to small and medium-sized enterprises (SMEs) for support in making decisions in the design phases of products in their life cycles.
A Volume Fracturing Percolation Model for Tight Reservoir Vertical Wells
Dianfa Du, Peng Liu, Lichuan Ren, Yuan Li, Yujie Tang, Fanghui Hao
November 30, 2023 (v1)
Subject: Environment
Keywords: Laplace transform, nonlinear seepage, productivity, volume fracturing vertical well
Based on the non-linear seepage characteristics of tight reservoirs and the reconstruction mode of vertical wells with actual volume fracturing, a seven-area percolation model for volume fracturing vertical wells in tight reservoirs is established. Laplace transform and Pedrosa transform are applied to obtain analytical solutions of bottom hole pressure and vertical well production under a constant production regime. After verifying the correctness of the model, the influence of the fracture network parameters on the pressure and production is studied. The research results indicate that as the permeability modulus increases, the production of volume fracturing vertical wells decreases. The penetration ratio of the main crack and the half-length of the main crack have a small impact on production, while the diversion capacity of the main crack has a significant impact on the initial production, but it is ultimately limited by the effective volume of the transformation. Under constant pr... [more]
A Modelling-Based Framework for Carbon Emissions Calculation in Additive Manufacturing: A Stereolithography Case Study
Vasiliki C. Panagiotopoulou, Aikaterini Paraskevopoulou, Panagiotis Stavropoulos
November 30, 2023 (v1)
Subject: Environment
Keywords: additive manufacturing, carbon calculation framework, carbon emissions, carbon footprint, holistic framework, stereolithography
Manufacturing is one of the most heavily contributing sectors to global warming via its high carbon emissions. Initiatives such as the Green Deal and Sustainable Goals by the United Nations are supporting the reduction of carbon emissions in the manufacturing sector, which can be completed by making manufacturing processes more sustainable and with less carbon footprint. This also applies to novel manufacturing processes such as additive manufacturing (AM). In this work, a previously developed framework for carbon footprint calculation was tailor-made and applied to a specific stereolithography (SLA) case. The different steps of the SLA were categorised per process, machine tool and system level, and the respective carbon emissions were calculated, either theoretically or via a life cycle assessment software. The carbon emissions at the process level were significant when compared to the total carbon emissions, and the carbon emissions of the isopropanol (IPA) bath accounted for more t... [more]
Review on Waste-to-Energy Approaches toward a Circular Economy in Developed and Developing Countries
Shahabaldin Rezania, Bahareh Oryani, Vahid Reza Nasrollahi, Negisa Darajeh, Majid Lotfi Ghahroud, Kamyar Mehranzamir
November 30, 2023 (v1)
Subject: Environment
Keywords: circular economy, developed and developing countries, policies and regulations, solid waste management, waste-to-energy
International interest in using waste-to-energy (WtE) technology toward a circular economy (CE) is developing, spurred by environmental challenges such as inefficient solid waste dumping, pollution, and resource depletion. Incineration, pyrolysis, gasification, landfill, and anaerobic digestion are standard WtE technologies. Although these methods have been used for many decades, all countries try to implement the best plans based on their technologies and capacities. Therefore, an up-to-date comprehensive study is needed to evaluate the existing barriers to draw a logical roadmap for WtE to CE. Therefore, this review addresses the recent policies adopted by developed and developing countries for WtE technologies. Based on the findings, most countries seek the most cost-effective and environmentally sustainable pathways in WtE to CE; meanwhile, international collaboration and governmental support are needed to overcome the existing barriers and find a sustainable and economically viabl... [more]
Bioavailability, Sources, and Transfer Behavior of Heavy Metals in Soil−Crop Systems from a High Geological Background Area Impacted by Artisanal Zn Smelting in Guizhou Province, Southwest China
Honghong Ma, Chen Zhao, Li Zhang, Zhizhuo Liu, Fugui Zhang, Huiyan Wang, Fei Guo, Shiqi Tang, Zheng Yang, Min Peng
November 30, 2023 (v1)
Subject: Environment
Keywords: bioavailability, farmland soil, heavy metals, soil contamination, soil–plant transfer factor
The environmental risk posed by heavy metals in agricultural soil is primarily influenced by their sources, bioavailability, and geochemical transfer behavior. This study focused on Weining County, a region in Guizhou province, Southwest China, with a high geological background and long-term impact from artisanal Zn smelting. Vertical soil profiles, crop, and rhizospheric soil samples were collected and analyzed for heavy metal concentration (As, Cd, Co, Cr, Cu, Hg, Ni, Pb, V, and Zn) including the total concentration and chemical fraction. The results revealed elevated concentrations of Cd (range: 0.7−6.9 mg·kg−1), Co (range: 19.3−120.0 mg·kg−1), Cu (range: 71.6−386.0 mg·kg−1), Ni (range: 51.0−121.0 mg·kg−1), and V (range: 310.0−721.0 mg·kg−1) in all soil samples compared to the background values of Guizhou Province. Chemical fractionation analysis indicated that Cr, Ni, As, Cu, and Zn were predominantly present in the residual fraction, while Hg and Pb were predominantly found in the... [more]
