Pleurotus ostreatus as a species with potentially high effectiveness in the removal of synthetic dyes belonging to different classes

• Published in: Desalination and water treatment 2019-09, Vol.161, p.376-386
• Main Authors: Przystaś, Wioletta, Zabłocka-Godlewska, Ewa, Grabińska-Sota, Elżbieta
• Format: Article
• Language: English
• Subjects: Biomass immobilisation; Decolourisation; Ecotoxicity; White rot fungi
• ISSN: 1944-3986
• DOI: 10.5004/dwt.2019.24314

The widespread use of dyes causes a lot of problems in their elimination from wastewater, which is connected with their complex chemical structure. Nowadays, considerable attention is focused on decolourisation processes making use of the white rot fungi. The possibility of using two strains of Pleurotus ostreatus for decolourisation of azo, triphenylmethane, and anthraquinone dyes was investigated. In order to increase the efficiency of the decolourisation process, the mycelium was immobilised on a natural waste material (pistachio shell) and inexpensive artificial (sponge) supports. To assess the environmental safety of the process, ecotoxicity studies were conducted. In contrast to most of the previous reports about fungi, significant differences in the efficiency of the removal of each dye used were observed between both strains. The dyes were more effectively removed by the K4 strain than by the BWPH strain, especially if its mycelium was immobilised on a sponge. Immobilisation of the mycelium significantly improved both the efficiency and speed of the removal of the tested dyes. Complete decolourisation of Remazol brilliant blue R (RBBR) was obtained after 48 h in samples with immobilised mycelium. At the same time, the other two dyes (brilliant green [BG] and Evans blue [EB]) were removed in more than 90%. In samples with non- mmobilised biomass the efficiency of decolourisation was 10% and 11% of RBBR, 22% and 85% of BG, 11% and 42% of EB, respectively, for strains BWPH and K4. Pistachio nut shells may be used as a cheap and good material for mycelium immobilisation, which improves the process of dyes removal. Ecotoxicity tests have shown that decolourisation of dyes by P. ostreatus conducted in appropriate conditions may contribute to the reduction of the negative impact of dyes on aquatic organisms.