4. Issues of pollution: Let's make a list of them

4-1: Nutrients pollution
4-2: Organic wastes

(1) Waste waters and sewage sludge:

Contents: organics, odor, toxic chemicals, fecal contamination, pathogens (e.g., cholera, typhoid fever) nutrients such as N, P, S, etc.

It may cause the problems of eutrophication (too much nutrients, too much oxygen consumption).

From: Brady & Weil 12th edition. Historical and predicted trends in municipal solid-waste management.