Investigation of Ability of Scenedesmus acutus، Scenedesmus incrass atulus and Scenedesmus obliquus in the Absorption of Cadmium from Industrial Wastewaters

The water crisis in the agricultural sector is one of the main challenges، and wastewater recycling is one of the ways to control this crisis. One of the limitations of using effluents in the agricultural sector is water pollution with heavy metals. Among the various methods used to remove heavy metals، biological methods are of great interest. Therefore، in this study، the ability of three microalgae of the genus Sandsmus، Scenedesmus acutus، Scendesmus incrassatulus، and Scenedesmus obliquus to remove cadmium from industrial effluents was studied. To investigate the effect of different parameters on the adsorption rate of microalgae، adsorption rate in different values of pH (3 to 7)، temperature (15 to 35 ° C)، amount of biosorbent (0.25 to 2 g)، metal concentration (20 to 200 mg/L and adsorbent contact time (30 to 150 minutes) were tested. The effect of all these parameters on the absorption rate was significant. The highest rate of cadmium (99%) uptake by microalgae occurred at pH 6، temperature 25 °C ، 1.5 g of biosorbent، the metal concentration of 150 mg /l and contact time of 150 minutes. But the amount of cadmium uptake by different species of microalgae was not significantly different.