Removal using copper sulfate

Copper sulfate, in small amounts, activates the zinc dust by forming zinc—copper couples. Arsenic(III) and antimony(TTT) oxides are used to remove cobalt and nickel they activate the zinc and form intermetaUic compounds such as CoAs (49). Antimony is less toxic than arsenic and its hydride, stibine, is less stable than arsine and does not form as readily. Hydrogen, formed in the purification tanks, may give these hydrides and venting and surveillance is mandatory. The reverse antimony procedure gives a good separation of cadmium and cobalt. 

Herbicides. An array of herbicides are registered for use in aquatic sites, but copper sulfate and diquat dibromide are of additional interest because they also have therapeutic properties (9,10). Copper sulfate has been used to control bacteria, fungi, and certain parasites, including Jchthjophthirius (ich). Diquat dibromide can control columnaris disease, but it also exhibits fungicidal properties (9,10). EPA recentiy proposed to limit the amount of diquat dibromide, endothaH, glyphosate, and simazine that can be present in drinking water therefore, the use of these compounds may be reduced if they cannot be removed from the effluent. 

Prominent among the heavy metals found in the wastewater generated in the copper sulfate industry are copper, arsenic, cadmium, nickel, antimony, lead, chromium, and zinc (Table 22.11). They are traced to the copper and acids sources used as raw materials. These pollutants are generally removed by precipitation, clarification, gravity separation, centrifugation, and filtration. Alkaline precipitation at pH values between 7 and 10 can eradicate copper, nickel, cadmium, and zinc in the wastewater, while the quantity of arsenic can be reduced through the same process at a higher pH value. 

Cuprasol Also called EIC. A process for removing hydrogen sulfide and ammonia from geothermal steam by scrubbing with an aqueous solution of copper sulfate. The resulting copper sulfide slurry is oxidized with air, and the copper sulfate re-used. The sulfur is recovered as ammonium sulfate. Developed by the EIC Corporation, MA, and demonstrated by the Pacific Gas Electric Company at Geysers, CA, in 1979. 

Zinc. Next to sodium, zinc is the most used reductant. It is available in powder, dust, and granular (mossy) forms. Zinc gets coated by a l er of zinc oxide which must be removed to activate it before it can reduce effectively. It can easily be activated by shaking 3 to 4 min. in a 1% to 2% hydrochloric acid solution. This means for every 98 ml of water volume, add 2 ml of coned hydrochloric acid. Then wash this solution with water, ethatiol, acetone, and ether. Ot activation can be accomplished by washing zinc in a solution of anhydrous zinc chloride (a very small amount) in ether, alcohol, or tetrahydrofuran. Another way is to stir 180 g of zinc in a solution of 1 g copper sulfate pentahydrate. Personally, I like the HCl acid method. 

Zinc dust is frequently covered with a thin layer of zinc oxide which deactivates its surface and causes induction periods in reactions with compounds. This disadvantage can be removed by a proper activation of zinc dust immediately prior to use. Such an activation can be achieved by a 3-4-minute contact with very dilute (0.5-2%) hydrochloric acid followed by washing with water, ethanol, acetone and ether [/55]. Similar activation is carried out in situ by a small amount of anhydrous zinc chloride [156 or zinc bromide [157 in alcohol, ether or tetrahydrofuran. Another way of activating zinc dust is by its conversion to a zinc-copper couple by stirring it (180g) with a solution of 1 g of copper sulfate pentahydrate in 35 ml of water [/55]. 

Drain the crystals of copper sulfate that have by this time accumulated in the original solution, if necessary evaporating the mother liquors from them to secure a second crop of crystals. Secure about half of the original material in this form and set aside the mother liquor for future use. Recrystallize the salt as in the original procedure, using a proportionate quantity of water. Again test a specimen of the crystals obtained for iron and convince yourself that it is still present. Those experiments show that the ferrous sulfate is not removed by several crystallizations. 

Clarification by removal of casein with such agents as calcium chloride, acetic acid, cooper sulfate, or rennin has often been employed to obtain a serum more suitable for refractometric measurements. Obviously the composition, and hence the refractive index, of such sera will depend on the method of preparation. Furthermore, some of the serum proteins may be precipitated with the casein by some of the agents used, particularly if the milk has been heated. Refractive index measurements of such sera are not generally considered as satisfactory as freezing point measurements for detection of added water (David and MacDonald 1953 Munchberg and Narbutas 1937 Schuler 1938 Tell-mann 1933 Vleeschauwer and Waeyenberge 1941). Menefee and Overman (1939) reported a close relation between total solids in evaporated and condensed products and the refractive index of serum prepared therefrom by the copper sulfate method. Of course, a different proportionality constant would hold for each type of product. 

The dehalogenation of naphthyridines with hydrogen over palladium on calcium carbonate in a weakly basic alcoholic solution gives excellent yields (90-95%) of reduced compounds.38,45,134,137,138 This method for removal of halogens has been extensively used and generally surpasses the classic hydrazine-copper sulfate reduction method. 

Lab grade hematite (Fe203) and copper sulfate (anhydrous and hydrated) were mounted on slides and used as controls to compare to mineral deposits that might have been found adhering to foe fibers. Rabbit hair and milkweed that had been colored with an aqueous hematite solution and with an aqueous copper sulfate (blue vitriol) solution were also used for comparison. Fibers removed from each simulated material were mounted in water (Refractive Index (Rl) of 1.0), and in Permount (Fisher Scientific) (RI of 1.55). The collected particulate matter and fibers removed from foe yam samples were similarly mounted and examined using optical microscopy. 

The Shell flue gas desulfurization (SFGD) process described in 1971 [4] removes sulfur oxides from flue gas in a PPR using a regenerable solid adsorbent (acceptor) containing finely dispersed copper oxide. At a temperature of about 400°C, sulfur dioxide reacts with copper oxide to form copper sulfate according to the reaction. 

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