The use of natural remediation methods to remove contaminants from waste
water is becoming more popular. Plants have been used for several decades, yet their
use for municipal waste water contaminated by heavy metals is limited to a few studies
which focus on the Mercury and Chromium (Bennicelli, et.al, 2004). This study
specifically attempted to determine the viability for using Lemna minor to remediate
municipally generated wastewater contaminated with copper.
The study used 100 ml samples of wastewater, artificially spiked with 8 mg/L of
copper sulfate and seeded with approximately 100 Lemna minor fronds. Each treatment
was repeated 15 times and distilled water was added daily to maintain 100 ml samples.
The addition of Lemna minor statistically lowered the copper concentration of the
treatment groups (55% reduction in total Cu concentration). No significant decrease was
seen in the control groups. While Lemna minor has metals accumulation potential, its
wide spread use is limited by the toxic effect of copper on Lemna minor at relatively low
levels.