Evaluation of Macroalgal Biomass for Removal of Hazardous Organic Dyes from Wastewater

Abstract

Dyes are defined as toxic, mutagenic, and dangerous pollutants to aquatic living organisms. Many adverse effects of these organic molecules on the environment such as decrease light penetration and photosynthesis which causes problems to aquatic groups, and which affect as well human health, because he is the first consumer of marine wealth, have led the researchers around the world to reduce this pollution. The wastewater must be treated carefully before discharge into main streams. Thus, great attention has been paid for many decades to the removal of dyes from industrial wastewater. Macroalgae also known as seaweeds belong to one of several groups of multicellular algae: brown, red, and green algae. This biomass can be used as dead material (adsorption) and even as living material (absorption) to remove various textile dyes. Hence, macroalgae are low-cost, non-toxic, and easily available biomaterials for the treatment of colored effluents. Adsorption of industrial dyes using marine macroalgae biomass can be an effective process and alternative to conventional methods. Macroalgal biomass is one of the most promising types of bio-adsorbents due to its rigid macrostructure, high uptake capacity, and immediate abundance. Some macroalgae have different affinities, depending on the chemical structure of each macroalga. In view of the pollution by organic pollutants and the possibility of using marine macro-algae, the present chapter was initiated to evaluate the adsorbent capacities of several macro-algae for the removal of industrial dyes in an aqueous solution. We highlight in this chapter (1) an overview on the chemical and structural properties of textile dyes, (2) toxicity and pollution of textile dyes, (3) the available technologies for hazardous organic dyes removal, (4) physicochemical parameters affecting adsorption of hazardous organic dyes, and (5) the current knowledge on the potential of using adsorbents prepared from macroalgae for the removal of dyes from aqueous solutions.