Efficiency of Chitosan as a Coagulant for Wastewater from Slaughterhouses

Objective:The purpose of this work was to obtain chitosan from shrimpexoskeletons, characterize it and evaluate its coagulant activity in the turbidity removal of wastewater from slaughtering Units. Methods/Analysis: Wastewater samples had three different turbidity measures(250, 560 and 863 NTU) and with three different doses of coagulant each (50, 100 and 150 mgL-1), according to a 32experimental design. Control and ANOVA tables were used to verify if there were statistically significant differences among data with a 95% confidence level. Findings: Chitosan with a molecular weight of 3.2x106 g mol-1 and a degree of deacetylation of 74% was obtained. When used as a coagulant it is possible to obtain turbidity removals greater than 90% when initial turbidity of wastewater was equal to or greater than 560 NTU. However, and due to acid nature of coagulant extracts, pH and alkalinity of samples were influenced. Effectiveness of chitosan in wastewater treatment with high organic load and difficult treatment was verified. Application: In conclusion, it is possible to obtain excellent quality chitosan from shrimp exoskeletons and its use is convenientin alkaline wastewater.