Soil environmental capacity and risk evolution of a typical Pb-contaminated farmland after remediation
The spatiotemporal development of soil heavy metal environmental capacity and risk evolution was investigated in a typical lead-contaminated farmland in north China.Various statistical methods were employed to comprehensively determine the geochemical baseline value of soil lead,which was then used as the background value of the farmland to calculate the soil lead static environmental capacity.Besides,the evolution of the existing environmental capacity,ecological/health risk assessments and remediation effectiveness evaluation were conducted during three-year lead remediation.The results showed that after remediation,the proportion of sites with soil lead content exceeding 350 mg·kg-1 decreased to zero,and the existing environmental capacity of soil lead significantly increased from 203.09 kg·hm-2 to 339.57 kg·hm-2,mostly observed in area applied the in situ immobilization combined with deep tillage technology.The risk evaluation results showed that the potential ecological risk of lead contamination in this farmland has been reduced to a low level,and the health risk also significantly decreased,with the non-carcinogenic and carcinogenic risks both within the acceptable range.The study reveals that after three years of remediation,the lead environmental capacity and risk levels of the farmland have significantly improved.The results can provide some references for the remediation and safe utilization of similar lead contaminated agricultural soils.
国家科技期刊平台
NSTL
万方数据
