High hardness well water

Well water has a total hardness of 285 ppm as calcium carbonate, with 250 ppm calcium and 35 ppm magnesium. The remaining feed water analysis is listed below (all species listed as ppm ion)  

The feed is make-up water to a 110 gpm RO operating at 75% recovery. Hence, the pretreatment system must treat 150 gpm of feed water. 

The sodium softener selected to treat this water is a duplex, 150-gpm system with 54-inch diameter by 72-inch side sheet vessels. Each vessel contains 50ft3 of resin. Since the duplex system operates with one vessel on line and one vessel in stand-by, the total system regenerates 2.4 times per day. At a salt dosage of 15 pounds per cubic foot, the system uses about 1,800 pounds (820 kg) of salt per day or 27.4 tons per month, assuming a 100% operating factor. At a salt cost of 80 per ton, the total month cost for salt is about 2,200.3 

Amortization of resin typically assumes a 5-year life or replacement cycle. With two vessels at 100ft3 of resin total, the monthly amortization is 100. 

Average cost for an antisealant in 2009 runs about 4.00 per pound.(4) At a dosage of 10.2 ppm, the daily cost for antiscal-ant is about 72.00 or about 2,200 per month. With acid feed, the antisealant requirement is about 905 per month. Sulfuric acid, at about 600 per ton, and 3.4 ppm feed rate, would add about 55 

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High M alk may exist and remain stable in hard well water due to CO2 partial pressures as long as the pressure is maintained and there is no escape of carbon dioxide. 

Both in situ cross-linking of partially hydroly2ed polyacrylamides (69) and injection of quaternary ammonium salt polymers having long hydrophilic side chains (70) have been used to reduce the permeabiUty of water-producing 2ones adjacent to production wells. This permeabiUty reduction decreases the produced water oil ratio as does injection of polyacrylamide in high hardness brine to reduce permeabiUty (71). 

The quality of natural water is extremely variable. Surface waters are generally turbid. Well waters, while clear, may have high hardness. There are also wide variations in the quality demanded by various uses. Therefore, the sort of treatment to be applied, depends both on the quality of the raw water and on the intended use. 

Note that the resin shows a preference for iron and manganese over hardness. Although sodium softeners will remove these metals, they are not adequately removed from the resin during regeneration. Therefore, sodium softeners operating on well waters with high iron or manganese... 

For this high-hardness case, the softener and antisealant options appear to be about the same when only antisealant (no acid) is used. When acid is feed in conjunction with the antisealant, the lower cost option is the chemical one when comparing cost of salt versus cost of antiscalant/acid. Note that any local variation in cost of either salt or antisealant can change the results. What is not accounted for is the affect a softener has on the ability to remove suspended solids and SDI out of feed water, such as any iron or manganese that may be in the well water. If the water were to contain soluble iron and manganese, the softener would remove these species... 

HEAT THE WATER. The better the water, the better the tea. If your tap or well water is hard (has a high mineral content), use filtered, spring, or bottled water. Bring the water to a rolling boil for every type of tea except pure white—for this delicate flower, heat just to the point of boiling. 

The modem water treatment plant is often called upon to perform wonders with the water fed to it. The clear, safe, even tasteful water that comes from a faucet may have started as a murky liquid pumped from a polluted river laden with mud and swarming with bacteria. Or, its source may have been well water, much too hard for domestic use and containing high levels of stain-producing dissolved iron and man-... 

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