Avaliação do Emprego de Cloreto Férrico e Tanino como Coagulantes na Remoção de Sólidos de Efluentes Industriais

Abstract

The circular economy has generated a lot of interest in the industrial sector, and one of the proposed principles is the reuse of waste generated by the industry. Considering this, it is important to apply adequate treatments for their reuse, thus avoiding inappropriate disposal, and to bringing economic advantages to the sector. The present proposal applied the alternative coagulants ferric chloride and tannin aiming at the removal of solids from the effluent generated in the painting booth of liquefied petroleum gas (LPG) containers of the company Supergasbras, located in Londrina-PR, considering it uses the iron sulfate. The experimental planning for the tests followed by varying two factors, sedimentation time and coagulant dosage, subdivided into 3 coded levels (+1, 0 -1), hence totalizing 9 experiments in duplicate. After the experiment, analyzes of pH, apparent color, turbidity and COD indicators were perfomed. Ferric chloride proved to be extremely efficient for turbidity removal and chemical oxygen demand, with values exceeding 90% of removal, in addition, the apparent color indicator also obtained a good result. However, in relation to the pH, all the tests with ferric chloride acquired an acid character, consequently it is necessary to use lime to correct the acidity. The application of the tannin organic coagulant, provided excellent efficiency in removing apparent color and turbidity, in addition to obtaining adequate pH values that comply with current legislation. Regarding the removal of the chemical demand for oxygen, it is approximately 90% for all tests using tannin as a coagulant.