This document provides an overview of waste water treatment processes. It discusses 3 stages of treatment: physical, chemical, and biological. Physical treatment includes screening, sedimentation, and flotation to remove solids. Chemical treatment uses neutralization, coagulation, and flocculation to remove dissolved and suspended materials. Biological treatment occurs in aerobic processes like activated sludge and anaerobic digestion to break down organic pollutants. The document also briefly discusses water treatment laws and regulations in India and the United States.