Comment by greenavocado | Hacker News Reader

Comment by greenavocado | Hacker News Reader

Parent Full thread

Hydrofluoric acid (HF) is a highly corrosive and dangerous substance that can pass through the skin and into the bones. There are many things wrong with it that make it different from other common acids like sulfuric acid.

Penetration: Unlike other acids that cause immediate pain and visible burns on the skin, hydrofluoric acid can penetrate the skin quickly without causing immediate pain or visible damage.

Skin damage: Once absorbed through the skin, hydrofluoric acid continues to cause deep tissue damage, which may not be immediately apparent.

Bone and joint damage: Hydrofluoric acid has a high affinity for calcium and can cause decalcification of the bones, leading to severe bone damage and potentially fatal electrolyte imbalances. It can also cause joint damage and pain.

Systemic effects: If left untreated, hydrofluoric acid poisoning can lead to systemic effects such as hypocalcemia (low blood calcium levels), hypomagnesemia (low blood magnesium levels), and hyperkalemia (high blood potassium levels), which can cause cardiac arrhythmias and death.

Treatment: Immediate treatment is crucial for hydrofluoric acid exposure. Calcium gluconate gel is typically applied to the affected area to neutralize the acid and prevent further damage. In severe cases, intravenous calcium and magnesium may be necessary to treat systemic effects.

The Occupational Safety and Health Administration (OSHA) has established a permissible exposure limit (PEL) for hydrofluoric acid at 3 ppm (parts per million) as an 8-hour time-weighted average (TWA) concentration. The National Institute for Occupational Safety and Health (NIOSH) recommends an even lower exposure limit of 3 ppm as a ceiling limit, not to be exceeded at any time.

Thanks ChatGPT!

Please, this is not ChatGPT! (If nothing else the math is actually correct, something LLMs suck at)

The average volume of water in one square kilometer of a river basin can vary greatly depending on the specific characteristics of the basin, such as its topography, geology, climate, and land use. Factors like precipitation, evaporation, infiltration, and water abstraction also play significant roles in determining the water volume within a basin.

However, to provide a rough estimate, we can use the concept of average runoff depth. Runoff depth is the average depth of water that would cover the entire basin if all the water flowing through it in a given time period were evenly distributed across the basin's surface.

In the United States, the average annual runoff depth varies widely, ranging from less than 0.1 inches (2.54 mm) in some arid regions to more than 40 inches (1,016 mm) in some humid regions. For this example, let's assume an average annual runoff depth of 20 inches (508 mm).

To calculate the volume of water in one square kilometer of the basin, we can use the following formula:

Volume = Area × Average runoff depth

Given:

Area of the basin = 1 square kilometer = 1,000,000 square meters Average annual runoff depth = 20 inches = 0.508 meters Volume = 1,000,000 m² × 0.508 m = 508,000 m³

This means that, on average, one square kilometer of this hypothetical river basin would contain about 508,000 cubic meters of water annually. However, it's essential to note that this is a highly simplified estimation, and actual water volumes can vary significantly depending on the specific characteristics of the basin and the time period considered.

The North Toe River has an approximate basin area of 2968.7 km²

2968.7 km² × (508000 m³/km²) / m³ = 1,508,099,600 m³ of water

Given:

Target concentration = 3 ppm = 3 mg/L

Volume of water = 1,508,099,600 m³

Concentration of concentrated HF = 48% w/w (weight by weight) = 480,000 mg/L (assuming the density of 48% HF is approximately 1 kg/L)

Step 1: Convert the volume of water from cubic meters to liters. Volume of water = 1,508,099,600 m³ = 1,508,099,600,000 L

Step 2: Calculate the mass of HF needed to reach the target concentration. Mass of HF = Target concentration × Volume of water Mass of HF = 3 mg/L × 1,508,099,600,000 L = 4,524,299 kg

Step 3: Calculate the volume of concentrated HF needed. Volume of HF = Mass of HF ÷ Concentration of HF Volume of HF = 4,524,299 kg ÷ (480,000 mg/L ÷ 1,000,000 mg/kg) = 9,425,623 L

Therefore, approximately 9,425,623 liters of 48% concentrated hydrofluoric acid would need to be added to the entire river basic to reach a concentration of 3 parts per million.

If the affected area is 1 km out of the 118.4 km length of the river, this would require in a spill of approx. 79,600 liters of 48% concentrated hydrofluoric acid to reach a concentration of 3 parts per million.

What I don't understand at all is how this is possibly an accident. It is hard to release such quantities of hydrofluoric acid by accident.

US environmental laws and industrial safety enforcement are basically a farce.

Not true, there is a significant improvement relative to 1969, the end of an era where a river in Ohio caught on fire 11 times between 1869 and 1969.

That doesn't contradict what I said. If you get a 65 on the test instead of a 30, your score significantly improved, but you still flunked.

You can't quantify the improvement in these terms because you yourself don't have a way to measure it.

Edit because I can't reply:

What is abundantly clear is the main areas with severe problems with water pollution today are Africa and the Indian Subcontinent: https://ourworldindata.org/clean-water

It's pretty clear from the number of ongoing current catastrophes (PFAS, more recently BPA, cities with lead pipes) that what we're doing now isn't enough. Can we start from that as a point of agreement?

Reply on news.ycombinator.com