Synergistic bromothymol blue dye degradation with hydrodynamic cavitation and hydrogen peroxide (HC-H2O2)

Polyane Ribeiro Machado,Deusmaque Carneiro Ferreira,Geoffroy Roger Pointer Malpass,Thiago Vinícius Ribeiro Soeira,Fausto De Souza Pagan,Julio Cesar De Souza Inácio Gonçalves

doi:10.4136/ambi-agua.2518

Polyane Ribeiro Machado, Deusmaque Carneiro Ferreira + Show 4 more

Open Access

https://doi.org/10.4136/ambi-agua.2518

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Abstract

This study assessed the degradation of bromothymol blue in a Venturi device based on a hybrid process that combines hydrodynamic cavitation (HC) and hydrogen peroxide (H2O2). A Rotatable Central Composite Design (RCCD) was used to optimize the following variables: pressure, reaction time and molar ratio of hydrogen peroxide. Degradation efficiencies were evaluated based on Chemical Oxygen Demand (COD) and color removals before and after Venturi treatment. Maximum COD (93.42%) and color (93.28%) removals were observed at 4.0 bar inlet pressure, at a treatment time of 25 minutes and at H2O2/effluent (dye) molar ratio of 30:1. The hydrodynamic cavitation/hydrogen peroxide system has great potential to remove normally recalcitrant organic pollutants.

Highlights

Dyes are widely used in different sectors such as the food industry, tattooing, textile and paper production, tanning, and others
The current study has made the option to perform a Chi-square (χ2) correspondence test, which showed that color and Chemical Oxygen Demand (COD) reduction levels were not independent at a 95% significance level (p
This study investigated the efficiency of the combination of hydrodynamic cavitation and H2O2 to remove color and COD from a bromothymol blue solution

Summary

Introduction

Dyes are widely used in different sectors such as the food industry, tattooing, textile and paper production, tanning, and others. A large proportion of the applied dyes are discharged into water bodies due to nonexistent and/or inadequate industrial wastewater treatment systems. It is estimated that approximately 2 tons, or about 20%, of all dyes consumed by the Brazilian textile industry, are annually discarded as effluent (Dallago et al, 2005). Dyes often damage aquatic ecosystems after reaching water bodies. Dyes are compounds capable of inhibiting the metabolic activity of microorganisms, a fact that reduces their likelihood of being naturally degraded in the environment. Incomplete degradation processes can lead to the formation of by-products that are highly toxic to humans and to aquatic organisms (Dillari et al, 2016)

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