Objective:To evaluate the presence of heavy metal cadmium in six species of shellfish at Pulicat Lake, Tamil Nadu, India. Methods: Six species of shellfish,Fenneropenaeus indicus,Fenneropenaeus monodon, Fenneropenaeus...
详细信息
Objective:To evaluate the presence of heavy metal cadmium in six species of shellfish at Pulicat Lake, Tamil Nadu, India. Methods: Six species of shellfish,Fenneropenaeus indicus,Fenneropenaeus monodon, Fenneropenaeus semisulcatus,Scylla serrata,Clibanarius longitarsus and Meretrix casta (M. casta) in Pulicat lake, Tamil Nadu, India were analysed for the presence of cadmium in the gills and muscles from January 2011 to December 2012. Results:The results showed seasonal variations in the uptake of cadmium. Very high accumulation of cadmium was found in the gills and muscles ofM. casta during post monsoon, summer, premonsoon and monsoon. The corresponding values of cadmium present in the gills of M. casta were 1.59, 1.56, 1.48 and 1.46μg/g in 2011 and 1.16, 1.25, 1.15 and 1.14μg/g in 2012. Whereas for muscles, they were 1.14, 0.11, 0.96 and 0.80μg/g in 2011 and 0.49, 0.34, 1.05 and 1.20μg/g in 2012. Conclusion:The results of the present study has shown that the accumulation of cadmium found in the gills and muscles were high in M. casta when compared to other species of shellfish. Thus, the consumption of the shellfish is safe, but does not exclude bioaccumulation risk in their meat. This present study has highlighted the need for estuarine biomonitoring to avoid possible contamination of shellfish and its consumers. The overall scenario of the shellfish accumulating high levels of cadmium indicates that the Pulicat lake is polluted with undesirable elements and the risk of consuming the meat of shellfish by man and other carnivores may lead to their toxicity. Stringent control measures are necessary to control the pollution of this precious lake to reduce the bioaccumulation of toxic metals in organisms.
Most thin-film photovoltaic modules are constructed on soda-lime glass(SLG)substrates containing alkali oxides,such as Na_(2)*** may diffuse from SLG into a module's active layers through P1 lines,an area between a mo...
详细信息
Most thin-film photovoltaic modules are constructed on soda-lime glass(SLG)substrates containing alkali oxides,such as Na_(2)*** may diffuse from SLG into a module's active layers through P1 lines,an area between a module's constituent cells where the substrate-side charge transport layer(CTL)is in direct contact with *** diffusion from SLG is known to cause several important effects inⅡ-Ⅵand chalcogenide solar modules,but it has not been studied in perovskite solar modules(PSMs).In this work,we use complementary microscopy and spectroscopy techniques to show that Na diffusion occurs in the fabrication process of *** diffuses vertically inside P1 lines and then laterally from P1 lines into the active area for up to 360 *** propose that this process is driven by the high temperatures the devices are exposed to during CTL and perovskite *** diffused Na preferentially binds with Br,forming Br-poor,l-rich perovskite and a species rich in Na and Br(Na-Br)close to P1 ***-Br passivates defect sites,reducing non-radiative recombination in the perovskite and boosting its luminescence by up to 5×.Na-Br is observed to be stable after 12 weeks of device storage,suggesting long-lasting effects of Na *** results not only point to a potential avenue to increase PSM performance but also highlight the possibility of unabated Na diffusion throughout a module's lifetime,especially if accelerated by the electric field and elevated temperatures achievable during device operation.
暂无评论