After the announcement of 700 tons of cyanide in the explosion site of Tianjin Port, many good-faith reminders appeared in the circle of friends. Some say that 700 tons of cyanide have been blown up in the air, and the coming rain covering Beijing, Tianjin and Hebei will bring them to everyone of us. According to an English-language message from a foreign embassy, people should avoid direct contact with the rainwater. Once contacted, they should take off all their clothes and take a bath and wash.

In the face of these news, the mood is really complicated.

As the "king of poisons", the toxicity of cyanide has been deeply rooted in the hearts of the people. The scientifically determined lethal dose is as lethal as the details of the agent's suicide depicted in the movie. The size of the rice grains hidden in the teeth can kill people. German slaughter of Jews with hydrogen cyanide during World War II cast a shadow of horror on its image.

There's a place in the world where 700 tons of cyanide are stored! This can poison the whole population of a mega-city!

Who on earth uses so much cyanide? What do they want to do? Wet mining of gold? Heavy l plating? ...

Let's put this aside. Now that this has happened, it is imperative to find ways to properly dispose of these cyanides. As a result, another piece of news blinded my eyes.

"Xxx13 is broadcasting: friends of Liaoning, Tianjin, Hebei and Beijing, do not rain today, because the explosion in Tianjin New Port confirmed that 700 tons of sodium cyanide has been floating in the atmosphere, water will become toxic, do not rain, remind every friend. "

Are you kidding me?

Not to mention that after the explosion, there is no general rainfall process in Beijing, Tianjin and Hebei. More importantly, cyanide is an ionic compound, which is not easy to volatilize. As a water-absorbent group, they have no way to "float" in the atmosphere.

Cyanide is reductive and reacts with strong oxidants such as nitrate to produce a violent explosion, which can be decomposed. According to the introduction of the fourth press conference on 15 August, it was preliminarily determined that the explosion site was accurately storing a large amount of calcium nitrate, potassium nitrate, ammonium nitrate and nitrocellulose. Therefore, the cyanide that has exploded can be removed without considering its harm.

For cyanide residues in the field, professionals have been engaged in hydrogen peroxide water treatment. Hydrogen peroxide can oxidize cyanide to non-toxic bicarbonate and ammonia, and the possible by-product hydrogen cyanide to carbon dioxide and nitrogen. Here, we should express our heartfelt respect to the brave disposal team at the scene.

Well, the only thing that could threaten us now is the cyanide that roams freely around the explosion area without explosion or oxidation by hydrogen peroxide.

How can they affect us? Inhalation, oral administration, skin.

There was no lethal high inhalation concentration far from the site of the incident. Cyanide itself can not volatilize. It reacts with water and carbon dioxide and slowly releases toxic hydrogen cyanide gas. However, hydrogen cyanide gas is easy to burn and oxidize at high temperature. Even if a high concentration of hydrogen cyanide gas cluster is formed in the field, it will be oxidized before it diffuses to the surrounding areas. In the case of rainfall, hydrogen cyanide is easier to hydrolyze into formate and its toxicity is greatly reduced.

As long as we do not drink rainwater and groundwater, we will not take the cyanide solution that may exist orally. Wearing long-sleeved clothes and masks and hats can isolate cyanide from precipitation and cut off the path of skin absorption. In this way, while predicting rainfall, an English news is the most reliable way to disseminate protective measures.

After the hydrogen peroxide treatment of cyanide at the explosion site, we need not be afraid of future rainfall. Instead, we should expect a light or moderate rain in Tianjin Port Area as soon as possible.

We should note that some journalists questioned the air quality around the explosion site. Some people said they could smell the pungent odor, while others said that the exposed skin had obvious discomfort. Some of the black smoke and colored smoke left at the explosion site made people wonder whether there was more pollution.

Yes. In addition to cyanide, there are toxic or corrosive substances such as cyclohexane amine, formic acid, dimethyl disulfide and other odorous substances. Although they are easy to participate in combustion and explosion and digestion, there may also be a small amount of leakage. At the same time, the fire has a large overfire area and complex combustion materials, which may also produce some toxic and harmful substances, such as benzopyrene, dioxins and other notorious POPs, or heavy l salt particles. Some of them are toxic or carcinogenic, which may cause immediate allergic reactions and other uncomfortable reactions. Even the conventional air pollutants sulfur dioxide and nitrogen oxides after full combustion belong to strong acidic substances, which can stimulate eyes, throat and skin. After they diffuse and subside in the air, they are more likely to have permanent impact on the environment around the fire site.

On the one hand, pollutants are easy to combine with the inherent suspended particles in the air, which aggravates air pollution. On the other hand, the deposition of pollutants into the Bohai Sea may aggravate the already fragile ecosystem of the Bohai Sea.

As a city with relatively complete urban sewage treatment system, a light rain scouring explosive pollutants should be within its affordability. perhaps