Influence of Tara (Caesalpinia spinosa) Gum as an Aid in the Coagulation-Flocculation Process to Remove the Turbidity of an Artificial Suspension of Bentonite

Abstract

The objective of this study was to determine the influence of tara gum (Caesalpinia spinosa) as a coagulation aid in the coagulation-flocculation process to remove the turbidity of an artificial suspension of bentonite. The primary coagulant used was aluminum sulfate type A and the coagulation assistant was tara gum. The jar test methodology was used, at speeds of 300 revolutions per minute (RPM) for 5 seconds in the fast mixing stage, 40 RPM for 20 minutes in the flocculation stage, and 0 RPM for 10 minutes in the sedimentation stage. High and low turbidity waters of 400 nephelometric turbidity units (NTU) and 30 NTU were analyzed. The results obtained with type A aluminum sulfate without a coagulation aid give residual turbidity results of 1.09 NTU for high turbidity samples and 0.57 NTU for the low turbidity sample. Adding tara gum as a coagulation aid reduced the turbidity levels in the two sample groups to 0.40 and 0.32 NTU of residual turbidity respectively, as well as a 40% reduction of aluminum sulfate for the tests with the sample of 30 NTU. Tara gum, as a coagulation aid in the coagulation-flocculation process, improves the reduction of residual turbidity by 63.3% in the case of the 400 NTU sample group and 56% in the case of the 30 NTU sample group.