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Radiotracer investigation of a pulp and paper mill effl uent treatment plant

Sarkar M., Sangal V. K., Bhunia H., Bajpai P. K., Pant H. J., Sharma V. K., Kumar A., Naithani A. K.

Nukleonika

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2017

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Vol. 62, No. 4

289--294

EN

The pulp and paper industry is highly dependent on water for most of its processes, producing a significant amount of wastewater that should be treated to comply with environmental standards before its discharge into surface-water reservoirs. The wastewater generated primarily consists of substantial amounts of organic, inorganic, toxic and pathogenic compounds in addition to nutrients, which are treated in an effluent treatment plant that often combines primary, secondary, tertiary and advanced treatments. However, the treatment methods vary from industry to industry according to the process utilized. The effective performance of effluent treatment plants is crucial from both environmental and economic points of view. Radiotracer techniques can be effectively used to optimize performance and detect anomalies like dead zones, bypassing, channelling, etc. in wastewater treatment plants. Experiments on the distribution of residence time were performed on the aeration tank and secondary clarifier of a full-scale pulp and paper mill to study the flow behaviour as well as locate system anomalies and hence evaluate the performance of the treatment plants using the radiotracer I-131. The convolution method was applied to model the system with an imperfect impulse radiotracer input. The aeration tank was working efficiently in the absence of any dead zones or bypassing. Various hydrodynamic models available in the literature were applied on the aeration tank and secondary clarifier to obtain the hydraulic representation of the systems.

2

Propagation of shear waves in viscoelastic medium at irregular boundaries

Chattopadhyay A., Gupta S., Sharma V.K., Kumari P.

Acta Geophysica

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2010

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Vol. 58, no. 2

196-214

EN

The aim of the paper is to study the shear wave propagation in a viscoelastic layer over a semi-infinite viscoelastic half space due to irregularity in the viscoelastic layer. It is of great interest to study the propaga-tion of shear waves in the assumed medium having a non planar boundary due to its similarity to most of the real situations. The perturbation method is applied to find the displacement field. The effect of complex wave number on dissipation factor is analysed. Finally, as an application, the result obtained has been used to get the reflected field in viscoelastic layer when the shear wave is incident on an irregular boundary in the shape of parabolic irregularity as well as triangular notch. It is observed that the amplitude of this reflected wave decreases with increasing length of the notch, and increases with increasing depth of the irregularity.

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Photocatalytic Degradation of Crystal Violet by Use of Copper Oxide as Semiconductor

Shah A., Mittal N., Bhati I., Sharma V. K., Punjabi P. B.

Polish Journal of Chemistry

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2009

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Vol. 83, nr 11

2001-2007

EN

The photocatalytic degradation of crystal violet on copper oxidesemi conductor suspended in aqueous solution has been carried out. The progress of reaction has been studied spectrophotometrically by observing absorbance of reaction mixture at different time intervals. The effects of various parameters such as concentration of crystal violet, pH of reaction mixture amount of semiconductor and intensity of light on the rate of reaction have also been observed. The photocatalytic degradation of crystal violet follows pseudo first order kinetics and the rate constant has been determined. Atentative mecha nism for the reaction has also been proposed.

4

A simple and reliable preparative high-performance liquid chromatographic technique for isolation of a bioactive flavone diglycoside from and extract of Cuminum cyminum seeds

Satti N. K, Amina M, Dutt P, Sharma V. K., Sharma P., Khan I., Gupta B. D, Suri K. A, Sharma S. C., Johri R. K, Sharma S. N

Acta Chromatographica

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2009

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Vol. 21, no. 3

499--512

EN

In this paper we describe a sensitive and reproducible reversed-phase high-performance liquid chromatography (HPLC) method with photodiode-array detection for isolation and quantification of the bioactive hydrophilic constituent 7-(1- O -β-D -galacturonide-4′-(1- O -β-D -glucopyranosyl)-3′,4′,5,7-tetrahydroxyflavone, 1 , from the seeds of Cuminum cyminum . Compound 1 was separated isocratically on a C 18 preparative column, in high purity, after removal of solvents. The purity and identity of the compound were established by use of LC-mass spectrometry and by spectroscopic techniques ( 1 H and 13 C NMR). The purity of 1 was also confirmed by HPTLC.

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Synthesis, Spectroscopic and Structural Characterization of Trivalent Chromium, Manganese, Iron and Cobalt Complexes with Schiff Bases Derived from o-Vanillin

Tripathi N., Shalini, Sharma V. K.

Polish Journal of Chemistry

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2008

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Vol. 82, nr 3

523-535

EN

A series of new coordination complexes in volving chromium(III), manganese(III), iron(III) and cobalt(III) with Schiff bases derived from condensation of o-vanillin with diamines viz. 1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane or 1,2-dia - minobenzene and monoamines viz., p-methylaniline or p-methoxyaniline have been prepared and characterized by elmental analysis, spectral (IR, electronic, 1H NMR, FAB mass), magnetic susceptibility and electrical conductance measurements. The IR spectra suggest that o-VDAEH2, o-VDAPH2, o-VDABuH2 and o-VDABH2 are dibasic tetradentate ligands to wards all the four metals giving the complexes with composition [M(L)(H2O)X] (X = Cl, and OAc; LH2 = o-VDAEH2, o-VDAPH2, o-VDABuH2 and o-VDABH2) while o-VPMEAH and o-VPMAH are monobasic bidentate ligands towards the metals giving the complexes with composition [M(Lc)3] (LcH = o-VPMEAH and o-VPMAH). Various physicochemical data suggest a six coordinated octahedral geometry for all the complexes. Studies were conducted to investigate the inhibiting potential of the complexes synthesized and the ligands, against various fungal and bacterial strains.