Modelling and economic evaluation of a guar gum–enhanced electrocoagulation process optimized by BBD with sludge characterization for DB183 dye removal

This study presented an electrocoagulation process integrated with guar gum coagulant aid as a natural and green material to degrade Disperse Blue183 dye as an environmental contaminant. Unlike traditional chemical coagulants (e.g., PAC, alum), GG is biodegradable, non-toxic, and capable of forming strong hydrogen bonding with dye molecules, thereby improving floc density and reducing secondary pollution. The operation variables of the process were optimized based on the aluminium plate as an electrode and dye removal with sludge characterization as an assessment indicator. Under optimum conditions (pH 9.0, time 35.0 min, and j 47.0 mA/cm²), electrocoagulation integrated with Guar Gum removed 96% of the Disperse Blue183 dye with a 150 mg/L of GG. The R² coefficient of 0.98 showed that the model is significant using Box-Behnken Design. SEM showed that the floc was dense and FTIR indicated hydrogen bonding between Guar Gum and Disperse Blue183 dye in the electrocoagulation process. Economic evaluation displayed that the current technique cost 0.94 $.m^{- 3}. These results confirm that Guar Gum coagulant aid can effectively promote floc structure in the electrocoagulation process and also provide a novel technique for practical applications to dye degradation from wastewater. The dense flocs observed and hydrogen bonding with dye indicate that the resulting sludge will have good settling properties.