Using Mouteh goldmine soil cyanobacteria for tailing damp soil bioremediation

Abstract

Introduction: Natural and human activities lead to soil degradation and soil salinization. In the last two centuries, world metal pollution level has increased extremely. Presence of some heavy metals in aquatic ecosystems is a constant threat to the health of human societies. The decrease of farmlands threatens food security. There are approximately 1 billion ha salt-affected soils all over of world, which can be made available resources after chemical, physical and biological remediation. Existence of many mines in the world and also in Iran and as a result, soil erosion and dust release from waste dams is matter of concern. Bioremediation using biological agents to detoxify and degradation of environmental pollutants- provides a suitable alternative method for substitution of current heavy metals removal strategies. Material and methods: Daily as a result of extraction operations by cyanidation in Mouteh gold mining complex, waste water and waste soil sediment widely achieved. In this study soil samples were collected from Mouteh Goldmine tailing damp soil in September 2018. The collected soil samples were cultured in BG11 medium and incubated for microalgae identification and biomass production. Also 5 gr soil inoculated with 0.5 gr biomass and the physico-chemical characteristics of the soil including pH, Na+ and K+, Pb and Cd, before and after the inoculation of soil with Cyanobacteria were determined.Results and discussion: in this study, cyanobacteria Phormidium tenue Gomont, Osillatoria tenuis C.Agardh ex Gomont, Lyngbya aestuarii Liebman ex Gomont and green Algae, Scenedesmus obliquus (Turpin) Kutzing were identified. Culture results of filamentous cyanobacteria on goldmine tailing damp soil showed that cyanobacteria can grow easily and produced a surface crust significantly. The results of the Physical analysis of the soil samples showed that O. tenuis decreased Na as a salinity element, and P. tenue absorbed high amounts of Pb as a heavy metal pollution element. Probably by using Mouteh Goldmine soil cyanobacteria, Osillatoria tenuis and Phormidium tenue for mine tailingdamp soil bioremediation, could play mine recovery from salinity and heavy metals and also preventing soil erosion and dust release from waste dams.Conclusion: Generally, it can be concluded thatdue to the existence of many goldmines in the word and Iran, daily as a result of extraction operations by cyanidation and high toxicity of cyanide, environmental adverse effects are observed. Dust release from waste dams can be affected health of living organisms like mining workers, plants and even soil microalgae which are close to the mine. By soil goldmine bioremediation can be processed biological resuscitation faster. The research results of African goldmine researchers on soil samples showed that cyanobacteria produced a surface crust significantly, that with the results of this research based on the growth of Phormidium tenue in the mine and producing a surface crust is consistent.