Interference of the coagulation process in the removal of organic compounds causing taste and odor by powder activated carbon adsorption processes

• Grant number: 19/01801-3
• Support Opportunities: Regular Research Grants
• Start date: June 01, 2019
• End date: September 30, 2021
• Field of knowledge: Engineering - Sanitary Engineering - Water Supply and Wastewater Treatment
• Principal Investigator: Sidney Seckler Ferreira Filho
• Grantee: Sidney Seckler Ferreira Filho
• Host Institution: Escola Politécnica (EP). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The most frequent problems of taste and odor in water supply are associated with the presence of metabolic byproducts produced by algae and other microorganisms, notably the MIB and Geosmina compounds. The conventional treatment of water supply does not have the capacity to remove both compounds and, therefore, when it occurs in raw water, different treatment technologies need to be incorporated in water production processes. Among these, the most commonly used for its removal has been the use of adsorption processes in powder activated carbon (PAC) and granular activated carbon (GAC).The application of PAC immediately upstream or downstream of the rapid mix has been the most attractive option for most water treatment plants, however, the major disadvantage of this type of application is that PAC particles tend to be incorporated into the flocs formed during the coagulation process as a consequence of precipitation of hydroxide in the form of iron and aluminum salts. Thus, there is a tendency of reduction in the efficiency of the adsorption process by an eventual interference in the kinetics of the mass transfer mechanisms of the adsorbate from the liquid phase to the surface of the adsorber. Motivated by the uncertainties about the best design to be used for PAC dosing in the removal of taste and odor compounds in the supply water, this research project aims to evaluate the interference of the coagulation process, more specifically the precipitation of the metal hydroxide , the efficiency of removal of organic compounds causing taste and odor in water supply by adsorption processes, as well as study the kinetics of the adsorption process and the influence of raw water (turbidity) and coagulant dosing on removal efficiency of organic compounds that cause taste and odor. (AU)