Evaluation of Type III Adhesive Mortar (ACIII) and Gypsum as Precipitating Agents of Copper and Lead

Abstract

Heavy metals exhibit characteristics such as nonbiodegradable nature, toxic character, bioaccumulation capability, and ability to transit over long distances. The widespread application of these metal ions in various industrial sectors has led to an increase in their release into the environment. Chemical precipitation has been one of the technologies used to remove heavy metals from wastewater, involving a process in which chemical agents are added to wastewater with dissolved toxic metal ions, which react with the metals, forming insoluble precipitates. Therefore, the present study aimed to assess the potential of gypsum and adhesive mortar type III (ACIII) as precipitating agents for lead (Pb) and copper (Cu) ions, as well as to evaluate the toxicity of precipitation products on Drosophila melanogaster. Experiments using ACIII mortar waste as a precipitating agent for Cu ions were obtained using a glass filter composed of 04 chambers and 04 antechambers, while the potential of gypsum as a Pb ion precipitant was evaluated by adding gypsum powder to a beaker containing a Pb ions solution. The toxicity of the precipitation products was evaluated by observing the mortality and negative geotaxis parameters on D. melanogaster. In the tests using ACIII mortar as a precipitating agent for Cu, retention percentages progressively varied, obtaining 98.82% at a concentration of 30 mg/L. Meanwhile, gypsum obtained retention percentages that varied from 32.83 to 98.61% for Pb. It was found that the precipitates of Cu and Pb resulted in alterations in the survival and locomotion rates of D. melanogaster only at the highest evaluated concentrations. In conclusion, the results obtained indicated that geomaterials such as ACIII mortar and gypsum have potential for the removal of Cu and Pb from aqueous solutions. Moreover, the precipitation stages by these materials also impact in decreasing the toxicity of metal ions to the evaluated model organism.