Asit K. Sen

Adsorption of mercury(II) by coal fly ash

Coal fly ash, an industrial solid waste, was found to have a good adsorption capacity for mercury(II). Adsorption of mercury(II) on coal fly ash conforms to Freundlichs adsorption model. Several parameters such as time of equilibration, effect of pH, effect of initial concentration of solute, effect of fly ash dose etc. were studied. The maximum adsorption was observed after shaking for 3 h. Solution pH was the most important parameter affecting the adsorption. The optimum pH range was 3.5–4.5. There was total adsorption of mercury below 10 mg l−1. The performance of coal fly ash as an adsorbent was found to be significant when compared with activated powdered charcoal.

Synthetic Inorganic Ion-Exchangers

Abstract A review of the development of the synthetic inorganic ion exchangers during the 1970–1976 period has been made. Synthesis, properties, and analytical applications of the hydrated oxides, acidic salts of multivalent metals, heteropolyacid salts, and synthetic zeolite-type materials that are used as ion-exchangers have been included in the survey. Only the more important contributions during the 1970–1976 period are included

Studies of toxic effects of Hg(II) on Pistia stratiotes

The uptake of Hg(II) and toxicity effect of the metal on some biochemical parameters in Pistia stratiotes L. were studied. The uptake of Hg(II) by the plants gradually increased with increase in concentration of Hg(II) in the culture medium. Maximum accumulation of Hg(II) was noted within 1 day. Maximum removal (about 90%) of Hg(II) was recorded below 20 ppm Hg(II). Accumulation of Hg(II) in roots was about four times higher than that in shoots. At 20 ppm, Hg(II) promoted senescence of Pistia plants by decreasing chlorophyll, protein, RNA, dry weight and activities of catalase and protease as well as increasing free amino acid content, peroxidase activity and the ratio of acid to alkaline pyrophosphatase activity over control values. At Hg concentrations below 20 ppm, these constituents were least affected.

Salvinia natans — as the scavenger of Hg(II)

The plant, Salvinia natans L., was found effective in the removal of Hg(H) from wastewater. Maximum accumulation was noted within a day and maximum removal (about 90%) was recorded below 5 ppm of Hg(II). Accumulation of the metal occurred mainly in the roots. The senescence of the plant started at and above 5 ppm of Hg(H). The biochemical constituents like chlorophyll, Hill-activity, Protein, RNA, dry weight, and activities of catalase and protease decreased while free amino acid content, peroxidase activity and the ratio of acid to alkaline pyrophosphatase activity increased over control values at and above 5 ppm of Hg(H).

Removal and uptake of copper (II) by Salvinia natans from waste water

The plant, Salvinia natans L., was found to be very useful in the removal of Cu (II) from waste water. Maximum accumulation was noted within one day and maximum removal (about 90%) was recorded below 50 μg mL−1 of Cu (II). Copper was successfully removed from the waste water of Hindusthan Copper Limited (HCL), ICC, Ghatsila, Bihar, India.

Pollution profile of damodar river sediment in Raniganj-Durgapur industrial belt, West Bengal, India

Abstract This paper reports on the pollution profile of Damodar river sediment as obtained from analysis of the river sediment at suitable selected sites in the Raniganj-Durgapur industrial belt, West Bengal, India. The parameters measured include (a) silica, mixed oxide, calcium, magnesium, total water-soluble exchangeable cation and anion, chemical oxygen demand, and (b) some toxic and other elements, such as sodium, potassium, arsenic, cadmium, chromium, mercury, manganese, lead, zinc, cobalt, copper, iron nickel, phosphorus, sulphur, and vanadium. The parameters listed under (a) led to the characterization of the sediment, and those under (b) gave an index of metal pollution of the sediment. The elements were estimated by inductively coupled plasma emission spectrometry.

Some industrial effluents in Durgapur and their impact on the Damodar river

Abstract The industrial waste effluents from two industries of Durgapur have been traced along the course of Tamla Nalah at selected sites up to its confluence with the Damodar river and downstream. There are evidences of contamination of the river with toxic pollutants—ammonia, phenol, cyanide, sulphide, and trace mercury from Tamla Nalah. The upstream river water (Durgapur barrage), which is believed to be fairly pure, is actually not much better than the downstream river water. Monitoring data for about a year are presented and discussed.

Studies on Hydrated Stannic Oxide. Part VI. Thin-Layer Chromatography of Some Anions on Hydrated Stannic Oxide: Quantitative Separation of Cr(VI) from Some Ores and Alloys

Abstract The analytical applications of hydrated stannic oxide as an ion-exchanger have been investigated by thin-layer chromatographic (TLC) technique. Binder-free thin-layers of hydrated stannic oxide are useful for some binary separations. Quantitative separation of Cr(VI) and Mo(VI) from some binary mixtures have been achieved. The method is applied to separate microgram-quantities of Cr(VI) quantitatively from several ores and alloys in ammonia buffer (pH 10) system.

Studies on hydrated stannic oxide part III electrophoretic behaviour of metal ions on hydrated stannic oxide impregnated papers

SummaryElectrochromatographic studies of 27 metal ions on hydrated stannic oxide impregnated papers have been carried out. Various background electrolytes were used for these studies at fixed voltages and time intervals. On the basis of the differential mobilities of the ions, which depends on the ion-exchange properties of hydrated stannic oxide and the nature of complexes formed with the electrolytes, some useful binary, termary and quaternary separations have been achieved.