Influence of physical and chemical parameters in the treatment of Basic Red dye 46 by atmospheric plasma

The pollution of natural effluents caused by the fabric dyeing process and inefficient treatment is an environmental problem that affects many sectors, such as agriculture. This work shows the results of the degradation process by plasma at atmospheric pressure of Basic Red 46 organic dye at an initial concentration of 0.1 mM in a volume of 500 mL in aqueous solution, adding FeSO4 in acid solution as an accelerating agent of the degradation process. During the treatment, the change in pH, electrical conductivity, total organic carbon, chemical oxygen demand, and turbidity are monitored as a function of the treatment time. The absorption spectrum was obtained every 20 min, during the 100 min of treatment, achieving a removal of the dye greater than 90% in the first 20 min. In addition, the optical spectrum of plasma emission was analyzed, identifying the presence of species such as CO, OH, N2, Hα, and Hβ mainly. The chemical and electrical cost of the treatment was studied, finding that the highest cost lies in the use of chemical agents in the treatment (approximately 70 dollars per m3) while the electrical cost is less than 2 dollars.