total volatile organic compounds
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TAPPI Journal ◽  
2021 ◽  
Vol 20 (10) ◽  
pp. 615-622
Author(s):  
HUANG SHAN-CONG ◽  
LIU CHANG ◽  
DAI LEI ◽  
DOU SHENG ◽  
DING MING-QI ◽  
...  

White water is highly recycled in the papermaking process so that its quality is easily deteriorated, thus producing lots of malodorous gases that are extremely harmful to human health and the environment. In this paper, the effect of hydrogen peroxide (H2O2) on the control of malodorous gases released from white water was investigated. The results showed that the released amount of total volatile organic compounds (TVOC) decreased gradually with the increase of H2O2 dosage. Specifically, the TVOC emission reached the minimum as the H2O2 dosage was 1.5 mmol/L, and meanwhile, the hydrogen sulfide (H2S) and ammonia (NH3) were almost completely removed. It was also found that pH had little effect on the release of TVOC as H2O2 was added, but it evidently affect-ed the release of H2S and NH3. When the pH value of the white water was changed to 4.0 or 9.0, the emission of TVOC decreased slightly, while both H2S and NH3 were completely removed in both cases. The ferrous ions (Fe2+) and the copper ions (Cu2+) were found to promote the generation of hydroxyl radicals (HO•) out of H2O2, enhancing its inhibition on the release of malodorous gases from white water. The Fe2+/H2O2 system and Cu2+/H2O2 system exhibited similar efficiency in inhibiting the TVOC releasing, whereas the Cu2+/H2O2 system showed better perfor-mance in removing H2S and NH3.


2021 ◽  
Vol 40 (2) ◽  
pp. 186-190
Author(s):  
F.C. Nkeshita ◽  
A.A. Adekunle ◽  
A. Abegunrin

The study predicted the concentration of indoor total volatile organic compounds (TVOC) concentration in a randomly selected room at the Umar Kabir male Hostel located at the Federal University of Agriculture, Abeokuta, Nigeria. Readings were taken using an active sampler to measure particulate matter, PM (1.0, 2.5 and 10), TVOC, Relative Humidity (RH), Temperature and Formaldehyde. Two network types namely; feedforward back propagation and the cascaded forward back propagation were adopted randomly to predict TVOC as an output variable using data set generated from six different parameters mentioned earlier. The best performing neural network was the cascaded feed forward with a coefficient of determination of 0.98 which exhibited the lowest mean square error of 0.000124 with a network structure of 6-15-1-1. The results show the ability of Artificial Neural Networks to map inputs and outputs in complex non-linear situations such as the existence of volatile compounds in the atmosphere. It can be adopted for monitoring environmental systems by engineers and public health workers, stakeholders can use such models for initiating environmental related policies aimed at safeguarding human health.


2021 ◽  
Vol 3 (1) ◽  
pp. 046-056
Author(s):  
Anand Kumar Varma S ◽  
Mahmood Anas M S ◽  
Harun Raseed M ◽  
Nithishbalasubramanian O ◽  
Madhan Kumar R

Air pollution in India particularly in metropolitan cities is a serious issue mainly due to vehicular emission, traffic congestion, burning of coal, fuelwood process. The objective of this project is to provide insightful details about the current situation of air quality across five locations in Chennai city and its impacts using an air quality detector meter. The concentration of pollutants namely Carbon dioxide (CO2), Formaldehyde (HCHO), Suspended Particulate Matter (SPM), Total Volatile Organic Compounds (TVOC) and, meteorological conditions like Temperature and Humidity are measured at five polluted areas in Chennai metropolitan city and Air Quality Index values are calculated. From the above Air Quality Index values, it is found that Marina Beach bus stop, Velachery bus stop, Mount Road government estate metro station, Koyambedu bus station, Alandur metro station are identified as problematic zones and health impacts are Published.


