DESENVOLVIMENTO DE UM MÉTODO ELETROQUÍMICO PARA CARACTERIZAÇÃO DE EFLUENTE INDUSTRIAL TRATADO PARA FINS DE FERTIRRIGAÇÃO

Abstract

Several industrial activities have been expanding, mainly the sugar cane industries, which generate a large volume of wastewater on a daily basis, which can cause damage to the environment and human health, making it necessary to search for solutions that minimize these impacts. Fertigation is one of the alternatives, however, since it is industrial liquid waste, there may be contaminants that make its application unfeasible. Thus, analysis of waste water characterization after treatment is necessary. In this sense, the present work aims to detect and quantify the nutrients Nitrogen (N) and Phosphorus (P) present in vinasse through the development of a new electrochemical method. The stillage samples were collected in an ethanol plant in the interior of Goiás State. A sulfuric acid solution was prepared as an electrolyte for further studies of the phosphate. Borate buffer was used as the electrolyte for the pH 06, 08 and 10 tests. To determine P the sodium molybdate was used. For the electrochemical analyzes, a cylindrical 3D printed polyethylene cell with 3 (three) electrodes was used, being Ag/AgCl (KClsat.) as the reference electrode, a stainless steel needle as an auxiliary and a gold CDtrode as the working electrode connected to a potentiostat, developed in laboratory in the institution itself. The study of the nitrate electrochemical behavior was performed from the preparation of a buffer solution, using the borate buffer with pH values 2, 4, 6, 8 and 10 at different potentials. Tests with nitrate, at pH below 06, did not have a good response. Nitrate can be determined without phosphate interference at potential 0.,9 V and for potential phosphate at 1 V. The method developed has several advantages such as simplicity of operation, quick analysis, low reagent consumption and good accuracy.