Earlier quoted context omitted.
> Are they earning money because regulations need to be met? Yes? If there aren't regulations, then waste will be disposed of by the cheapest method, which usually involves dumping it into the atmosphere and/or water. This is how it used to be until environmental campaigning in the 70s and 80s got the regulations introduced in the West, and far more recently in China.
Whey is waste in the dairy industry, yet it's sold profitably as a dietary supplement and used all over the processed food market. Unfit oranges, apples etc. are waste to the fruit producers, but juices love it. Cow shit is a complete waste but is used as a fertilizer. Although, a bunch of cow shit is also thrown into rivers. Wasted food is ground into powder and given to animals. I guess food might be an exception.…
Much of the history of the petrochemicals industry is trying to find valuable things to do with less-valuable fractions and non-oil stuff that comes up from wells. Of course, if it's not valuable it tends to be flared off and contributes to global warming.
> Wasted food is ground into powder and given to animals
.. although since the CJD epidemic I think this is extremely limited. By regulations.