NOPR Collection:

Study of xanthate group distribution during ripening of viscose

1999-05-01T00:00:00Z

Title: Study of xanthate group distribution during ripening of viscose Authors: Koutu, B B; Bhagwat, V W Abstract: The dexanthation of sodium cellulose xanthate has been studied for a viscose prepared from sulphite and kraft pulps. The ripening of viscose was carried out in the presence of an ion-exchange resin which eliminates the rexanthation of cellulose molecule. The decomposition rate of cellulose xanthate at carbon position 2, 3 and 6 were determined. The gamma number at C_2,3 decreases continuously during the ripening of viscose, whereas gamma number at C₆ increases initially and passes through a maximum. The viscose prepared from a sulphite pulp showed higher dexanthation rate than that of kraft pulp. Page(s): 172-175

Photocatalytic degradation of leather dye, Acid green 16 using ZnO in the slurry and thin film forms

1999-05-01T00:00:00Z

Title: Photocatalytic degradation of leather dye, Acid green 16 using ZnO in the slurry and thin film forms Authors: Sakthivel, S; Neppolian, B; Palanichamy, M; Arabindoo, Banumathi; Murugesan, V Abstract: The photocatalytic degradation of leather dye, Acid green 16 was studied in aqueous solution in the presence of ZnO catalyst by solar oxidation process. The effects of various parameters like concentration of dye, amount of catalyst, irradiation time and pH on the efficiency of decolourisation and degradation were studied. The degradation of Acid green 16 and organic intermediates was found to be more effective in alkaline pH range. The decolourisation and degradation were followed by UV Visible spectrophotometric and COD methods respectively. It is suggested that photocatalytic degradation will be a useful technique for the removal of dye in wastewater from leather industries. Page(s): 161-165

Hydrodynamics of single-stage turbulent bed contactor with downcomer

1999-05-01T00:00:00Z

Title: Hydrodynamics of single-stage turbulent bed contactor with downcomer Authors: Soundarajan, K; Krishnaiah, K Abstract: The use of downcomer (DC) in a turbulent bed contactor (TBC) is novel and instrumental in enhancing its gas-treating capacity and extending its range of operation when compared to the conventional TBC operation (without DC). However, the hydrodynamic behaviour for the novel operation of a TBC with DC is very much similar to that of the conventional TBC operation. Experimental data are collected on liquid and gas holdups, bed expansion and pressure drop in TBC with DC over a wide range of variables and correlations are developed for the above hydrodynamic aspects for single-stage operation employing light and dense particles. Page(s): 152-160

Activated carbon from krishnachura fruit (Delonix regia) and castor seed (Ricinus communis L.)

1999-05-01T00:00:00Z

Title: Activated carbon from krishnachura fruit (Delonix regia) and castor seed (Ricinus communis L.) Authors: Howlader, Mohammad Masbahuddin; Hossain, Quazi Sohel; Chowdhury, A M Sarwaruddin; Mustafa, A I; Mottalib, M A Abstract: Activated carbons were prepared from the husk of krishnachura (Delonix regia) fruit and the hull of castor (Ricinus communis L. ) seed using zinc chloride and steam-N₂ as activating agent. The activating agent steam-N₂ was used only for krishnachura whi le ZnCl₂ was used both for activating krishnachura and castor samples. It was found that the adsorptive capacity of carbons produced by using ZnCl₂ and steam-N₂ as activating agent is comparable with that of commercially available samples. The adsorptive capacity was measured by permanganate method and the carbons produced were employed for the decolorization of molasses solution. Page(s): 146-151