The assessment of efficiency of saponin as bio-surfactant in removal of nickel and vanadium from soil contaminated by petroleum, Case study: Ahwaz oil pumping unit

This study aims to evaluate efficiency of saponin, a bio-surfactant, in removal of heavy metals like nickel and vanadium from the soils which are smeared by crude oil and it was conducted according to properties of soils locating within Shahid Chamran oil Pump Station in 2016. For this purpose, after conducting primary studies and in order to determine pilot conditions of test, soil properties were initially studied in this zone and then 5 sampling stations were selected. Parameters of nickel and vanadium were measured along with the TPHs and pH. The studied phases included three variables of temperatures within ranges of (15, 25, 35°C), pH range (6, 7, 8) and concentration of oil compounds within ranges of 10000 and 30000ppm. The findings from assessment on efficiency of removal of heavy metals showed that the conditions with variables of temperature (35°C) and pH (about 9) included the best efficiency of removal of nickel and vanadium. Under concentration 10000ppm, the efficiency for removal of nickel shows rate of 42.98% at constrained mode for removal of nickel and 32.46% to efficiency for removal vanadium. In concentration 30000ppm, rate of efficiency for removal of nickel was 44.34% and also yield of 35.24% for removal of vanadium. This indicates by rising of concentration in oil compounds, the rate of efficiency increased in efficiency of soil washing.