Chapter 354 Gas Mask
The stench of sewage came like a tidal wave, the foul and moist fishy smell went straight to the brain, choking people to the point of being unable to breathe.
"Oh my god, this place stinks! What's going on? Is it connected directly to the toilet? Just now... Hey, what's wrong with you!?"
Matthew pinched his nose, tears streaming down his face, and asked vaguely with a stone in his mouth, but as soon as he turned around, his heart sank.
In the pitch-black environment, everyone only saw Bifang leaning against the wall and retching continuously, his face was pale, his eyes were full of bloodshot, and his sticky saliva was unconsciously flowing out and dripping onto the ground.
"Hey, hey, are you okay?"
Matthew was so frightened that he almost jumped up, and hurried forward to support Bifang. This was much more terrible than vomiting himself. If something happened to Bifang now, he would be doomed as well.
Matthew knew very well that he was just a small pendant.
"It's okay, I'll take it easy!"
Bifang leaned against the wall and slowly sat down on the ground. He cut off a piece of clothes below his waist, soaked it with clean water, and covered his mouth and nose with it. Only then did he feel better.
The smell that even normal people find disgusting is amplified a hundred times in Bifang's nasal cavity. The nasal mucosa feels like it's on fire, and every olfactory cell is wailing wildly. It's almost the same as facing a stink bomb!
Digging up the memory of the stinkiest toilet you've ever used, and then increasing the smell dozens of times, that's probably how Bifang feels now. The fact that he has been able to hold on until now is a manifestation of his strong willpower.
After taking a few breaths, Bifang became a little more conscious. The remaining distance was less than a hundred meters, but unless he stopped breathing from now on, he would not be able to move forward.
But a round trip is 200 meters, and in the middle you have to find a suitable location to make a bomb. It would take at least five minutes to do it, and that’s five minutes of continuous activity.
Hearing Bifang say that he couldn't handle it, Matthew panicked: "What should I do then?"
"Don't be impatient, let me think about it..."
Bifang was still a little confused. The plan was perfect, but he never expected that he would be stumped by this section of sewer. The smell here was too stimulating.
"It's hard for a normal sewer smell to exceed the physiological limit of humans. I suspect there may be hydrogen sulfide and perhaps methane here. Super-large factories are equipped with septic tanks to prevent sewage from accumulating. After being abandoned for several months, the gas filtration system here may have malfunctioned. Coupled with the failure of the exhaust fan, the sewer air is not circulating, causing the hydrogen sulfide content in the air to far exceed the normal standard."
"Last July, a 19-year-old girl died of hydrogen sulfide poisoning in Busan, South Korea. The 19-year-old female student went to a public toilet near the swimming pool and never came out. 20 minutes later, her companions saw that the situation was not good and rushed into the toilet to find that the girl had fallen to the ground and was unconscious. The toilet smelled so bad that even her companions almost fainted. They kept vomiting while trying to save her. The girl was not rescued afterwards and the cause of death was hydrogen sulfide poisoning."
"It was also because of a malfunction in the gas filtration system that a large amount of hydrogen sulfide was produced, which was then released from the exhaust vent of the public toilet where the girl died. In the narrow toilet, the concentration of hydrogen sulfide was as high as 1000ppm, which is 60 times higher than the safety standard of 15ppm. At high concentrations, hydrogen sulfide can even cause an 'electric shock-like' death in a few seconds. The mechanism of cyanide poisoning is similar."
Matthew, who was standing by, heard his eyes widen and his breathing became lighter. He looked around and saw Bifang following suit. He quickly tore off a piece of cloth from his body, wet it and covered his mouth and nose with it.
"It's useless." Bifang shook his head. "I covered my mouth and nose to relieve the irritation. The wet towel is just a fiber fabric. It can't block these gas molecules, and it has no anti-toxic effect. If it can effectively block the smoke and poisonous gas, the air will also be isolated outside, making it impossible to breathe."
[Damn, is this so dangerous? I will never go to a public toilet again]
[Scary, so scary]
[Lao Fang knows too much, he is a chemist]
[Ah, I checked it out! When hydrogen sulfide enters the blood, it quickly finds an oxidized cytochrome oxidase and combines with the trivalent iron ion of heme. The trivalent iron of this enzyme should be reduced to the reduced cytochrome oxidase of divalent iron, transferring electrons in the redox process, thereby utilizing molecular oxygen.]
