Single and multi angle nephelometric approach to the study of coag-flocculation of coal effluent medium using Brachystegia eurycoma coagulant (BEC)

Abstract

Coag-flocculation behavior of Brachystegia eurycoma coagulant (BEC) in respect of pH variation in coal washery effluent has been investigated at room temperature using various dosages of unblended BEC. Coag-flocculation parameters such as order of reaction α, rate constant (K and Ks), coagulation period, τ1/2 e.t.c were determined. Turbidity measurement was employed using the single angle nephelometric method while BEC processing was based on work reported by Adebowale and Adebowale. Maximum parameter values are recorded at K of 6.6667×10-3m3/kg.s; dosage of (0.2 and 0.4kg/m3), pH2 and τ1/2 of 1.7293s while the minimum values are recorded at 5.00×10-4m3/kg.s, dosage of 0.3kg/m3, pH 6 and τ1/2 of 23.0572s. Minimum value of coag-flocculation efficiency is >98%; thus establishing BEC as a potential effective coag-flocculant. Parameters obtained lie within the range of previous works and confirm that the theory of perikinetics holds for coag-flocculation of the coal washery effluent using BEC at the experimental conditions.