Novel data on genotoxic assessment of bismuth sulfide nanoflowers in common carp Cyprinus carpio.

The environmental impacts and risks of nanomaterials that are commonly used in different technologies are of great concern as their toxic effects on the aquatic ecosystem remain unclear. In this study, bismuth sulfide (Bi2S3) nanoflowers (nfs) were synthesized using a microwave-based hydrothermal process, and their genotoxic effects were investigated in the common carp, Cyprinus carpio. Bi2S3 nanoflowers were applied to common carp for 96 h. LC50 value (LC50 = 350 mg/L-1) was determined for acute toxicity with probit analysis, and three sublethal concentrations (35, 87, and 175 mg/L-1) were selected accordingly for genotoxicity tests. Such LC50 value - 350 mg L-1 for the common carp makes these nanoflowers non-toxic to aquatic organisms according to the EU-Directive 93/67/EEC classification scheme. Toxicological evaluations of the sublethal concentrations of Bi2S3 nanoflowers demonstrated that the 35 and 87 mg L-1 Bi2S3nfs groups were generally harmless and similar to the control group. Only the 175 mg L-1 Bi2S3nfs group had significant DNA damage frequency and nuclear abnormalities than the control and other Bi2S3nfs groups. To the best of our knowledge, this is a novel data on genotoxicity reported for fish species exposed to Bi2S3 nanoflowers; however, further systematic studies need to be performed to fully estimate the effects of Bi2S3 nanoflowers on aquatic life.

Preparation and characterization of activated carbons from Lemon Pulp for oxytetracycline removal.

This study aims to remove oxytetracycline (OTC) that harms the ecosystem, with activated carbon (LPAC) obtained from Lemon Pulp (LP). Characterization and properties of LPAC were analyzed by Brunauer-Emmett-Teller (BET), Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), X-ray diffraction (XRD) and point of zero charge (pHPZC) analyses. BET surface area, pore volume and pHPZC of LPAC produced by carbonization at 400 °C and activation with KOH at 800 °C were obtained as 1333.01 m2/g, 0.391 cm3/g, and 6.81, respectively. pH, reaction time, initial OTC concentration, and adsorbent amounts were optimized in the adsorption study performed with LPAC with high porosity and micropores. Kinetic evaluation was made with pseudo-first-order, pseudo-second-order, and intra-particle diffusion models and Freundlich, Langmuir, and Temkin equations are used to investigate their isotherms under reaction equilibrium conditions, and also the results were analyzed by statistical method (ANOVA). In pseudo-second-order kinetic and Freundlich isotherm models, where the best results were obtained, R2 values were calculated as 0.999 and 0.995, respectively. Maximum OTC removal efficiency was found as 104.22 mg/g. Overall, this research indicates that LPAC for the treatment of water contaminated with antibiotics is environmentally friendly green material.

Adsorption kinetics of malachite green onto activated carbon prepared from Tunçbilek lignite.

Adsorbent (T3K618) has been prepared from Tunçbilek lignite by chemical activation with KOH. Pore properties of the activated carbon such as BET surface area, pore volume, pore size distribution, and pore diameter were characterized by t-plot based on N2 adsorption isotherm. The N2 adsorption isotherm of malachite green on T3K618 is type I. The BET surface area of the adsorbent which was primarily contributed by micropores was determined 1000 m2/g. T3K618 was used to adsorb malachite green (MG) from an aqueous solution in a batch reactor. The effects of initial dye concentration, agitation time, initial pH and adsorption temperature have been studied. It was also found that the adsorption isotherm followed both Freundlich and Dubinin-Radushkevich models. However, the Freundlich gave a better fit to all adsorption isotherms than the Dubinin-Radushkevich. The kinetics of adsorption of MG has been tested using pseudo-first-order, pseudo-second-order and intraparticle diffusion models. Results show that the adsorption of MG from aqueous solution onto micropores T3K618 proceeds according to the pseudo-second-order model. The intraparticle diffusion of MG molecules within the carbon particles was identified to be the rate-limiting step. The adsorption of the MG was endothermic (DeltaH degrees = 6.55-62.37 kJ/mol) and was accompanied by an increase in entropy (DeltaS degrees = 74-223 J/mol K) and a decrease in mean value of Gibbs energy (DeltaG degrees = -6.48 to -10.32 kJ/mol) in the temperature range of 20-50 degrees C.