Filtration 24-hour filter sample

Experimental Technique. The solid material (1-3 g) with known particle size and standard water (30-50 ml) containing the radionuclide of interest were shaken in glass bottles for 8-12 hours at constant temperature (25°C or 65 C). The phases were separated by centrifugation (50 min, 7000 rpm) and the distribution coefficient of the radionuclide was determined from measurements of the remaining activity of the water. Filtration of the samples through 0.2 pm membrane filter did not change the values. 

Ammonia chloride is destroyed in reactor 5 immediately after the ammonolysis is finished. For this purpose, a 15% solution of NaOH is prepared in reactor 6. The agitator is switched on and the contents of reactor 6 are agitated until sodium hydroxide dissolves completely. The alkali solution prepared in this way is sent through batch box 4 into reactor 5, and the contents are mixed for 5-10 minutes. The reactive mixture is held for about an hour and sampled to determine the ammonia chloride destruction shown by the absence of NH4C1 in the aqueous layer. The lower layer, the aqueous NaCl solution, is poured into settling box 9, the top layer, the hexame-thyldisiloxane solution of hexamethyldisilazane, is poured through a rundown box into collector 10 and then in druck filter 11, which operates below 0.07 MPa. The filtrate is collected into collector 12, from where it is sent into tank 13 for rectification. The tank is heated with vapour (up to 1 MPa). 

To a mixture of 50 ml of water, 3 ml of dilute ammonia solution and 6 ml of 10 per cent ammonium nitrate solution add 0 8 g of sample, warm on a water-bath for fiye minutes and add 25 ml of 01N silver nitrate. Warm for fifteen minutes, shaking frequently, cool, dilute to 200 ml with water and allow to stand for sixteen hours. Filter, wash the residue with water, neutralise the combined filtrate and w-ashings to litmus paper with concentrated nitric acid and add 3 ml of the acid in excess. Titrate the excess silyer nitrate with 0-1N ammonium thiocyanate using ferric alum as indicator. 1 ml 0 1N silyer nitrate = 0 02146 g C H OaN Cl. 

Dissolve the sample as for zirconium. Add 2 ml hydrogen peroxide (30 %) and 2 ml hydrogen fluoride (50 %). Add the solution onto the column and elute as for zirconium, collecting the fraction of the eluate between 80 and 280 ml. Precipitate yttrium fluoride at 70-80 C and stir for one hour. Filter off on a membrane filter. Dissolve 50 mg vanadium(III) oxide, 50 mg manganese(II) chloride dihydrate and 50 mg cobalt(II) chloride hexahydrate in the filtrate and add dropwise 6 ml 0.5 M barium nitrate while stirring. Filter off the precipitate, wash with ethanol and dry at 80°C. 

Add about 25 ml of boiled-out distilled water to about 0.5 g accurately weighed (by difference method) lime sample taken in an iodine titration flask and boil for 5-10 minutes. Cool, add a few clean dry glass beads and about 100 ml of a 10% sucrose solution. Stopper the flask and shake for 1 minute after every 5 minutes for a period of half an hour. Filter, by suction, through a Buchner funnel. Wash the residue 3-4 times with 10-ml portions of a 5% sucrose solution. Collect the filtrate and washings in a 250-ml measuring flask and make up to the mark with boiled-out distilled water. Take 50 ml of this solution in a titration flask. Add 2 drops of phenolphthalein indicator and titrate with N/10 HCI solution until the pink coiour disappears. Take concordant readings. 

A 30 ml sample of broth from penicillin fermentation is filtered in the laboratory on a 3 cm2 filter at a pressure drop of 5 psi. The filtration time is 4.5 minutes. Previous studies have shown that the filter cake of Penicillium chrysogenum is significantly compressible with S = 0.5. If 500 litres of fermentation broth from a pilot plant have to be filtered in 1 hour, what size of filter is required for a pressure drop of 10 psi and 5 psi Neglect the resistance of the filter medium. 

Leaves from the five plants were combined and divided into two equal weight samples. One sample was leached in distilled water for 2 hours at a ratio of 15 gms leaf fresh weight to 100 ml water. The leaf leachate was decanted and used directly in the bioassay. The second sample was ground in a blendor with distilled water at a ratio of 1 gm leaf fresh weight to 100 ml water. After standing for 15 min, the mixture was filtered and the filtrate was used directly in the bioassay. 

Following variant II, after treating by the modifier, the solid phase was separated by filtration and additionally washed off with 0.2 liters of water under vacuum of the water-jet pump. Further, as in variant I, one part of the product was dried at 105°C for two hours (product C), while the other was dried at 20°C until a sample mass became constant (product D). The products were investigated by the powder X-ray phase analysis (PXRD) using nickel-filtered CoKa radiation. 

The process can take one of two forms. In one, the sample and liquid are shaken (or otherwise agitated) together in the same container, the resultant mixture filtered, and the filtrate, which then contains the analyte, collected. In the other, fresh liquid is continuously cycled over a period of hours through the solid sample via a continuous evaporation-condensation process (that usually does not require an extra filtration step), and the liquid is collected. This latter method is known as a Soxhlet extraction. Soxhlet extraction will be discussed in more detail in Chapter 11. 

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