scholarly journals Carbon dioxide, COVID-19 and the importance of restaurant ventilation: a case study from Spain approaching Christmas 2021

2021 ◽  
Author(s):  
Teresa Moreno ◽  
Wes Gibbons
Keyword(s):  
Co2 Concentration ◽  
Infection Risk ◽  
Concentration Data ◽  
Co2 Concentrations ◽  
Restaurant Managers ◽  
Co2 Levels ◽  
Run Up ◽  
Poor Ventilation ◽  
Airborne Disease

Restaurants present an especial challenge in the prevention of the spread of COVID-19 via exhalatory bioaerosols because customers are unprotected by facemasks while eating, so that ventilation protocols in such establishments become especial important. However, despite the fact that this pandemic airborne disease has been with us for two full years, many restaurants are still not successfully prioritising air renovation as a key tool for reducing infection risk. We demonstrate this in the run-up to the 2021 Christmas celebrations by reporting on CO2 concentration data obtained from a hotel breakfast room and restaurants during the 5-day Spanish holiday period of 4th-8th December. In the case of the breakfast room, poor ventilation resulted in average CO2 levels ranging from 868 to 1237 on five consecutive days, with the highest levels coinciding with highest occupancy numbers. Inside the five restaurants, three of these were well ventilated, maintaining stable average CO2 concentrations below 700ppm. In contrast, two restaurants failed to keep average CO2 levels below 1000ppm, despite sporadic, but ineffective, attempts by one of them to ventilate the establishment. More effort needs to be made to foster in both restaurant managers and the general public an improved awareness of the value of CO2 concentrations as an infection risk proxy and the relevance of ventilation issues to the propagation of respiratory diseases.

scholarly journals Carbon dioxide dynamics in an agricultural headwater stream driven by hydrology and primary production

2020 ◽  
Vol 17 (9) ◽  
pp. 2487-2498 ◽  
Author(s):  
Marcus B. Wallin ◽  
Joachim Audet ◽  
Mike Peacock ◽  
Erik Sahlée ◽  
Mattias Winterdahl
Keyword(s):  
Carbon Dioxide ◽  
Primary Production ◽  
Large Scale ◽  
Co2 Concentration ◽  
Base Flow ◽  
Concentration Data ◽  
Entire Study ◽  
Co2 Concentrations ◽  
Variable Nature ◽  
Co2 Dynamics

Abstract. Headwater streams are known to be hotspots for carbon dioxide (CO2) emissions to the atmosphere and are hence important components in landscape carbon balances. However, surprisingly little is known about stream CO2 dynamics and emissions in agricultural settings, a land use type that globally covers ca. 40 % of the continental area. Here we present hourly measured in situ stream CO2 concentration data from a 11.3 km2 temperate agricultural headwater catchment covering more than 1 year (in total 339 d excluding periods of ice and snow cover). The stream CO2 concentrations during the entire study period were generally high (median 3.44 mg C L−1, corresponding to partial pressures (pCO2) of 4778 µatm) but were also highly variable (IQR = 3.26 mg C L−1). The CO2 concentration dynamics covered a variety of different timescales from seasonal to hourly, with an interplay of hydrological and biological controls. The hydrological control was strong (although with both positive and negative influences dependent on season), and CO2 concentrations changed rapidly in response to rainfall and snowmelt events. However, during growing-season base flow and receding flow conditions, aquatic primary production seemed to control the stream CO2 dynamics, resulting in elevated diel patterns. During the dry summer period, rapid rewetting following precipitation events generated high CO2 pulses exceeding the overall median level of stream CO2 (up to 3 times higher) observed during the whole study period. This finding highlights the importance of stream intermittency and its effect on stream CO2 dynamics. Given the observed high levels of CO2 and its temporally variable nature, agricultural streams clearly need more attention in order to understand and incorporate these considerable dynamics in large-scale extrapolations.

scholarly journals The The Effects of Adsorbent Mass Using Red Brick Powder on The Results of Biogas Purification

2020 ◽  
pp. 1-7
Author(s):  
Slamet Wahyudi
Keyword(s):  
Design Method ◽  
Physical Adsorption ◽  
Van Der Waals ◽  
Anaerobic Bacteria ◽  
Co2 Concentration ◽  
Concentration Data ◽  
23 Factorial Design ◽  
Brick Powder ◽  
Co2 Levels ◽  
Biogas Purification

