Membrane filtration of two sulphonamides in tertiary effluents and subsequent adsorption on activated carbon

The adsorption behaviour of two polar organic micropollutants (N-n-butylbenzenesulphonamide and sulphmethoxazole) onto powdered activated carbon (PAC) under competitive conditions prior to and after filtration with a tight ultrafiltration membrane was examined. The sulphonamides were spiked into microfiltered tertiary municipal effluent in microg L(-1) quantities. Ultrafiltration of these effluents resulted in better adsorbability for both the micropollutants and the background organic matter in the permeates compared to the feed waters. This behaviour seems to be caused by a reduced blocking of micropores by lower concentrations of high molecular weight compounds in membrane filtrates. A combined treatment of ultrafiltration prior to adsorption can therefore reduce the carbon demand for potentially harmful micropollutants in effluents.     

The Arbuzov Reaction in Fused-Ring Pyrimidines

2,4-Dichloroquinazolines type compounds (I–III) react with trimethyl phosphite preferentially at the 2-position. In II, the chlorine atoms both at C₂ and C₄ were replaced practically simultaneously by the —P(=O) (OMe)₂ group.     

Über die Reduktion von Wüstit mit Wasserstoff-Wasserdampf- und Kohlenmonoxyd-Kohlendioxyd-Gemischen

Herstellung der Wüstitproben und Versuchsdurchführung. Reduktionskinetik des Wüstits bei deckender Eisenschicht. Gaswechselversuche und Bestimmung der kritischen Kohlenstoffaktivität. Reduktionskinetik des Wüstits bei poröser Eisenschicht.     

Developmental differences in rats of suppressive effects of extinction as a function of extinction sessions.

Used 1 or 2 extinction sessions, 2 extinction procedures, and 2 ages of rats (23 and 95-120 days old) in a developmental analysis of the effects of extinction. Ss were 96 male Long-Evans hooded rats. The apparatus was a Y maze with 3 discriminably different arms. After 10 sessions of positive reinforcement, Ss received either 1 or 2 extinction sessions in which responding in 1 arm was no longer reinforced. Following extinction, responding in all 3 arms was again reinforced. Recovery data show that (a) the suppressive effects of extinction were greater for adults than infants and (b) the 2nd extinction session had a greater impact on the adults. Results support the hypothesis that younger rats have greater difficulty than older ones in inhibiting a response. (17 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Surface active betaines as protective agents against denaturation of an enzyme by alkyl sulfate detergents

A homologous series of higher alkyl sulfate surfactants inactivate β-fructofuranosidase (invertase) at levels coinciding with their critical micelle concentrations. It was possible to renature the enzyme by passing it through an anion exchange column. This inactivation was prevented by surface active betaines present at equimolar or higher concentrations than those of the anionics. Effective surfactant betaines include those with carboxylate, sulfonate, or phosphate radicals in their zwitterions. Betaines lacking surface active properties did not prevent denaturation indicating that the effects are due to comicellization. Studies with enzymes may point to appropriate anionic/zwitterionic surfactant ratios in solubilization procedures or detergent applications where biological properties must be preserved and anionic surfactants are required as components.