Water wash

Waste from cooling systems. Cooling water systems also give rise to wastewater generation. Most cooling water systems recirculate water rather than using once through arrangements. Water is lost from recirculating systems in the cooling tower mainly through evaporation but also, to a much smaller extent, through drift (wind carrying away water droplets). This loss is made up by raw water which contains solids. The evaporative losses from the cooling tower cause these solids to build up. The buildup of solids is prevented by a purge of water from the system, i.e., cooling tower blowdown. Cooling tower blowdown is the source of the largest volume of wastewater on many sites.  [c.294]

The solubility of hydrocarbon liquids from the same chemical family diminishes as the molecular weight increases. This effect is particularly sensitive thus in the paraffin series, the solubility expressed in mole fraction is divided by a factor of about five when the number of carbon atoms is increased by one. The result is that heavy paraffin solubilities are extremely small. The polynuclear aromatics have high solubilities in water which makes it difficult to eliminate them by steam stripping.  [c.168]

The term c//agenes/s describes all chemical and physical processes affecting a sediment after deposition. Processes related to sub-aerial weathering and those which happen under very high pressures and temperatures are excluded from this category. The latter are grouped under the term metamorphosis . Diagenesis will alter the geometry and chemistry of the pore space as well as the composition of the rock. Many of these changes are controlled by the oxidising potential (eH) and the acidity/alkalinity (pH) of the pore-water which circulates through the formation. Consequently, the migration of hydrocarbons and the displacement of water out of the pore system may end or at least retard diagenetic processes.  [c.86]

Production and injection rates of the fluids will be monitored on a daily basis. For example, in an oil field we need to assess not only the oil production from the field (which represents the gross revenue of the field), but also the GOR and water cut. In the case of a water injection scheme, a well producing at high water cut would be considered for a reduction in its production rate or a change of perforation interval (see well performance below) to minimise the production of water, which not only causes more pressure depletion of the reservoir but also gives rise to water disposal costs. The total production and injection volumes are important to the reservoir engineer to determine whether the depletion policy is being carried out to plan. Combined with the pressure data gathered, this information is used in material balance calculations to determine the contribution of the various drive mechanisms (e.g. oil expansion, gas expansion, aquifer influx).  [c.333]

The total silver content discharged may either be expressed as a concentration in tlte water used to rinse the film (mg/1, ppm), or as an amount of silver in the rinsing water per m of film processed (silver freight, mg/m ). Legislation in tenns of amount of silver per unit surface area of film processed is preferable, since it better reflects the actual total amount of silver being discharged and the performance of the photographic processing system. Concentration-based legislation does not necessarily reflect ecological performance, since use of less rinsing water (which is ecologically sound), will, for a given amount of silver being discharged, result in higher and therefore apparently less favorable silver concentrations in the rinsing water (Dilution is no solution for pollution). In what follows, the amount of silver is expressed as  [c.604]

Silicon and germanium readily react with even very dilute solutions of caustic alkali. Silicon is so sensitive to attack that it will dissolve when boiled with water which has been in contact with glass  [c.171]

The other halides dissociate at lower temperatures and, if put into water, all are decomposed, the proton transferring to water which is a better electron pair donor  [c.226]

Pure water for use in the laboratory can be obtained from tap water (hard or soft) by distillation if water of great purity is required, distillation must be carried out in special apparatus, usually made of quartz, not glass or metal precautions must be taken to avoid any spray getting into the distillate. Water which is sufficiently pure for most laboratory purposes can, however, be obtained by passing tap water through cation-exchangers and anion-exchangers as described above, when the water is deionised .  [c.275]

The action of concentrated sulphuric acid liberates hydrogen fluoride, which attacks glass, forming silicon tetrafluoride the latter is hydrolysed to silicic acid by water, which therefore becomes turbid,  [c.348]

Never use unprotected bark corks for an apparatus ih which a carefully dried liquid is to be distilled, etc., as these corks always contain appreciable quantities of water, which is exuded when the cork comes into contact with a hot liquid. Rubber stoppers should therefore be used in these circumstances.  [c.40]

Bromine. Slip the glass cover of a jar momentarily aside, add 2-3 ml. of bromine water, replace the cover and shake the contents of the jar vigorously. Note that the bromine is absorbed only very slowly, in marked contrast to the rapid absorption by ethylene. This slow reaction with bromine water is also in marked contrast to the action of chlorine water, which unites with acetylene with explosive violence. (Therefore do not attempt this test with chlorine or chlorine water.)  [c.87]

When the solution has been boiling for hours, remove A, cool the contents, and then pour the ethanolic solution of the ester into a separating-funnel containing about 200 ml. of water, finally rinsing out the flask with a few ml. of water which are also doured into the funnel. Since the pensity of ethyl benzoate is only  [c.105]

