Ultrasound efficiency in relation to sodium hypochlorite and filtration adsorption in microbial elimination in a water treatment plant

Abstract

Processes like ultrasound, chlorination and filtration-adsorption were compared to eliminate microorganisms and to adjust established parameters of public drinking water. A mini water treatment plant (WTP-CB), in pilot scale, was projected and built to evaluate each process influence as: decontamination, coagulation-flocculation, sedimentation and filtration. Total and fecal coliforms, Escherichia coli and heterotrophic bacteria and physic/chemical parameters were quantified from water. Ultrasound, chlorination and filtration-adsorption were efficient to inactivate and/or eliminate bacteria. Ultrasound decontamination in addition to coagulation-flocculation, sedimentation and filtration, could be considered as an alternative treatment water solution where prechlorination, coagulation-flocculation, sedimentation and filtration were used. The chlorination itself was efficient in inactivating bacteria despite of the coagulation-flocculation process; however, in the absence of the coagulation process, the resultant water did not achieve the established parameters. The filtration-adsorption was an important process to eliminate bacteria, showing that the filter retained particles, suspended solids, besides chemical substances and microorganisms.