Effectiveness of Immobilized Nirmali Seeds and Free Nirmali Seeds as a Bio Coaugulant in Removal of Turbidity of Water.

Abstract

Water treatement is an essensial process due to water scarcity. While previous studies have extensively explored raw and powdered forms of Nirmali seeds as a bio coagulant, this study introduces a novel approach by immobilizing Nirmali seed powder within calcium-alginate beads to assess its potential for turbidity removal. The natural surface water from the Kelani river was treated with bio coagulant with four treatments which are immobilized bio coagulant wet basis, immobilized bio coagulant dry basis, raw Nirmali seed powder and alum as the control treatment and range of doses from 0.5 g/L to 3 g/L. To determine the optimum dosage for turbidity removal and coagulation/flocculation efficiency the jar tester was conducted according to the standardized procedure. After treatment Alum has shown greatest efficiency in removal of turbidity of water while immobilized bio-coagulants (wet and dry basis) showed very low turbidity reduction, at all doses. The high increase in turbidity is also observed after being treated with raw Nirmali seed powder. The reasons for the limited effectiveness of the immobilized bio coagulants is likely due to the slow release of bioactive compounds into water, the reduced availability of active binding sites due to encapsulation, and the physical form of the seeds potentially influencing interaction with colloidal particles. These findings suggest that while the immobilization technique offers a novel and potentially eco-friendly delivery method, it may hinder the coagulation efficacy of Nirmali seeds in turbidity removal applications. The values of electrical conductivity were highly increased in water which treated with alum while other treatment showed no significant increase. The results of the present study clearly demonstrate that immobilization of the Nirmali seed powder into calcium alginate beads did not effectively remove the turbidity of the water.