Adsorption of Cr (VI) in water by modified biochar with ethylenediaminetetraacetic acid

Abstract

Abstract Hexavalent chromium is a type of heavy metal that is highly toxic to humans, causing dermatitis, lung cancer, and other diseases. It is also very difficult to degrade and can build up in the food chain and enter the human body as food, which has an effect on human health. Heavy metal pollution often leads to a reduction in the quality of agricultural soil to the extent that the degree of soil fertility decreases, resulting in lower yields of agricultural products. Therefore, it is of great significance to take effective measures to control heavy metal pollution in order to maintain human health and environmental safety. In this paper, it was determined that the research would focus on peanut shells as its object of study. The biomass char was subjected to a chemical modification process that entailed the introduction of chelating groups onto its surface. The biomass char was characterized before and after modification using a scanning electron microscope, and adsorption of Cr(VI)-containing wastewater with the application of the modified biomass char was carried out. The effects of solution pH, input amount and other factors on the adsorption effect of Cr(VI) by biomass char were explored separately, and the adsorption mechanism of this experiment was discussed more deeply through adsorption kinetic experiments. The results showed that the EDTA-modified biomass charcoal particles became smaller and the pores became larger, which was favorable for adsorption. Removal of 82.59% of Cr(VI) was measured under optimal conditions, and the maximum amount of adsorption was 32.048 mg·g -1 , which was better than those of unmodified biomass charcoal. The kinetic analysis showed that the process of modified biomass charcoal adsorption of Cr(VI) was chemisorption.