Acid-volatile sulfides (AVS) are an important metal-binding phase in sediments. For sediments that contain an excess of AVS over simultaneously extracted metal (SEM) concentrations, acute or chronic effects should not result from the metals Cd, Cu, Ni, Pb and Zn. While AVS phases may exist in surface sediments, the exposure to dissolved oxygen may oxidize the AVS and release metals to more bioa...

In this study, concentration of 17 elements, including As, Ba, Cd, Co, Cu, Hg, Mn, Ni, Pb, Zn, Ca,Fe, Mg, Na, P, S, Si, as well as methylmercury in 31 surface sediments were assessed. The sampling stations were Gulf of Golestan, Miankale Island, Babolsar, Nowshahr and Anzali, which represented the most important harbors in the Golestan, Mazandaran and Gilan provinces in the southern parts of th...

the levels of 19 organochlorine pesticides (ocps) in surface water and under water sedimentsfrom tanks located nearby the prime agricultural areas of kanyakumari district, tamil nadu, india wereinvestigated to evaluate their pollution risks. a total of 36 surface water samples at 9 sampling sites and27 sediment samples at 9 sampling stations were collected from tanks, which were the water sourc...

dianchi lake is one of the most three seriously eutrophic lakes in china. in the present study, the phosphorus (p) and nitrogen (n) fractions in 37 surface sediments samples collected in the dianchi lake were investigated. the total phophorus (tp) in sediments was divided into two parts: inorganic p (ip) and residual p (res-p). the results showed that the total phosphorus content in surface se...

During cruise SO 58 of the FRG research vessel Sonne in 1988, surface sediments were collected from the deep waters of the Sulu Trench (Philippines) for organic geochemical investigations. The purpose of geochemical analyses of surface sediments is to obtain information on the nature and origin of gaseous hydrocarbons detected in these sediments and from this information to estimate the hydroca...

There were similar distribution characteristics for acid volatile sulfides (AVS) and simultaneously extracted metals (SEM) in surface sediments, and the concentrations of AVS and SEM decreased from the deposition area to the center of the bay (lake). The ratio of AVS to SEM was <1 in the surface sediments, indicating that heavy metals in surface sediments may be bioavailable. The concentration ...

Vertical and temporal variations of acid-volatile sulfides (AVS) and simultaneously extracted metals (SEM) in sediment can control biological impacts of metals. To assess the significance of these variations in field sediments, sediments spiked with cadmium, copper, lead, nickel, and zinc were deployed in Narragansett Bay for four months and recolonization by benthic organisms investigated. In ...

Phosphorus (P) retention is an important ecosystem service provided by sediments and soils. However, when shallow aquatic sediments and poorly drained soils dry and re-flood, they can be a source, rather than a sink, of P. Using experimental drying and re-flooding in the laboratory, we assessed the resultant sediment–water P exchange in a biogeochemically diverse set of sediments from 16 sites ...

Selected heavy metals (Cr, Cu, Ni, Pb and Zn) in surface sediments from the coastal Shandong Peninsula (Yellow Sea) have been determined to evaluate the spatial distribution and potential ecological risk. Results showed that heavy metal concentrations in the sediments generally met the criteria of China Marine Sediment Quality. However, both the enrichment factor (EF) and geoaccumulation index ...

Platinum contamination in estuarine and coastal sediments has been evaluated in three cores collected from the Tagus Estuary and Prodelta shelf sediments. Elevated concentrations, up to 25-fold enrichment compared to background values, were found in the upper layers of the estuarine sediments. The degree of Pt enrichment in the estuarine sediments varied depending on the proximity to vehicular ...