Filter sprinkling

Filter Beds. The sprinkling filter beds of sewage plants are composed of closely screened mineral aggregate of 38—64 mm or 51—76 mm that meet a severe soundness test. Much of this requirement is suppHed by dense, fine-grained, hard limestone and dolomite. 

To clean a mercury spill, consolidate the droplets with a piece of cardboard. Then suck the mercury into a filter flask with an aspirator. A disposable Pasteur pipet attached to a hose makes a good vacuum cleaner. To remove residual mercury, sprinkle elemental zinc powder on the surface and dampen the powder with 5% aqueous H2S04 to make a paste. Mercury dissolves in the zinc. After working the paste into contaminated areas with a sponge or brush, allow the paste to dry and sweep it up. Discard the powder as contaminated mercury waste. This procedure is better than sprinkling sulfur on the spill. Sulfur coats the mercury but does not react with the bulk of the droplet [D. N. Easton, Management and Control of Hg Exposure, Am. Lab., July 1988, p. 66],... 

It is first established whether the product is a single compound. This is done by dusting a small sample of the dye on moistened filter paper. A mixture can frequently be recognized from spots of different color. (Mixtures of water-insoluble dyes can often be detected by sprinkling a small sample onto concentrated sulfuric acid, advantageously placed in a depression in a white porcelain plate for the purpose.) Attempts are then made to purify the dye by reprecipitation until a pure material is obtained. Every effort is made to obtain the purest sample possible. This is a general rule for all dye analyses. 

Sprinkle the wire with two pints of the wine, and expose it to the air until it be covered with rust then add the rest of the wine macerate for ten days, with occasional agitation, and filter. 

This is effected by either maceration, percola tion, infusion, or decoction, as clrcumstanoef T uire the solution thus obtained is poured off aud the remaining soluble matter either pressed or washed out, aud added to the solution it is next allowed time to settle, then decanted, and strained or filtered and if this fails to render the liquid clear, it is clarified by white of egg, and filtered Canton flannel, first soaked m water, being generally employed for this purpose. When water acidulated with occtio acid is employed, vegetable substances are usually macerat in it in the cold, or the dilute acid is sprinkled over the bruised plant, if fresh, and the juice expressed by strong pressure. 

SPILL CLEAN-UP ventilate area of spill use a specialized charcoal-filtered vacuum o suction pump to collect all visible material sprinkle the entire area of the spill with elementa zinc powder use a 5-10% sulfuric acid solution to dampen the zinc powder to create a paste-liki consistency after paste dries to a light gray color, it may be swept up and disposed of properly residual material is removed with soap and water. 

Packed absorbers are columns whose contact zones are filled with bodies of various shapes. For the most part, the contact of gas with liquid takes place at the wetted surface of the orifice, where the sprinkled liquid flows down. The large surface area of the orifice per unit volume of the device makes it possible to create a sufficiently large contact surface that is required for efficient mass exchange of phases, in relatively small volumes. One of the constructions of such an absorber is shown in Fig. 2.18. The absorber consists of an entrance separator 1, a contact zone filled with orifice 2, and a filter-separator 3. In the same figure, a few kinds of orifices are shown. 

Protein stain. Dissolve 0-425 g of bromocresol green in 125 ml of 0-1N sodium hydroxide by sprinkling the dye on the surface of the alkali and stirring. Add the solution to 2 litres of 0 1 N acetic acid and filter the pH of the mixture should be 3-6. The reagent is stable for some time but should be filtered at intervals. 

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