Removal of microcystin-LR by cork-based and commercial activated carbons

Cyanotoxins and mainly microcystin-LR (MCLR) is a potent and ubiquitous freshwater toxin that poses a risk for human and animal health. According to the Guidelines for Drinking Water Quality published by WHO in 2011, the maximum concentration of MCLR allowed in water for human consumption is 1 g.L-1. The methods currently used to achieve effective MCLR removal are highly costly and so, the search for new, cost effective adsorbents to be incorporated in the water treatment technologies is an important issue that has been addressed by the scientific community. The present study is focused in this thematic being the first description of the application of industrial pre-treated cork derived activated carbons for the removal of MCLR. The material selected for the study was steam activated at 800 C, presenting a mesopore (0.22 cm3g-1) and micropore (0.28 cm3g-1) network [1]. Commercial activated carbons with different textural characteristics were also tested. Batch kinetic adsorption assays were performed in controlled conditions of temperature, light and agitation, and MCLR was quantified by HPLC-DAD. For MCLR concentrations between 0.5 and 8 gcm-3, after 1h of contact time the cork derived material presents removal efficiencies > 90 %. These results are identical to those of the best commercial samples, highlighting the influence of the mesopore network in the adsorption process of MCLR. The successful removal of MCLR from aqueous solutions with cork derived activated carbons may constitute a cost efficient approach to water treatment and an alternative to commercially available activated carbons.Watercork – Valorização de subprodutos da indústria de cortiça na remoção de contaminantes (orgânicos) em águas - Cianotoxinas, Agência de Inovação (adi) - QRE