Treatment of wastewater containing Pb and Fe using ion‐exchange techniques

Treatment of wastewater containing lead and iron was examined using two different ion‐exchange resins namely Duolite ES 467 (containing amino‐phosphonic functional groups) and a chelating ion‐exchange resin (containing hydroxamic acid functional groups). Initially different sorption parameters such as contact time, pH, concentrations of sorbent, sorbate and chloride ion were studied. The sorption kinetics was observed to be fast and equilibrium could be reached within 30 min. Lead sorption efficiency increased with increase in pH whereas the opposite trend was observed with iron. The presence of chloride ions greatly reduced the Pb sorption efficiency in the case of Duolite ES 467. Column studies were carried out to recover Pb and Fe individually using Duolite ES 467 resin. The maximum uptake of Pb at pH 2 and 3 was observed to be 11.63 and 33.96 g dm^?3 of resin respectively. Similarly, for Fe at pH 2 and 3 the uptake was observed to be 10.07 and 6.96 g dm^?3 of resin respectively. In the presence of chloride ions, column studies were carried out using Duolite ES 467 for iron and chelating ion‐exchange resin containing hydroxamic acid functional groups for lead sorption. Hydroxamic acid resin's loading capacity remains constant for at least up to 20 cycles. Copyright © 2005 Society of Chemical Industry     

Computer-aided veterinary learning at the University of Cambridge

An approach of computer-assisted learning in veterinary education at the University of Cambridge, involving the development of four types of learning module, is outlined. A tutorial on regional perineural anaesthesia in the horse, based on the familiar tape-slide format but with significant improvements, is described. A question and answer self-assessment package and a computer-based 'digital lecture' are also discussed, together with a case simulation involving the investigation of a polydipsic dog. All the tutorials were developed using standard software packages and image digitising processes. The philosophy behind the development of these computer-assisted learning packages is discussed.     

Stimulation of gluconeogenesis with 1,3-butanediol in the perfused rat liver

An intensified synthesis of glucose is observed in gluconeogenesis from endogenous precursor only for the first 30 min of perfusion. Pyruvate introduction into the medium raises phosphoenolpyruvate carboxykinase and fructose-1,6-diphosphatase activities in the liver and determines maintenance of the glucose formation high rate for 90 min of perfusion. 1,3-butanediol is found to have a stimulating effect on gluconeogenesis from pyruvate. Introduction of 1,3 bytanediol into perfusate decreases the redox state of free NAD-pairs, increases the content of phosphoenolpyruvate, malate. ATP and the phosphoenolpyruvate carboxykinase and fructose-1.6-diphosphatase activity in the perfused liver.     

Induction of avidin in the chick oviduct by tissue damage. Effect of promethazine chloride, CaCl2 and hydrocortisone on local induction

The local effect of the mechanical induction of avidin by ligature was studied in diethylstilbestrol-primed chicks. The highest induction of avidin was always found in the immediate vicinity of the silk ligature of the oviduct. The locality of the induction was highly dependent on the position of the ligature. The nonligated parts of the ligated oviduct also showed a slight avidin induction. These results indicate a strictly local effect of avidin induction by ligature. An antihistamine, promethazine chloride, has a potentiating effect on the avidin induction by ligature when administered after the ligature. On the other hand, membrane stabilization by hydrocortisone or CaCl2 did not influence the ligature-induced avidin synthesis. On the basis of these results it is concluded that the avidin induction is not mediated by histamine activation or membrane damage.