Abstract: This paper provided an overview on the adverse effects of contaminated sediment and on the in situ capping technology,a simply operated and low cost technology for the remediation of contaminated sediment. When doing capping, some clean materials are placed on the top of contaminated sediment to control the pollution of contaminated sediment by fence, fixation and absorption. The characteristics of capping material, such as particle diameter,specific surface area, microporosity and density greatly correlate with the effect of remediation,which should be accorded with the optimum capping material selection and capping thickness determination. The advantages and disadvantages of in situ capping technology, as well as its applicable conditions and ranges were discussed. Several modes of in situ capping constructions, their excellence and shortcomings were introduced,and a great many of domestic and overseas successful in situ capping projects were illustrated. The prospects of in situ capping applied in China were analyzed.

Key words: Soil drought, N, Endogenous hormone, Stomatal conductivity, Maize