Phytochemicals and phyto-disinfectant properties of citrus species (Citrus limon, Citrus aurantifolia and Citrus sinensis) for pond water purification

The health concern associated with the use of chemical disinfectant in water purification has necessitated the search of safe and effective water treatment agents from natural sources. The leaf, stem, seed and bark of Citrus limon, Citrus aurantifolia and Citrus sinensis were investigated for phytochemicals and disinfectant properties on contaminated pond water at concentrations of 0.1, 0.2, 0.3, 0.4 and 0.5 g/L. Microbial quality of the water sample was investigated at 12 hrs interval. The leaf and bark of C. aurantifolia and the bark of C. limon contains all the phytochemicals tested. Steroids and alkaloids were present in all parts of the plant. Cardiac glycosides and terpenes were present in all parts of Citrus sinensis.  A total of 10 different bacteria isolates were identified from ponds water sample. The stem of Citrus aurantifolia completely eliminated the total viable count, total coliform count, fecal coliform count after 12 h. The leaf, bark and seed of C. aurantifolia at 0.3, 0.4 and 0.5 g/L, leaf and bark of C. limon and C. sinensis at 0.1-0.5 g/L eliminated the various bacteria after 24 hours. However, the stem and seed of C. limon were less active; only concentrations of 0.4 and 0.5g/L eliminated the organism after 24 h of treatment. The plant materials had minimum inhibitory concentration in the ranged of 16 and 128 mg/g and minimum bactericidal concentrations in the ranged 16 and 256 mg/g against all the isolates. It is concluded that the leaf, stem bark and seed of citrus species contains various phytochemicals and have the potentials to serve as a disinfectant for water treatment.