Column extraction and separation of some metal ions by diethylenetriamine polysiloxane immobilized ligand system

An extraction chromatographic solid porous polysiloxane functionalized by chelating diethylenetriamine ligand of the general formula P-(CH2)3-NH(CH2)2NH(CH2)2NH2, (Where P represents [Si-O]n siloxane network) has been evaluated for the separation of Co(II), Ni(II) and Cu(II) from aqueous solutions. The chromatographic parameters of the separation method have been optimized. The ligand system retained Co(II), Cu(II) and Zn(II) effectively when used as a metal ion extractant by controlling the pH value. The ligand system also shows a good separation of a mixture of metal ions Co(II), Ni(II) and Cu(II) when used as chromatographic stationary phase. The optimum separation pH values were 4.5, 4 for Co(II) and Ni(II) respectively, while a solution of 0.1 M HNO3 was used to elute Cu(II). Metal ions were also preconcentrated at pH 5.5. The chemisorbed metal ions were regenerated from the solid extractant using 0.5 M HCl

Preparation of Immobilized-Polysiloxane Salicylaldehyde Propylimine and Its Application

A porous solid polysiloxane ligand system of the general formula P-(CH2) 3-C7H6NO,(where P represents [Si-O] n siloxane network) has been prepared by modification of the immobilized 3-aminopropylpolysiloxane, P-(CH2) 3NH2 with an exsess of salicylaldehyde. The new modified polysiloxane system exhibits good potential for uptake of Co 2+ and Cu 2+ metal ions. This ligand system gives more stable complexes with the divalent metal ions than its parent 3-aminopropylpolysiloxane precursor. Characterization was achieved using elemental analysis and FTIR spectroscopy

Synthesis and Applications of a New Polysiloxane-Immobilized Macrocyclic Ligand System

Insoluble porous solid, macrocyclic 22-membered ring, 1-oxa-6,9,12,15,18-pentaaza-2,22-disilacyclododocosane polysiloxane ligand system has been prepared by the reaction of a macro-silane agent with tetraethylorthosilicate. The macro-silane agent was prepared by the reaction of imino-bis(N-2-aminoethylacetamide) ligand with 3-iodopropyltrimethoxysilane in 1:3 molar ratio. The new prepared polysiloxane system exhibits variable potentials for the extraction of metal ions (Fe3+, Co2+, Ni2+, Cu2+, Zn2+, Ag+, Cd2+, Hg2+, and Pb2+) from aqueous solutions. The ligand system shows high capacity to extract silver, lead, and mercury. Chemisorption of the metal ions by the ligand system at the optimum conditions was found in the order Ag + > Pb2+ > Hg2+ > Cu2+ > Ni2+ > Fe3+ > Co2+ > Cd2+ > Zn2+

Uptake of divalent metal ions (Cu2+, Zn2+, and Cd2+) by polysiloxane immobilized diamine ligand system

Porous solid siloxane polymers carrying diamine functional group of formula P–(CH2)3NH–CH2CH2NH2 (where P–represents a silica-like siloxane framework) have been prepared by replacement of the iodine in iodopolysiloxane with ethylenediamine. The iodofunctionalized polysiloxane was prepared by polycondensation of Si(OEt)4 and (MeO)3Si(CH2)I. The polysiloxane diamine ligand system exhibits high potential for preconcentration of divalent metal ions (Cu2+, Zn2+, and Cd2+). The tendency to chemisorb these divalent metal ions by the diamine ligand system at the optimum conditions was found in the order: Cu2+ > Zn2+ > Cd2+. Diamine ligand system suffers from leaching of ligand containing groups upon treatment with acidic solutions

PREPARATION OF IMMOBILIZED-POLYSILOXANE IMINO(2-AMINOETHYLACETAMIDE) AND ITS APPLICATION

porous solid polysiloxane ligand system of the general formula P-(CH2)3-NH-CH2COONHCH2CH2NH2, (where P represents [Si-O]n siloxane network) has been prepared by modification of the immobilized 3- aminopropylpolysiloxane, P-(CH2)3NH2, with ethyl chloroacetate followed by ethylenediamine. The new modified polysiloxane system exhibits good potential for uptake of metal ions (Co2+, Cu2+, Zn2+ and Pb2+). This ligand system gives more stable complexes with metal ions than its parent 3- aminopropylpolysiloxane precursor. Thermogravimetric analyses of this ligand system and its copper complex show high stability at relatively high temperature

Synthesis and structural characterization of a new macrocyclic polysiloxane-immobilized ligand system

A new porous solid macrocyclic 1,4,7,11,14-pentaazapentadecane-3,15-dione polysiloxane ligand system of the general formula P–(CH2)3–C11H22O2N5 (where P represents [Si–O] n siloxane network) has been prepared by the reaction of polysiloxane-immobilized iminobis(N-(2-aminoethyl)acetamide) with 1,3-dibromopropane. The FTIR and XPS results confirm the introduction of the macrocyclic functional ligand group into the polysiloxane network. The new macrocyclic polysiloxane ligand system exhibits high potential for the uptake of metal ions (Fe3+, Co2+, Ni2+, Cu2+ and Zn2+)

