Removal precipitation

Clarifiers typically are used in chemical precipitation and biological treatment processes to remove precipitated metal soHds and suspended biological soHds. To prevent the sludge blanket from becoming too thick or heavy, part of the sludge blanket is removed continuously or intermittently from the system and thickened prior to disposal. 

A-Homo-estra-, 4, )-triene-3, l-dione (50). A solution of bromo ketone (49 0.2 g), silver perchlorate (0.5 g) and 20% aqueous acetone (30 ml) is heated at reflux with stirring for 30 min and then allowed to cool to room temperature. The mixture is filtered to remove precipitated silver bromide (ca. 0.19 g) and the filtrate is diluted with water (200 ml) and then extracted with chloroform. The chloroform extracts are washed, successively with water, 5% sodium bicarbonate solution, water and saturated salt solution. After being dried over anhydrous magnesium sulfate, the solvents are removed at reduced pressure to give a solid. Recrystallization from ethyl acetate gives A-homo-estra-l,4,5(10)-triene-3,17-dione (50 0.17 g) mp 193-197°. 

The concentrate was treated with dry acetone (22 liters), the mixture well mixed, and then filtered to remove precipitated solid impurities. Further dry acetone (4 liters) was added to the filtrate, then the product started to crystallize slowly. Crystallization was allowed to proceed at a temperature between 0° and 3°C for 16 hours and then the product (563 g) was collected by filtration. Dry ether (7.5 liters) was added to the filtrate, and after several hours a second crop (203 g) of solid was collected. The two crops were combined to give sodium 2,6-dimethoxyphenylpenicillin monohydrate (766 g, 73%) as a white crystalline solid. 

Purification of photoprotein. The dialyzed photoprotein solution was centrifuged to remove precipitates, and then subjected to fractional precipitation by ammonium sulfate, taking a fraction precipitated between 30% and 50% saturation. The protein precipitate was dissolved in 50 ml of 10 mM sodium phosphate, pH 6.0, containing 0.1 mM oxine ( pH 6.0 buffer ), dialyzed against the same buffer, and the dialyzed solution was adsorbed on a column of DEAE-cellulose (2.5 x 13 cm) prepared with the pH 6.0 buffer. The elution was done by a stepwise increase of NaCl concentration. The photoprotein was eluted at 0.2-0.25 M NaCl and a cloudy substance (cofactor 1) was eluted at about 0.5 M NaCl. The photoprotein fraction was further purified on a column of Sephadex G-200 or Ultrogel AcA 34 (1.6 x 80 cm) using the pH 6.0 buffer that contained 0.5 M NaCl. 

Isolation of Sesquiterpene Lactones. The ether extract was evaporated and dissolved in 952 ethanol. Then an equal volume of 42 aqueous lead acetate was added. After 1 hour the mixture was filtered to remove precipitated chlorophyll and phenolic products and the ethanol removed under vacuum. The aqueous layer was extracted with chloroform giving a dark colored oil from which the sesquiterpenes were isolated by a combination of chromatographic procedures, i.e., LH-20 gel permeation, silica gel using both packed columns and thin layer plates. A variety of solvents were also used to purify the individual sesquiterpene lactones, e.g., benzene-acetone (1 1), ethyl acetate, chloroform-methanol (9 1). On thin layer chromatographic plates, spots were visualized by spraying with 22 aqueous KMn04 solution. 

General treatment goals for patients with skin disorders are to relieve bothersome symptoms, remove precipitating factors, prevent recurrences, avoid adverse treatment effects, and improve quality of life. 

Potassium (R)-(+)-2,3-epoxypropanoate (Potassium glycidate). The crude acid from the preceding step (74.5 g, 0.44 mol) is dissolved in absolute ethanol (300 mL) and cooled to -20°C. Under N2, a filtered solution of potassium hydroxide (86%, 55.5 g, 0.85 mol) in absolute ethanol (300 mL) is slowly added. After 2 hr, the mixture is allowed to warm to 0°C and stirred at this temperature for 14 hr. The solution is filtered to remove precipitated salts. Half of the solvent is removed by rotary evaporation without warming and an additional crop of salt (2-4 g) is isolated by filtration. The combined salts are dried under vacuum to give 105 g of a 1 1 mixture of KBr and potassium glycidate. 

In Step 7, after the energetics hydrolysate from the continuously stirred tank hydrolysis operation has been pumped into a holding tank, acid is added to precipitate aluminum, and the hydrolysate is filtered through an automatic filter press to remove precipitated aluminum compounds. The liquid effluent goes to the dunnage hydropulper (Step 9). The filter cake from the press is sent to an electrically heated screw conveyor (Step 15) for 5X treatment. 

Modify the design to incorporate equipment for removing precipitated aluminum compounds to... 

Millipore. Determination of Aqueous Compound Solubility Using a 96-Well Filter Plate to Remove Precipitated Solids Prior to UVA/is spectroscopic analysis, Protocol Note PC2445EN00, 2003. 

The aqueous and organic layers are separated using a 500-mL separatory funnel. The organic layer is washed 3 times with 100 mL of deionized water. An emulsion commonly forms during this step, so saturated sodium chloride may be added to the mixture or used instead of water to aid in the separation of the layers. The organic layer is separated, filtered to remove precipitates, and evaporated to dryness under flowing nitrogen. The crude product is transferred to a 500-mL Erlenmeyer flask with 35 mL of chloroform. To this solution, 300 mL of pentane is added to precipitate the product. 

When a sample of the niobium (V) chloride-pyridine or niobium(V) bromide-pyridine reaction mixture was dissolved in dilute acid, filtered to remove precipitated niobium oxides, and treated with concentrated sodium hydroxide solution, the same set of spectra were observed for the resulting solution as for the l-(4-pyridyl) pyridinium dihalides. The spectra before and after heating the solutions from the reaction mixtures are shown in Figure 2. Here also the peaks occurred at 432 and 365 m/x, with the 432-m, peak absent after heating. 

Preparation of Dianiline Derivative of Glutaconaldehyde. A sample of the niobium(V) chloride-pyridine reaction mixture was hydrolyzed in dilute aqueous ammonia, and the solution was filtered to remove precipitated niobium (V) oxide. 

The checkers recorded [oi]q8 +18.9° (CHCI3, c 1.85) for this material and noted some unidentified impurities in the 1H NMR spectrum. The submitters indicate that 3 mL of methanol can be added to the yellow liquid followed by filtration to remove precipitated solids. 

Divide homogenate equally between tubes and centrifuge 20 min at 18,000 X g, 4°C to remove precipitated proteins. 

To remove precipitated particles in the BOE process, the substrates were removed every 2-5 min and dipped in a 1 M HC1 solution for 10-20 s. Adding HC1 directly into the HF etch bath will have a similar effect [105,109-111]. 

Remove precipitated/V-methylmorpholine hydrochloride by filtration and wash it with DME (5x2 mL). 

Add pronase to the supernatant to a final concentration of 200 tig/mL. Incubate overnight at 37°C with constant shaking. Remove precipitates by centrifugation. 

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