Bis-acylhydrazones of 2,6-pyridinedicarbaldehyde are introduced as planar pentadentate ligands for the coordination of lanthanide(III) ions. With large cations (e.g. lanthanum(III)) 1 : 1 as well as 2 : 1 ligand-to-metal complexes are formed depending on the stoichiometry of the reaction. The different complexes are distinguished by NMR spectroscopy and ESI MS in solution and they can be characterized by X-ray diffraction. With the small lutetium(III) ion only the 1 : 1 complex is formed. In the 1 : 1 compounds, anions such as nitrate fill up the coordination site at the metal ion. However, in some cases anion substitution by solvent molecules is observed in the solid state leading to cationic and even dicationic coordination compounds.

A B S T R A C TThe mixture of adsorbents of moringa seed (BK) and natural zeolite of Lampung (ZAL) is placed in a fixed bed adsorber column arranged at a certain height according to the designed height ratio. BK is processed by extraction to remove its oil content while ZAL is activated by chemical and physical treatments. Composition ratio of BK-ZAL (cm/cm) was varied i.e.1:1, 1:2 and 1:3 and concentrations of Pb entering adsorber were 1 ppm and 2 ppm. The adsorption conditions were 20-35 mesh of adsorbent size, 4 cm column diameter of adsorber, 5 cm bed height, and 8 liters/3 hours flowrate. Upflow adsorption was performed in the fixed bed adsorption column for 3 hours and Pb solution of the adsorber output was taken at every 30 minutes. Analysis of Pb content was performed by Atomic Absorption Spectroscopy (AAS). The BK Adsorbent before and after extracted, and after adsorption were characterized using Fourier Transmission Infra Red (FTIR). ZAL before and after activation were characterized using X-Ray Diffraction (XRD), X-Ray Fluorescence (XRF), and Fourier Transmission Infra Red (FTIR). The characterization results of XRD, XRF and FTIR showed that the crystalline phases of ZAL increased, the activation process of ZAL only caused a shift in the peak, no significant change in the structure of solids, and the content of impurities in ZAL reduced after activation, thereby enhancing its ability to adsorb Pb. AAS analysis results showed that the best combination adsorbent BK-ZAL (cm/cm) was 1: 2 with the highest effectiveness of the entrapment of Pb metal reached 99.90%. The adsorption capacity of adsorbent was 2.25 mg Pb/ gram adsorbent as calculated using Freundlich equilibrium model.

Zeolite Lynde Type A (LTA) has been widely applied, such as adsorbent, catalyst, membrane, ion exchanger, and even molecular sieve. As molecular sieve, the zeolite LTA has high dehydration ability and has a prospect as separation agent such as water removal from the ethanol-water mixture to obtain high purity bioethanol. Furthermore, it can repeatedly be used, lower energy usage, and environmentally friendly. Due to the number of advantages possessed, this research conducted to synthesize the zeolite LTA. The sources of silica and alumina used are from Coal Bottom Ash (CBA), PLTU Tarahan, Indonesia. CBA is a waste of coal burning that has not fully utilized. This effect of aging time was examined to obtain the highest percentage of its crystallinity. The results showed that 36 hours aging gave a product of zeolite with the best characteristics. The XRD analysis reported that this zeolite had 89.43% of crystallinity. The FTIR identification showed the presence of double rings structure which is characteristic of zeolite LTA. Finally, the result of SEM expressed the morphology of zeolite A on 3.163 μm of crystal size.