Cd In Sediment Samples Research Articles

Heavy metal pollution and mobility of sediment in Tajum River caused by artisanal gold mining in Banyumas, Central Java, Indonesia.

The heavy metals Cu, Pb, Zn, and Cd in the stream sediment of the Tajum River were studied based on 12 sediment samples obtained from upstream to downstream. The artisanal mining activities in the study area generated mining processing waste (tailing) and are the primary source of heavy metal pollution. The samples were analyzed for metal concentration as well as metal mobility based on sequential extraction analysis. Heavy metal analysis for the concentration of the metals showed that the value of Cu, Pb, Zn, and Cd in sediment samples transcends the mean crust. The change of the heavy metal concentrations in stream sediment between the upstream and downstream areas showed that higher levels were located near mining activities in upstream and that these decreased with distance to downstream. The result of the sequential extraction study revealed that Cu and Pb were more found in the exchangeable and carbonate fraction of about 26% and 24%. Meanwhile, Zn and Cd were present in the Fe-Mn oxide, an organic and residual fraction of about 90% and 85%, respectively. The mobility factor assessment revealed that the heavy metals investigated had an average mobility factor of 25.89%, 23.9%, 14.4 %, and 9.24% for Cu, Pb, Zn, and Cd, respectively. Overall, Zn and Cd in sediment in the study area were less mobile compared with Cu and Pb.

Temporal evolution of the environmental quality of the Vallona Lagoon (Northern Mediterranean, Adriatic Sea)

Guidance Document 25/2010, suggests sediment and biota are the most suitable matrices for the trend monitoring purpose, because they integrate the pollution over time and space. So, from 2005 to 2014, the sediment and biota concentrations of heavy metals (As, Cd, Cr, Hg, Ni, Pb) were analysed in the Vallona Lagoon (northern Adriatic Sea, Italy), widely used for intensive and extensive bivalve farming. The contamination levels in sediment and biota were compared with Environmental Quality Standard (EQS) and threshold levels (TL) for human health.The results identified critical issues related to Cd in sediment samples as well as to Hg and Pb in biota which were not only ascribable to the physiological and seasonal variability of organisms. The Cr and Ni levels in sediment were higher than the EQS. However, the concentration increases at biota stations close to sites where EQS excesses were observed in sediment were not verified.

Fractionation profile, mobility patterns and correlations of heavy metals in estuary sediments from olonkoro river, in tede catchment of western region, Nigeria

This work was carried out to determine the concentrations, bioavailability and mobility of heavy metals in the sediments of Olonkoro River, Tede, Oyo State, Nigeria. The river sediments were sampled at ten selected locations and the samples were analyzed for some heavy metals to determine the concentration, speciation and distribution pattern of the metals. The sediments were obtained specifically at upstream, middle-stream and downstream of the river. In general, the total metal concentrations were in the order: Fe>Zn>Mn>Cu>Pb>Cd in sediment samples and for Tessier’s sequential fractionation, manganese was found to be more in the exchangeable phase, Fe in the Residual, Zn in carbonate-bound metal while Pb was greater in the exchangeable form and Cu was found to be more concentrated in the organic phase. Percent of bioavailable and non-bioavailable proportions of heavy metals for Mn, Fe, Cu, Zn, Pb, and Cd in the sediment samples varied between 12.92-87.08, 11.57-88.43, 0.29-99.71, 10.76-89.24, ND-100 and ND, respectively. This clearly indicates that with the exception of Cu and Cd the metals are highly bioavailable leading to their having a higher impact on the target system, subsequently leading to contamination of the water. The high percent bioavailability is an indication of poor retention in the residual geochemical form partly due to saturation of the sediment (river). The pH value was found to be basic but within the WHO standards throughout all locations. The high percentage of Mn, Cd and Pb in the bioavailable forms suggested the need to keep close surveillance on these metals because of their high toxicity.

Speciation and determination of priority metals in sediments of Oyun River, Ilorin, Kwara, Nigeria

This work was carried out to determine the concentrations, bioavailability and mobility of priority metals in sediments of Oyun River, Sango, Ilorin, Nigeria. The river sediments were sampled at six selected locations and the samples were analyzed for some certain priority metals to determine the concentration, speciation and distribution pattern of the metals. The sediments were obtained specifically at upstream, middle-stream and downstream of the river. In general, the total metal concentrations was in the order: Mn > Pb > Cu > Cd in sediment samples and for Tessier’s sequential fractionation, manganese was found to be more in the exchangeable phase, while Pb was higher in the residual form and Cu was found to be more concentrated in the organic phase. Total priority metal bio-availability and mobility of Pb, Mn, Cu and Cd in the samples varied between 0-83.61 mg/kg, 93.01-96.65 mg/kg, 23.53-45.88 mg/kg and 0-100 mg/kg, respectively. This clearly indicates that with the exception of Cu, the metals are highly bioavailable leading to it having a higher impact on its target system, subsequently leading to contamination of the water. The high percent bioavailability is an indication of poor retention in the residual geochemical form partly due to saturation of the sediment (river). The pH value was found to be basic but within the WHO standards throughout all locations. The high percentage of Mn, Cd and Pb in the bioavailable forms suggested the need to keep close surveillance on these metals because of their high toxicity. KEY WORDS : Speciation, Mobility, Priority metals, Sediments, Bioavailability, Pearson correlation, Principal component analysis Bull. Chem. Soc. Ethiop. 2016 , 30(2), 199-208. DOI: http://dx.doi.org/10.4314/bcse.v30i2.4

Distribution of polychlorinated biphenyls (PCBs), lead, and cadmium in Manko Tidal Flat, Okinawa

Concentrations of polychlorinated biphenyls (PCBs), Pb, and Cd in sediment samples from the Manko Tidal Flat, an important area for migratory birds in Okinawa, were analyzed. High concentrations of PCBs were detected in the sediment samples from sites under a bridge at the end of the Manko Flat, whereas Pb and Cd concentrations did not indicate specific pollution. The spatial distribution and homologue proportion of PCBs indicated that these PCBs are probably attributed to the residue of paints used on the bridge in the 1970s. PCBs were detected in tilapias from sites in the Manko Flat and in a river connecting to the flat without head constructions. PCBs were also detected in small invertebrates, tanaids, in the flat. The distribution of PCB concentrations in the fauna was parallel to that in the sediments. The average PCB homologue proportions in tilapias and tanaids were similar to those in sediments.