Salinity hardness

Alkalinity, Chemical Oxygen Demand by potassium permanganate method (CODMn), Dissolved Oxygen (DO), Total and Calcium Hardness, Salinity, Sulfides, Cu, Cr and Fe were the monitored quality parameters, using standard titrimetric analytical methods according to Romanian regulations and UV-VIS spectrometry by standard addition method (Chirila et al., 2005). 

A recent publication by Flaaten et al. has claimed that borates, notably sodium metaborate, unlike conventional alkalis, exhibit a remarkable tolerance toward hardness ions, in this application [19], This discovery will allow (notably carbonate) reservoirs with hard saline brines to benefit from the use of ASP flooding technology, where previously this was not possible. The metaborate ion is known to form ion-pair complexes with hardness ions, for example, the reaction with calcium ion is as follows ... 

Recent laboratory studies have demonstrated the potential utility of borates as alkaline agents in chemical enhanced oil recovery. Compared with existing alkalis, sodium metaborate has an unusually high tolerance toward the hardness ions, Ca + and Mg +, paving the way for the implementation of alkali-surfactant-polymer floods for the large number of high-hardness saline carbonate reservoirs. In the absence of surfactants, borate solutions exhibit a strong tendency for spontaneous imbibition, or uptake into oil-wet or mixed-wet carbonate cores, with consequently improved recovery of oil compared with solutions of other salts and alkalis. 

Consider effective water treatment techniques that reduce the hardness/salinity/iron content of the water. These treatment options need to be researched with regard to their practicahty and cost effectiveness in the oil industry. 

If poUed, most aquaculturists would probably indicate a preference for well water. Both freshwater and saline wells are common sources of water for aquaculture. The most commonly used pretreatments of well water include temperature alteration (either heating or cooling) aeration to add oxygen or to remove or oxidize such substances as carbon dioxide, hydrogen sulfide, and iron and increasing salinity (in mariculture systems). Pretreatment may also include adjusting pH, hardness, and alkalinity through the appHcation of appropriate chemicals. 

The polymers exist in saline solution as tightly coiled chains and are readily adsorbed owing to relatively low solubiUty in hard water. Subsequent injection of soft, low salinity water uncoils the adsorbed polymer chains increasing water viscosity and reducing rock permeabiUty. This technology could also be used to reduce the permeabiUty of thief 2ones adjacent to injection wells. However, mechanical isolation of these 2ones may be necessary for cost-effective treatments. 

Acrylamide—polymer/Ct(III)catboxylate gel technology has been developed and field tested in Wyoming s Big Horn Basin (211,212). These gels economically enhance oil recovery from wells that suffer fracture conformance problems. The Cr(III) gel technology was successful in both sandstone and carbonate formations, and was insensitive to H2S, high saline, and hard waters (212). 

If the technical regulations are adhered to for constructional steels in neutral waters, there are no conditions for H-induced corrosion. On the other hand, hardened and high-strength materials with hardnesses above HV 350 are very susceptible [60,82,92], since anodic polarization encourages crack formation in saline media and anodic pitting occurs with acid products of hydrolysis [93]. 

Because of their good electrolyte and hard water stability, ether carboxylates are used in medium (3-10% salt) to high- (10-24% salt) salinity reservoirs in combination with ether sulfates, resp. sulfonates to improve the stability of the microemulsion [188]. 

The hydrogel is allowed to stand for a few days during which time a process called sinerisis takes place. During sinerisis the condensation of the primary particles, one with another, continues and the gel shrinks further, accompanied by the elimination of more saline solution that exudes from the gel. After three or four days, sinerisis is complete and the gel becomes firm and can now be washed free of residual electrolytes with water. The washed product is finally heated to 120°C to complete the condensation of the surface silanol groups between the particles, and a hard xerogel is formed. It is this xerogel that is used as the LC stationary phase and for bonded phase synthesis. It is not intended to discuss the production of silica gel in detail and those interested are referred to "Silica Gel and Bonded Phases", published by Wiley (1). 

D and 5 0 data on fluid inclusions and minerals, 8 C of carbonates, salinity of inclusion fluids together with the kind of host rocks indicate that the interaction of meteoric water and evolved seawater with volcanic and sedimentary rocks are important causes for the formation of ore fluids responsible for the base-metal vein-type deposits. High salinity-hydrothermal solution tends to leach hard cations (base metals, Fe, Mn) from the country rocks. Boiling may be also the cause of high salinity of base-metal ore fluids. However, this alone cannot cause very high salinity. Probably the other processes such as ion filtration by clay minerals and dissolution of halite have to be considered, but no detailed studies on these processes have been carried out. 

