Effect of phosphate minerals on phytoremediation of arsenic contaminated groundwater using an arsenic-hyperaccumulator

- Pteris vittata was used to remediate arsenic-contaminated groundwater.
- Phosphate rock (PR) and hydroxyapatite (HA) were applied as sparingly-soluble phosphate sources.
- Nitrogen and P concentrations in the solutions were monitored to check eutrophication pollution.
- PR was an ideal P source to facilitate As removal from contaminated groundwater by P. vittata.

To investigate the effect of phosphate sources on phytoremediation of arsenic (As) contaminated groundwater using Pteris vittata, a hydroponic experiment was conducted. Sparingly-soluble phosphate minerals (phosphate rock, PR, and hydroxyapatite, HA) and soluble Hoagland solution (HS, containing ammonium phosphate) were chosen as phosphate sources. Arsenic content in the residual nutrient solutions was analyzed to acquire the phytoextraction effect. The results showed that As concentrations in the nutrient solutions treated with sparingly-soluble P decreased more rapidly than that treated with soluble P. For treatment with sparingly-soluble PR, P. vittata reduced As concentration more rapidly than that in HA treatment and HS control. Nitrate and P concentrations in the residual solutions were also monitored to check eutrophication pollution. Phosphorus in the residual solutions in PR or HA treatment was not detected and 0.5 μg L−1, respectively, much lower than HS control. These results indicated that sparingly-soluble PR could be an ideal P source to facilitate As removal from contaminated groundwater by P. vittata and ensure the nutrient quality of the residual water after phytoremediation.