The invention relates to a method for repairing lead-
chromium composite contaminated soil by combining
humic acid and sudangrass. The method effectively solves the problem that
humic acid reduces thebiological availability of
heavy metals lead and
chromium, relieves the poisons of the
heavy metals lead and
chromium to the sudangrass, creates conditions for the growth of sudangrass in moderately and severely contaminated areas, and improves the remediation efficiency of the sudangrass on the lead-chromium composite contaminated soil.
Humic acid is uniformly scattered on the
surface layer, withthe chromium content of 275.4 mg / kg or above and the lead content of 989.7 mg / kg or above, of the lead-chromium contaminated soil, the soil is plowed, raked and ridged, sudangrass seeds are sowed, watering is conducted once every 3-7 days in the
plant growth process, management is conducted according to the
normal growth requirement of the sudangrass, the sudangrass grows for 30 days, soil samples are collected and measured, the lead content of soil is smaller than or equal to 218 mg / kg, and the chromium content of soil is smaller than or equal to 95 mg / kg, so the national
environmental standard requirements are met, and remediation of the lead-chromium contaminated soil is achieved. The method is simple, can effectively solve the problems of heavy
metal combined
pollution, difficult survival of plants and the like, and also has the advantages of soil improvement,
fertility enhancement,
crop growth promotion, low cost and environmental friendliness.