Optimization of guava juice wastewater electrochemical treatment

Gilmar Dos Santos,Javier Alonso Villegas-Aragón,Joel Alonso Palomino-Romero,Silvanio Silvério Lopes Da Costa,Joel Marques Da Silva

doi:10.33448/rsd-v10i2.12474

Gilmar Dos Santos, Javier Alonso Villegas-Aragón + Show 3 more

Open Access

https://doi.org/10.33448/rsd-v10i2.12474

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Abstract

Wastewater from guava juice production was treated by two electrochemical processes: Electroflotation (EF) and Electrocoagulation (EC). Using Box-Behnken experimental design, these processes were optimized in order to find the values of treatment time, initial pH and current density that lead to the maximum chemical oxygen demand (COD) removal efficiencies. Aluminum electrodes were used in EC treatment and an iron cathode and a ruthenium dioxide / titanium dioxide anode were applied in EF treatment. EC treatment resulted in maximum COD removal of 60%, when treating the wastewater for 40 minutes, with initial pH 4.5 and current density of 35 A/m2. On the other hand, EF only removed 25% of the wastewater COD (treatment time 40 minutes, initial pH 7.0 and current density 45 A/m2). Aluminum sulfate addition improved the wastewater conductivity, lowering electricity consumption rates. Moreover, the treatment combining EF and this chemical coagulant lead to better results than the ones found when using EF alone.

Highlights

Industries are one of the main sources of wastewater generation
3.1 EC Optimization Table 2 shows the operational conditions used in the 17 runs of EC planned with Box-Behnken Experimental Design, as well as the chemical oxygen demand (COD) reduction efficiency obtained in each case
COD was reduced by 58%, 60% and 56% and turbidity removal reached 77%, 88% and 77% respectively

Summary

Introduction

Industries are one of the main sources of wastewater generation. High amounts of wastewater carrying varied contaminants are usually generated by these locations. In the case of food and beverage industries, it is remarkable the generation of large amounts of wastewater that, usually are free from toxic pollutants, present high levels of organic loads (Alvarez et al, 2011). Biological processes are chosen to treat these types of wastewaters and others that, carry considerable amounts of organic matter. In these processes, microorganisms degrade organic compounds in the presence or absence of oxygen, depending on the used technique. As highlighted by Drogui et al (2008), generally being an economically viable and efficient option, biological techniques of treatment demand large areas and long detention times, what can make their implementation impracticable

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