waste water treatment

Brewer's waste, also known as brewer's grain or spent grain, is a byproduct of thebrewing process. Beer begins with a mash of barley (and sometimes other grains) and hot water, which after an hour or so of enzymatic activity, converts the grain's starch into sugar and is then drained and rinsed to extract that sugar.

Probably the easiest way to put spent grain to work is composting it. In most cases spent brewery grain could be classified as a nitrogenous waste (fresh = green matter) on the same level as grass clippings.