Run 90 ml. of dry ether into the flask and start the stirring. Weigh out 2 5 g. of lithium aluminium hydride, and then divide 0 5 g. of this amount into very small portions add these portions in turn cautiously to the stirred ether to remove any traces of water which in spite of the above precautions may be present in the reaction flask. Then add the remaining 2 0 g. of the hydride more rapidly. When the addition is complete, continue stirring the mixture for 15 minutes the hydride should dissolve in the ether except for a slight grey suspension. (If at the end of this period the larger particles of the hydride have not disintegrated, boil the stirred mixture under reflux on a water-bath for a further 15 minutes.)  [c.156]

Add 23 g. of powdered (or flake ) sodium hydroxide to a solution of 15 ml. (18 g.) of nitrobenzene in 120 ml. of methanol contained in a 250 ml. short-necked bolt-head flask. Fix a reflux water-condenser to the flask and boil the solution on a water-bath for 3 hours, shaking the product vigorously at intervals to ensure thorough mixing. Then fit a bent delivery-tube to the flask, and reverse the condenser for distillation, as in Fig. 59, p. 100, or Fig. 23(D), p. 45). Place the flask in the boiling water-bath (since methanol will not readily distil when heated on a water-bath) and distil off as much methanol as possible. Then pour the residual product with stirring into about 250 ml. of cold water wash out the flask with water, and then acidify the mixture with hydrochloric acid. The crude azoxybenzene separates as a heavy oil, which when thoroughly stirred soon solidifies, particularly if the mixture is cooled in ice-water.  [c.212]

Place 8 g. of the pure powdered azoxybenzene and 25 g. of iron filings (both reagents being quite dry) in a 75 ml. distilling-flask F and mix thoroughly by shaking. Cork the flask and fit to the side-arm a boiling-tube B to act as receiver (Fig. 66) cut or file a groove G in the boiling-tube cork to allow escape of air. Now heat the mixture directly with the Bunsen flame, waving the latter around the base of the flask to ensure uniform heating heat gently at first and later more strongly. The red liquid azobenzene distils over smoothly and eventually solidifies in the receiver. When no more distillate passes over, detach the boiling-tube, and then, in order to eliminate basic impurities which are formed as byproducts in the reaction, add 20-30 ml. of dilute hydrochloric acid (i vol. of concentrated acid 2 vols. of water) which have been heated to about 70° cork the tube securely and shake the mixture, so that impurities in the molten drops of azobenzene are thoroughly extracted by the acid, which usually becomes dark in colour. Now cool in water until the globules of azobenzene solidify, and then filter at the pump. Break up the azobenzene with a spatula on the filter, wash thoroughly with water, and drain. Recrystallise from a minimum of boiling methylated spirit, filtering the hot solution through a small fluted filter-paper. The azobenzene separates as reddish-orange crystals, m.p. 67-68°. Yield, 4 g. A second recrystallisation from methylated spirit may be necessary to obtain a satisfactory melting-point.  [c.213]

The formation of the Grignard reagent is inhibited by traces of water, which also decompose the reagent when it is formed. Therefore the apparatus used must be thoroughly dry, and the ether anhydrous (p. 82). Specially prepared magnesium turnings should preferably be used if magnesium ribbon is employed, it should first be drawn through two layers of fine emery paper to remove the superficial film of oxide, etc.  [c.281]

When the reaction is complete, heat the stirred mixture carefully under reflux over a Bunsen burner and asbestos gauze for I hour if the mixture becomes too thick for efficient stirring, add up to 15 mL of acetic acid. Now decant the hot mixture into 500 ml. of vigorously-stirred ice-cold water wash the residual zinc thoroughly with glacial acetic acid (2 portions each of I -2 ml.), decanting the acid also into the stirred water.  [c.294]

To prepare COj-free water, almost fill a large aspirator or bottle with distilled water, and then securely close the neck with a rubber stopper cairying two delivery-tubes, one passing just through the stopper into the aspirator and the other passing right down to the bottom, connect the former delivery-tube to a water-pump. Join three wash-bottles in series, the first two con taining 50% aqueous KOH solution and the third containing distilled water to a depth of at least 10 cm. connect this wash-bottle to the long delivery-tube of the aspirator. When the water-pump is in operation, air is drawn through the two KOH wash-bottles (where CO, and all other acid gases are absorbed), then through the water wash-bottle (which absorbs any alkali spray) and finally through the distilled water in the aspirator, from which all CO, is slowly extracted. Using a moderately vigorous stre of air, about la litres of CO,-free water can be prepared in 3 hours with this apparatus.  [c.448]

