Comparative Study of the Effectiveness of Banana and Lemon Peels Powder as Natural Coagulants for Domestic Wastewater Treatment

Abstract

The effect of chemical coagulants on the properties of effluent of treated wastewater necessitated the investigation of the use of natural-based coagulants as possible alternatives. Natural coagulants used were used with the aim of investigating their effectiveness in treating domestic wastewater compared to alum. One (1) litre of domestic wastewater was treated with fifteen (15) different total dosages of 0.8 g, 2.4 g and 4.0 g of banana peel, lemon peel and mixture of banana and lemon peels powder and one (1) dosage of 0.25 g of alum. The parameters tested were pH, turbidity, total dissolved solids (TDS), hardness and colour. The raw wastewater had values of pH, TDS, turbidity, colour and total hardness as 4.7, 901 mg/l, 899mg/l, 8440 pt-co and 1245 mg/l respectively. The best percentage removals were 86.2%, 73.7% and 76.4% for turbidity, TDS and colour at the optimum dosage of 2.4 g/l lemon peels powder. Lemon peel of 2.4g/l also led to improvement of pH from 4.7 to 6.5 (27.7% increase). Maximum hardness reduction was 24.9% with mixture of 0.6 g lemon and 0.2 g banana peels powder. Generally, lemon peels powder showed the potential to perform better as natural coagulant in wastewater treatment and in combination with banana peels. It gave better results than alum except in colour reduction which was 85.6% using alum. It is therefore recommended that lemon peel should be used for domestic wastewater treatment.