No abstract

We investigated the contamination of marine plastic debris from the Indonesian Cilacap coast and the North Atlantic gyre by polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs). The mean concentrations of 15 PAHs in gyre were 58 and 142 ng/g in polyethylene (PE) and polyethylene terephthalate (PET) debris, respectively, while PE and polypropylene (PP) Indonesian debris exhibited an average content of 552 ng/g (mainly naphthalene). The mean concentration of 61 PCBs in open ocean debris was 12.2 ng/g, while coastal debris showed a worryingly high mean value of 1.4×10 4 ng/g, with the notable presence of CB6, 101 and 173. PE gyre debris contained mostly high molecular weight PAHs such as benzo(g,h,i)perylene and indeno(1,2,3-cd)pyrene and low-chlorinated PCBs such as CB52, 77 and 105, whereas PET debris contained low molecular weight PAHs (mainly acenaphthylene and phenanthrene) and high-chlorinated PCBs such as CB204. Highlights • First results on the pollution of plastic debris from Indonesian coast and North Atlantic gyre • The cumulative PAHs and PCBs' concentration is 91 ng/g in North Atlantic gyre debris. • Indonesian coastal debris are 150 times more polluted than North Atlantic gyre ones • PAHs' concentrations in PET from the North Atlantic gyre are slightly higher than in PE • Fingerprints of PAHs and PCBs in marine plastic contrasted according to the microplastic source.

Samples of pure zinc aluminate (ZnAl2O4) and doped both with lead (Pb2+) at different ratios (0, 0.5, 1, 1.5, 2 and 2.5% mol) and a constant amount of lanthanum (La: 1% mol), were prepared by the citrate sol-gel technique, and then annealed at 900°C for 2h. In order to study the structural, optical and thermal properties; different characterization methods were used, such as: powder X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX), differential scanning calorimetry (DSC), TGA, Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy. The Analyzes by XRD revealed the presence of the cubic single phase ZnAl2O4 for all samples, with a crystallites size between 19 and 25 nm. These results were confirmed using FTIR, Raman spectroscopy and SEM. Also, photocatalytic study for different samples of ZnAl2O4 shows that they can be used like as photocatalyst and good adsorbents for degradation of Hexamethyl crystallized violet dye in aqueous solution.

No abstract