Polyatomic molecules vibrate in a very complicated way, but, expressed in temis of their normal coordinates, atoms or groups of atoms vibrate sinusoidally in phase, with the same frequency. Each mode of motion functions as an independent hamionic oscillator and, provided certain selection rules are satisfied, contributes a band to the vibrational spectr um. There will be at least as many bands as there are degrees of freedom, but the frequencies of the normal coordinates will dominate the vibrational spectrum for simple molecules. An example is water, which has a pair of infrared absorption maxima centered at about 3780 cm and a single peak at about 1580 cm (nist webbook).  [c.288]

The set-up of Fig. 11, 41, 3 ensures the complete condensation of the steam when a rapid flow of steam is necessary for satisfactory results, and is useful in the distillation of large volumes of liquids of low vapour pressure, such as nitrobenzene. Thus the flask A containing the mixture may be of 3-litre capacity and B may be a 1-litre flask the latter is cooled by a stream of water, which is collected in a funnel and conducted to the sink. The receiver C must be of proportionate size all stoppers  [c.147]

The success of this preparation depends upon the use of the apparatus (1) depicted in Fig.///, 57, 1, which permits of the automatic separation of the water produced in the reaction this will be termed a water-separator tube. Convenient dimensions for students preparations are indicated in the diagram. Determine the volume v of the tube up to the neck, i.e., between A and B, by adding water from a burette. The quantity of water which should be eliminated, assuming a quantitative conversion of the alcohol into the ether, may be computed from the equation  [c.311]

C22H23N3O9. An organic reagent used for the detection and estimation of aluminium. It is a brownish-red powder, soluble in water which gives a red lake with aluminium which can be estimated colorimetrically. It can also be used for detecting scandium and indium.  [c.26]

The achievable silver concentrations depend mainly on the regeneration rate of the fixer. The steady-state silver concentration in the first fixing step is inversely proportional to the regeneration rate. The dilution factor in the second step is equal to the ratio of the carry-over (e.g. 40 ml/m ) and the regeneration. An doubling of the regeneration rate will result in A of the original silver level in the rinsing section. A standard regeneration rate of 1200 ml/m will result in a decrease of the silver level by a factor of 20, compared to the standard situation. Contrarily to electrolysis, the daily production does not affect the silver content in the rinsing water, which makes cascade fixing a preferable technology in case of high daily productions (>15 m per processor per day).  [c.608]

An important problem involving reactions of solid surfaces is the deterioration of wall paintings and stone monuments. A significant source of damage to frescoes is the presence of water, which can degrade the binding media, alter pigments, and promote microbial growth and the collection of dirt and pollutants. While environmental factors such as relative humidity and surface temperature can be controlled by conservators, the presence of hygroscopic salts facilitate water absorption. Deliquescent salts, those that absorb water to produce a saturated solution at the surface of the painting, are especially problematic. Ferroni and co-workers have studied the cycles of deliquescence and recrystallization in calcium nitrate, Ca(N03)2 4H2O [176, 177]. Their understanding of the reactions at solid surfaces of paintings has helped define conditions to minimize their wetting by water vapor and subsequent deterioration. Stone sculptures and buildings decay through a process where the calcium carbonate reacts with sulfur oxides found in atmospheric pollutants to produce a more soluble salt. Gypsum (calcium sulfate dihydrate) produces black scabs on stone surfaces which not only ruin the appearance of the object but weaken the material and eventually flake off to expose a fresh surface to continue the cycle of decay (see Ref. [178]).  [c.284]

Regardless of how many single-particle wavefiinctions i are available, this number is overwhelmed by the number of n-particle wavefiinctions ( ) (Slater detenninants) that can be constructed from them. For example, if a two-electron system is treated within the Flartree-Fock approximation using 100 basis fiinctions, both of the electrons can be assigned to any of the % obtained m the calculation, resulting in 10,000 two-electron wavefimctions. For water, which has ten electrons, the number of electronic wavefiinctions with equal numbers of a and p spin electrons that can be constructed from 100 single-particle wavefimctions is roughly  [c.34]

The fabrication of an alumina spark-plug body is a good example of ceramic manufacturing. The manufacturing process begins witli an alumina powder (figure C2.11.2) comprised of individual alumina particles of tire desired size distribution. To enlrance densification, precursors of CaO, M O, and Si02 are typically mixed witli tire alumina powder to produce several weight per cent of a glass phase during sintering. This mixture is tlien transfonned into a slurry of ceramic particles dispersed in water, which is subsequently granulated witli an organic binder by spray drying. Spray drying produces larger clusters of particles called agglomerates or granules tliat have improved powder flow, packing, and fonnability (figure C2.11.3). These granules are tlien pressed and machined to produce a powder compact of tire desired size and shape tliat is held togetlier by tire organic additives. Finally, tliis powder compact is sintered to produce a dense ceramic spark-plug body (figure C2.11.4). The mechanical and electrical properties of tliis body are detennined by tire microstmeture of tire poly crystalline alumina ceramic produced on sintering (figure C2.11.5).  [c.2762]

