Arsenic Removal from Aqueous Solutions by Salvadora persica Stem Ash

Arsenic is a naturally occurring metalloid, which is widely distributed in nature and is regarded as the largest mass poisoning in history. In the present study, the adsorption potential of Salvadora persica (S. persica) stem ash in a batch system for the removal of As(V) from aqueous solutions was investigated. Isotherm studies were carried out to evaluate the effect of contact time (20–240 min), pH (2–11), initial arsenic concentration (50–500 μg/L), and adsorbent dose on sorption efficiency. Maximum removal efficiency of 98.33% and 99.32% was obtained at pH 6, adsorbent dosage 3.5 g/L, initial As(V) concentration 500 μg/L, and contact time 80 and 60 min for S. persica stem ash at 300 °C and 500 °C, respectively. Also, the adsorption equilibriums were analyzed by the Langmuir and Freundlich isotherm models. Such equilibriums showed that the adsorption data was well fitted with the Freundlich isotherm model for S. persica stem ash at both 300 °C and 500 °C (R2 = 0.8983 and 0.9274, resp.). According to achieved results, it was defined that S. persica stem ash can be used effectively for As(V) removal from the aqueous environment.