Biogas is produced by the digestion of anaerobic bacteria to the degraded organics waste. However, the application of biogas is not effective because it consists of impurities such as carbon dioxide (CO2), hydrogen sulfide (H2S), water vapor (H2O), and other impurity gases. Physical Adsorption is the simplest method of immobilization of biomolecules such as CO2 which is attached to the surface through the weak bonds like van der waals forces. One of the physical adsorption to reduce CO2 levels in biogas is to use brick powder. The goal of this research is to determine the effectivity of brick powder as a purification adsorbent to the reduction of CO2 levels using the 23 factorial design method. The application of 200 and 400 grams brick powder adsorbents, with the biogas flow rate of 1 and 2 liters/minute, was researched at intervals 5 and 20 minutes, for the CO2 concentration data and heating values of biogas. Gas Chromatography (GC) is used to determine the concentration of adsorption gases especially CO2 and CH4. The results showed that the biggest effectivity reduction in CO2 concentration is 59,28%. The Increasing of brick powder adsorbent mass caused the decrease of CO2 concentration in the biogas purification. Brick is a porous material containing SiO2 – Al2O3, so it has the ability to form Van Der Waals bonding forces with CO2.

scholarly journals Carbon dioxide dynamics in an agricultural headwater stream driven by hydrology and primary production

2020 ◽  
Author(s):  
Marcus B. Wallin ◽  
Joachim Audet ◽  
Mike Peacock ◽  
Erik Sahlée ◽  
Mattias Winterdahl
Keyword(s):  
Carbon Dioxide ◽  
Primary Production ◽  
Large Scale ◽  
Co2 Concentration ◽  
Headwater Stream ◽  
Concentration Data ◽  
Entire Study ◽  
Co2 Concentrations ◽  
Variable Nature ◽  
Co2 Dynamics

Abstract. Headwater streams are known to be hotspots for carbon dioxide (CO2) emissions to the atmosphere and are hence important components in landscape carbon balances. However, surprisingly little is known about stream CO2 dynamics and emissions in agricultural settings, a land-use type that globally cover ca 40 % of the continental area. Here we present continuously measured in-situ CO2 concentration data from a temperate agricultural headwater stream covering more than one year of open-water season. The stream CO2 concentrations during the entire study period were generally high (median 3.44 mg C L−1, corresponding to partial pressures (pCO2) of 4778 µatm) but were also highly variable (IQR = 3.26 mg C L−1). The CO2 concentration dynamics covered a variety of different time-scales from seasonal to hourly, and with an interplay of hydrological and biological controls. The hydrological control was strong (although with both positive as well as negative influences dependent on season) and CO2 concentrations changed rapidly in response to rainfall and snowmelt events. However, during growing-season baseflow and receding flow conditions, aquatic primary production seemed to control the stream CO2 dynamics resulting in elevated diel patterns. Given the observed high levels of CO2 and its temporally variable nature, agricultural streams clearly need more attention in order to understand and incorporate these considerable dynamics in large scale extrapolations.

scholarly journals Elevated field atmospheric CO2 concentrations affect the characteristics of winter wheat (cv. Bologna) grains

2017 ◽  
Vol 68 (8) ◽  
pp. 713 ◽  
Author(s):  
Francesca Verrillo ◽  
Franz-Werner Badeck ◽  
Valeria Terzi ◽  
Fulvia Rizza ◽  
Letizia Bernardo ◽  
...  
Keyword(s):  
Co2 Enrichment ◽  
Co2 Concentration ◽  
Triticum Aestivum L ◽  
Interactive Effects ◽  
Elevated Concentration ◽  
Co2 Concentrations ◽  
Co2 Levels ◽  
Carbon Dioxide Co2 ◽  
Atmospheric Co2 Concentrations ◽  
The Impact

