Ecology treatment of a real industrial effluent with chitosan: Characterization and design of coagulation-flocculation process

Coagulation-flocculation (C-F) process is frequent in treating industrial wastewater. Coagulants and flocculants are mostly inorganic, but these products can cause serious ecological problems. Chitosan (QS) is considered effective in this process and is friendly to the environment. The objective of the work was to study the treatment of a real effluent from the graphic industry using C-F with chitosan and project the design of an agitated industrial system. For effluents with low Total solid, the optimal dose of QS is near 7.81 mg/L, while for larger content of Solid, it is 31.3 to 62.5 mg/L. The pH that favours this process is between 6-7. A working temperature of 25 °C also benefits the sedimentation treatment. QS additions generate laboratory-scale solids sedimentation after 5 minutes. At 20 minutes, a significant reduction in UV-Visible absorbance is observed.