Removal of trace chromium (VI) from contaminated water: bio-sorption by Ipomea aquatica.

ABSTRACT

Ipomea aquatica is a wetland plant, which floats in water bodies and is being used as a vegetable. This plant has ability to remove Cr(VI) from the contaminated water by transforming Cr (VI) to Cr (III). This adsorption of Cr(VI) basically takes place in roots of this plant. The contact time required to bring down Cr(VI) concentration below the permissible level (0.05 mg/1) is 30 to 40 days for this plant, and that varies with varying initial concentration. The lower level of contamination requires greater contact time than the higher one to bring down Cr(VI) below the permissible level. Recovery (94 +/- 1%) of chromium from the treated plant has been reported in this paper, and at the same time disposal problem also dose not arise. The study revealed that the plant Ipomea aquatica adsorbs Cr(VI) from the contaminated water very slowly compared to the other reported plants.