The aim of this study was to investigate the impact of elevated concentration of carbon dioxide (CO2), as expected over coming decades, on yield and quality of winter bread wheat (Triticum aestivum L.). Plants (cv. Bologna) were grown by using the free-air CO2 enrichment (FACE) system at Fiorenzuola d’Arda under ambient (control) and elevated (570 ppm, e[CO2]) CO2 concentrations for two growing seasons. We addressed whether there would be a response of wheat grains to elevated CO2 concentration in terms of the contents of nitrogen (N), micro- and macronutrients, proteins and free amino acids. Under e[CO2], total wheat biomass and grain yield increased in both years of the study. Grain N percentage was reduced under e[CO2], but grain N yield (kg ha–1) was increased. Among macro- and micronutrients, a decrease in zinc concentration was observed. The proteome pattern was significantly different in grains grown at the two different CO2 levels, but the observed changes were highly dependent on interactions with prevailing environmental conditions. Finally, a negative trend was observed in the early germination rates of seeds from plants grown under e[CO2] compared with the controls. The results suggest that the expected increase in CO2 levels and their interactive effects with environmental variables may influence agronomic performance by increasing yield and negatively affecting quality.

scholarly journals Effects of Climatic Conditions, Season and Environmental Factors on CO2 Concentrations in Naturally Ventilated Primary Schools in Chile

2021 ◽  
Vol 13 (8) ◽  
pp. 4139
Author(s):  
Muriel Diaz ◽  
Mario Cools ◽  
Maureen Trebilcock ◽  
Beatriz Piderit-Moreno ◽  
Shady Attia
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Primary Schools ◽  
Co2 Concentration ◽  
Building Design ◽  
Climatic Conditions ◽  
Indoor Environmental Quality ◽  
Co2 Concentrations ◽  
The Impact

Between the ages of 6 and 18, children spend between 30 and 42 h a week at school, mostly indoors, where indoor environmental quality is usually deficient and does not favor learning. The difficulty of delivering indoor air quality (IAQ) in learning facilities is related to high occupancy rates and low interaction levels with windows. In non-industrialized countries, as in the cases presented, most classrooms have no mechanical ventilation, due to energy poverty and lack of normative requirements. This fact heavily impacts the indoor air quality and students’ learning outcomes. The aim of the paper is to identify the factors that determine acceptable CO2 concentrations. Therefore, it studies air quality in free-running and naturally ventilated primary schools in Chile, aiming to identify the impact of contextual, occupant, and building design factors, using CO2 concentration as a proxy for IAQ. The monitoring of CO2, temperature, and humidity revealed that indoor air CO2 concentration is above 1400 ppm most of the time, with peaks of 5000 ppm during the day, especially in winter. The statistical analysis indicates that CO2 is dependent on climate, seasonality, and indoor temperature, while it is independent of outside temperature in heated classrooms. The odds of having acceptable concentrations of CO2 are bigger when indoor temperatures are high, and there is a need to ventilate for cooling.

scholarly journals Seasonal Variation Analysis Method of GHG at Municipal Solid Waste Incinerator

2020 ◽  
Vol 12 (18) ◽  
pp. 7425
Author(s):  
Seongmin Kang ◽  
Joonyoung Roh ◽  
Eui-chan Jeon
Keyword(s):  
Seasonal Variation ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Ghg Emissions ◽  
Co2 Concentration ◽  
Waste Incineration ◽  
Seasonal Effect ◽  
Waste Incinerator ◽  
Waste Composition

The greenhouse gas emissions of the waste incineration sector account for approximately 43% of the total GHG emissions and represent the majority of the CO2 emissions from waste in Korea. Improving the reliability of the GHG inventory of the waste incineration sector is an important aspect for the examination of global GHG emission management according to the Paris Agreement. In this study, we introduced a statistical approach to analyze seasonal changes through analysis of waste composition and CO2 concentration in Municipal Solid Waste incinerators and applied the methodology to one case study facility. The analysis results in the case study showed that there was no seasonal variation in waste composition and CO2 concentrations, except for wood. Wood is classified as biomass, and the GHG emissions caused by biomass incineration are reported separately, indicating that the effect of an MSW incinerator on GHG emissions is not significant. Therefore, the seasonal effect of CO2 concentration or waste composition may not be an impact when calculating GHG emissions from case study facilities’ MSW incinerators. This study proposed an approach for analyzing factors that affect the GHG inventory reliability by analyzing seasonal characteristics and variation through the statistical analysis, which are used for the calculation of the GHG emissions of an MSW incinerator.

