scholarly journals Role of snow and cold environment in the fate and effects of nanoparticles and select organic pollutants from gasoline engine exhaust

2016 ◽  
Vol 18 (2) ◽  
pp. 190-199 ◽  
Author(s):  
Yevgen Nazarenko ◽  
Uday Kurien ◽  
Oleg Nepotchatykh ◽  
Rodrigo B. Rangel-Alvarado ◽  
Parisa A. Ariya

A novel snow chamber system is used to examine the effects of snow and freezing temperatures on exhaust-derived air pollutants.

2012 ◽  
Vol 253-255 ◽  
pp. 2227-2230 ◽  
Author(s):  
Ting Nien Wu ◽  
Chih Ping Chang ◽  
Tser Son Wu ◽  
Yun Hwei Shen

In Taiwan, 3% ethanol (E3) blending fuel was introduced to the market to lessen the pressure of energy deficit and carbon reduction from global warming. This study is aimed at discovering the environmental impacts of exhaust emissions imposed by ethanol blending fuels. The tested fuels are 0%, 5%, 10%, 15% and 20% of ethanol blending, and engine testing set rotation speeds at 1500, 2500 and 3500 rpm to simulate slow, normal and fast speeds of vehicle driving. Gaseous emissions from engine exhaust were collected to determine the concentrations of CO, NOx, HC, BTEX, formaldehyde and acetaldehyde. Ethanol blending fuels were found able to reduce the emission of regulated air pollutants (CO, NOx and HC) and containing toxic compounds (BTEX) more or less. However, formaldehyde and acetaldehyde emissions were greatly enhanced due to ethanol combustion in the engine. With the use of ethanol blending fuels, the environmental impact on the release of formaldehyde should be aware and carefully controlled.


1992 ◽  
Vol 25 (11) ◽  
pp. 403-410 ◽  
Author(s):  
B. E. Rittmann

Microbiological detoxification of hazardous organic pollutants is highly promising, but its reliable implementation requires a sophisticated understanding of several different substrate types and how they interact. This paper carefully defines the substrate types and explains how their interactions affect the bacteria's electron and energy flows, information flow, and degradative activity. For example, primary substrates, which are essential for growth and maintenance of the bacteria, also interact with degradation of specific hazardous pollutants by being inducers, inhibitors, and direct or indirect cosubstrates. The target contaminants, which often are secondary substrates, also have the interactive roles of self-inhibitor, inhibitor of primary-substrate utilization, inducer, and a part of an aggregate primary substrate.


1995 ◽  
Vol 31 (1) ◽  
pp. 61-70 ◽  
Author(s):  
Graham F. White

Many organic pollutants, especially synthetic surfactants, adsorb onto solid surfaces in natural and engineered aquatic environments. Biofilm bacteria on such surfaces make major contributions to microbial heterotrophic activity and biodegradation of organic pollutants. This paper reviews evidence for multiple interactions between surfactants, biodegradative bacteria, and sediment-liquid interfaces. Biodegradable surfactants e.g. SDS, added to a river-water microcosm were rapidly adsorb to sediment surface and stimulated the indigenous bacteria to attach to the sediment particles. Recalcitrant surfactants and non-surfactant organic nutrients did not stimulate attachment Attachment of bacteria was maximal when biodegradation was fastest, and was reversed when biodegradation was complete. Dodecanol, the primary product of SDS-biodegradation, markedly stimulated attachment. When SDS was added to suspensions containing sediment and either known degraders or known non-degraders, only the degraders became attached, and attachment accelerated surfactant biodegradation to dodecanol. These cyclical cooperative interactions have implications for the design of biodegradability-tests, the impact of surfactant adjuvants on biodegradability of herbicides/pesticides formulated with surfactants, and the role of surfactants used to accelerate bioremediation of hydrocarbon-polluted soils.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Marlene Cervantes González

Abstract Persistent Organic Pollutants (POPs) are exogenous, artificially made chemicals that can disrupt the biological system of individuals and animals. POPs encompass a variety of chemicals including, dioxins, organochlorines (OCs), polychlorinated biphenyl (PCBs), and perfluoroalkyl substances (PFASs) that contain a long half-life and highly resistant to biodegradation. These environmental pollutants accumulate over time in adipose tissues of living organisms and alter various insulin function-related genes. Childhood Metabolic Syndrome (MetS) consists of multiple cardiovascular risk factors, insulin function being one of them. Over the years, the incidence of the syndrome has increased dramatically. It is imperative to explore the role of persistent organic pollutants in the development of Childhood Metabolic Syndrome. Some epidemiological studies have reported an association between prenatal exposure to POPs and offspring MetS development throughout childhood. These findings have been replicated in animal studies in which these pollutants exercise negative health outcomes such as obesity and increased waist circumference. This review discusses the role of prenatal exposure to POPs among offspring who develop MetS in childhood, the latest research on the MetS concept, epidemiological and experimental findings on MetS, and the POPs modes of action. This literature review identified consistent research results on this topic. Even though the studies in this review had many strengths, one major weakness was the usage of different combinations of MetS criteria to measure the outcomes. These findings elucidate the urgent need to solidify the pediatric MetS definition. An accurate definition will permit scientists to measure the MetS as a health outcome properly and allow clinicians to diagnose pediatric MetS and provide individualized treatment appropriately.


