The invention discloses a method for eluting
heavy metals Cu, Zn, Pb and Cd in soil by use of
EDTA calcium salt. Through adoption of the method, the
heavy metals in soil can be effectively reduced. The method comprises the following steps: adopting a physical method to enable a heavy
metal extracting agent, namely, EDTA to be combined with
calcium oxide to form an eluting agent, namely, Ca-EDTA which has an excellent removing effect on the
heavy metals in soil; determining an optima eluting condition through a series of experiments bychanging the concentration of the eluting agent, the
solid-
liquid ratio, the eluting time and the continuous eluting times; finally, realizing the excellent removal effect in a short time (2 h) under the condition that the lower concentration of the eluting agent is 2.5 mmol / l, the
solid-
liquid ratio is 1: 5 and the continuous eluting times are three. The eluting agent, namely, Ca-EDTA used in the method is lower in
turbidity and has better settleability, the follow-up treatment is more convenient, the effect on
soil fertility is low, and
after treatment, plants can grow normally in the soil, so that convenience is brought to large trials in the future, and a certain treating time and cost can be reduced.