Run-off from animal production facilities contain bacteria, organic matter, nitrates, and phosphates. Fruit and Vegetable Processing . Waste water contains high concentrations of dissolved organic matter and may be highly alkaline from the use of lye. Most of this water is now recycled. Petroleum Refining .
Oil is mixed with water in the refining process to remove salts and other impurities.
It is then separated and collected. Most of this water is now recycled. Pulp and Paper . The use of bisulfite and sulfurous acid or sulfur dioxide in the pulping process yields a waste sulfite liquor containing various wood by-products. This can be reduced or recycled into various useful products.