Bioremediation of Heavy Metal Contaminated Soils Originated from Iron Ore Mine by Bio-augmentation with Native Cyanobacteria

Abstract

The soil in the Sangan iron-mining region in the east of Iran is contaminated with a high concentration of heavy metals, especially iron. The release of these pollutants into environment results in the transfer and accumulation of iron through the food chains, hence a reasonable solution is required to restore it. Bioaugmentation is an environmental friendly option to reduce the hazard effects of heavy metal in the contaminated soil. In this study, the consortia of two indigenous cyanobacteria isolated from soil of Sangan iron mining and used to bioremediate soil contaminated with iron, chromium, copper, lead, and nickel. The experiments were carried out by three treatment methods, including control soil, surface soil sprayed with cyanobacteria, and soil mixed with cyanobacteria for six months under laboratory condition. The scanning electron microscope showed the development of a network of filaments of the inoculated cyanobacteria (Oscillatoria sp. and Leptolyngbya sp.) with soil particles in both treatments. Bio-augmentation of the soil increased initial nitrogen content from 406 mg/kg in control to 664 mg/kg in soil mixed with cyanobacteria and 710 mg/kg in soil sprayed with cyanobacteria. Cyanobacteria inoculation decreased the available concentration of lead and nickel. The nonavailable heavy metal of soil in sample sprayed with cyanobacteria was in decreasing order: Cr > Fe > Ni > As > Pb > Cu. The maximum metal removal efficiency was 32%. In soil mixed with cyanobacteria increased in the root and hypocotyl lengths of radish and lettuce was observed compared to that in the control soil, indicated in the improvement of soil quality after bioremediation.

Cyanobacteria as a potential bioasset for restoring degraded land

“…Bioremediation properties of cyanobacteria were examined by planting Lactuca sativa (lettuce) and Raphanus sativus (radish) and it was observed that the hypocotyl and root length was longer as compared to the control. Bioaugmentation potential of cyanobacteria in soil was of the order: Cr > Fe > Ni > As>Pb > Cu with 32% maximum metal removal efficiency (Biglari Quchan Atigh et al, 2020). In another study, cyanobacteria ( Nostoc sp ., Anabaena sp ., and Chlorella sp .)…”

Recent Developments in Microbe–Plant-Based Bioremediation for Tackling Heavy Metal-Polluted Soils

“…Microbes are collected from the remediation site, separately cultured, genetically grown, and returned to the location. This process helps increase the growth and population of microorganisms, which enhance the solubility, mobility, accumulation of HMs, and increase the remediation efficacy ( Atigh et al, 2020 ). However, it also reduces the risk of these pollutants either through chemically altering their chemical structure or by decreasing their bioavailability ( Mandal et al, 2016 ; Hassan et al, 2019 ; Zanganeh et al, 2021 ).…”

“…However, it also reduces the risk of these pollutants either through chemically altering their chemical structure or by decreasing their bioavailability ( Mandal et al, 2016 ; Hassan et al, 2019 ; Zanganeh et al, 2021 ). Recently this method is applied to various HM contaminated soil using different types of bacteria and fungal strains which include Oscillatoria sp., Leptolyngbya sp., Portulaca oleracea, Perenniporia subtephropora, Aspergillus niger MH541017 , Daldinia starbaeckii, Tremates versicolor , and Tremates versicolor ( Atigh et al, 2020 ; Hassan et al, 2020a ; Zanganeh et al, 2021 ).…”

Copper(II) bioremoval by thermophile Cyanobacterium aponinum

“…In another study, the bioremoval of some metals [Zn(II), Cd(II), Cu(II), Pb(II)] by the secreted substances of Cylindrospermopsis raciborskii was investigated and it was found that the molecules secreted by the cyanobacteria showed the highest affinity for Cu(II) [14]. Heidari et al [15] showed that when Oscillatoria sp. and Leptolyngbya sp.…”