Exploring the Feasibility of Carbon Capture Onboard Ships
Sadi Tavakoli, Gunnar Malm Gamlem, Donghoi Kim, Simon Roussanaly, Rahul Anantharaman, Kevin Kusup Yum, Anders Valland
November 6, 2023 (v1)
Subject: Environment
Keywords: amine, Carbon Capture, Carbon Dioxide, IMO, Maritime
International shipping is crucial for global freight transport, but is mainly based on fossil fuels, leading to significant greenhouse gas (GHG) emissions. Global GHG emissions must peak by 2025 and drop by at least 43% by 2030 to limit global warming within 1.5◦C. This calls for urgent action in all sectors as well as shipping. Scaling up alternative fuels may take too long, considering technical modifications onboard the vessels, as well as fuel production and infrastructure for distribution. Many alternative fuels are also inherently dependent on access to clean electricity, which is already in a shortage. Carbon capture from ships is another route to emission reduction that can be implemented faster and without increasing the demand for renewable electricity.
Tankers, dry bulk carriers, and container vessels contribute a majority of global shipping emissions and are therefore prime candidates for carbon capture and storage. Solvent-based post-combustion capture is mature and suita... [more]
Changing Law of Permeability of Coal Reservoirs under Variable Pressure Conditions and Its Influence on Extraction Efficiency of Coalbed Methane
Jianbao Liu, Zhimin Song, Chengtao Yang, Bing Li, Jiangang Ren, Shengjie Chen
September 21, 2023 (v1)
Subject: Environment
Keywords: bedding direction, extraction efficiency, gas pressure, metamorphic degree, permeability, true triaxial seepage experiment
Coal permeability data are critical in the prevention and control of coal and gas outbursts in mines and are an important reservoir parameter for the development of coalbed methane. The mechanism by which permeability is affected by gas pressure is complex. We used a self-developed true triaxial seepage experimental device that collects lignite and anthracite coal samples, sets fixed axial pressure and confining pressure, and changes gas pressure by changing the orientation of the coal seam to study the influence of the gas pressure on the permeability of the coal seam under the conditions of different coal types and different bedding orientations. Coal permeability decreased rapidly and then decreased slowly and tended to be stable with the increase in gas pressure. This conformed to the power exponential fitting relationship, and the fitting degree reached more than 99%. The comparison of the two anthracite coal samples showed that the sample’s permeability with a bedding plane verti... [more]
The Fermentation of a Marine Probiotic Bacterium on Low-Cost Media Formulated with Industrial Fish Gelatin Waterstreams and Collagen Hydrolysates
José Antonio Vázquez, Adrián Pedreira, Iván Salmerón, Dyah H. Wardhani, Jesus Valcarcel
September 21, 2023 (v1)
Subject: Environment
Keywords: bioconversion, collagen hydrolysates, gelatin effluents, marine probiotic bacteria, Phaeobacter sp. DIFR 27-4, Sustainability
Chemical effluents generated by the isolation of fish gelatin and collagen hydrolysates produced from the enzyme proteolysis of skin wastes are protein-rich substrates that could be used as nutrients in bacterial bioprocessing. In this study, the suitability of such nutrients in supporting the growth of a marine probiotic bacterium, Phaeobacter sp. DIFR 27-4, was studied. Both gelatin effluents and collagen hydrolysates were obtained from the skins of shark, tuna, salmon and turbot. The chemical composition of the substrates included the complete presence of all quantified amino acids. Low-cost marine culture media were formulated with these protein materials alongside a very low concentration of yeast extract and marine water. In batch cultures with gelatin effluents, the growth rates of the strain DIFR 27-4 were somewhat lower than those found in the control marine commercial media. In the case of the hydrolysates, the bacterial production of biomass was similar or higher than that o... [more]
Application of Landfill Gas-Water Joint Regulation Technology in Tianjin Landfill
Jun Liu, Tianqi Pan, Huihui Zhao, Yan Guo, Guanyi Chen, Li’an Hou
September 21, 2023 (v1)
Subject: Environment
Keywords: aerobic remediation, biochemical treatment, dynamic respiratory index, rapid stabilization
Landfills have long been widely used to dispose of Municipal Solid Waste (MSW). However, many landfills have faced early closure issues in recent years due to overload operations. Although in-situ aeration technology can quickly stabilize MSW, low oxygen utilization rates present a general problem that results in high energy-consuming and operating costs. This research aims to improve oxygen utilization efficiency by observing the dynamic respiratory index and the removal of contaminants. Three continuous reactors were constructed and designed with targeted aeration and re-circulation schemes for different landfill ages. The results show that a well-designed aerobic, semi-aerobic, and anaerobic reactor can fully degrade the organic components of MSW with different landfill ages, and the quantity of waste has been reduced by more than 60%. Additionally, it was disclosed that gas-water joint technology has a promotional effect on activating microorganisms.
