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The [Ru04]" ion can be generated in aqueous base at pH 11 from aquated ruthenium trichloride with excess brómate, and this reagent will catalytically oxidize primary alcohols, activated alkyl halides, aldehydes, 1,2-diols, and nitroalkanes to carboxylic acids, while secondary alcohols and secondary halides are oxidized to ketones, brómate being the cooxidant. These oxidations are compared with those effected catalytically by Irani-[Ru(0H)203]1 2" in aqueous base at pH 14 with persulfate as cooxidant. A new preparation for organic-soluble salts of [Ru04]" avoiding the use of Ru04 is described.Oxo complexes of ruthenium are effective catalysts for the selective oxidation of various organic substrates.2 Thus the ruthenate ion Irani-[Ru(0H)203]2", which is stable above pH 12 in aqueous base,3 4"5 with persulfate as cooxidant will oxidize primary alcohols to carboxylic acids and secondary alcohols to ketones;6•7 the perruthenate ion [Ru04]", which is stable from pH 8 to 12 in aqueous base,3"5 will also effect such oxidations stoichiometrically in solution.6 The organic-soluble "TPAP" ((n-Pr4N)[Ru04]) with /V-methylmorpholine /V-oxide is an efficient selective catalyst for converting primary alcohols to aldehydes and secondary alcohols to ketones.8Here we report a simple means of generating [Ru04]" in aqueous base and using this catalytically with Br03" as cooxidant. Comparative studies on irani-[RuVI(0H)203]2" with persulfate as cooxidant are also reported, notwithstanding the necessary pH differences of the solutions used, since differences in reactivity and oxidative selectivity might be expected between ruthenium-

The adsorption capacities of mesoporous silica modified with N‐(3‐(trimethoxysilyl)propyl)ethylenediamine (MCM‐41‐NH2) and its 4‐hydroxysalicylidene Schiff‐base, MCM‐41‐N‐Hdhba, as sorbents for removal and recovery of copper(II) ions from aqueous media have been investigated. The sorption uptake is highly dependent on the pH, contact time, temperature, diverse ions, mass of sorbent as well as initial Cu(II) ions concentration. At pH 6, the two sorbents, MCM‐41‐NH2 and MCM‐41‐N‐Hdhba, show 96.4% and 99.9% Cu(II) ions removal, respectively. Langmuir isotherm gave the best fit of the experimental data with maximum adsorption capacities 138.8 and 222.2 mg g−1 for MCM‐41‐NH2 and MCM‐41‐N‐Hdhba, respectively. The uptake kinetics were modeled using a pseudo‐second‐order rate equation and the thermodynamic parameters (ΔH°, ΔG° and ΔS°) verified favorable, spontaneous, and exothermic for MCM‐41‐NH2 and endothermic for MCM‐41‐N‐Hdhba adsorption processes. Successive adsorption–desorption studies indicated that MCM‐41‐NH2 and MCM‐41‐N‐Hdhba maintain their adsorption and desorption efficiencies constant over five cycles. Of particular importance is the fact that MCM‐41‐NH2 and MCM‐41‐N‐Hdhba were able to remove 95% of Cu(II) ions from polluted river and tap water. The structures and physicochemical properties of the sorbents before and after adsorption of Cu(II) ions were characterized by using spectroscopic (FTIR and XRD), morphological (TEM‐EDX), thermal, elemental analysis, and magnetic susceptibility measurements. © 2017 American Institute of Chemical Engineers Environ Prog, 37: 746–760, 2018

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New bio‐composite, semi‐interpenetrating biopolymers (obtained from hydrolyzed carboxymethyl cellulose grafted polyacrylonitrile [h‐CMC‐g‐PAN] and sodium alginate [Na‐Alg] using CaCl2 as a cross linker; semi‐interpenetrating biopolymers [s‐IPNs]) have been prepared and fully characterized using spectroscopic (FTIR, scanning electron microscopy, EDS), elemental analysis, and thermal analysis measurements measurements. The morphology and structure of these s‐IPNs are different from those obtained with solely h‐CMC‐g‐PAN and Na‐Alg indicating successive functionalization. The availability of the functional‐rich bio‐composites has afforded an excellent opportunity to test them as sorbents for the uptake of toxic Cd(II) ions from aqueous media. Subsequently, the uptake of Cd(II) ions was shown to be dependent on the pH, shaking time, temperature, amount of sorbent, and the initial concentration of the Cd(II) ions. The maximum Cd(II) ion uptake was 99.5% at pH 6, using 50 mg of sorbent with 120 min shaking time at 25°C. The adsorption isotherm fitted well with Langmuir model, with calculated maximum adsorption capacity 49.75 mg g−1. The kinetic studies were modeled using a pseudo second‐order reaction. The thermodynamic parameters (ΔHo, ΔGo, and ΔSo) of the uptake of Cd(II) ions onto s‐IPNs were found to be −13,176.07 Jmol−1, −4,572.7 Jmol−1, and 28.87 J K−1 mol−1, respectively, verifying spontaneous exothermic process. Successive desorption and reusability of s‐IPNs for the uptake of Cd(II) indicated, its high efficiency over three cycles.