scholarly journals Elevated CO2 Concentrations and Water Stress Affect the Ability of Italian Ryegrass to Remediate Herbicides and Enhance its Allelopathic Effect

2019 ◽  
Vol 37 ◽  
Author(s):  
L.P. SILVEIRA ◽  
A.R. FEIJÓ ◽  
C. BENETTI ◽  
J.P. REFATTI ◽  
M.V. FIPKE ◽  
...  
Keyword(s):  
Water Stress ◽  
Elevated Co2 ◽  
Co2 Concentration ◽  
Italian Ryegrass ◽  
Allelopathic Effect ◽  
Irrigated Rice ◽  
Allelopathic Potential ◽  
Co2 Concentrations ◽  
Temporal Persistence ◽  
The Impact

ABSTRACT: The long temporal persistence of select herbicides negatively impacts crops sown in succession to irrigated rice. One way to reduce these compounds in the soil over time is through phytoremediation. However, elevated CO2 concentrations may interfere with the phytoremediation process. Another consequence of climate change is the production of allelopathic compounds by forage species used as remedial agents. This study aimed to evaluate the impact of elevated CO2 concentration and drought stress on the remediation of soil samples contaminated with imazapyr + imazapic herbicides by Italian ryegrass and any subsequential affect on the allelopathic effect of this species. We report that the increasing CO2 decreased the phytoremediation potential of ryegrass. Water stress combined with a CO2 concentration of 700 µmol mol-1 caused increased allelopathy. Overall, these are the first data to indicate a significant effect of higher CO2 levels with respect to both phytoremediation efficacy and allelopathic potential of the plant species used in phytoremediation.

scholarly journals Impact of anthropogenic ocean acidification on thermal tolerance of the spider crab <i>Hyas araneus</i>

2009 ◽  
Vol 6 (2) ◽  
pp. 2837-2861 ◽  
Author(s):  
K. Walther ◽  
F. J. Sartoris ◽  
C. Bock ◽  
H. O. Pörtner
Keyword(s):  
Heart Rate ◽  
Thermal Tolerance ◽  
Thermal Sensitivity ◽  
Co2 Concentration ◽  
Spider Crab ◽  
Thermal Window ◽  
Co2 Levels ◽  
Hyas Araneus ◽  
Q10 Values ◽  
Critical Temperature Tc

Abstract. Future scenarios project combined developments of elevated CO2 concentrations and global warming and their impact on marine ecosystems. The synergistic impact of both factors was addressed by studying the effect of CO2 accumulation on thermal tolerance of the cold-eurythermal spider crab Hyas araneus. Animals were exposed to present day normocapnia (380 ppm CO2), CO2 levels expected towards 2100 (710 ppm) and beyond (3000 ppm). Heart rate and haemolymph PO2 (PeO2) were measured during progressive short term cooling from 10 to 0°C and during warming from 10 to 25°C. An increase of PeO2 occurred during cooling with highest values reached at 0°C under all three CO2 levels. Heart rate increased during warming until a critical temperature (Tc) was reached. The putative Tc under normocapnia was presumably >25°C, from where it fell to 23.5°C under 710 ppm and then 21.1°C under 3000 ppm. At the same time, thermal sensitivity, as seen in the Q10 values of heart rate, rose with increasing CO2 concentration in the warmth. Our results suggest a narrowing of the thermal window of Hyas araneus under moderate increases in CO2 levels by exacerbation of the heat or cold induced oxygen and capacity limitation of thermal tolerance.

scholarly journals Effect of elevated carbon dioxide on biology and morphometric parameters of yellow stem borer, Scirpophaga incertulas infesting rice (Oryza sativa)

2022 ◽  
Vol 24 (1) ◽  
Author(s):  
GOURI SHANKAR GIRI ◽  
S. V. S. RAJU ◽  
S. D. MOHAPATRA ◽  
MUNMUN MOHAPATRA
Keyword(s):  
Carbon Dioxide ◽  
Larval Instar ◽  
Co2 Concentration ◽  
Elevated Carbon Dioxide ◽  
Stem Borer ◽  
Developmental Period ◽  
Morphometric Parameters ◽  
Scirpophaga Incertulas ◽  
Yellow Stem Borer ◽  
Co2 Concentrations

