Adding nitrogen to concrete could significantly reduce global levels of potentially harmful nitrogen oxides (NOx) created by the construction industry in developing towns and cities, a new study reveals. Researchers believe that concrete nitrogenation could contribute to a reduction in NOx emissions by 3.4-6.9 megatonnes (Mt) -- representing 6-13% of industry-related emissions in 2021. By 2050 the process could reduce NOx by a total of 131-384 Mt. It could represent the equivalent to 75-260 years potentially lost to premature death and reduced quality of life, estimated in terms of disability-adjusted life years (DALY). NOx are highly reactive toxic air pollutants which can contribute to acid rain, ozone layer depletion and pose significant health threats -- particularly in relation to respiratory disease -- contributing to air pollution-related mortality.

Internet Archive link (aka no paywall): https://web.archive.org/web/20230318235147/https://www.nytimes.com/2023/03/15/climate/epa-states-pollution-smog.html

"The Biden administration on Wednesday finalized a rule forcing factories and power plants in 23 Western and Midwestern states to sharply cut smog-causing pollution that is released from their smokestacks and fouls the air in Eastern states.

Known as the “good neighbor” rule, the new regulation strengthens and expands an earlier interstate air pollution standard that was enacted during the Obama administration. While that rule directed power plants to clean up their emissions, the revised rule enforces similar controls on mills, factories and other industrial facilities.

The Environmental Protection Agency is required by the Clean Air Act to periodically review and revise the rule. After failing do so during the Trump administration, it is now strengthening restrictions under a court-ordered deadline.

The good neighbor rule holds that states should take measures to ensure that their pollution doesn’t affect downwind states. It directs coal-burning power plants and industrial facilities such as iron, steel, cement and concrete manufacturers in the Western and Midwestern states to reduce their emissions of nitrogen dioxide, a pollutant that causes smog and is linked to asthma, lung disease and premature death...

“Every community deserves fresh air to breathe,” E.P.A. Administrator Michael S. Regan said. “We know air pollution doesn’t stop at the state line.”

The tighter rules on power plants will come into force later this year, while the new controls on factories and other industrial polluters will take effect in 2026.

The revised rule is one of a stack of climate and clean air regulations expected this year from the Biden administration, including stricter controls on planet-warming emissions from cars, trucks, power plants and oil and gas wells and mercury pollution from power plants. Collectively, they are designed to strengthen the clean air and climate protections that had been rolled back by the Trump administration, and to accelerate the nation’s transition away from fossil fuels and toward renewable energy.

The E.P.A. estimates that the updated good neighbor rule will cut emissions of nitrogen oxide in the affected states by 50 percent from 2021 levels by 2027, preventing 1,300 premature deaths, avoiding more than 2,300 hospital and emergency room visits, preventing 1.3 million cases of asthma and avoiding 430,000 lost school days and 25,000 missed work days..."

-via The New York Times, 3/15/23

Excerpt:

The U.S. Environmental Protection Agency (EPA) published a notice Friday denying petitions by the states of Delaware and Maryland for it to recognize that upwind state pollution sources are interfering with their ability to meet ozone standards.

The states had used a provision of the Clean Air Act to petition for reduced nitrogen oxide emissions from coal plants in Pennsylvania, West Virginia, Indiana, Kentucky and Ohio, but the EPA found that there wasn't enough evidence that the plants were contributing to elevated ozone levels in the downwind states, InsideClimateNews reported.

"The 111-page notice of denial from the agency shows that Acting EPA Administrator Andrew Wheeler, a former coal industry lobbyist, is following in the fossil fuel-friendly policy direction set by his predecessor, Scott Pruitt, while being more cautious to spell out the agency's legal reasoning," InsideClimateNews reporter Marianne Lavelle wrote.

Maryland's Attorney General Brian Frosh said Monday that the state would appeal the EPA's decision, The Associated Press reported.

"We intend to appeal EPA's decision to the U.S. Court of Appeals for the D.C. Circuit, so that Marylanders do not have to continue suffering the consequences of other states' pollution," Frosh said.

Coughing-Emoji for Greenpeace Deutschland e.V.

Nitration of a methoxybenzoic acid. 

The tricky party is that the reaction starts at 45 °C, it is highly exothermic, uses high excess of nitric acid and it should be kept at maximum 40 °C. So what happens? Instant overreaction. 

If this is not bad enough, the yield of the preferred nitro compound is only 10-15% and a LOT nitrous fumes forms during the reaction as seen on the pictures. 

Interesting part is that the gas bubbler contained some water and the formed dinitrogen trioxide is being dissolved in it forming a blue solution. N2O3 is the anhydride of the unstable nitrous acid (HNO2), and produces it when mixed into water. However when it is in high concentrations, it stays in N2O3 form for a while and could be observed, just as in this case. 

If a base is added, the corresponding salt of nitrous acid could be formed: