Salman Ahmady-Asbchin, Naser Jafari,
Volume 1, Issue 1 (12-2014)
Abstract
Methods of physical and chemical adsorption of heavy metals have disadvantages in some ways- such as high cost and ineffectiveness at low concentrations. In recent decades methods of biological uptake of heavy metals have been investigated. The biological adsorbents include bacteria, fungi and alga, among which algae have the highest efficiency of metal uptake. This study indicated that Alginic acid is most responsible for the uptake of metals, such as nickel (II) and cadmium (II). Fucus serratus, brown alga, used as a cost-effective adsorbent for the biological uptake of cadmium and nickel ions simultaneously in a batch reactor in this study. Surface structure of algae has also been investigated. Adsorption kinetics have been measured and the results have indicated that the equilibrium time is about 300 minutes. The adsorption isotherm was interpreted by means of the Langmuir equation. The maximum adsorption rate for cadmium (II) and nickel (II) turned out to be about 0.85 and 0.95 mmol/g, respectively.
Fereshteh Mohamadhasani Javar, Mehdi Rahimi,
Volume 10, Issue 2 (9-2023)
Abstract
Heavy metal contamination (HMs) of water and soil is the most serious problem caused by industrial and mining processes and other human activities. Mycoremediation is a biotechnological method that employs fungi to remove toxic contaminants from the environment in an efficient and cost-effective manner. Pleurotus species are considered to be the most popular and widely cultivated species worldwide, and this may be due to their low production cost and high yield. It has been indicated that Pleurotus species may improve plant growth in metal-contaminated soils through enhancing nutrition uptake or by alleviating toxicity of the metals. In this experiment, the fungus was grown in vitro in liquid and solid media for 3 weeks on five different concentrations (0, 15, 30, 45, 60 ppm) of five heavy metals (Cd, Zn, Ni, Pb, Mn) as sulphate and the effect of these metal on radial growth, biomass production and metal content of fungal biomass were determined. Based on the results, this fungus showed a great variety of tolerance against the metals, as that growth parameters were increased in the case of two metals contamination (Zn and Mn) and inhibition of growth was observed even at the low concentrations of nickel, cadmium and lead (15 mg/liter). The amount of metal accumulation in the fungal mycelium also increased with the increase of the metal concentration in the culture medium. In this research, for the first time, the growth parameters and the amount of accumulation of heavy metals in axenic conditions have been investigated and described.
