Phytoremediaton of diethylene glycol contaminated wastewater by Echinodorus cordifolius.

Diethylene glycol (DEG) is one of several diols used as a raw material in the production of plasticizers and polyester resins. It has been associated with a number of mass poisonings in several countries. Conventional methods of remediation of DEG contaminated wastewaters are still not very effective. This paper presents an alternative method for remediation of DEG-contaminated waters using the plant Echinodorus cordifolius. The effects of DEG on E. cordifolius were studied along with the plant's efficiency at treating DEG-contaminated wastewater in a constructed wetland. We found that DEG was toxic to the plants with an LD50 of 6238 mg L(-1). The plants exhibited decreased water uptake and showed wilting, chlorosis and necrosis. SEM images showed injury to the cortex tissue. In the constructed wetland, E. cordifolius plants were able to remove and degrade DEG from wastewater, decreasing the pH from 12 to 6.8 and the COD and TDS by approximately 98% and 67%, respectively, in 7 days, while accumulating Ca in the cells.