2021 ◽  
Vol 3 (10) ◽  
Author(s):  
Abiel Kwok ◽  
Christopher Hong ◽  
Ezra Kwok

AbstractThe novel air purification technology, Nano-Confined Catalytic Oxidation (NCCO), has been proven to be effective at eliminating air pollutants. With the increasing legalization and decriminalization of medicinal and recreational cannabis and related products, respectively, in many countries and jurisdictions around the world, concerns have been raised about indoor air quality from smoking cannabis products, such as marijuana, which produce gaseous pollutants and intense odour. In this study, NCCO technology has been evaluated for its effectiveness in reducing key marijuana concentrations in polluted indoor air by direct measurements and odour intensity assessments by human volunteers. For the odour intensity measurements, 20 non-cannabis adults participated in the odour assessment. The results are remarkable and statistically significant. The reduction in Dronabinol, a pharmaceutical form of Tetrahydrocannabinol (THC), Cannabidiol (CBD) and Cannabinol, averages 93.4%, whereas that in airborne marijuana compounds with no air purification only averages 6.2%. The technology also demonstrates statistically significant reductions in PM2.5, PM10 and total volatile organic compounds generated from marijuana smoke. The technology was able to restore high levels of harmful particulate matter to normal baseline levels. Furthermore, the odour assessment conducted by a group of 20 volunteers also confirmed statistically significant reductions in marijuana odour by 55.6% after 50 min of air purification.


2021 ◽  
pp. 004051752110457
Author(s):  
Qi Wang ◽  
Tingting Hu ◽  
Wenqi Zhang ◽  
Zhenlin Jiang ◽  
Pinhua Rao

As many countries in the world are paying increasing attention to air quality, reducing the concentration of pollutants in the air, protecting human health and improving the ecological environment have become problems that need to be solved urgently. This paper describes how ceria and cobalt tetroxide@polyacrylonitrile (CeO2/Co3O4@PAN) nanofiber membranes are produced using electrospinning technology, which have broad applications for the removal of air pollutants. Results show that CeO2/Co3O4@PAN has high electrostatic attraction to particulate matter (PM). CeO2/Co3O4@PAN membranes show better mechanical properties, thermal stability and air-purification performance than pure PAN membranes. Nanofiber membranes with 5 wt% of CeO2/Co3O4 have excellent removal efficiency: 93.4% and 94.5% for PM2.5 and PM10, respectively, and 96.2% and 98% for formaldehyde and total volatile organic compounds, respectively. They also show low pressure drops, high stability and good recyclability. This work shows that they are promising candidates as highly stable, recyclable and efficient agents for the removal of air pollutants.


Author(s):  
Monika Śmiełowska ◽  
Mariusz Marć ◽  
Bożena Zabiegała

AbstractThis study was focused on child-dedicated chocolate food products that contain a plastic package with a small toy inside (also known as chocolate eggs). Three types of these products that are commercially available on the Polish market, with different prices, chocolate composition, and main types of polymers used in the toy manufacturing process, were investigated. The polymers were identified using Fourier-transform infrared (FT-IR) analysis and emissions of selected toxic volatile organic compounds of toy and packaging samples were identified using stationary emission micro-chamber. Total volatile organic compounds emissions were also estimated. Moreover, the content of polybrominated diphenyl ethers (PBDEs) as bioaccumulative semi-volatile organic compounds was checked in all parts of the cheapest product. The highest PBDE concentrations, which ranged from 5.32 ± 0.79 to 1768 ± 289 ng/g, were recorded in chocolate samples. This demonstrates the need for consumer knowledge on the safety of such products available on the Polish market to be broadened. This is one of the many examples of studies showing that products sold on the European market do not always comply with the Conformité Européenne (CE) declaration of conformity. Furthermore, the presence of phased-out PBDEs in toys may provide evidence of wrong recycling practices. Forward-looking considerations showed that, based on assessments of the hazard quotient (HQ) and cancer risk of BDE-209 and assuming each child has contact with one toy and eats one of the studied chocolate products per day, there is no high risk associated with the exposure of children to PBDEs.


