a dose of 32 g activated carbon per kg contaminated sediment the ddt concentration in the sediment was 18 1 mg ddt per kg sediment the 83 reduction in ddt indicates that about 15 mg ddt transferred to the activated carbon this determination is based on a linear sorption isotherm for the sediment over an aqueous concentration range of approximately an order of magnitude the dose of activated carbon and the determined amount of ddt transferred indicates that the sorptive loading was very high at about 15 mg ddt per 32 g activated carbon or equivalently about 470 mg ddt per kg activated carbon reduction of spmd uptake after 1 and 6 months of treatment with activated carbon regenerated activated carbon 75 200 u03bcm was mixed with ddt contaminated sediments at varying concentrations and treatment times reduction of spmd uptake was measured as described above results are shown in fig4 with error bars indicating range of replicates these data show the effectiveness of regenerated activated carbon increases with dose and contact time achieving 95 reduction in available ddt levels with 6 month contact of 3 2 weight percent carbon additional tests showed 99 reduction in available ddt levels after twenty six months of contact with 3 2 weight percent carbon this work shows activated carbon amendment can be used to reduce the availability of ddt from laurtizen channel sediments to water with a continuous decrease in spmd uptake after contact for six months and twenty six months compared to one month ddt.