Making activated carbon from the wood of the Juniperus excelsa and investigating arsenic adsorption in the effluents of factories containing arsenic

Abstract

Nowadays, industries are developing so fast that often only their economic dimension is considered and their environmental consequences are overlooked. Industrial and municipal effluents mostly contain metal ions that cannot be easily destroyed, metabolized, and transformed into less hazardous substances. Their presence in the environment is considered a very serious threat. Arsenic is one of these metal ions. It is among the heavy metal ions. Arsenic disrupts the nervous system, blood circulation, digestion, and skin and threatens human health. It causes the death of people with acute poisoning. Thus, the removal of heavy metals, including arsenic, is crucial to prevent the destruction of the environment and damage to humans and animals. This study aimed to achieve the desired outcome with less energy and cost to help design the process of removing pollutants and accelerating the cleaning of industrial effluents containing various metals. This study investigated the separation of arsenic toxic pollutants from aqueous solution by surface adsorption on activated carbon obtained from the sawdust of the Juniperus excelsa.  First, carbon was prepared from the sawdust of the Juniperus excelsa and chemically activated using phosphoric acid. To identify the properties of the studied activated carbon, iodine number, and electron microscope were used. Then, the adsorption characteristics of activated carbon in the removal of arsenic metal pollutants were evaluated. Design Expert statistical software was used in the design of experiments and analysis of the results. In pollutant adsorption experiments, the effect of adsorbent dosage, contact time, and solution pH factors were studied. By evaluating the results of the desirable separation conditions as described in contact time of 4 hours, adsorbent dose of 1.0 g, and pH of 9, the adsorption value of 75.967% was obtained.

Keywords: Adsorption, , Activated carbon, Arsenic, Sawdust