The Electric Active Starch Flocculation of Protein and its Degradation Products in Leather Effluents

There is a large amount of protein or its degradation products in leather effluents, which are difficult to deal with, such as NH3-N and SS (suspended solids), etc., so it is significant to remove all the protein residues in effluents and reduce the content of pollutants. This experiment simulates the main effluent compositions which contained protein and its degradation products, and then handled with electrochemical assisted starch flocculate to reduce the content of protein residues in effluents, whilst decreasing the value of COD and BOD. Based on experiment results and the DPS statistical software analysis, the optimal conditions to remove the protein residues would be obtained, among 2.5 g/L protein degradation products, 5 g/L starch content, 5 g/L chloride ion concentration and 20 min electrolysis time, respectively, under which the best removal rate is 36.17%. The flocculation was analyzed by Fourier transform infrared spectroscopy (FTIR), nanoparticle size potential analyzer (Zeta analyzer) and atomic force microscopy (AFM), and then presumed the removal mechanism of the protein residues in effluents.