The course aims to provide theoretical and practical knowledge in the field of applied treatment technologies at drinking water and wastewater treatment plants. The first part of the semester deals with drinking water treatment technologies. (1) water bases and contaminants in the raw water, (2) disinfection of drinking water, iron, manganese, arsenic and ammonium ion removal technologies, (3) removal of dissolved gases and solid particles from drinking water, (4) complex technologies for drinking water treatment. The second part of the semester deals with wastewater treatment technologies: (1) the definition of wastewater, (2) mechanical wastewater treatment, (2) basics of biological wastewater treatment, (3) basics of chemical wastewater treatment, the removal of phosphorous and nitrogen from wastewater, (4) sludge formation during wastewater treatment, aerobic and anaerobic treatment and disposal of sludge.