scholarly journals Review of Sunset OC/EC Instrument Measurements During the EPA’s Sunset Carbon Evaluation Project

Atmosphere ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 287 ◽  
Author(s):  
Steven Brown ◽  
Hilary Minor ◽  
Theresa O’Brien ◽  
Yousaf Hameed ◽  
Brandon Feenstra ◽  
...  

To evaluate the feasibility of the Sunset semicontinuous organic and elemental carbon (OC/EC) monitor, the U.S. Environmental Protection Agency (EPA) sponsored the deployment of this monitor at Chemical Speciation Network (CSN) sites with OC and EC measurements via quartz fiber filter collection in Chicago, Illinois; Houston, Texas; Las Vegas, Nevada; St. Louis, Missouri; Rubidoux, California; and Washington, D.C. Houston, St. Louis, and Washington also had collocated Aethalometer black carbon (BC) measurements. Sunset OC generally compared well with the CSN OC (r2 = 0.73 across five sites); the Sunset/CSN OC ratio was, on average, 1.06, with a range among sites of 0.96 to 1.12. Sunset thermal EC and CSN EC did not compare as well, with an overall r2 of 0.22, in part because 26% of the hourly Sunset EC measurements were below the detection limit. Sunset optical EC had a much better correlation to CSN EC (r2 = 0.67 across all sites), with an average Sunset/CSN ratio of 0.90 (range of 0.7 to 1.08). There was also a high correlation of Sunset optical EC with Aethalometer BC (r2 = 0.77 across all sites), though with a larger bias (average Sunset/Aethalometer ratio of 0.56). When the Sunset instrument was working well, OC and OptEC data were comparable to CSN OC and EC.

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3175
Author(s):  
Ravindra Prajapati ◽  
Kirtika Kohli ◽  
Samir K. Maity ◽  
Brajendra K. Sharma

Plastic is referred to as a “material of every application”. From the packaging and automotive industries to the medical apparatus and computer electronics sectors, plastic materials are fulfilling demands efficiently. These plastics usually end up in landfills and incinerators, creating plastic waste pollution. According to the Environmental Protection Agency (EPA), in 2015, 9.1% of the plastic materials generated in the U.S. municipal solid waste stream was recycled, 15.5% was combusted for energy, and 75.4% was sent to landfills. If we can produce high-value chemicals from plastic wastes, a range of various product portfolios can be created. This will help to transform chemical industries, especially the petrochemical and plastic sectors. In turn, we can manage plastic waste pollution, reduce the consumption of virgin petroleum, and protect human health and the environment. This review provides a description of chemicals that can be produced from different plastic wastes and the research challenges involved in plastic waste to chemical production. This review also provides a brief overview of the state-of-the-art processes to help future system designers in the plastic waste to chemicals area.


1999 ◽  
Vol 01 (03) ◽  
pp. 329-347 ◽  
Author(s):  
REBECCA A. EFROYMSON

The Toxic Substances Control Act (TSCA) is the legislation used by the U.S. Environmental Protection Agency to regulate releases of genetically engineered microorganisms. The rule defining the scope of the notification requirements for releases of microbial products of biotechnology was published in April 1997. The Environmental Protection Agency (EPA) had some latitude regarding the extent to which various categories of microorganisms would be regulated, but the agency was constrained by requirements of TSCA and an interagency agreement about how to regulate products of biotechnology. This paper investigates the extent to which the scope of oversight is based on risk. A risk-based rule is defined as one where the reporting requirements are based on potential for exposure or expected adverse effects. The evolution of the rule is described, and risk-based components are discussed. In conclusion, the scope of oversight of microbial releases is determined to be based on risk to the extent that legislation and institutional constraints permit.


Sign in / Sign up

Export Citation Format

Share Document