Soil Heavy Metal Pollution In Situ Remediation Technique-based On Plant Evapotranspiration Bionic Development

In recent years,the environmental pollution caused by heavy metals has become a serious problem concerned by the whole society.Soil heavy metal pollution directly affect the sustainable development of social economy,therefore,certain solutions should be carried immediately for remediation.At present,a remediation technique with simple operation,high repair efficiency,lower repair cost,no secondary pollution need to be developed.Moreover,this way of remediation should be applied fast and efficiently in various polluted soils among numerous remediation technologys.Water transmission rate and the heavy metal adsorption capacity of phyto-mimic device adsorbent fillers both were analyzed by laboratory test in this research.9 kinds of adsorbent fillers were screened out for phyto-mimic device,and the phyto-mimic method which is a new and feasible soil remediation technology was proved to have the effect of reducing soil heavy metals.System optimization of the phyto-mimic device,and the soil type,filler,pipe height,simulation blade material,activated carbon ratio and other factors on plant bionic affect the repair device were examined further.Results showed that the height and the rate of evaporation have a negative correlation with the remediation device,while the correlation between the effect of activated carbon amount and evaporation rate of the device was not obvious.The material effect of simulation "blade" on the evaporation rate was: Glass fiber yarn> glass fiber cloth> cotton yarn,and the evaporation rates were: 100.13 g?d^-1,64.75 g?d^-1 and 61.61 g?d^-1,respectively.Finally,industrial soil and farmland soil contaminated by heavy metals were repaired using phyto-mimic method in field experiment.Results showed that pollution in both farmland and industrial soil were decreased in field remediation,and the Cd concentrations were reduced 48.15% in plots 1 and 37.50% in plot 2,respectively.While Zn,Cr,Ni,Fe in industrial soil were reduced 27.03%,17.33%,31.60%,5.17%,respectively.The study takes material selection,feasibility research,system optimization and practical application as a whole,and it has great significance to the development of new type of soil remediation technology against heavy metals.