The difference in the kinds of metals enriched in Kuroko, base metal vein-type and precious metal vein-type deposits could be explained in terms of the HSAB (hard, soft, acids and bases) principle (Pearson, 1963). According to this principle, relatively hard cations (base metal (Cu, Pb, Zn, Fe, Mn, Ag) ions) tend to combine preferentially with chloride ion in hydrothermal solution, while soft cations (Au, Ag, Tl, Hg ions etc.) combine with H2S and HS . The differences in salinity of ore fluids in base-metal-rich deposits (base metal vein-type deposits and Kuroko deposits) and base-metal-poor deposits (precious metal vein-type deposits) is also in accordance with the HSAB principle. 

Babich, H. and Stotzky, G., Temperature, pH, salinity, hardness, and particulates mediate nickel toxicity to eubacteria, an actinomycete, and yeasts in lake, simulated estuarine, and sea waters, Aquat Toxicol, 3, 195-208, 1983. 

In general, silver concentrations in surface waters of the United States decreased between 1970-74 and 1975-79, although concentrations increased in the north Atlantic, Southeast, and lower Mississippi basins (USPHS 1990). About 30 to 70% of the silver in surface waters may be ascribed to suspended particles (Smith and Carson 1977), depending on water hardness or salinity. For example, sediments added to solutions containing 2 pg Ag/L had 74.9 mg Ag/kg DW sediment after 24 h in freshwater, 14.2 mg/kg DW at 1.5% salinity and 6.9 mg/kg DW at 2.3% salinity (Sanders and Abbe 1987). Riverine transport of silver to the ocean is considerable suspended materials in the Susquehanna River, Pennsylvania — that contained as much as 25 mg silver/kg — resulted in an estimated transport of 4.5 metric tons of silver to the ocean each year (USEPA 1980). The most recent measurements of silver in rivers, lakes, and estuaries using clean techniques show levels of about 0.01 pg/L for pristine, nonpolluted areas and 0.01 to 0.1 pg/L in urban and industrialized areas (Ratte 1999). 

Elevated whole-body calcium content after 48 h LC50 (48 h) range for water hardnesses between 6 and 309 mg CaC03/L, or between 4.2 and 13.6°/oo salinity LC100 (96 h)... 

Dyer, S.D., J.R. Coats, S.P. Bradbury, G.J. Atchison, and J.M. Clark. 1989. Effects of water hardness and salinity on the acute toxicity and uptake of fenvalerate by bluegill (Lepomis macmchirus). Bull. Environ. Contam. Toxicol. 42 359-366. 

Figure 2. Factor two (hardness) vs. Factor one (salinity) factor score plot for 679 samples. Data entry errors identified.

Two factors characterized most of the waters sampled in the monitoring program. The factor loadings for Factor one indicate that the following chemical species participate in correlated behavior that permits the separations and distinctions described above alkalinity, bicarbonate, B, Cl, conductance, F, Li, Mo, and Na. To simplify discussions in the plots shown earlier this group of species was called the salinity factor. Specific conductance in natural waters usually correlates well with hardness and not as well with bicarbonate, but the current study finds specific conductance closely related to bicarbonate and unrelated to hardness (Ca, Mg, sulfate). This indicates that the ions responsible for increased conductance are probably not calcium or magnesium, rather they are more likely sodium, fluoride, and chloride. 

Alluvial well waters and springs are chemically similar. They all exhibit moderate hardness and low salinity. These charactersltlcs may describe varying degrees of saturation in the uppermost stratum. This study also indicates that the measured water quality parameters are not capable of separating alluvial waters from springs and seeps. Additional parameters are necessary to differentiate the two water types. 

The A. marina bioassay is routinely used in the UK, but only in more saline conditions (Thain and Bifield, 2001). The survival of this polychaete in our study was hardly affected by the sediments tested during the study, but the number of casts produced varied considerably (Table 6). Significant effects with the above sediment in vivo bioassays used here have been demonstrated in other studies, not only in Dutch harbour sediments, but also marine and estuarine environments (Matthiessen et ah, 1998 Kater et al., 2001 Stronkhorst, et al., 2003b). 

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