Investigating the effect of zeolite, sunflowers biochar and activated carbon on Pb stabilization in soils with different characteristics

Due to the effects of heavy metals on human health, removing them from the environment is essential. In this study, performance of several adsorbents in the removal of Pb from the soil solution was evaluated. A factorial experiment was conducted in a randomized design with three replications. Treatments included three types of adsorbents (zeolite, sunflower biochar and active carbon), four levels of Pb (0, 300, 600 and 900 mg/L of lead nitrate) and three different soil samples. According to the results, the best pH for absorbance of Pb was 5 and the proper balance time was 24 hours. Also, by increasing the adsorbent weight, the removal of Pb from the solution increased. In most cases Langmuir model described the data better than Freundlich. Since the total concentration of Pb desorption with zeolite and Biochar was less than active carbon, these adsorbents have higher efficiency than active carbon.