SHEFROL® bioreactor enhances the ability of pistia (pistia stratiotes) in the phytoremediation of greywater.

The efficacy of the well-known phytoremediation plant pistia (Pistia stratiotes), also called water lettuce or water cabbage, in treating sewage (greywater) was tested by its use as the main bioagent in the recently developed and patented 'sheet flow root level' (SHEFROL®) bioreactor. In contrast to previously reported systems, based on constructed wetland or stabilisation pond technologies, in which pistia needed wastewater hydraulic retention times (HRTs) of 24 h or more in enabling significant treatment of greywater, it achieved similar results in SHEFROL® several times more quickly, at the HRTs of only 4–6 h. Given that HRT directly influences reactor size, hence the system cost, the faster rate of treatment gives SHEFROL® a major economic advantage. In other ways, also, SHEFROL® appeared ideal for the use of pistia because of the reactor's ease of operation, robustness, very low requirement of energy or materials, and negligible ecological footprint. [ABSTRACT FROM AUTHOR]