Water draining

Naphthyl Acetate. CHgCOOCi H,. Dissolve 1 g. of pure 2-naphtnol in 5 ml. (r8 mols.) of 10% sodium hydroxide solution as before, add 10 g. of crushed ice, and i-i ml. (1-14 g., 1 5 mols.) of acetic anhydride. Shake the mixture vigorously for about 10-15 minutes the 2-naphthyl acetate separates as colourless crystals. Filter at the pump, wash with water, drain, and dry thoroughly. Yield of crude material, 1-4 g. (theoretical). Recrystallise from petroleum (b.p. 60-80 ), from which, on cooling and scratching, the 2-naphthyl acetate separates as colourless crystals, m.p, 71 yield, 10 g. 

Prepare a mixture of 30 ml, of aniline, 8 g. of o-chloro-benzoic acid, 8 g. of anhydrous potassium carbonate and 0 4 g. of copper oxide in a 500 ml. round-bottomed flask fitted with an air-condenser, and then boil the mixture under reflux for 1 5 hours the mixture tends to foam during the earlier part of the heating owing to the evolution of carbon dioxide, and hence the large flask is used. When the heating has been completed, fit the flask with a steam-distillation head, and stcam-distil the crude product until all the excess of aniline has been removed. The residual solution now contains the potassium. V-phenylanthrani-late add ca. 2 g. of animal charcoal to this solution, boil for about 5 minutes, and filter hot. Add dilute hydrochloric acid (1 1 by volume) to the filtrate until no further precipitation occurs, and then cool in ice-water with stirring. Filter otT the. V-phcnylanthranilic acid at the pump, wash with water, drain and dry. Yield, 9-9 5 g. I he acid may be recrystallised from aqueous ethanol, or methylated spirit, with addition of charcoal if necessary, and is obtained as colourless crystals, m.p. 185-186°. 

To obtain the benzoic acid, add an excess of concentrated hydrochloric acid carefully with stirring to the aqueous alkaline solution remaining from the original extraction. When no further precipitation of benzoic acid occurs, cool the solution (if perceptibly warm) in ice-water, and then filter at the pump. Wash the benzoic acid thoroughly with cold water, drain, and then recrystallise from a large volume of boiling water. Benzoic acid is obtained as colourless crystals, m.p, 121° yield, 19-20 g. 

To obtain the free acid, dissolve the potassium salt in 50 ml. of cold water, filter the solution if a small undissolved residue remains, and then boil the clear solution gently whilst dilute sulphuric acid is added until the separation of the acid is complete. Cool the solution and filter off the pale orange-coloured crystals of the benzilic acid wash the crystals on the filter with some hot distilled water, drain well, and then dry in a desiccator. Yield of crude acid, 4 g. Recrystallise from benzene (about 50 ml.) to which a small quantity of animal charcoal has been added, filtering the boiling solution through a preheated funnel fitted w ith a fluted filter-paper, as the benzilic acid readily crystallises as the solution cools alternatively, recrystallise from much hot water. The benzilic acid is obtained as colourless crystals, m.p. 150°. 

Meanwhile, filter the original cold reaction product at the pump, and wash the sulphonyl-methylaniline on the filter first with 10% sodium hydroxide solution (to ensure complete removal of the sulphonyl-aniline) and then with water drain thoroughly. Recrystallise from ethanol toluene-/)-sulphonyl-methylaniline, C H5N(CH3)S02C4H4CH3, is thus obtained as colourless crystals, m.p. 95° yield, 7-5 g. 

Dissolve 1 g. of anthracene in 10 ml. of glacial acetic acid and place in 50 ml. bolt head flask fitted with a reflux water-condenser. Dissolve 2 g. of chromium trioxide in 2 ml. of water and add 5 ml. of glacial acetic acid. Pour this solution down the condenser, shake the contents of the flask and boil gently for 10 minutes. Cool and pour the contents of the flask into about 20 ml. of cold water. Filter off the crude anthraquinone at the pump, wash with water, drain well and dry. Yield, 1 g. Purify by re crystallisation from glacial acetic acid or by sublimation using the semi-micro sublimation apparatus (Fig. 35, p. 62, or Fig. 50, p. 70). 

