Estudo de poluentes orgânicos por GCXGC/TOFMS em lodo gerado em ETA por coagulação convencional e a utilização de um biopolímero à base de tanino

Abstract

The demand for drinking water has increased dramatically with the population growth of the last century. In summary, watercourse pollution has also increased, requiring improvements in the water purification process. On a large scale, water treatment plants (WTTPs) are processing larger volumes of water with lower quality and increasing the volume of sludge generation in the process. The organic contaminants contained in this type of waste are of great importance and of great concern because their exact composition is not known. In the present study, the efficiency of aluminum sulfate coagulants and a biodegradable tannin-derived biopolymer in the coagulation stage of conventional water treatment were evaluated, where the parameters of pH, color, turbidity, electrical conductivity and temperature of the raw and treated water. The biopolymer used proved to be more effective in removing color and turbidity compared to the chemical coagulant, in addition it generates a biodegradable residue without added aluminum. Additionally, a rapid analytical method was used to identify organic pollutants through a non-target analysis of sludge from an ETA located in the Médio Paraíba do Sul Hydrographic Basin. For this purpose, sludge extracts were obtained via QuEChERS and subsequent analysis was performed by comprehensive two-dimensional gas chromatography, using a cryogenic free thermal modulator coupled to a time-of-flight mass spectrometer (GC×GC/TOFMS). Through this method, it was possible to perform the separation of 831 compounds in approximately 19 minutes of analysis. Among the number of compounds tentatively identified in the samples, several contaminants considered emerging were found, such as pharmaceuticals, petroleum derivatives and toxic industrial residues.