PHYTOREMEDIATION OF COPPER AND IRON BY WATER HYACINTH (EICHHORNIA CRASSIPES) AT VARYING PH LEVELS

Copper and iron are common pollutants in freshwater systems that in excess are detrimental to aquatic life. Although they are bio essential metals in low concentrations, anthropogenic activities have led to toxic concentrations of copper and iron in many freshwater systems. This study investigated the ability of water hyacinth (Eichhornia crassipes) to phytoremediate copper and iron contaminated water samples at varying pH levels. Based on published phytoremediation research, preliminary experiments were performed to assess the extent to which water hyacinth would remediate copper at a neutral pH. Results suggest that water hyacinth is successful at extracting metal ions from a 3.5 ppm copper contaminated water solution, with the most copper removed in the first few minutes followed by a steady decrease in the rate of remediation. Contaminated water can often have varying pH levels in the real world; thus this study specifically focused on how varying the pH of water samples can influence the capacity and extent to which water hyacinth can successfully extract metal ions. Experiments used water contaminated with copper and iron at pH levels 3.5 – 3.7 (acidic), 6.5 – 6.7 (neutral), and 9.5 – 9.7 (basic). There were 3 in-laboratory systems of a 10 ppm solution of copper or iron and each was manipulated to make the pH acidic, basic, or neutral. One water hyacinth plant was introduced to each system and water samples were taken every day for 1 week. Atomic absorption spectroscopy and visible spectrophotometry were used to analyze the copper and iron concentration in the water samples. It is hypothesized that the plant will perform as it did in preliminary studies, however it is unclear whether the increase in metal concentration and/or the non-neutral pH conditions will enhance or reduce the phytoremediation ability of water hyacinth.