Mechanical stabilization methods for improving chemical stability of contaminated dredged material used for upland disposal are presented. Assessments of long term environmental consequences involving effects on heavy metal immobilization, TOC, COD, BOD, anion release, gas production and -composition after addition of lime, calcium carbonate, cement, coal fly ash and gypsum to fine grained Hamburg harbour sediments have been studied. Best results are attained with CaCO3 dure to insitu pH conditions and sufficient buffer capacity, which is of prime importance for metal immobilization and gas production.
