Fosfor Removal – Sukim Water Treatment Chemicals

In many wastewater types, the solid form of phosphorus, which is undissolved and accounts for approximately 10% of the phosphorus in water, is removed through primary sedimentation.

Except for the amount used by microorganisms for cell synthesis, removing the remaining dissolved phosphorus via conventional biological treatment is quite difficult. The effects of conventional and other treatment systems on phosphorus removal are presented in the table below.

Chemical, physical, and biological methods can be used for phosphorus removal. Chemical precipitation using iron or aluminum salts or lime is widely applied for phosphorus removal. Biological phosphorus removal is based on the principle that microorganisms, under stress, adsorb more phosphorus than needed for their growth. Many biological processes have been developed as alternatives to chemical treatment.

Effects of Various Treatment and Process Methods on Phosphorus (P) Removal

The basis of chemical phosphorus removal is the conversion of dissolved phosphorus into solid particulate form, enabling its separation from the medium. Some phosphorus is removed in the classical secondary treatment system, in both the primary and secondary treatment processes. In primary sedimentation, removal is limited to phosphorus in solid particulate form and depends on the efficiency of the coagulant. In secondary treatment, phosphorus enters the structure of microorganisms, and it is removed by separating the microorganisms that settle in the final sedimentation stage. Thus, the amount of phosphorus removed by conventional secondary treatment is a function of microbial growth.

Under suitable conditions, aluminum, iron, and calcium cations form insoluble precipitates with orthophosphate. Therefore, dissolved orthophosphate is the primary phosphorus removed via chemical treatment. Other phosphate forms (polyphosphates, colloids, and phosphorus-containing particles) are removed by secondary treatment mechanisms such as adsorption, coagulation, sedimentation, filtration, or biological methods.