Pages: 1-8

Abstract

Inorganic anions are such as toxic substances that can be harmful to humans and animals at low concentrations. In the meantime, nitrate ions are considered as a serious threat to surface water and groundwater resources due to their high solubility. Nitrate contamination of water can be caused by the discharge of municipal and agricultural wastewater, the unhealthy disposal of industrial and sanitary waste. Among the effective parameters on the nitrate adsorption process by natural adsorbents are adsorbent mass, initial concentration of nitrate, pH and adsorbent contact time with solution. The main purpose of this study is to evaluate the parameters affecting nitrate adsorption by sawdust of beech tree using analytical hierarchy process. To determine the most important parameters affecting the nitrate adsorption, four parameters pH, contact time, adsorbent mass and initial concentration of nitrate were studied, each of which has four levels. Expert Choice software was used to evaluate the most important parameters and their levels. The results of this study showed that the contact time parameter had the most effect on the nitrate adsorption process from aqueous solutions and pH parameter had the least effect on this process. The results of ranking the levels of each criterion showed that with increasing adsorbent mass, initial concentration of nitrate, pH and contact time to optimum point increased nitrate adsorption. Also, after passing through optimum point, with increasing adsorbent mass, initial concentration of nitrate, pH and contact time decreased nitrate adsorption‎‎.