Organic matter water washing

Filter on the porcelain funnel with the pump and wash three or four times with small quantities of cold water. Press the piecipitate down and dry on a porous plate in the vacuum-desiccator. When thoroughly dry, weigh out about 0-5 to i gram of the compound into a porcelain or platinum crucible, and heat gently with the lid on, and then moie strongly until the organic matter is completely burnt away. Cool the crucible in the desic-ca.or and weigh. 

Tests should also be done in the presenee of organic matter (e.g. albumin) and in hard water. It is important to remember when performing viable counts that care must be taken to ensure that, at the moment of sampling, the disinfection process is immediately arrested by the use of a suitable neutralizer or ensuring inactivation by dilution (Table 11.4). Membrane filtration is an alternative procedure, the principle of whieh is that treated cells are retained on the filter whilst the disinfectant forms the filtrate. After washing in situ, the membrane is transferred to the surface of a solid (agar) reeoveiy medium and the eolonies that develop on the membrane are counted. 

FIGURE 15.7 Secondary changes in the total group composition of soluble organic matter as a result of simulated water washing extracts of the Miocene lignite and shale (both of the Bechatow open cast mine, Poland), the Upper Devonian shale (the Holy Cross Mountains, Poland), and the Upper Carboniferous bituminous coal (the Upper Silesia Coal Basin, Poland). 

A soil sample is placed in a centrifuge tube, mixed with 0.5 M HC1 for 1 hour, and centrifuged. The HC1 solution is removed and the soil washed with water to remove the acid. The soil is then extracted with 0.5 M NaOH for 18 hours with shaking, followed by centrifuging to remove dissolved organic matter from soil (adapted and condensed from Reference 21). 

The BioTrol soil washing system is a patented, water-based volume reduction process used to treat excavated soil. It separates slightly contaminated, coarse, washed soil particles from heavily contaminated fine soil particles. The process operates on the premise that (1) contaminants tend to be concentrated in the fine size fraction of soil (sUt, clay, and soil organic matter) and (2) contaminants associated with the coarse soil fraction (sand and gravel) are primarily surficial. The BioTrol soil washing system can be used to treat soils contaminated with petroleum hydrocarbons, pesticides, polychlorinated biphenyls (PCBs), various industrial chemicals, and metals. 

The selenium filtered from the reaction mixture is refluxed with 31. of 95% ethanol for 1 hour, which converts the red amorphous form to the gray hexagonal form and frees it of organic matter. This metallic selenium is removed by filtration, washed with water, and converted to the dioxide by the method of Baker and Maxson.2... 

R. Haines has analyzed the alkaline deposit—called duka, hurka, or kara—found near Aden in Arabia it contains 5T05 per cent. Na2C03 24 94 NaCI traces of magnesium chloride and sodium sulphate 19 66 water and organic matter and 4 35 of sand. It is used for adding strength to snuff, and for washing. 

The aqueous solution thus obtained is filtered and 200 c.c. (corresponding with 4 grams of the leather) evaporated on a water-bath and the residue dried at ioo° this represents total soluble matter or loss on washing. The dried residue is then incinerated, the ash representing the soluble mineral matter or soluble ash (which may be examined qualitatively) the difference gives the soluble organic matter. 

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