domestıc wastewater treatment plants 


Domestic wastewater treatment plants are classified according to the number of people they serve. Mechanical, biological and chemical processes are used in wastewater treatment.

In mechanical-physical cleaning, which is generally determined as the first step, undissolved suspended solids are removed from waste water. These particles are separated using pretreatment steps, such as grid, filtering, pre-settling or dissolved air flotation, depending on the density. Light materials such as oil and grease float, and high-density materials settle to the bottom. Components such as grills, sieves, oil traps, sand traps, flotation and pre-settlements are used for mechanical cleaning.

Biological treatment is a process in which nutrients and pollutants in wastewater are broken down and removed by micro-organisms. While dissolved oxygen is required for the carbon compounds and ammonium degradation (nitrification) in wastewater, an oxygen-free environment is required for nitrate degradation (denitrification).

The third step covers the removal of substances that are difficult or impossible to disintegrate, such as medicinal products, toxic substances and heavy metals, and especially phosphorus compounds, using coagulation, flocculation and precipitation. In addition, disinfection is applied to the treated wastewater by methods such as UV radiation, ozonation and chlorination. At the last stage, adsorbable substances can be removed by using activated carbon filter.

SETAS offers urban wastewater services in proven technologies such as; biological treatment, anaerobic treatment, digestion, separation, chemical dosing, disinfection, sludge treatment and odor control