Studies On The Distributions Of Sulfide And Restoration In Cultural Sediments Of RuShan Bay

The tidal flatmud of RuShan Bay is wide and fertile. RuShan Bay is an important culture area of economic shellfish. In the last ten years, the tidal flatmud of RuShan Bay became aging and its' productivity decreased because of high concentrations of sulfide and orgnic matters in sediments. The researchs on sulfide distributions and the removal technique of sulfide in this area are significant, which can provide theoretical foundations for the culture distributions of the tidal flatmud and make a model for the restoration of cultural environment sediments.The sulfide distributions in the east Valley of Rushan Bay were investigated. The regulations of the surface layer distributions, vertical distributions and seasonal variations are detailed. The comparisons in cultured and uncultured areas are also detailed in this paper. The results show that the sulfide concentrations in cultured area are higher than that in uncultured area. Then the acute toxic effects of sulfide on Ruditapes philipinarum are studied. In order to remove sulfide and restore cultural sediment environment, the Acid Volatile Sulfide (AVS) removal tests used by ferric oxide and the influencing factors are studied in the laboratory. Then both of red soils riched by ferric-oxide and iron ores are added to the marine cultured sediment in the east Valley of Rushan Bay. The restoration of environment itself is taken as control.1. The results show that the redox environmental states in the east Valley of Rushan Bay belong to weak reduction environment. In the sediment of surface layer, the sulfide and redox potential distributions take on this basic trend: the sulfide concentrations in the north side are higher than that in the south side. Generally, the sulfide concentrations increase with the depth. The seasonal variation of sulfide concentrations is obvious: the sulfide concentrations are highest in August, higher in June and low in October. The sulfide concentrations have been obviously influenced by shellfish cultivations. The sulfide concentrations in the cultured areas are higher...