Multi-biological combined system: A mechanistic approach for removal of multiple heavy metals

In this work, interactions of diverse fungal species by the manipulation of cell concentrations has been utilized as the driving feature for the removal of hazardous multi-metals from the aqueous solutions. This study is focused on the exploitation of internal structures of microbes as a repository of lead (Pb(II)) and nickel (Ni(II)). For the concerned purpose 24 heavy metal resistant fungi are isolated from different industrial waste sites to form different microbial combinations as a single unit 'consortia' for achieving highest possible removal rates. Polymerase chain reaction and DNA sequencing are involved for the biochemical characterization and phylogenetic analysis of the screened isolates. The identification and screening studies reveal isolated strains as two Pb resistant fungi viz. K1SF-Pb15 (Aspergillus terreus) and SEF-Pb (Talaromyces islandicus) which have shown metal removal up to 93% and two Ni(II) tolerant fungal isolates namely, MEF-Ni-11 (Neurospora crassa) and Ni-1 (Aspergillus flavus) with removal efficiency of more than 91%. Relationship has been validated between the biosorption capacity and efficiency of the novel consortium under the influence of variable pH, time duration, initial concentration of Pb(II) and Ni(II), and inoculum size which has led to the foundation of effective and economical parameters for its exploitation in practical fields. The fungal consortia when applied on various industrial effluents has exhibited more than 95% of removal for both Pb(II) and Ni(II) simultaneously. The detailed mechanistic insight has shown the involvement of physical, chemical and ionic forces for the removal of heavy metals. So the designed novel multi-biological combined system acted as a repository for Pb(II) and Ni(II) ions with a greater potential which can be guided by the mechanistic methodology for the retrieval and remediation of multiple heavy metals from the real waste water samples. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

This study demonstrates the interactions of diverse fungal species for the removal of hazardous multi-metals from aqueous solutions through the manipulation of cell concentrations. By constructing microbial consortia, removal rates of over 95% for lead and nickel were achieved. The research also validates the relationship between biosorption capacity and efficiency of the novel consortium under different conditions.