Sustainable use of natural and chemical coagulants for contaminants removal from palm oil mill effluent: A comparative analysis

Abstract

• Raw Palm Oil Mill Effluent characterized; sample treated and 4000 mg/L Alum dose was obtained as the optimum. • 1000 mg/L of Ferric chloride significantly increased the removal efficiency in the experimental sample. • Chitosan as a biopolymer showed continuous removal efficiency until the optimum dose was reached at 400 mg/L. • Moringa Oleifera dose of 2000 mg/L as a natural coagulant was very efficient in heavy metals removal from the sample. • Zeolite dose of 1000 mg/L showed significant increase in removal efficiency as it provides the highest removal percentages for Cadmium, Zinc and Iron. This article aimed at determining the optimum coagulant dose for various coagulants. This is to ascertain coagulant with the potential for higher removal of contaminants. By fixing the initial pH, settling time, coagulant aid dose, rapid mixing speed & time, slow mixing speed & time as constant parameters, the study assessed the process efficiency in terms of percentage removals for TSS, oil & grease, COD, NH 3 -N, turbidity and colour. The results indicated that the optimum dosage for FeCl 3 , moringa oleifera , aluminum sulphate, chitosan and zeolite was found to be 1000, 2000, 4000, 400 and 1000 mg/L, respectively. Results were analysed using the one-way analysis of variance (One-Way ANOVA) of Statistical Package for Social Sciences (SPSS) Version 17 where P-values for all contaminants tested across various coagulants and their dosages found to be <0.05. Thus, the null hypothesis is discredited which indicate there is significant improvement in the removal efficiencies.