Evaluating Nationwide Non-Point Source Pollution of Crop Farming and Related Environmental Risk in China
Yang Duan, Hongqiang Jiang, Xiao Huang, Wenhui Zhu, Jie Zhang, Bo Wang, Wenjun Wu
September 21, 2023 (v1)
Subject: Environment
Keywords: non-point source pollution, nutrient balance, nutrient budget, pollution risk assessment, spatial and temporal distribution
The increase in non-point source (NPS) pollution from agricultural cultivation and production sources has been cited as one of the main reasons for water eutrophication. This study built a national NPS database and estimated the nutrient (including both nitrogen (N) and phosphorus (P)) balance and NPS pollution of crop farming at the county level in 2015. Finally, the NPS pollution risks were assessed, and relative policy suggestions were provided. The results indicated that (1) in 2015, the total amounts of N and P surpluses in China were 7.95 and 7.39 million tons, respectively. The south of the Yangtze River had a relatively higher nutrient surplus compared to that in northern China. (2) The NPS emissions for N and P in China were 168.84 × 104 tons and 8.93 × 104 tons, respectively, with the highest NPS loads occurring in the eastern part of the Sichuan Basin, southern China and southwestern China, while the lowest loads occurred in northeast China. (3) The potential risk assessment... [more]
Doxycycline Removal by Solar Photo-Fenton on a Pilot-Scale Composite Parabolic Collector (CPC) Reactor
Faiza Bensaibi, Malika Chabani, Souad Bouafia, Hayet Djelal
September 21, 2023 (v1)
Subject: Environment
Keywords: CPC reactor, doxycycline, germination index, solar photo-Fenton process, wastewater treatment
In this study, the solar photo-Fenton (SPF) process was investigated for the degradation of doxycycline (DOX) using a solar compound parabolic collector (CPC) reactor and a borosilicate serpentine tube with an irradiated volume of 1.8 L. The influence of the operating parameters, such as H2O2, Fe2+ dosage, and DOX concentration, was investigated. The optimum H2O2, Fe2+ dosage, and DOX concentration were found to be 4, 0.1, and 0.06 mM, respectively. The results of photo-Fenton experiments fitted the pseudo-first-order kinetic equation (R2 = 0.99). The efficiency of the treatment under optimized conditions was analyzed by an HPLC analysis of the samples, chemical oxygen demand (COD), and total organic carbon (TOC). The results obtained showed that the solar photo-Fenton process achieved a DOX degradation of 95.07%, a COD elimination of 81.43%, and a TOC elimination of 73.05%. The phytotoxicity tests revealed a 73.32% decrease in the germination index of watercress seeds, demonstrating t... [more]
Calibration of Sensor Network for Outdoor Measurement of PM2.5 on High Wood-Heating Smoke in Temuco City
Carlos Muñoz, Juan Huircan, Francisco Jaramillo, Álex Boso
September 20, 2023 (v1)
Subject: Environment
Keywords: air pollution, low-cost sensor, particle-matter calibration, spatial–temporal distribution
In order to ascertain the spatial and temporal changes in the air quality in Temuco City, Chile, we created and installed a network of inexpensive sensors to detect PM2.5 particulate matter. The 21 measurement points deployed were based on a low-cost Sensiron SPS30 sensor, complemented with temperature and humidity sensors, an Esp32 microcontroller card with LoRa and WiFi wireless communication interface, and a solar charging unit. The units were calibrated using an airtight combustion chamber with a Grimm 11-E as a reference unit. The calibration procedure fits the parameters of a calibration model to map the raw low-cost particle-material measurements into reliable calibrated values. The measurements showed that the concentrations of fine particulate material recorded in Temuco present a high temporal and spatial variability. In critical contamination episodes, pollution reaches values as high as 354 µg/m3, and at the same time, it reaches 50 µg/m3 in other parts of the city. The con... [more]
Analysis of Greenhouse Gas Emissions Characteristics and Emissions Reduction Measures of Animal Husbandry in Inner Mongolia
