Relationship between chlorine decay and nanobubble application in secondary treated wastewater

Abstract

There has been numerous research on the uses of treated wastewater that needs chlorine disinfection, but none have looked at the impacts of injecting nanobubbles (NBs) on the decomposition of residual chlorine. Gas NB injection in treated wastewater improves its properties. The kinetics of disinfectant decay could be impacted by changes in treated wastewater properties. This paper studies the effect of various NB injections on the residual chlorine decay of secondary treated wastewater (STWW). It also outlines the empirical equations that were developed to represent these impacts. The results show that each type of NBs in treated wastewater had a distinct initial chlorine concentration. The outcomes demonstrated a clear impact on the decrease of the needed chlorine quantity and the reduction of chlorine decay rate when utilizing NB injection for the STWW. As a result, the residual chlorine will remain for a longer time and will resist any microbiological growth under the application of NBs on treated wastewater. Moreover, NBs in secondary treated effluent reduce chlorine usage, lowering wastewater disinfection costs. HIGHLIGHTS The nanobubble (NB) injection in the secondary treated wastewater reduced the required chlorine dose.; Different types of NBs have different bulk chlorine decay.; Bulk chlorine decay for different NBs has been determined.;

Keywords

• chlorine decay kinetics
• disinfection
• nanobubble application
• residual chlorine
• secondary treated wastewater