Treatment Stages

Treatment Stages

Mekorot’s wastewater treatment consists of four stages:

 

  • Pretreatment: The stage where the coarse or suspended material is removed.

 

  • Primary treatment: A physical energy intensive process which aims to reduce the load on the biological treatment (secondary). In this process, about 30% of the organic substances and 40% to 60% of the suspended solids are removed through gravitational settling.

 

  • Secondary treatment: A biological process that aims to decompose the organic substances in wastewater. The process is performed by using bacteria and microorganisms that digest the material waste, while inserting oxygen into the liquid by mechanical means. In order to facilitate the removal of pollutants from the wastewater, the bacteria population is allowed to proliferate, until it reaches a quantity that is sufficient to digest the contaminating materials in a given period of time. During the digestive stage, the bacteria grow into larger chunks that can be separated from the liquid through gravitational settling. After settling, secondary effluents of high quality are obtained which are permitted to be used in agriculture, pursuant to the regulations of the Ministry of Health.

 

  • Tertiary treatment: During this stage, the removal of contaminants, bacteria and other microorganisms that are found in secondary effluents is guaranteed. This is done by filtering the effluents through a deep and sterilization granular (particulate) bed. The reclaimed effluents are permitted for the unrestricted irrigation of all agricultural crops.