Coagulant Performance of Banana Tree Trunk and Banana Leaf Biomass for Water Treatment

Abstract

The search for environmentally friendly, cost-effective alternatives to chemical coagulants has increased interest in plant-based materials for water treatment. This study compared the performance of banana tree trunk and banana leaves as natural coagulants for the purification of contaminated water. Qualitative phytochemical screening, Antimicrobial analysis, and Jar test procedures were done using standard methods. Phytochemical screening revealed the presence of saponins, flavonoids, alkaloids, tannins, carbohydrates, and steroids, with steroids occurring in higher concentration in the leaves (++), while resins were absent in both samples. Jar tests and coagulation trials showed that banana leaves achieved superior coagulation efficiency compared to the trunk. At an optimal dosage of 100 mg/L, banana leaves removed 78.9% turbidity and 74.3% suspended solids, while the trunk required 150 mg/L to achieve 65.4% turbidity and 62.8% suspended solids removal. Raw water turbidity of 78 NTU was reduced to 21 NTU after coagulation and filtration, representing a ~73% reduction. Colour decreased from 20 ptCo to 11 ptCo, which falls within the Nigerian Standard for Drinking Water Quality (NSDWQ) limit of 15 ptCo. Other physicochemical parameters, including total hardness, alkalinity, electrical conductivity, chloride, and total dissolved solids, remained within permissible limits throughout treatment, while pH remained within the acceptable range of 6.50–8.50. Antimicrobial assays demonstrated significant inhibitory activity against Escherichia coli (24 mm), Staphylococcus aureus (28 mm), Pseudomonas aeruginosa (19 mm), and Candida albican (28 mm) at 500 mg/mL, with banana extracts showing comparable or superior effects to conventional antibiotics in some cases.