Seaweed Superheroes: Cystoseira barbata-Incorporated Electrospun Fibers for Lead Ion Sequestration.

The efficient removal of lead ions at low concentrations is paramount in combating the significant threat posed by water pollution resulting from industrial activities and population growth. In this study, electrospun C. barbata/PAN fibers were developed to efficiently remove lead(II) ions from water. The morphology, structure, and mechanical properties of the fibers were examined, highlighting that the augmentation of the surface area through the conversion of C. barbata into the polymer fibers facilitates increased metal bonding sites during sorption. C. barbata/PAN fibers exhibited superior characteristics, including higher surface area, smaller pore size, and increased pore volume, compared to powdered C. barbata. The effects of factors such as shaking time, algae percentage, sorbent amount, pH, metal concentration, and temperature on Pb(II) sorption were investigated by the batch method. At an initial ion concentration of 100 µg L-1 and pH 4.0, C. barbata (5 wt %)/PAN fiber demonstrated a notable sorption efficiency of 89-90% (270 µg/g) after 60 min. The equilibrium data align with the Freundlich and Dubinin-Radushkevich isotherm models, whereas the pseudo-second-order kinetic model provides the most suitable description. The characterization of fibers after sorption revealed that carboxyl, hydroxyl, and sulfonyl groups play an active role in Pb(II) sorption.

The influence of marine fish farming on water and sediment quality: Ildir Bay (Aegean Sea).

The aim of this study was to examine the possible effects of the physicochemical parameters of the water at a fish farm where aquaculture activities are carried out (temperature, pH, salinity, total dissolved solids, electrical conductivity, dissolved oxygen, Secchi depth, nitrite-nitrogen, nitrate-nitrogen, phosphate-phosphorus, ammonium-nitrogen, silica, chlorophyll-a, and suspended particle matter) and in the sediments (%burnable organic matter and %organic carbon). The area of study was an open sea network cage farm where European seabass (Dicentrarchus labrax), gilthead seabream (Sparus aurata), and meagre (Argyrosomus regius) species are cultivated with an annual capacity of 7900 tons in the Bay of Çesme Ildir (Aegean Sea). Samples of surface and bottom water and sediment were taken seasonally from four stations (three cage and one reference station) between December 2013 and October 2014. The study found that the maximum concentrations of ammonium-nitrogen, phosphate-phosphorus, and nitrite-nitrogen were observed in summer, whereas those of nitrate-nitrogen, silica, and chlorophyll-a increased in spring. In comparison with other studies conducted in the region, the amounts of nutrients, except for silica, were found to be considerably lower. Nonetheless, the values of silica and phosphate-phosphorus exceeded the limits for clean seawater. There has been no similar study conducted in recent years due to increased aquaculture capacity in this bay.

Assessment of trace metal contamination in the sea cucumber (Holothuria tubulosa) and sediments from the Dardanelles Strait (Turkey).

This study was performed to determine the concentrations of some trace metals (Cd, Cu, Pb, Ni, Zn, and Fe) in Holothuria tubuosa (Gmelin, 1788) belonging to Echinoderm species and in sediments that they live at three different stations (Gelibolu, Umur Bey/Lapseki, and Dardanos) on Dardanelles Strait between April 2013 and March 2014. The mean trace metal concentrations determined in H. tubulosa and sediment were as follows: Cd 0.18 mg/kg, Cu 2.43 mg/kg, Pb 2.09 mg/kg, Ni 14.58 mg/kg, Zn 16.86 mg/kg, and Fe 73.46 mg/kg and Cd 0.70 mg/kg, Cu 5.03 mg/kg, Pb 14.57 mg/kg, Ni 27.15 mg/kg, Zn 54.52 mg/kg, and Fe 3779.9 mg/kg, respectively. It was detected that the statistical difference between trace metals determined seasonally in muscle tissue of H. tubulosa was significant (p > 0.05). As a result of the study, it was detected that H. tubulosa is a bioindicator species in determining Ni trace metal in sediment. The results were compared to the limit values of National and International Food Safety, and it was detected that Cd and Ni concentrations measured in sediment were above LEL of Ni and Cd concentrations according to Sediment Quality Guidelines.