Mine tailing soils created from the copper extraction in Touro Mine （Northwest Spain） are very degraded both physically and chemically. Three plots in this mine tailing were amended with Technosols in different prop...Mine tailing soils created from the copper extraction in Touro Mine （Northwest Spain） are very degraded both physically and chemically. Three plots in this mine tailing were amended with Technosols in different proportions in each one to know if this mixture improved the physico-chemical characteristics of the mine soil and contaminated it with heavy metals. The Technosols were made of organic wastes, including mussel residues, wood fragments, sewage sludges and paper mill ashes. An unamended area was used as a control soil. Pseudototal and diethylenetriaminepentaacetic acid （DTPA）-extractable contents of A1, Cr, Cu, Fe, Mn, Ni, Pb and Zn were determined in soil samples. The untreated soil had significant limitations for vegetation growth. All the Technosols improved the properties of the mine soil by increasing organic carbon and pH value, but they added Ni, Pb or Zn to the soil. It is advisable to check whether the heavy metal concentrations of the wastes are hazardous or not before adding to soils. It is also necessary to study the effect of these wastes over time and in more areas to conclude if they are actually favourable to restore degraded mine soils.展开更多
The mobility and bioavailability of heavy metals in soils is largely governed by sorption and desorption phenomena.Cu2+ and Pb2+ are among the most potentially toxic heavy metals and they are present,often concomitant...The mobility and bioavailability of heavy metals in soils is largely governed by sorption and desorption phenomena.Cu2+ and Pb2+ are among the most potentially toxic heavy metals and they are present,often concomitantly,in many polluting spills and in agrochemicals.The objective was to assess and compare the competitive sorption and desorption capacities and sorption hysteresis of Cu2+ and Pb2+,as well as their migration through the profiles of four natural soils:a Humic Umbrisol,an Umbric Cambisol,an Endoleptic Luvisol and a Humic Cambisol.In all horizons Pb2+ was invariably sorbed and retained to a greater extent than Cu2+.The sorption and retention of Cu2+ were most in?uenced by pH,e?ective cation exchange capacity(CECe) and Mn oxide content.On the other hand,the fixation capacity of Pb2+ was most in?uenced by pH,CECe,and Mn oxide and organic matter contents.pH and CECe were the individual soil properties most markedly in?uencing Cu2+ and Pb2+ sorption and retention.In all the horizons Pb2+ exhibited greater hysteresis than Cu2+.In each soil the hysteresis in the A horizon was greater than that in the B horizon,except in the Bt horizon of the Endoleptic Luvisol,due to its high pH and vermiculite content.Based on migration indices,Pb2+ was less mobile than Cu2+ in the studied soils.展开更多
文摘Mine tailing soils created from the copper extraction in Touro Mine （Northwest Spain） are very degraded both physically and chemically. Three plots in this mine tailing were amended with Technosols in different proportions in each one to know if this mixture improved the physico-chemical characteristics of the mine soil and contaminated it with heavy metals. The Technosols were made of organic wastes, including mussel residues, wood fragments, sewage sludges and paper mill ashes. An unamended area was used as a control soil. Pseudototal and diethylenetriaminepentaacetic acid （DTPA）-extractable contents of A1, Cr, Cu, Fe, Mn, Ni, Pb and Zn were determined in soil samples. The untreated soil had significant limitations for vegetation growth. All the Technosols improved the properties of the mine soil by increasing organic carbon and pH value, but they added Ni, Pb or Zn to the soil. It is advisable to check whether the heavy metal concentrations of the wastes are hazardous or not before adding to soils. It is also necessary to study the effect of these wastes over time and in more areas to conclude if they are actually favourable to restore degraded mine soils.
基金Supported by the Ministry of Science and Innovation of Spain (No.CGL2010-16765/BTE)the FEDER and the Xuntade Galicia in partnership with the University of Vigo through "Angeles Alvarino" and "Parga Pondal" research grants to F. A. Vega and E. F. Covelo,respectively
文摘The mobility and bioavailability of heavy metals in soils is largely governed by sorption and desorption phenomena.Cu2+ and Pb2+ are among the most potentially toxic heavy metals and they are present,often concomitantly,in many polluting spills and in agrochemicals.The objective was to assess and compare the competitive sorption and desorption capacities and sorption hysteresis of Cu2+ and Pb2+,as well as their migration through the profiles of four natural soils:a Humic Umbrisol,an Umbric Cambisol,an Endoleptic Luvisol and a Humic Cambisol.In all horizons Pb2+ was invariably sorbed and retained to a greater extent than Cu2+.The sorption and retention of Cu2+ were most in?uenced by pH,e?ective cation exchange capacity(CECe) and Mn oxide content.On the other hand,the fixation capacity of Pb2+ was most in?uenced by pH,CECe,and Mn oxide and organic matter contents.pH and CECe were the individual soil properties most markedly in?uencing Cu2+ and Pb2+ sorption and retention.In all the horizons Pb2+ exhibited greater hysteresis than Cu2+.In each soil the hysteresis in the A horizon was greater than that in the B horizon,except in the Bt horizon of the Endoleptic Luvisol,due to its high pH and vermiculite content.Based on migration indices,Pb2+ was less mobile than Cu2+ in the studied soils.
