Dilution is the Cure for Pollution…
in aquariums. For many years, I had various aquariums. While the saltwater aquariums were interesting and very challenging, I still love my freshwater planted tanks. There’s a very good reason for this… I’m lazy.
Aquariums are tiny little ecosystems. As soon as you put fish in them, the trouble starts. Fish are polluters. They pee, crap, and drop food all over the place. Fish pee is high in nitrogen compounds, which are toxic to fish.
The cure for this is dilution. Every week or so, you remove between 15%-50% of the water in the tank and replace it with clean (prepared!) water. Assuming a tank is well mixed (and they should be), you will remove about 15% to half of the toxic nitrogen compounds. If you siphon up the poo and uneaten food, then you prevent further build up as well.
In the freshwater tank, there are some beneficial bacteria that can chemically alter nitrogen compounds, but not very much. The key to pollution is dilution.
In the saltwater tank, there are highly beneficial bacteria and much of the effort in a saltwater tank is keeping them happy. With a light enough nitrogen load (few fish and other animals), the bacteria will keep the nitrogen compounds from reaching toxic levels.
That’s the really hard part. You have to keep a dozen parameters in perfect synchronicity for the saltwater tank. The freshwater tank is more forgiving. Plus, you can add plants. Live aquatic plants are great nitrogen sinks. They suck it up and build more leaves and such. It’s much easier to trim a couple of leaves off a plant than do a major water change.
In 2005, Hurrican Rita caused a massive amount of damage to the town I was living in. We were six weeks without power. My saltwater tank… well, the less said about it the better. It was horrible… we’re talking anatomy lab in a non-air-conditioned building in Texas high summer bad. The freshwater tank? I didn’t lose a single fish. No pumps were running, no filters were running, the only light was from the windows and the only food was the plants and the minuscule shrimp I had growing in the tank. Six weeks without power and I didn’t lose a single fish. I tested the water and it was the same as when I left.
Maybe plants are a key to pollution as well.
The reason I bring this up is that we don’t have any way of diluting the pollution on Earth. As I was walking today, a dump truck drove by and it smelled horrid. But only for a second. Then the wind diluted the pollution to the point I couldn’t smell it. But unlike my aquariums, we can’t just replace half our atmosphere with clean, unpolluted air. We can’t replace half the ocean with clean, prepared saltwater.
Whatever pollution we generate stays in our system.
Excess carbon dioxide acidifies the oceans and is a greenhouse gas. Methane (mainly from farting cows and natural gas leaks) is a more potent greenhouse gas than CO2, but it only stays in the atmosphere for a few years instead of thousands like carbon dioxide. The sulfur and nitrogen compounds cause acid rain. And don’t get me started on oils and that kind of thing.
Plants may be a help, they are a help. But as the temperature increases, plants lose the ability to clean the air. Don’t let the climate change deniers fool you. Some increase in carbon dioxide is helpful for plants, but only a very small increase. After that, it becomes harmful to plants to. We (as a species) are also destroying our natural plant cover and replacing them with seasonal plant cover. And that doesn’t remove material from the system, it just borrows it and replaces it shortly (corn grows, then becomes methane from farting cows).
I often try to think of a way we could permanently git rid of some of this pollution. But right now, fossil fuels are adding 9 gigatons (9,000,000,000 tons) of carbon dioxide to the atmosphere every year.
Think of this like the US government budget. At this point, we’re reducing the deficit. That is, how much in debt we go each year. But the total debt is still increasing, even at a slower rate. Same with carbon dioxide. As we convert more to renewables and the like, we reduce the amount of carbon dioxide produced. But all the research that even if we stopped fossil fuel use tomorrow, we’re commited to a 4 degree Celsius rise in the average global temperature… and we’re nowhere near ready to stop fossil fuel production.