NISCAIR Online Periodicals Repository Community: IJCT Vol.18 [2011]

Electrical conductivity and ion exchange studies of nano sized cerium (IV) tungsto iodate — A new cation exchanger

Sat, 29 Oct 2011 22:58:59 GMT

Title: Electrical conductivity and ion exchange studies of nano sized cerium (IV) tungsto iodate — A new cation exchanger

Authors: Indulal, C R; Vaidyan, A V; Kumar, G Sajeev; Raveendran, R

Abstract: Nano particles of cerium tungsto iodate, a tetravalent metal acid salt, have been prepared by chemical co-precipitation method. The particle size of the sample has been calculated from its X-ray diffraction pattern and the average grain size is found to be 25 nm. The size is further characterized by SEM, TEM and FTIR analyses. Its dielectric behaviour at various temperatures (50°-110°C) and frequencies is also investigated. The dielectric constant values increase with the decrease in frequency and the increase in temperature. Moreover, the sample in its protonated form is subjected to ion exchange capacity studies. The data reveals that the sample works as a good ion exchanger.

Page(s): 488-490

Oxidative decolourisation of methylene blue using heat-treated sea nodule residue

Sat, 29 Oct 2011 22:58:59 GMT

Title: Oxidative decolourisation of methylene blue using heat-treated sea nodule residue

Authors: Satapathy, P K; Acharya, B; Das, N N

Abstract: The characterisation of heat-treated sea nodule leached residues by various physicochemical methods (XRD, FT-IR and surface area measurement) and their catalytic activity towards decolourisation of methylene blue (MB) under varying experimental conditions have been studied. Oxidative decolourisation of aqueous MB in batches shows an increase in decolourisation with the increase of catalyst dose, while a decrease in activity is observed with the increase in initial pH of the solution and MB concentration. More than 85% of 10 mg/L MB is decolourised within 30 min with a catalyst dose of 0.6 g/L at pH ~ 3. The effect of different electrolytes on catalytic activity has also been studied.

Page(s): 483-487

Extraction study of microgram amounts of lanthanum (III) ions from salicylate medium using high molecular weight amine

Sat, 29 Oct 2011 22:58:59 GMT

Title: Extraction study of microgram amounts of lanthanum (III) ions from salicylate medium using high molecular weight amine

Authors: Mandhare, A M; Anuse, M A; Kolekar, S S

Abstract: This paper reports solvent extraction behaviour of lanthanum (III) from salicylate medium (0.0065–0.0085 M) in a xylene solution of 2-octylaminopyridine (2-OAP). The effect of important variables like equilibrium time, nature of diluents, concentration of salicylic acid, extractant and metal ion on the extraction is investigated. Based on partition data the stoichiometry of the extracting species is formulated as [2-OAPH⁺. La(sal)₂^-]. The reagents like sulphuric acid (0.5-0.6 N), acetic acid (0.8-1.0 M) and hydrochloric acid (0.1 M) have been found effective for the stripping of the metal ions. 2-OAP is stable even after prolonged acid contact, no emulsion formation takes place and the extraction efficiency remains unaffected even after 10 recycling steps. The procedure is robust as demonstrated by the high recovery (99.5%) of lanthanum (III) in the presence of several cations and anions which are commonly associated with it. The proposed method is satisfactorily applied to the separation of lanthanum (III) from binary, ternary mixtures and also from real samples. The selectivity of the extraction is enhanced by using suitable sequestering reagents.

Page(s): 475-482

Removal of hazardous triphenylmethane dye through adsorption over waste material-mango bark powder

Sat, 29 Oct 2011 22:58:59 GMT

Title: Removal of hazardous triphenylmethane dye through adsorption over waste material-mango bark powder

Authors: Srivastava, Ruchi; Rupainwar, D C

Abstract: This study deals with the use of low cost, easily available, high efficiency and ecofriendly adsorbent as an ideal alternative to the currently used expensive methods of removing dye from waste water. The potential of mango bark powder for the removal of malachite green (triphenylmethane dye) from simulated water has been investigated. Studies are conducted to delineate the effect of pH, temperature, initial dye concentration and adsorbent concentration. Equilibrium isotherms are determined to assess the maximum adsorption capacity of the adsorbent. The adsorption data have been correlated with Freundlich and Langmuir isotherms which are used to suggest a plausible mechanism of the ongoing adsorption processes. The maximum adsorption capacity obtained from Langmuir equation is found to be 4.22 × 10³ mol.g^-1on mango bark powder. The adsorption of dye is found to be a second–order rate equation. Thus, low cost mango bark powder can be an attractive option for dye removal from diluted industrial effluents.

Page(s): 469-474