Adsorption of Azo Dyes from Textile Wastewater by Spirulina Platensis

Abstract

Due to the mushrooming of industrial activities nowadays, the released contaminants have posed risks to the stability of ecological system. In particular, the mixture consisting of colourants used in the textile industry and water resources is detrimental to human health. In order to circumvent this problem, strategies such as precipitation, membrane filtering, adsorption and electrochemical procedures have been applied. It is commonly known that adsorption is economical, eco-friendly and easy to operate. In this study, microalg, which is a kind of cyanobacteria (i.e. Spirulina plantensis), was used to eliminate azo-dyes from the aqueous solution via adsorption. Microalg was tested at various conditions (i.e. pH, dye concentration, temperature, biomass amount and contact time). The removal percentages of Acid Black 210 and Acid Blue 7 dyes by using microalg biomass at pH=2 were 95.35 % and 92.56 %, respectively. Meanwhile, conditions such as 100 mg/L dye concentration and 0.5 g/L biomass would lead to removal percentages of 98.55 % and 97.05 % for Acid Black 210 (60 minutes contact time) and Acid Blue 7 (75 minutes contact time), respectively. The spectrofotometric measurements show that adsorption method has a great potential for removing colourants in aqueous solutions. It could serve as an alternative method for.