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Arsenic hyperaccumulating fern: Implications for remediation of arsenic contaminated soils

Fayiga, Abioye O., Saha, Uttam K.
Geoderma 2016 v.284 pp. 132-143
Pteris vittata, aluminum, aluminum oxide, arsenic, arsenites, bioavailability, exudation, ferns and fern allies, fronds, groundwater, hyperaccumulators, iron, nutrition, phosphates, phytoremediation, plant age, polluted soils, redox potential, soil properties, toxicity, vacuoles
The ability of hyperaccumulating plants to tolerate, translocate and accumulate very high concentrations of toxic contaminants makes them suitable candidates for phytoremediation of contaminated soils and water. Though there are several arsenic tolerant plants, Chinese brake fern (Pteris vittata L.) is the first arsenic hyper-accumulator and the most widely studied. A lot of work has been done to understand the detoxification mechanisms of arsenic hyperaccumulation in this fern. It has been suggested that vacuolar sequestration of arsenite in the fronds may be responsible for the high tolerance of P. vittata to arsenic. Studies on phytoextraction and rhizofiltration of arsenic contaminated soils and groundwater have been very successful in reducing contaminant levels. Numerous studies have shown that arsenic uptake by P. vittata depends majorly on soil and plant factors. Soil properties like soil arsenic concentrations, bioavailability of arsenic, partitioning of soil arsenic, redox potential, phosphate concentration and presence of co-contaminants may limit or enhance arsenic uptake by P. vittata. Plant characteristics like plant age, nutrition, root exudation and biological associations also influence greatly arsenic accumulation by P. vittata. An integration of these factors can be used to increase the efficiency of As hyperaccumulators in phytoremediation of arsenic contaminated soils and groundwater. Phytoremediation of arsenic contaminated soils is best in soils with low Fe/Al oxides, low redox potential, and low available P though addition of phosphates increases arsenic extraction.