Produced water treatment precipitated solids

For the raw water of Example 10.8, using the lime-soda process in the spht treatment mode to remove the total hardness to 130 mg/L as CaCO containing magnesium hardness of 40 mg/L as CaCO, calculate the total mass of calcium carbonate solids produced from the precipitation of calcium from the noncarbonate hardness of calcium. 

Overall, the data obtained were promising, but some of the limitations of the galvanic stripping that were identified require additional evaluation. On the positive side, it was demonstrated that running in a continuous mode is possible and that a concentrated ferrous sulfate solution can be produced. A number of by-product uses appear to be potentially possible and include water treatment chemicals, electrolytic iron or a precipitated or crystallized solid iron salt. 

Somewhat paradoxically, measures taken to reduce air and water pollution (Figure 15.1) have had a tendency to increase production of hazardous wastes. Most water treatment processes yield sludges or concentrated liquors that require stabilization and disposal. Air scrubbing processes likewise produce sludges. Baghouses and precipitators used to control air pollution all yield significant quantities of solids, some of which are hazardous. 

Perchloric acid is produced industrially by two routes. The traditional method exploits the very high aqueous solubility of sodium perchlorate (209 g/100 mL of water at room temperature Treatment of such solutions with hydrochloric acid gives perchloric acid, precipitating solid sodium chloride ... 

Sludge Precipitated mechanically or biologically separated solid matter produced during water and or sewage treatment or industrial processes. Such solids may be amenable to biological control. 

Selenic Acid.—Selenic Acid, H2Se04, is also a il colourless syrupy liquid it can be produced by direct oxidation of selenium by chlorine water, but on concentra-I tion the resulting hydrochloric acid reduces the selenic acid I to selenious acid, as hydriodic acid reduces sulphuric acid. It is best prepared by addition of copper carbonate to the mixture of selenic and hydrochloric acids obtained in that way selenate and chloride of copper are formed the 1 mixture is evaporated to dryness, and the copper chloride is dissolved out with alcohol, leaving the insoluble selenate 1 behind. The selenate is dissolved in water, and on treatment with sulphuretted hydrogen, copper sulphide is precipitated, and removed by filtration the selenic acid is then concentrated if it contains a trace of water, it is a heavy liquid 5 but if quite anhydrous, it forms a solid, melting at 58°. 

Solid-state cellulose can also be noncrystalline, sometimes called amorphous. Intermediate situations are also likely to be important but not well characterized. One example, nematic ordered cellulose has been described [230]. In most treatments that produce amorphous cellulose, the whole fiber is severely degraded. For example, decrystallization can be effected by ball milling, which leaves the cellulose as a fine dust. In this case, some crystalline structure can be recreated by placing the sample in a humid environment. Another approach uses phosphoric acid, which can dissolve the cellulose. Precipitation by dilution with water results in a material with very little crystallinity. There is some chance that the chain may adopt a different shape (a collapsed, sixfold helix) after phosphoric acid treatment. This was concluded because the cellulose stains blue with iodine (see Figure 5.12), similar to the sixfold amylose helix in the starch-iodine complex. 

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