Heavy Metal Removals using Inexpensive Natural Materials

The accumulation of heavy metals in the wetlands may cause significant damage to the environment. In this study, an experimental study was performed to reduce the amount of heavy metals using inexpensive and available materials. For this purpose, three metal ions of lead, chromium, and nickel, which had high values in the wetland were studied. Three treatments of sawdust, straw and zeolite clinoptilolite (ZC) were used in laboratory columns to investigate the heavy metal removals. The laboratory columns with a length of 1 m and a diameter of 160 mm were prepared and the wastewater were passed through them. The results showed that the maximum adsorption of lead metal ions in straw (37.6%) was better than sawdust (33%) and zeolite (12.2%). Besides, the maximum chromium adsorption in zeolite (44.4%) was higher than sawdust (40.2%) and straw (37.6%). Finally, for nickel adsorption, sawdust (39.4%) gave better results than straw (35.9%) and zeolite (33.3%). However, it seems that all the treatments used are relatively effective in removing the studied heavy metals. However, for maximum Adsorption, it is better to use a mixture of the studied treatments. The results of the one-way analysis of variance showed that the absorption rate of all three heavy metals in the treatments was significant at the 1% level and all three adsorbents had the ability to absorb the investigated heavy metals. Also, according to the LSD test, except for lead absorption by zeolite, there was no significant difference between the adsorbents used.