Alkaline detergents

Tin is anodic to steel in alkaline solutions, the corrosion rate for a continuous coating being similar to that of pure tin, and tinned articles that are washed in aerated alkaline detergents slowly lose their coating. 

Tannin-containing woods can also suffer from dark-brown stains produced by alkali, usually from a concrete or a detergent source. Conversely, fair-faced concrete can be similarly stained by the run-off water from unprotected hardwood surfaces. Some woods, e.g. afzelia, ayan and idigbo, give yellow contaminating dyes with alkaline detergents and should not be used in washrooms and kitchens. 

Aqueous cleaning, in which spraying of aqueous acidic or alkaline detergent solutions is followed by normal and deionized water rinses. Strong detergents dissolve greases, oils and possibly oxides. It is necessary to rinse thoroughly to avoid later attacks. 

The internal components such as the guide, disc holder, disc insert, nozzle, guide ring and spindle should be cleaned by immersion in a commercial high-alkaline detergent. 

The permeate flow tended to decrease with the operating time due to progressive fouling of the membrane. Depending on the quality of the feed, a film was formed on the surface of the membrane that reduced permeate flow and the quality of the exit water, causing an increase in the pressure difference. To prevent this and the consequent pollution, the membranes were cleaned periodically with acids and alkaline detergents, as well as antisealant and biocides. Several different membranes from Toray and Osmonics were assayed to choose the most suitable one. 

Detojet [Alconox], TM for a low foaming, heavy duty alkaline detergent. 

ASTM Method D 501, Standard Test Methods of Sampling and Chemical Analysis of Alkaline Detergents, Annual Book of ASTM Standards, American Society for Testing and Materials, Philadelphia, 1989. 

Small Areas Ventilation. In heavily contaminated areas, employ vacuum devices equipped with High Efficiency Particulate Air (HEPA) filters to remove as much agent as possible. If necessary, wash with copious amounts of alkaline detergent and water. Do not use bleach or detergents containing bleach as they may interact with agents to produce highly toxic decomposition products. Porous surfaces may be difficult to decontaminate. 

Polished, washed with hot alkaline detergent, cleaned in ammoniacal peroxide, washed with water, dried at 100°C... 

Cleaning of the membrane was performed with 0.3 wt% nitric acid at 45 °C and the alkaline detergent Ultrasil 11 at 0.25 wt% and 55 °C. The membrane flux did not always fully recover after each chemical cleaning. A 200 mg/L CI2 solution administered as sodium hypochlorite (NaOCl) would, however, restore the original flux. 

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