Fit securely to the lower end of the condenser (as a receiver) a Buchner flask, the side-tube carrying a piece of rubber tubing which falls well below the level of the bench. Steam-distil the ethereal mixture for about 30 minutes discard the distillate, which contains the ether, possibly a trace of unchanged ethyl benzoate, and also any biphenyl, CeHs CgHs, which has been formed. The residue in the flask contains the triphenyl carbinol, which solidifies when the liquid is cooled. Filter this residual product at the pump, wash the triphenyl-carbinol thoroughly with water, drain, and then dry by pressing between several layers of thick drying-paper. Yield of crude dry product, 8 g. The triphenyl-carbinol can be recrystallised from methylated spirit (yield, 6 g.), or, if quite dry, from benzene, and so obtained as colourless crystals, m.p. 162. ... 

Steam-distil the ethereal solution and discard the distillate. The residue in the flask is triphenyl-carbinol and solidifies on cooling. Filter at the pump, wash with water, drain and dry. Yield of crude product 0 6 g. Recrystallise when dry from benzene to obtain colourless crystals m.p. 162°. 

Example. Dissolve 0 3 g. of />-chlorobenzoic ncid in a small quantity of warm ethanol (about 10 ml.), and ctlrefully add 5 o aqueous sodium hydroxide drop- wise until the solution is just pink to phenolphthalein. Evaporate to dryness on a water-bath. Dissolve the sodium -chlorobenzoate in a minimum of water, add a solution of 0-5 g. of phenacyl bromide in ethanol (about 5 ml.), and boil the mixture under reflux for i hour, and then cool. The phenacyl ester usually ciy stallises on cooling if it does not, add water dropnise with stirring to the chilled solution until separation of the ester just begins. Filter the ester, wash on the filter with water, drain and recrystallise from ethanol m.p. 90 . The /)-bromophenacyl ester is similarly prepared, and after recrystallisation from aqueous ethanol has m.p. 128 . (M.ps., pp. 543-545.)... 

Benzylthiouronium salts. Add 0 5 g. of sulphanilic acid to 10 ml. of water and 5 ml. of 10% NaOH solution, zndgently warm the shaken mixture until a clear solution is obtained. Cool, add 1 drop of phenol-phthalein solution, and then add dilute HCl dropwise with shaking until the pink colour is just discharged. Now add very dilute NaOH solution until the pink colour yt/rZ returns. Cool and add with shaking a solution of 0-5 g. of benzylthiouronium chloride in 5 ml. of water. The thiouronium salt rapidly separates filter at the pump, wash with water, drain and recrystallise from ethanol. Colourless crystals, m.p. 185°. (M.ps., p. 548.)... 

Method 2. In a 500 ml. round-bottomed flask, equipped with a reflux condenser, place 20 5 g. (20 ml.) of anUine, 21 5 g. (20 ml.) of acetic anhydride, 21 g. (20 ml.) of glacial acetic acid, and 01 g. of zinc dust (1), Boil the mixture gently for 30 minutes, and then pour the hot Uquid in a thin stream into a 1 Utre beaker containing 500 ml. of cold water whilst stirring continually. When cold (it is preferable to cool in ice), filter the crude product at the pump, wash with a Uttle cold water, drain well and dry upon filter paper in the air. The yield of acetaniUde, m.p. 113°, is 30 g. It may be recrystaUised as in Method 1 aflFording 21 g, of pure acetaniUde, m.p. 114°. 

Hydrolysis of benzanilide. Place 5 g. of benzanilide and 50 ml. of 70 per cent, sulphuric acid in a small flask fitted with a reflux condenser, and boU gently for 30 minutes. Some of the benzoio acid will vapourise in the steam and solidify in the condenser. Pour 60 ml. of hot water down the condenser this will dislodge and partially dissolve the benzoic acid. Cool the flask in ice water filter off the benzoic acid (anifine sulphate does not separate at this dilution), wash well with water, drain, dry upon filter paper, and identify by m.p. (121°) and other tests. Render the filtrate alkaline by cautiously adding 10 per cent, sodium hydroxide solution, cool and isolate the aniline by ether extraction. Recover the ether and test the residue for anifine (Section IV,100). 

