Application of Dual Coagulant (Alum + Barley) in Removing Colour from Leachate

Faculty of Civil and Environmental Engineering, Universiti Tun Hussein Onn Malaysia, 86400 Parit Raja, Batu Pahat, Johor, Malaysia

^* Corresponding author: nursha@uthm.edu.my

Abstract

Coagulation/flocculation is one of the treatment method for highly polluted leachate. One of the main affecting factor for this process is the coagulant used. Coagulant is divided into natural and chemical coagulant. In the current study, Alum (chemical coagulant) and barley (natural coagulant) were used as dual coagulant. The aim of this study is to examine the effectiveness of dual coagulant made from alum and barley in removing colour from the effluent of Simpang Renggam landfill leachate aeration lagoon through coagulation/flocculation method. Coagulation/flocculation process with single alum coagulant, single barley coagulant and dual coagulant (alum+barley) were examined by evaluating the optimum values of pH and dose. Optimum dose and pH for alum and barley as single coagulant were; 3 g/L & pH 5; 0.8 g/L & pH 6. Higher removal of colour was recorded for alum compared to barley. Application of alum and barley as dual coagulant had higher colour removal than alum and barley as single coagulant. The optimum pH and dose for dual coagulant were at pH 6, 3.0 g/L of alum and 0.8 g/L of barley respectively. However, at pH 6, 2 g/L alum and 1.6 g/L barley, the removal of colour was similar to alum at 3 g/L. It can be concluded that barley as coagulant aid able to reduce 33 % usage of alum at par removals of colour. Thus, the dual coagulant consist of alum and barley has the potential to be applied as a coagulant for leachate treatment.