The current study was designed for using banana peels to remove zinc, chromium and nickel from industrial waste-water. Three forms of these peels (fresh, dried small pieces and powder) were tested under some environmental factors such as pH, temperature and contact time. Current data show that banana peels are capable of removing zinc, chromium and nickel ions at significant capacity. Furthermore, the powder of banana peels had highest capability in removing all zinc, chromium and nickel ions followed by fresh peels whilst dried peels had the lowest bioremoving capacity again for all metals under test. The highest capacity was for chromium then nickel and finally zinc. All these data were significantly (LSD peel forms = 2.761 mg/l, LSD metal ions = 1.756 mg/l) varied. In case of chromium, these figures were 65.0 ± 1.0 mg/l, 54.0 ± 2.0 mg/l and 41.7 ± 1.5 mg/l for powder, fresh and dried peels respectively. Regarding nickel ions, these data were 56.7 ± 1.5 mg/l for peel powder, 47.7 ± 2.2 mg/l for fresh peel and 47.7 ± 2.2 mg/l for dry peel. While for zinc ions, the biosorption capacity was 51.7 ± 0.8 mg/l, 41.0 ± 1.0 mg/l and 34.7 ± 0.9 mg/l for powder, fresh and dry peels respectively. However, some examined factors were found to have significant impacts upon bioremoval capacity of banana peels such as pH, temperature, and contact time where best biosorption capacity was found at pH 4, at temperature 50 Cº and contact time of 1 hour. It is true that banana peels were varied significantly in case of metal ions and increasing examined factor (pH, temperature. And contact time). Regarding pH, the highest bioremoval ability was found at pH 5 for all heavy metals, but with the sequence of Cr, Ni, and Zn and the data were 59.4 ± 0.83 mg/l, 54.0 ± 0.0 mg/l and 39.1 ± 1.86 mg/l respectively. Similar pattern of bioremoval capacity was detected for temperature which was 50 C º where it was 66.7 ± 2.91 mg/l for chromium, 57.7 ± 1.12 mg/l for nickel and 52.0 ± 1.12 mg/l for zinc. However, in case of contact time, the capacity of biosorbing of these metals was again similar to those of pH and temperature factors where it was found to be 74.0 ± 1.76 mg/l , 66.0 ± 2.25 mg/l and 66.0 ± 1.95 mg/l for Cr, Ni, and Zn respectively but at 1 hour contact time.
Background: With the increasing demands for adult orthodontics, a growing need arises to bond attachments to porcelain surfaces. Optimal adhesion to porcelain surface should allow orthodontic treatment without bond failure but not jeopardize porcelain integrity after debonding.The present study was carried out to compare the shear bond strength of metal bracket bonded to porcelain surface prepared by two mechanical treatments and by using different etching systems (Hydrofluoric acid 9% and acidulated phosphate fluoride 1.23%). Materials and Methods: The samples were comprised of 60 models (28mm *15mm*28mm) of metal fused to porcelain (feldspathic porcelain). They were divided as the following: group I (control): the porcelain surface left u
... Show MoreThe effect of thickness variation on some physical properties of hematite α-Fe2O3 thin films was investigated. An Fe2O3 bulk in the form of pellet was prepared by cold pressing of Fe2O3 powder with subsequent sintering at 800 . Thin films with various thicknesses were obtained on glass substrates by pulsed laser deposition technique. The films properties were characterized by XRD, and FT-IR. The deposited iron oxide thin films showed a single hematite phase with polycrystalline rhombohedral crystal structure .The thickness of films were estimated by using spectrometer to be (185-232) nm. Using Debye Scherrerś formula, the average grain size for the samples was found to be (18-32) nm. Atomic force microscopy indicated that the films had
... Show MoreThe reaction oisolated and characterized by elemental analysis (C,H,N) , 1H-NMR, mass spectra and Fourier transform (Ft-IR). The reaction of the (L-AZD) with: [VO(II), Cr(III), Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II)], has been investigated and was isolated as tri nuclear cluster and characterized by: Ft-IR, U. v- Visible, electrical conductivity, magnetic susceptibilities at 25 Co, atomic absorption and molar ratio. Spectroscopic evidence showed that the binding of metal ions were through azide and carbonyl moieties resulting in a six- coordinating metal ions in [Cr (III), Mn (II), Co (II) and Ni (II)]. The Vo (II), Cu (II), Zn (II), Cd (II) and Hg (II) were coordinated through azide group only forming square pyramidal
... Show More