[Continued: However, hydrogen sulfide will rob trivalent iron, thus blocking the human respiratory chain and causing tissue cell hypoxia. In addition, hydrogen sulfide also has a strong cytotoxic effect on the lungs in the respiratory system, causing serious damage to lung tissue and pulmonary edema!!!]
Quick-reacting netizens have already started searching and found out the hazards of hydrogen sulfide.
"What do we do now?"
Seeing that the wet towel was of no use, Matthew didn't know what to do. As a photographer, he had no idea how to save himself in this situation.
Unexpectedly, Bifang waved his hand, signaling Matthew to be patient: "Don't worry, there are often poisonous gases in the sewers, so I was prepared before I came down. In this case, we can make a simple gas mask. Do you remember what I asked you to do before you came down?"
"You mean the charcoal?"
Matthew quickly put down his backpack and took out a handful of black charcoal particles from it. This was what Bifang asked him to make this morning, but he didn't explain the reason. Now he vaguely understood it.
Bifang took the bag of charcoal and explained, "Gas masks are generally composed of four parts: gas filter material, smoke filter material, isolation material, and strong sealing material."
"We are dealing with toxic gases, so we must have adequate filtering materials. There are only a few types of materials that can be easily found in the wild: lime soil particles, activated carbon, and charcoal."
Bifang took out an empty plastic bottle, poked a small hole in the bottom with a screwdriver as the air inlet for the gas filter canister, and cut an arc at the other end, then put it on his face to fit it, ensuring that the shape was suitable for the person's nose and face.
"All three materials are easy to obtain, especially charcoal. However, I processed it a little bit and made activated charcoal with better effects. The preparation of activated charcoal is also very simple. Just use firewood to make charcoal, then knock it into small pieces of charcoal. Put the small pieces of charcoal into a clean fine nylon mesh bag, tie the bag, and put it into an acid solution and boil it for more than 30 minutes to wash out the oil."
Matthew at the side suddenly realized. "No wonder you asked me to put vinegar in it this morning! It's acetic acid, right?"
"That's right." Bifang nodded. "Vinegar contains acetic acid. If you don't have vinegar, you can use other acids, such as hydrochloric acid , sulfuric acid, or even citric acid. Citric acid is added to many foods and even some cosmetics. You can use it. Alkaline sodium carbonate can also be used. If there is really nothing, you can even induce vomiting and cook it with stomach acid."
Bifang nodded.
He put a sponge at the bottom of the hole in the plastic bottle, then put in sawdust to 7cm, compacted to 5cm, put in a layer of gauze, put in 3cm of activated carbon, and then put another layer of sponge.
The simple gas mask is completed.
"We can just use a sealing material as a mask. A plastic bag will do. Make sure it is soft, thick, transparent, and airtight."
Bifang squeezed the can body out of the bag, sealed the joint securely with tape, added a fixing tape through the can body, and handed it to Matthew.
"The rest of the way is up to you."
"Okay... eh?" Matthew took the gas mask and was about to put it on his head. He was stunned when he heard this and pointed at himself, "Me?"
Bifang nodded: "It's you. To be honest , my sense of smell is much more developed than that of ordinary people. The smell I smell is several times that of you. I can't go in anymore."
"And don't use antifreeze to ignite it. Just sprinkle it on the ground. Don't use an open flame. Use the method I taught you last time to wrap potassium permanganate and antifreeze in newspaper to ignite it. The ignition process takes about 30 seconds. Once it's done, just throw it on the ground and run towards me! Be quick, understand?"
Bifang looked serious. The appearance of hydrogen sulfide made him change some of his ideas.
Nine out of ten gases in the sewer are flammable and explosive, so he never used open flames from beginning to end.
If the flashlight in my hand was not a highly sealed military flashlight, I might not even know how to use it.
The power of the explosion depends on the amount of explosives. A barrel of antifreeze and half a barrel of gasoline exploded completely, which might attract some people, but the limit is definitely limited.
But what if it’s hydrogen sulfide and methane in the entire sewer?
If we blow up half the street, how many people will be attracted there?
