Phosphate Removal from Sewage by Chemical Precipitation and its Effect on Other Characteristics

Abstract

It is observed that Phosphate is seen in the sewage samples in the industry and reduction of it is required. Removing Phosphate (P) from domestic wastewater is largely done to reduce the risk of eutrophication in any water that the wastewater will be released into. Phosphorous being a nutrient can be recovered from the waste water and put to good use like in fertilizers. There are different technologies that are being used to achieve the removal of P-content from sewage like – Physical, Chemical, Biological and Ion Exchange amongst others. The main objective of our research study is to find out suitable chemical for removal of Phosphate from sewage using chemical precipitation as removal mechanism. In the current study, selection of suitable chemical for chemical precipitation amongst Alum and FeCl3 is done to reduce the P-content in the sewage up to 0.2 mg/L. Using lab trials, dosage for the same is calculated and accordingly the on-field trials were carried out to check the efficacy of the method. The study also included the study the influence of chemical addition onto the various characteristics of the sewage. The on-field trials gave an idea about the working of chemical precipitation in the current system and how it affects entire wastewater treatment system.