The heats of formation of the gaseous atoms, 4, are not very different clearly, it is the change in the bond dissociation energy of HX, which falls steadily from HF to HI, which is mainly res ponsible for the changes in the heats of formation. 6. We shall see later that it is the very high H—F bond energy and thus the less easy dissoeiation of H—F into ions in water which makes HF in water a weak aeid in comparison to other hydrogen halides.  [c.73]

TIk experimentally determined dipole moment of a water molecule in the gas phase is 1.85 D. The dipole moment of an individual water molecule calculated with any of thv se simple models is significantly higher for example, the SPC dipole moment is 2.27 D and that for TIP4P is 2.18 D. These values are much closer to the effective dipole moment of liquid water, which is approximately 2.6 D. These models are thus all effective pairwise models. The simple water models are usually parametrised by calculating various pmperties using molecular dynamics or Monte Carlo simulations and then modifying the  [c.235]

The distiUing flask B, acting as a receiver, is connected by means of rubber pressure tubing to a filter flask E (which, inter alia, serves as a reservoir to equalise the pressure and the latter to a manometer and water pump. The glass tube connecting the suction flask E with the pump should extend to the bottom of the flask in order that any water which may flow back owing to unequal pressure in the water main may be sucked out as soon as the water pressure returns if the flow back of the water is appreciable, it may be checked by opening the stop-cock G until the original water pressure is restored. The manometer illustrated is easily constructed and is particularly suitable for elementary students. Two slots are provided on the meter scale (graduated in mm.) so as to enable accurate adjustment of the zero to the level of the mercury in the small reservoir the adjustment is best made when the manometer is connected to a pump and the mercury has risen to a height of about 750 mm.  [c.104]

Acetanilide from water. Weigh out 4 0 g. of commercial acetanilide into a 250 ml. beaker. Add 80 ml. of water and heat nearly to the boiling point. The acetanilide will appear to melt and form an oil in the solution (for theory, see Section 1,18). Add small portions of hot water, whilst stirring the mixture and boiling gently, until all the solid has dissolved (or almost completely dissolved). [If the solution is not colourless, allow to cool slightly, add about 0-5 g. of decolourising carbon, and continue the boiling for a few minutes in order to remove the coloured impurities.] Filter the boiling solution through a fluted filter paper (for preparation, see Section 11,29) supported in a short-necked funnel if the solution cannot be filtered in a single operation, keep the unfiltered portion hot by heating with a small flame over a wire gauze. Alternatively, the solution may be filtered through a hot water funnel (Fig. II, 1, 6, a). Collect the filtrate in a 250 ml. beaker. When all the solution has been filtered, cover the beaker containing the hot filtrate with a clock glass and cool rapidly with stirring. Allow to stand for about 30 minutes to complete the separation of the solid. Filter with suction through a small Buchner funnel (see Figs. II, 1, 7, a and c), wash the crystals twice with 5 ml. portions of cold water (to remove the adhering mother liquor), and press them in the funnel with the back of a large, flat glass stopper. Remove the funnel from the filter flask, invert it on two thicknesses of filter or absorbent paper resting upon a pad of newspaper, and allow the crystals to dry in the air. It is advisable in air drying to  [c.232]

Ethyl n-butyrate. Use a mixture of 88 g. (92 ml.) of n-butyric acid, 23 g. (29 ml.) of ethanol and 9 g. (5 ml.) of concentrated sulphuric acid. Reflux for 14 hours. Pour into excess of water, wash several times with water, followed by saturated sodium bicarbonate solution until all the acid is removed, and finally with water. Dry with anhydrous magnesium sulphate, and distU. The ethyl n-but3rrate passes over at 119 5-120-5°, Yield 40 g. An improved yield can be obtained by distilhng the reaction mixture through an efficient fractionating column until the temperature rises to 125°, and purifying the crude ester as detailed above under methyl acetate.  [c.383]

See pages that mention the term Water wash : [c.86]    [c.182]    [c.211]    [c.214]    [c.256]    [c.308]    [c.328]    [c.342]    [c.391]    [c.77]    [c.119]    [c.2779]    [c.2815]    [c.613]    [c.711]    [c.17]    [c.196]    [c.156]    [c.260]    [c.298]   
Fluid Catalytic Cracking Handbook (2000) -- [ c.29 , c.260 ]