An experiment was conducted at Research Farm, National Rice Research Institute, Cuttack, Odisha, India to quantify the effect of elevated carbon dioxide (CO2) concentrations on the biology and morphometric parameters of yellow stem borer (Scirpophaga incertulas, Pyralidae, Lepidoptera). Yellow stem borer is one of the major pest of rice in the whole rice growing regions of South East Asia. The effect of three carbon dioxide concentrations i.e. 410 ppm (ambient), 550 ppm and 700 ppm on the duration of the developmental period as well as morphometric parameters of each stage of the lifecycle of the pest was analysed. It was found that, there was an increase in the duration of the developmental period of each stage of life cycle as the concentration of CO2 increases. However, the life span of the adult moth was significantly lower under the elevated CO2 concentrations when compared with ambient CO2 concentration. Morphometric parameters viz., mean length, width and weight of each larval instar, pupa and adult were found to be significantly higher in elevated concentrations of CO2 as compared to ambient concentration.

scholarly journals Konsentrasi Co2 Pada Ruang Kelas Dengan Sistem Ventilasi Alami, Tipe Jendela Gantung Atas

2018 ◽  
Vol 1 (1) ◽  
pp. 137-144
Author(s):  
Basaria Talarosha ◽  
Valencia Rosardy
Keyword(s):  
Natural Ventilation ◽  
Co2 Concentration ◽  
Learning Performance ◽  
Opening Angle ◽  
The Public ◽  
Public Elementary Schools ◽  
Co2 Concentrations ◽  
Size Number ◽  
Window Opening ◽  
The City

Proses pernafasan menghasilkan udara yang mengandung 4,4% volume CO2 sehingga konsentrasi CO2 di dalam ruang kelas dapat menjadi lebih tinggi dari ruang luar jika ventilasi tidak mencukupi. Konsentrasi CO2 > 1000 ppm akan mengganggu kesehatan dan konsentrasi belajar yang berdampak pada penurunan performa belajar siswa. Penelitian sebelumnya menunjukkan adanya hubungan antara konsentrasi CO2 di dalam ruang kelas dengan ukuran, jumlah, posisi dan tipe jendela pada ruang kelas yang menggunakan sistem ventilasi alami. Tipe jendela gantung atas disebutkan memiliki performa yang paling buruk dalam menetralkan konsentrasi CO2 di dalam ruang. Studi bermaksud mengukur kadar konsentrasi CO2 di dalam sebuah ruang kelas pada salah satu sekolah dasar negeri di kota Medan yang menggunakan tipe jendela gantung atas. Pengukuran konsentrasi CO2 dilakukan pada kondisi sudut bukaan jendela sisi koridor ruang kelas 10 dan 30 masing -masing selama tiga (3) hari. Hasil studi menunjukkan konsentrasi CO2 maksimum pada kondisi sudut bukaan jendela 10 lebih rendah dari pada kondisi sudut bukaan jendela 30LI, namun konsentrasi CO2 rata-rata pada kedua posisi jendela masih di bawah ambang batas konsentrasi CO2 yang diijinkan untuk kesehatan (<1000 ppm).   The breathing process produces air containing 4.4% of the volume of CO2 so that the concentration of CO2 in the classroom can be higher than the outside space if there is insufficient ventilation. CO2 concentration> 1000 ppm will interfere with the health and concentration of learning which has an impact on decreasing student learning performance. Previous research has shown a correlation between CO2 concentrations in classrooms with the size, number, position and type of windows in classrooms that use natural ventilation systems. The upper hanging window type is said to have the worst performance in neutralizing CO2 concentrations in space. The study intends to measure the level of CO2 concentration in a classroom in one of the public elementary schools in the city of Medan that uses a type of upper hanging window. Measurements of CO2 concentrations were carried out at the corridor opening angle of the class 10 and 30 for three (3) days, respectively. The results showed that the maximum CO2 concentration at the window opening angle 10 was lower than the 30LI window opening, but the average CO2 concentration in both window positions was still below the threshold of the permissible CO2 concentration for health (<1000 ppm).

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