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Open Access | Published on August 10, 2024

The Bioremoval of Toxic Dyes Using Chlorella Algae in Airlift Bioreactor

Aljuboori Ahmed
Almukhtar Riyadh
Abstract

Malachite green (MG) and Crystal Violet (CV) are used mainly as dyestuff and antimicrobials in aquaculture. They have a severe toxic effect on the environment. Several techniques were used to remove impurities from an aqueous solution: chemical, physical, and electrical. Among all these techniques, using dry algae is a more economical and helpful process. This study aims to investigate using an airlift reactor in the removal of MG and CV by chlorella algae as a biosorbent under different variables. The experiments were carried out in an airlift bioreactor. The experiments were carried out under the effect different operating conditions of initial dye concentration (5-40 ppm), alga dosage (0.3-1.8 gm/l), pH (3–10), air flow rate (0-40 ml/min), temperature (298-318 K) and contact time (5-60 min). The results show that the introduce of air bubbles significantly enhances the removal efficiency of the dye. The best removal effectiveness was 95.2% for MG dye and 96.1% for CV dye. The thermodynamics results reveal that the processes are exothermic for both dyes. Kinetic and adsorption isotherms results show the best fit is pseudo-second order and Langmuir model. The mass model result shows that the liquid film diffusion model was the best-fitted for both dyes.

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Keywords
Algae, bioremoval, dyes, Airlift Bioreactor