Performance of Cationic Hemicelluloses Arising from Peanut Shell Residue from Agroindustry in Application as Primary Coagulant in Physical-Chemical Treatment of Dairy Wastewater

This study aimed to evaluate the synthesis of Cationic Hemicelluloses (CH) extracted/synthesized from peanut hull residue from agroindustry and also evaluate it as a primary coagulant in a physical chemical treatment of synthetic dairy wastewater (SDW). Hemicelluloses were cationized by etherification reaction in alkaline medium with 2,3-epoxy-propyl-trimethyl-ammonium chloride (ETA). FTIR indicated cationization occurrence by an increase of the methyl group band in (1475 cm -1 ), supported by theoretical analysis. CH elemental analysis showed 1.92% (±0.09) of nitrogen and a Degree of Substitution (DS) of 0.32 (±0.01), similar to literature data. The evaluation of the CH solutions were performed in the Jar test on turbidity, apparent color, TSS, COD and BOD 5.20 for a coagulation pH range 5 to 11 and dosages from 100 to 900 ppm. Coagulation diagrams were determined using the spatial interpolation method of the data by Kringing regression model. The optimal point selected occurred at the dosage of 400 ppm (coagulation pH 9.00 and 7.38), promoting removals of 94.79% and 98.67% (turbidity removal); 56.72% and 65.21% (apparent color); 79.76% and 97,22% (TSS); 47.83% and 62.50% (COD) and 73.93% and 62.39% (BOD 5.20 ), for CH and TSG respectively. The flakes morphology was analyzed through the application of the image capture non-intrusive method. Fractal Dimension (Df) of the flakes stabilized after 10 min at values of 1.319 (± 0.020) and 1.871 (± 0.001), with range diameters of 0.023-0.254 mm and 0.032-5.718 mm, for CH and TSG respectively. CH coagulant maintained color and turbidity removals for higher dosages