Feasibility studies of natural plants coagulants in the removal of selected water contaminants

The greatest public health concern about water is directed to its ever increasing number of contaminants. Public distribution systems, though accessible only to a limited population, mainly make use of chemicals in the treatment processes. Such water treatment systems overlay burden on the developing nation’s financial resources. Moreover, reports states that such chemicals can cause severe health hazards. These points out the need for low-cost, replicable non-chemicals, which would be effective in the treatment of water contaminants. In the present study, treatment potentialities of vegetative parts of certain hydrophytic / mesophytic plants like Lagenandra toxicaria Dalz, Aloe barbedensis Mill., Canna indica. L and Bacopa monnieri (L.) Wettst, on Turbidity, Hardness, Iron and microbial count of contaminated water has been worked out.. Batch treatment has been followed and the performance evaluation of plants under varying concentration of plant materials and retention time has been worked out. Turbidity of water samples were monitored instrumentally (APHA, 1995), whereas hardness and iron content were assessed using EDTA titrimetric method (APHA, 1995) and thiocyanate method (Goswami and Kalita, 1988) respectively. Total coliforms and E.coli were estimated using pour plate method of NIO (1998). On an overall assessment, it has been noticed that the plants under experimentation showed differential responses to contaminants. Lagenandra toxicaria was noted to be effective in reducing turbidity at all concentrations of the plant material especially at higher retention time. The material was also noted to be effective in the removal of Iron and Total coliform content. Similarly Aloe barbedensis was found to be effective in the treatment of Turbidity. The decrease in turbidity was significant with increasing concentration and retention time. It was also noted to be effective in the treatment of iron and Total coliforms at initial stages. Canna indica was noted to be least effective in the treatment of selected water contaminants other than Total coliforms and E. coli. Bacopa monnieri was effective in the treatment of Iron content, Total coliforms and E. coli content.