Biosorption of nickel by Halobacillus sp. KN57 isolated from the Miankaleh Wetland, Iran

Heavy metals are generally discharged from untreated wastewater in the aquatic ecosystem. This study was aimed to investigating the effective parameters in the sorption of nickel metal by a native halophile bacterium isolated from sediments of the Miankaleh Wetland in the north of Iran. Halobacillus sp. KN57 as the most resistant Gram-positive strain was selected and identified by phenotypic and phylogenetic properties (16S rRNA). The optimum contact time, pH, temperature, salinity, and initial biosorbent concentration of nickel for this strain were 100 min, 7, 30°C, 10%, 1 g.L-1, and 150 mg.L-1, respectively. The nickel biosorption was 111.11 mg/g by the selected strain under the laboratory conditions, followed Langmuir isotherm with a correlation coefficient of more than 0.98 and the maximum single layer sorption. In addition, the kinetics of nickel biosorption of this strain correspond to a pseudo second order kinetic model with a correlation coefficient of more than 0.99. Scanning electron microscopy was applied to confirm the biosorption of Ni2+ by Halobacillus sp. KN57. Finally, the FT-IR spectrum identified that the amide, carbonyl, and amine functional groups were participated in binding to nickel ions. The results showed that the native bacterial strain (Halobacillus sp. KN57) isolated from Miankaleh Wetland, is potentially a promising biosorbent for sorption of nickel metal

Heavy metal concentrations in gill and liver tissues of Rutilus kutum and Chelon aurata in the coast of Babolsar, southern Caspian Sea

Heavy metal accumulation in the aquatic ecosystems is a main concern which threats human health. In this study two commercial fish species, Rutilus kutum and Chelon aurata were selected for assessing heavy metal (Cd, Pb, Zn) concentrations in gill and liver tissues at Babolsar’s coast, the southern Caspian Sea, Iran. Babolsar is one of the important fishery stations in the southern Caspian Sea. The results showed that liver tissue of C. aurata significantly accumulated higher concentration of Cd, Pb and Zn compared to that of R. kutum, but these results were not significant for gill tissue. Liver tissue accumulated higher concentration of Cd and Pb compared to gill tissue in C. aurata, but these results were not significant for R. kutum. It is concluded that the liver tissue of C. aurata has higher potential to accumulate heavy metal pollution compared to liver tissue of R. kutu

Intra-urban spatial variation of magnetic particles: monitoring via leaf saturation isothermal remanent magnetisation (SIRM).

Motorised traffic generates large numbers of particulate pollutants in the urban environment. Exposure to small particles has been associated with adverse effects on human health. Biomonitoring of magnetic particles accumulated on leaf surfaces may provide information on the concentration of, and exposure to, atmospheric particles at high spatial resolution. In this study, leaf saturation isothermal remanent magnetisation (SIRM) of three urban tree types (Carpinus betulus and Tilia sp. with hairy and non-hairy leaves) was measured at high spatial resolution in the city of Ghent, Belgium, in June and September 2009. We compared leaf SIRM between land use classes with different urban habitat quality. In a multiple regression model, we tried to explain the spatial variability in the leaf SIRM by tree species, sampling height, distance to the nearest road and its traffic intensity, tram frequency and a measure for regional traffic emissions (derived from traffic intensity of and the distance to the most important highways around the city in the main four wind directions). We found that the leaf SIRM was significantly influenced by tree species, distance to the nearest road and its traffic intensity and tram frequency. The SIRM significantly increased with increasing traffic intensity and tram frequency and by decreasing distance to the nearest road. It is concluded that the leaf SIRM is a good bio-indicator for monitoring spatial variation of magnetic particles in urban environments

Leaf saturation isothermal remanent magnetization (SIRM) as a proxy for particulate matter monitoring: inter-species differences and in-season variation.

In recent studies, the saturation isothermal remanent magnetization (SIRM) of leaves has been used for monitoring of atmospheric particulate matter. This study examined leaf SIRM of tree species with different leaf surface characteristics in the urban environment of Gent (Belgium). Leaf SIRM was measured from co-located trees of Carpinus betulus (with ‘hairy’ leaves) and Tilia sp. (‘non-hairy’ leaves) at locations with contrasting traffic density (and particulate pollution level). The measurements were conducted twice during the growing season (June and September 2009). The highest SIRM values were observed for C. betulus, and the lowest for the non-hairy Tilia sp. leaves. The SIRM was significantly higher in locations with high traffic density and in September. Differences between species were independent of pollution level and sampling time, except between hairy and non-hairy Tilia sp. Monthly measurements of leaf SIRM on Tilia platyphyllos and C. betulus trees revealed high in-season variation, which may be due to a combination of short and long-term leaf surface processes. It is concluded that the leaf SIRM, a proxy for particulate matter deposition, depends on leaf surface structure, leaf maturity, and particulate pollution level