System flush stand

System flushes are typically used when an RO system goes off-line, comes back on-line, and during stand-by mode. The purpose of the off-line and stand-by flushes is to rid the feed/concentrate side of the membrane of either high concentrations of feed water species or to stir up materials that may have settled on the membrane during down time. The on-line flush (when the membranes come back on line) is to reduce the conductivity in the RO permeate before sending the permeate on to further processing or to the ultimate use. Flush water is typically sent to drain. 

Phenyl Tellurium Dichloride Diethylamide A system consisting of a 200 ml round bottom flask, a reflux condenser, a dropping funnel, and a magnetic stirrer is flushed with dry nitrogen, the flask is flame-dried, and charged with 50 m/ of anhydrous benzene and 3.1 g (10 mmol) of phenyl tellurium trichloride. 1.5 g (10 mmol) of trimethyl(diethylamino)silane are added dropwise to the stirred benzene solution, stirring is continued for 3 h, and the mixture is filtered in a Schlenk-type apparatus. 50 ml of petroleum ether (b.p. 30-60°) are added to the filtrate, the resultant slurry is allowed to settle 3 h, the clear supernatant liquid is decanted, petroleum ether is added to the decantate, and the solution is allowed to stand overnight. The yellow crystals are filtered and dried under vacuum yield 1.3 g (31%) m.p. 105° (dichloromethane-/petroleum ether). 

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