P-Naphthyl acetate. Dissolve 5 0 g. of p-naphthol in 25 ml. of 10 per cent, sodium hydroxide solution in a 250 ml. reagent bottle, add 60 g. of crushed ice, and 5-7 g. (5 -5 ml.) of acetic anhydride. Shake vigorously for 10-15 minutes the p-naphth acetate separates as colourless crystals. Filter with suction, wash with water, drain and dry in the air. Recrystallise from light petroleum (b.p. 60-80°) or from dilute alcohol. The yield of pure product, m.p. 71°, is 6-5 g. 

Pour the aqueous solution remaining from the ether extraction with stirring into a mixture of 80 ml. of concentrated hydrochloric acid, 80 ml. of water and about 100 g. of crushed ice. Filter the precipitated benzoic acid at the pump, wash it with a little cold water, drain, and recrystallise from boiling water. The yield of benzoic acid (colourless crystals), m.p. 121°, is 18g. 

In a 500 ml. round-bottomed flask place 65 ml. of rectified spirit, 50 g. (47 5 ml.) of pure benzaldehyde (1) and a solution of 5 g. of sodium cyanide (96-98 per cent.) CAUTION) in 50 ml, of water. Attach a reflux condenser (preferably of the double surface type) and boil the mixture gently for half an hour (2). Cool the contents of the flask (preferably in an ice bath). Filter the crude benzoin, wash it with cold water, drain well (3) and dry. The yield of crude benzoin, which is white or pale yellow in colour, is 45 g. 

Place 27 g. of o-phenylenediamine (Section IV,92) in a 250 ml. round-bottomed flask and add 17 -5 g. (16 ml.) of 90 per cent, formic acid (1). Heat the mixture on a water bath at 100° for 2 hours. Cool, add 10 per cent sodium hydroxide solution slowly, with constant rotation of the flask, until the mixture is just alkaline to litmus. Filter off the crude benzimidazole at the pump, wash with ice-cold water, drain well and wash again with 25 ml. of cold water. Dissolve the crude product in 400 ml. of boiling water, add 2 g. of decolourising carbon, and digest for 16 minutes. Filter rapidly at the pump through a pre heated Buchner funnel and flask. Cool the filtrate to about 10°, filter off the benzimidazole, wash with 25 ml. of cold water, and dry at 100°. The yield of pure benzimidazole, m.p. 171-172°, is 26 g. 

Water leaves the field either as surface mnoff, carrying pesticides dissolved in the water or sorbed to soil particles suspended in water, or as water draining through the soil profile, carrying dissolved pesticides to deeper depths. The distribution of water between drainage and mnoff is dependent on the amount of water appHed to the field, the physical and chemical properties of the soil, and the cultural practices imposed on the field. These factors also impact the retention and transformation processes affecting the pesticide. 

Clean air header by blowing Keep water drained Load desiccants and dry out header Underground Drains Cleanliness and tightness Seals established Steam... 

As diseussed in Chapter 17, legislative eontrols ineluding stringent eonsent eonditions are applied in the UK to all diseharges to speeified sewers. (Diseharge of effluent to surfaee water drains is prohibited.) Limits, or even total prohibitions, are plaeed upon eertain ehemieals to avoid... 

Certain refinery wastewater streams are treated separately, prior to the wastewater treatment plant, to remove contaminants that would not easily be treated after mixing with other wastewater. One such waste stream is the sour water drained from distillation reflux drums. Sour water contains dissolved hydrogen sulfide and other organic sulfur compounds and ammonia which are stripped in a tower with gas or steam before being discharged to the wastewater treatment plant. 

The whole system should be designed for ease of decontamination. The cupboard will incorporate a wash-down system. Adequate drainage in the cupboard and ductwork is required. Water drained from the system, including that from the fan casing, should be collected and properly disposed of. It should not be possible for water to get onto the work surface. 

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