Arsenic is a contaminant found in water through both natural and anthropogenic sources. Anthropogenic inputs are largely due to agricultural and industrial processes. Natural inputs occur from weathering of geologic features. The Environmental Protection Agency (EPA) has set standards within the United States. The EPA declares water contaminated with arsenic (As+5) as a health hazard when a set standard of 10 ppb has been exceeded. This research is set out to determine a natural plant-based polymer which removes As+5 at an economical and environmentally friendly concentration when compared to synthetic polyacrylamide. This study looks at Opuntia (cactus), Trigonella foenum-graecum (fenugreek), Abelmoschus esculentus (okra), psyllium hydrophilic mucilloid husks, sodium alginate, and Tamarindus indica L.(tamarind) as plant polymers in comparison to the widely used polyacrylamide. The bridging mechanism proposed in this study utilizes London-dispersion. These forces allow As+5 to adsorb onto the polymer and work as a flocculant. Simulated water samples were made at 500 ppb, and the Jar Test was ran with varying times. To obtain results, HACH EZ Arsenic Test Kit and Fourier-transform infrared spectroscopy (FTIR) was utilized. Cactus has the highest removal rate of 85% at a concentration of 3.0g/L at 60 minutes. Sodium alginate had the lowest removal rate of -100% at a concentration of 0.5 g/L at 60 min. Polyacrylamide was able to remove 70 % at a concentration of 2.0 g/L at 30 min. The okra polymer displayed inconclusive results. Current research is being conducted on simulated water with an As5+ concentration of 100 ppb to determine which polymer is best to reduce the concentration of As5+ to the EPA approved 10 ppb.

Removal of arsenic (V) via plant-based polymers

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.