Design of Effluent Treatment System

Wastewater are produced from human activities either it from residential, industrial or commercial. In order to choose the stages of treatment system that are needed. We should know the characteristics of that wastewater and the percentage of pollutant removal are needed for compliance to the standard that are implement in our country.

There are three stages of effluent treatment system which are primary treatment, secondary treatment and tertiary treatment. Basically, primary treatment is known as physical-chemical treatment where to remove the suspended solid in the wastewater. For example is screening, coagulation, flocculation. From this stage we can remove heavy metals in the wastewater. In general, heavy metal will precipitate at ph range 8 to 11. So that, by adding the base/alkali solution till the pH achieved that level the precipitation process of the heavy metal will be started. After complete the precipitation process, it can continue by adding coagulation reagent in order to coagulate/form suspended particle. After that, it will go through for flocculation process which involve addition of flocculation reagent such as polymer. Flocculation reagent is to aggromerate the fine particle size to the bigger size if particle/suspended solid. For removal that particulate, the wastewater Will proceed to clarifier. The supernatant (liquid phase) will continue for next stage of treatment. While the sludge that are obtain from the suspended particle will be press in order to dry up the sludge before it will send to proper landfill.