Biohydrogen Production by Modified Anaerobic Fluidized Bed Reactor (AFBR) Using Mixed Bacterial Cultures in Thermophilic Condition

Anaerobic fluidized bed reactor (AFBR) with slight modifications was investigated to increase biohydrogen production at high temperature. The modifications include a decrease in the total liquid volume to 3.3 L, in addition to an external work in the form of high temperatures, high dilution rates and high rates of de-gassed effluent recycling. These modifications were applied to overcome the thermodynamic constrains preventing the simultaneous achievement of high hydrogen yield (HY) and hydrogen productivity (HP) in an (AFBR). Bacterial granulation successfully induced under a high temperature of 65oC. The bacterial granules consisted of a multispecies bacterial consortium comprised of thermophilic clostridial and enterobacter species. Hydrogen production rate (HPR) of 7.57 L H2/L/h and hydrogen yield of 5.82 mol H2/ mol glucose were achieved at a hydraulic retention time (HRT) of 1 h and effluent recycle rate of 3.6 L/ min, with V/F er equal to 0.9

Композитное дизельное топливо: термическое поведение лимонных и апельсиновых корок в дизельном композите

This study aimed to investigate the thermal combustion behavior of lemon peel powder, LPP and orange peel powder, OPP composite fuel diesel. The pyrolysis experiments of the diesel/citrus composite fuel were conducted in combustion chamber. The results showed that the citrus/diesel composite fuel sustains its combustion properties at 30 % of the added citrus peels powder,. The results showed that calorific values of diesel containing 30 % LPP or 15 % LPP + 15 % OPP were very close to that of the pure diesel. The maximum calorific values were obtained at α = 0.85, 0.80 and 0.90 for 30 % OPP, 30 % LPP and 15 % OPP + 15 % LPP composite fuels respectivelyЭто исследование было направлено на изучение характеристик теплового сгорания порошка лимонной кожуры, порошка LPP и апельсиновой корки, а также дизельного топлива в композиционном топливе OPP. Эксперименты по пиролизу дизельного/цитрусового композиционного топлива проводились в камере сгорания. Результаты показали, что композит цитрусовые/дизельное топливо сохраняет свойства горения при добавлении 30 % порошка кожуры цитрусовых. Кроме того, теплотворная способность дизельного топлива, содержащего 30 % LPP или 15 % LPP + 15 % OPP, была очень близка к теплоте сгорания чистого дизельного топлива. Максимальные теплотворные способности были получены при α = 0,85, 0,80 и 0,90 для смесевых топлив 30 % OPP, 30 % LPP и 15 % OPP + 15 % LPP соответственн

Extraction and preconcentration capacity of bifunctionalized diamine-thiol polysiloxane immobilized ligand system towards some divalent cations

Porous solid bi-organofunctionalized diamine-thiol polysiloxane immobilized ligand system of the general formula P-(CH2)3- X, (where P represents [Si-O]n siloxane network and X represents a mixture of diamine; -NH(CH)2NH2 and thiol; -SH functional groups) has been prepared by hydrolytic polycondensation of TEOS with a mixture of 3-mercaptopropyltrimethoxysilane and 3- (2-aminoethylimino)propyltrimethoxysilane agents. The ligand system was evaluated for extraction and preconcentartion of a series of divalent metal ions from aqueous solutions including: Co2+, Ni2+, Cu2+, Zn2+, Cd2+ and Pb2+. Both batch and dynamic methods were used to examine maximum sorption capacity. The maximum binding capacity followed the sequence; Cu2+ > Pb2+ > Cd2+ > Ni2+ > Zn2+ > Co2+ at pH 5.5. Measurement of variation of sorption of metal ions with temperature yielded negative values of ΔG° and

A review on polysiloxane-immobilized ligand systems: synthesis, characterization and applications

The immobilized silica gel ligand systems made by modification of silica surfaces have been briefly summarized. Short background was described based on the synthesis methods and their applications. In this review more attention towards the functionalized polysiloxane xerogels and their postmodification has been given. Polysiloxane-immobilized ligand systems bearing organofunctionalized ligand groups of general formula P–(CH2)3–X (where P represents a three-dimensional silica like network-matrix and X is an organofunctional group) were prepared through the sol–gel process by hydrolytic polycondensation of Si(OR)4 and the appropriate silane coupling agent (RO)3Si(CH2)3X (where R is an alkyl group, e.g CH3 or C2H5). There are many other immobilized ligand systems, which were prepared by treatment of post-polysiloxane precursors with an appropriate organofunctional ligand. Variety of