Magnesium ions microbes

The first level of treatment, with sand filters and chlorination to remove suspended matters and disinfection of pathogens, may be good enough for the low-cost water. The removal of discoloration and bad smell is accomplished by activated charcoal absorption. Ozone and ultraviolet treatments are much more expensive for the removal of microbes and organic matter, and should be considered only when necessary to solve a technical problem, or to satisfy an advertisement need. Reverse osmosis is the most effective method used to recover clean water from brackish water, and to remove inorganic minerals such as sodium, copper, iron, and zinc. The removal of calcium and magnesium ions can be accomplished by the method of ion exchange with sodium, which would also increase the sodium concentration, and could cause objections. Different levels of treatment require a variety of costs, and can produce different levels of customer satisfaction. 

The prerequisite for the toxic effect of heavy metals is penetration of the cell wall. For this, certain carriers are needed to transport the heavy metals through lipophilic centres in the cell membrane. Oxines, 2-mercapto-pyridine-N-oxides (III. 11) and dialkyl-dithiocarbamates (III.9) are examples of compounds capable of complexing heavy metal ions such as Cu ions and transporting them into the microbe cell. The carriers named are also toxic, as such, to micro-organisms. But, as a copper carrier, copper-8-hydroxyquinoline is about 100 times more effective than 8-hydroxyquinoline (oxine III. 11.4). Once heavy metal ions have overcome the cell wall with the aid of the carrier molecules, they may compete with magnesium, calcium and potassium ions for receptor sites, inhibit enzymes and cause non-specific precipitation of proteins. 

Natural waters. The corrosivity of natural waters depends on their constituents, such as dissolved solids, gases, and sometimes colloidal or suspended matter. The effects may either stimulate or suppress the corrosion reaction. Constituents or impurities in water include dissolved gases such as oxygen, COj, SOj, NHj, HjS, some of which are the result of bacterial activity. Dissolved mineral salts are mostly calcium, magnesium sodium, bicarbonate, sulfate, chloride, and nitrate. The effect of each of these ions on corrosion rate is different, but the chlorides have received the most study in this regard. Organic contaminants of water can directly affect the corrosion rate of metals and alloys. Bacteria, under optimum conditions can double their number in 10-60 minutes. This characteristic is typical of the widespread biodeterioration caused by microbes in aU indnstries, of which corrosion is a special case. With a few exceptions such as synthetic polymers, all materials can be attacked by bacteria. 

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