I have heard of Mercedes Blue Tech amonia injected diesels. On a recent Truck U show on Speed Vision, they claimed Dodge's new amonia injected diesel produced 98% water vapor, with only 2% Co. Is this true?
Can amonia work on gas engines? Could this whole green house gas thing be cured by amonia?
I don't think much urea ends up as waste. It's a useful fertilizer and building block for other chemicals.
That's aside from the obvious waste stream. Which would likely have public health concerns. They are likely invalid, but would be bad for PR. We can process sewage back into drinking water, but public perception would be the biggest hurdle to doing so.
Meh, let nature process the sewage back into drinking water, use sewage-derived clean water for other non-human-consumption purposes if it was that important...but it's not. If it's clean enough to drink then it's clean enough to just dump it anywhere.