Types of microorganisms, growth, enzymatic activities, metabolic processes, and factors affecting these bio-processes, microbial role and activities in drinking water and wastewater treatment, importance of microorganisms in the geo-chemical cycle including carbon, nitrogen, phosphorus, and sulphide, biofilms formation in water and sewer networks, impacts and abatement methods, self-purification and eutrophication processes in receiving water bodies, applications of mass balance for biological systems description with or without biosolids recirculation. Environmental microbiology lab sessions include wastewater microbiology; methods for microbial isolation and characterization, examine the efficiency of treatment units, determine design criteria for wastewater treatment systems.