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"Model adsorpsi senyawa koordinasi Ni2+-H2O, Ni2+-NH3, Nit+-EDTA dan Nit+-CN pada permukaan alumina digambarkan berdasarkan variasi variabelnya, yaitu pH, spesies ligan dan alumina serta kuat ion. Metode adsorpsi yang digunakan adalah pengguncangan. Pengujian juga dilakukan secara visual dengan menggunakan Scanning Electron Microscope (SEM).Alumina yang digunakan berasal dari AICI3 dengan variasi suhu kalsinasi 600°C dan 900°C. Alumina jenis 1 yang diperoleh dengan pemanasan 600°C merupakan campuran fasa x dan n-alumina, sedangkan alumina jenis 2 merupakan campuran fasa x, ri, 7, 0 dan rc-alumina.Adsorpsi maksimum Ni2+-H2O dan Ni2+-NH3 pada kedua jenis alumina terjadi pada pH 3, sedangkan adsorpsi maksimum sistem yang mengandung Nit+ EDTA dan Ni2+-CN diperoleh pada pH 10. Pengujian dengan Isoterm Adsorpsi Langmuir dan Freundlich pada pH maksimum menunjukkan bahwa proses adsorpsi mengikuti persamaan Langmuir yang membentuk lapisan monolayer pada permukaan homogen.Percobaan menunjukkan bahwa adsorpsi Ni2+-H2O dan Ni2+-NH3 memiliki pola adsorpsi yang sarna dan keduanya lebih mudah teradsorpsi pada alumina jenis 1 yang bersifat lebih asam. Tetapi pada sistem Ni2+-H2O pola adsorpsi tidak dipengaruhi oleh permukaan kuat ion sehingga diperkirakan adsorpsi terjadi pada Bidang Helmholtz dalam akibat adanya interaksi antara ion logam Ni dengan sisi aktif Oksigen pada permukaan alumina. Sedangkan adsorpsi Nit+ NH3 dipengaruhi oleh kuat ion dan diperkirakan terjadi pada Bidang Helmholtz luar akibat terjadinya proses pengendapan senyawa Ni(OH)2 pada permukaan alumina.Adsorpsi sistem campuran Ni2+-H2O dengan Nit+-EDTA dan Nit+ H2O dengan Ni2+-CN menunjukkan pola adsorpsi yang sama, lebih mudah teradsorpsi pada alumina jenis 2 yang bersifat lebih basa dan dipengaruhi oleh kuat ion, sehingga disimpulkan bahwa proses adsorpsi terjadi pada Bidang Helmholtz luar karena adanya interaksi elektrostatik antara ligan yang kaya akan elektron dengan pusat aktif Aluminium pada permukaan alumina, selain terjadinya pengendapan senyawa Ni(OH)2 pada permukaan alumina, pada kondisi pH tinggi.Pengujian dengan Scanning Electron Microscope (SEM) tidak menunjukkan keberadaan Nikel di sekitar permukaan Aluminium yang diamati sehingga disimpulkan tidak ada interaksi langsung antara Nikel dengan Aluminium.

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Adsorption Models of Nickel (II) Coordination Complex Compounds on to the Alumina SurfaceAdsorption models of coordination complex compounds of Ni2+-H20, Ni2+-NH3, Nit+-EDTA and Nit+-CN on to surface of alumina is described by variation of some variables; pH, types of alumina, and the ionic strength.

Sample of alumina synthesized from AIC13. More acidic alumina which is calculated in 6000C provides mixed of x-and n-alumina phase, whereas alumina which is treated in 900°C contains x,n,-y4 and rs-alumina.

Maximum adsorption of Ni2+-H2O and Nit+ NH3 on both type of alumina occurs in pH 3, but systems contain EDTA and CN ligand in pH 10. Test of Isotherm adsorption in the maximum pH give that adsorption process following Langmuir equation to form monolayer adsorbate on homogenous surface.

The result give that adsorption of Ni2+-H2O and Ni2+-NH3 have similar patterns. The difference is Ni2+-H2O adsorpted in Inner Helmholtz Plane by interaction beetwen Ni2+ with Oxygen site of alumina surface and system contains NH3 in Outer Helmholtz Plane by precipitation of Ni(OH)2 on to alumina surface. Adsorption system contains EDTA and CN have another similar patterns and adsorpted in Outer Helmholtz Plane because any electrostatic interaction between ligand and aluminum site of alumina."

"Copper(II) and nickel(II) complexes of 14-membered hexaazamacrocyclic ligand with C-methyl substituent have been synthesized by one-pot reaction and characterized by elemental analyses, FT-IR, electronic spectra, and LC-MS. Complex types are [Cu(C18H42N6)(ClO4)2] (1), [Ni(C18H42N6)](ClO4)2 (2), and [Cu(C22H50N6)(ClO4)2] (3). The results of spectroscopic techniques indicated that both complexes 1 and 3 containing copper(II) are octahedral geometry, whereas the complex 2 is a square-planar geometry in which the metal center coordinates to the four nitrogen atoms of macrocyclic ligand in a square planar fashion.All complexes were also screened for their antibacterial activity against on two bacteria strains. These results show that copper(II) and nickel(II) complexes were tested for antibacterial activity against gram positive, Staphylococcus aureus which was more active than the against gram negative, bacteria Escherichia coli.The results showed a good antibacterial activity of all complexes which suggests their potential applications as antibacterial agents."

"This work investigates the comparative adsorptive removal of Ni (II) ions from aqueous solution using coconut shell and banana peel. Optimum conditions for adsorption were determined by experimental design, while Analysis of Variance (ANOVA) and BonferroniHolm Posthoc significance statistical tests on operational parameters were also conducted. The parametric effect of adsorbate dose, adsorbent dose, pH, contact time, particle size and temperature were varied individually, and their effect on the percentage of Ni (II) ion removal was estimated. The maximum percentage removal was achieved at a pH of 8.0 by both adsorbents. The optimum conditions obtained for both adsorbents were 4.5 g adsorbent dose, 30 min contact time and 25 oC for coconut shell, and 4.5 g adsorbent dose, 120 mins and 25 oC for banana peel. The Langmuir isotherm best described the adsorption, with correlation coefficient (R2 ) values of 0.9821 and 0.9744 for banana peel and coconut shell respectively. The mean free energy from the Dubinin-Radushkevich isotherm suggested chemisorption, and the adsorption mechanism was found to fit the second order."