Abstract:

The effect of different capping methods on pH,Eh and organic content in the overlying water and sediment in 60 days was studied by using calcium bentonite or cinder as capping material for insitu sediment treatment.As capping materials in sediment insitu treatment,both cinder and bentonite could isolate sediment organic from overlying water,with bentonite displaying better effects than cinder.This could be seen from the reduction of organic content in the sediment by 25%.Moreover,the pH of sediment had the tendency to decrease in the reaction system,adhering to the order of pH changes in an anaerobic environment,with a pH of ca.75,while Eh tended to increase even though the sediment was still in an anaerobic environment according to tested data,between 80-110 mV.On the other hand,after capping with cinder,organic content of sediment was reduced by 20%; pH or Eh tended to increase in the system.After capping with cinder or bentonite,due to their capping isolation and absorption of organic,the CODCr released by overlying water was reduced