2011 ◽  
Vol 11 (1) ◽  
pp. 3461-3492
Author(s):  
S.-M. Li ◽  
J. Liggio ◽  
L. Graham ◽  
G. Lu ◽  
J. Brook ◽  
...  

Abstract. This paper presents the results of laboratory studies on the condensational uptake of gaseous organic compounds in the exhaust of a light-duty gasoline engine onto preexisting sulfate and nitrate seed particles. Significant condensation of the gaseous organic compounds in the exhaust occurs onto pre-existing inorganic particles on a time scale of 2–5 min. The amount of condensed organic mass (COM) is proportional to the seed particle mass, suggesting that the uptake is due to dissolution, not adsorption. The solubility decreases as a power function with increased dilution of the exhaust, ranging from 0.23 g/g at a dilution ratio of 81, to 0.025 g/g at a dilution ratio of 2230. The solubility increases nonlinearly with increasing concentration of the total hydrocarbons in the gas phase (THC), rising from 0.12 g/g to 0.26 g/g for a CTHC increase of 1 to 18 μg m−3, suggesting that more organics are partitioned into the particles at higher gas phase concentrations. In terms of gas-particle partitioning, the condensational uptake of THC gases in gasoline engine exhaust can account for up to 30% of the total gas+particle THC. By incorporating the present findings, regional air quality modelling results suggest that the condensational uptake of THC onto sulfate particles alone can be comparable to the primary particle mass under moderately polluted ambient conditions. These findings are important for modelling and regulating the air quality impacts of gasoline vehicular emissions.


2021 ◽  
Author(s):  
Qinyi Li ◽  
Alba Badia ◽  
Rafael P. Fernandez ◽  
Anoop S. Mahajan ◽  
Ana Isabel López-Noreña ◽  
...  

<p>Ocean-going ships supply products from one region to another and contribute to the world’s economy. Ship exhaust contains many air pollutants and results in significant changes in marine atmospheric composition. The role of Reactive Halogen Species (RHS) in the troposphere has received increasing recognition and oceans are the largest contributors to their atmospheric burden. However, the impact of shipping emissions on RHS and that of RHS on ship-originated air pollutants have not been studied in detail. Here, an updated WRF-Chem model is utilized to explore the chemical interactions between ship emissions and oceanic RHS over the East Asia seas in summer. The emissions and resulting chemical transformations from shipping activities increase the level of NO and NO<sub>2</sub> at the surface, increase O<sub>3</sub> in the South China Sea, but decrease O<sub>3</sub> in the East China Sea. Such changes in pollutants result in remarkable changes in the levels of RHS as well as in their partitioning. The abundant RHS, in turn, reshape the loadings of air pollutants and those of the oxidants with marked patterns along the ship tracks. We, therefore, suggest that these important chemical interactions of ship-originated emissions with RHS should be considered in the environmental policy assessments of the role of shipping emissions in air quality and climate.</p>


2010 ◽  
Vol 4 (3-4) ◽  
pp. 79-82
Author(s):  
Emil Cukic

This research is carried out in order to be determined the role of Chamber system in development of agricommerce along with successful preparation of Serbia for EU accession. On February 28, 1857 Prince Aleksandar Karaðorðeviæ signed the Decree, called THE CONSTITUTION OF THE TRADE. By this Decree, the first BusinessAssociation in Serbia was constituted. Under the Law on retail stores passed in June 1910, the first chambers were established. Those were the following: • The Chamber of TRADE • The Chamber of CRAFTS • The Chamber of INDUSTRY • The Chamber ofWORKERS Today, in conditions of economic and social reforms and transfer toward market oriented economy, chambers in Serbia chose to reconsider their role, by using experiences of chambers in countries with developed market economy.The chamber strives to be organized as independent, business oriented and expert association of economic operators. The structure of economy, from the aspect of important economic indicators (total revenue, profit), shows dominant share of manufacturing andagro-industry, trade, financial and other services sectors, transport, telecommunication, and construction industries. By generating over 30% of GDP and employment, Belgrade plays vital role in the economy of the whole Serbia. That is an advantage, but also the responsibility to constantly stimulate faster development and higher living standards by inciting the positive changes in economic and overall environment.


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