Author(s):  
Nur Faseeha Suhaimi ◽  
Juliana Jalaludin ◽  
Suhaili Abu Bakar

This study aimed to investigate the association between traffic-related air pollution (TRAP) exposure and histone H3 modification among school children in high-traffic (HT) and low-traffic (LT) areas in Malaysia. Respondents’ background information and personal exposure to traffic sources were obtained from questionnaires distributed to randomly selected school children. Real-time monitoring instruments were used for 6-h measurements of PM10, PM2.5, PM1, NO2, SO2, O3, CO, and total volatile organic compounds (TVOC). Meanwhile, 24-h measurements of PM2.5-bound black carbon (BC) were performed using air sampling pumps. The salivary histone H3 level was captured using an enzyme-linked immunosorbent assay (ELISA). HT schools had significantly higher PM10, PM2.5, PM1, BC, NO2, SO2, O3, CO, and TVOC than LT schools, all at p < 0.001. Children in the HT area were more likely to get higher histone H3 levels (z= -5.13). There were positive weak correlations between histone H3 level and concentrations of NO2 (r = 0.37), CO (r = 0.36), PM1 (r = 0.35), PM2.5 (r = 0.34), SO2 (r = 0.34), PM10 (r = 0.33), O3 (r = 0.33), TVOC (r = 0.25), and BC (r = 0.19). Overall, this study proposes the possible role of histone H3 modification in interpreting the effects of TRAP exposure via non-genotoxic mechanisms.


2021 ◽  
Vol 13 (12) ◽  
pp. 6875
Author(s):  
Irene Poza-Casado ◽  
Raquel Gil-Valverde ◽  
Alberto Meiss ◽  
Miguel Ángel Padilla-Marcos

Indoor air quality (IAQ) in educational buildings is a key element of the students’ well-being and academic performance. Window-opening behavior and air infiltration, generally used as the sole ventilation sources in existing educational buildings, often lead to unhealthy levels of indoor pollutants and energy waste. This paper evaluates the conditions of natural ventilation in classrooms in order to study how climate conditions affect energy waste. For that purpose, the impact of the air infiltration both on the IAQ and on the efficiency of the ventilation was evaluated in two university classrooms with natural ventilation in the Continental area of Spain. The research methodology was based on site sensors to analyze IAQ parameters such as CO2, Total Volatile Organic Compounds (TVOC), Particulate Matter (PM), and other climate parameters for a week during the cold season. Airtightness was then assessed within the classrooms and the close built environment by means of pressurization tests, and infiltration rates were estimated. The obtained results were used to set up a Computational Fluid Dynamics (CFD) model to evaluate the age of the local air and the ventilation efficiency value. The results revealed that ventilation cannot rely only on air infiltration, and, therefore, specific controlled ventilation strategies should be implemented to improve IAQ and to avoid excessive energy loss.


2021 ◽  
Author(s):  
Xin Chen ◽  
Boyu Zhang ◽  
Danling Wang ◽  
Li Chen ◽  
Zhenxia Du ◽  
...  

Abstract Many parts of the vehicle cabin generate volatile organic compounds (VOCs) and they are hazardous to humans. In this study, VOCs in the inner liner of automobile spare tire, and separately the significant materials used in it, like raw rubber and resins, were detected by gas chromatography-mass spectrometry (GC-MS) coupled with extracting method of static headspace sampling (SHS). By comparison, the sources of VOCs can be traced back to raw rubbers and resins. And the results indicated that alkylphenol resins are the most volatile raw materials, which would release 2,4,4-trimethyl-1-pentene, and 2,2,4,6,6-pentamethyl-3-heptene. Secondly, chlorobutyl rubber (CIIR) contained 3-methyl-pentane and methyl-cyclopentane. At the same time, through replacements of raw materials in initial formulation, such as alkylphenol resins and natural rubber (NR) with low VOCs, the total volatile organic compounds (TVOCs) discharged in inner liner could be reduced. We expected that the information gained from this work could provide references and positive significance for the manufacture of environmental-friendly tire products.


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