Yingnan Cao, Xiaoxia Yang, Fang Yang, Ying Sun, Qianqian Wang, Futian Ren, Lei Nie, Aodemu, Weiying Feng
September 20, 2023 (v1)
Subject: Environment
Keywords: animal husbandry, emissions reduction, greenhouse gases
Global warming has had a profound impact on human life, with animal husbandry being a significant contributor to greenhouse gas emissions and playing a crucial role in the global greenhouse gas budget. Inner Mongolia is a major contributor to these emissions, making it vital to study the link between greenhouse gas emissions and animal husbandry in this region for the purpose of reducing emissions. In this study, the emissions of greenhouse gases (CH4, N2O, and CO2) from livestock and poultry breeding from 2010 to 2020 and the emissions of each city from 2020 were estimated, the emissions characteristics were analysed, and the low carbon emissions reduction technical measures were proposed. The results show that (1) the overall greenhouse gas emissions from 2010 to 2020 in Inner Mongolia showed a fluctuating trend; the main emissions sources were gastrointestinal fermentation and faecal management. The annual average CH4 emissions were 994,400 ta−1, and the annual average N2O emissions... [more]
The Influence of a Key Indicator kv on the Diffusion Range of Underwater Oil Spill
Hong Ji, Yaxin Wang, Ting Wang, Ke Yang, Zhixiang Xing
September 20, 2023 (v1)
Subject: Environment
Keywords: a key indicator kv, fitting curve, oil spill, physical model experiment, submarine pipeline
As oil spills cause harm to the survival and environment of the ocean, the objective of the present paper is to study the oil migration range using the key indicator kv, which is defined as the ratio of oil spill speed to ocean current speed. The correctness of diffusion models created and estimated for subsea oil spills can be verified by experiments. We also considered the effect of key indicators on the horizontal and vertical dispersion ranges of oil spills. The study’s findings show that, under various kv settings, the horizontal and vertical spreading heights of oil spills both increase as kv rises. When kv is equal, the leakage velocity and water flow velocity increase synchronously, and over time, the horizontal distance and vertical diffusion height of the oil spill gradually increase. In the early stages of an oil spill, when kv = 50, 100, or 150, the vertical spreading velocity will rapidly decrease. The vertical spreading speed of spilled oil increases as kv rises when the... [more]
Environmental Life Cycle Analysis of Açaí (Euterpe oleracea) Powders Obtained via Two Drying Methods
Natalia Salgado-Aristizabal, Tatiana Agudelo-Patiño, Sebastian Ospina-Corral, Ignacio Álvarez-Lanzarote, Carlos Eduardo Orrego
September 20, 2023 (v1)
Subject: Environment
Keywords: açaí crop, environmental life cycle analysis, Euterpe oleracea, spray drying, vacuum drying, waste management
Açaí is a fruit native to Brazil that is found in Colombia, and it is recognized for containing more than 90 compounds with anticancer, anti-inflammatory, and other biological activities. In this study, a cradle-to-gate life cycle analysis (LCA) was conducted for the production of açaí powder, following the methodology outlined in the ISO 14040 standard. The investigation focused on examining the impact of utilizing or not utilizing the residues generated during the pulp extraction step as fertilizers. Four scenarios were analyzed and compared: (i) production of açaí powder via vacuum drying, (ii) via spray drying, and via the same two types of drying but using residues from the pulping operation as fertilizer (Scenarios 3 and 4). It was found that to produce 1 kg of açaí in a crop cycle, 1.17 kg of CO2 eq is produced. The drying stage in Scenarios 1 and 2 generated 8.04 and 7.93 kg of CO2 eq, respectively. Similarly, when solid waste is used as fertilizer, CO2 emissions barely increas... [more]
Showing records 170 to 194 of 3422. [First] Page: 1 4 5 6 7 8 9 10 11 12 Last
(0.05 seconds)
[Show All Subjects]

[0.07 s]