Water Hardness Levels Research Articles

Branchial Ionic Flux Responses in Rainbow Trout to Chloramine-T after Acclimation to Different Levels of Water Hardness

Abstract Whole-body unidirectional and net Na+ and Cl– fluxes were determined in rainbow trout Oncorhynchus mykiss exposed to chloramine-T (9 mg/L) alone or in combination with 17 mmol NaCl/L (0.1 % weight per volume, w/v) after acclimation to either city of Ottawa tap water (TW: Na+ 0.121 ± 0.004 mmol/L; K+ 0.015 ± <0.001 mmol/L; Ca2+ 0.351 ± 0.004 mmol/L; Cl– 0.141 ± 0.002 mmol/L) or artificial soft water (ASW: Na+ 0.043 ± 0.003 mmol/L; K+ 0.005 ± <0.001 mmol/L; Ca2+ 0.063 ± 0.002 mmol/L; Cl– 0.026 ± 0.002 mmol/L). Preexposure fluxes revealed that ASW-acclimated fish had reduced rates of Na+ uptake and efflux compared with TW-acclimated fish. However, rates of Cl– uptake among ASW-acclimated fish were comparable with those of TW-acclimated fish. Exposure to chloramine-T in TW resulted in significant increases in the Cl– efflux, giving rise to a significant and negative net flux. Exposure of ASW-acclimated fish to chloramine-T caused a significant negative increase in the Na+ efflux and net flux but only...

Creative funding brings RO to small system

Both the drinking water and the economy have improved in Las Animas, Colo.The problematic nature of water quality in the Arkansas River east of Pueblo, Colo., has made the development of good public water supplies a challenge. The Colorado municipality of Las Animas, which has wells in the river's alluvial aquifer, has been plagued by high levels of water hardness and dissolved solids. This factor and the region's marginal economy have impeded the ability of this rural community to grow. Thanks to the pooling of funds from several sources, the construction of a reverse osmosis treatment plant has become a reality. Much of the cost of the new plant was paid through grant funds.

A survey of commercial laundry detergents ‐ how effective are they?: Part III: powders, liquids and hard water

The effectiveness of 42 detergents, 11 non‐phosphate containing powdered detergents, 12 phosphate containing powdered detergents, 11 unbuilt liquid detergents and eight built liquid detergents, of varying formulations, in cleaning a standard soiled fabric in water of varying hardness was evaluated. Powdered detergents were found to be significantly affected only at very high water hardness levels. There was no significant difference between washing in warm and hot water for the liquid detergents, except for a melaleucaoil based detergent which performed significantly better in hot water. Increasing water hardness had no significant effect on liquid detergents. Powdered detergents performed better than liquid detergents in cleaning the standard soiled fabric. While no one detergent was significantly better than the others, in general, washing with detergents that contained phosphates did give somewhat better results in warm water. Detergents that contained bleach as an additive did not result in whiter fabric.

Detergency of binary mixtures of LAS/STPP and LAS/Zeolites: influence of (Ca++) on the washing liquor

The influence of sodium tripolyphosphate (STPP) or zeolites on the detergency performance of linear alkylbenzene sulfonate (LAS) has been evaluated at different water hardness levels. This study demonstrates that STPP or zeolite behaves either as a sequestrant or through an important synergism with LAS, showing a minimum and a maximum in detergency performance, depending on the water hardness level. There is an optimum LAS/builder ratio for each individual water hardness level. This optimum has to be determined experimentally as it will not always necessarily coincide with the highest surfactant and/or builder concentrations.

The effects of water hardness level on washing quality using commercial laundry detergents

The water hardnesses were determined for 10 samples of water. A wide variation of water hardnesses were found ranging from very soft to very hard. The effectiveness of six commercial laundry detergents of different formulations were evaluated. The detergent containing a non-ionic surfactant with a phosphate builder was found to give the best whiteness results, regardless of water hardness. Because of the possible environmental problems associated with the use of phosphates, consumers may wish to select the next most effective detergent formulation, which varied between water samples.

Water Hardness, Detergent Type, and Prewash Product Use as Factors Affecting Methyl Parathion Residue Retained in Protective Apparel Fabrics

The purpose of this study was to examine the effect of water hardness, detergent type, and prewash product on methyl parathion residue remaining in fabric after laundering. Measured water hardness had not been included as a variable in earlier studies. Its effect is particularly important as water hardness may interfere with the cleaning effectiveness of the detergent, the detersive action of an anionic product being reduced more than that of a nonionic product. The factorial design included (a) two detergents (nonionic and anionic) (b) a prewash product (laundered with or without) (c) fabric finish (unfinished or repellent finished) and (d) five levels of water hardness (0, 300, 600, 900, and 1200ppm). Unlaundered 8 X 8 cm specimens were spiked with 0.2 ml of methyl parathion. Residue was extracted following laundering and quantity remaining was determined by gas chromatography. The results showed that the repellent finish was effective in limiting methyl parathion absorption. After laundering, residues were greater for a soil-repellent finished fabric than the unfinished fabric even though the initial contamination was lower for the soil-repellent finished fabric. As level of water hardness increased, residue retained increased. The anionic phosphate detergent was less efficient in methyl parathion removal than was heavy duty liquid detergent; however, use of a prewash product before laundering with the anionic detergent resulted in residues on unfinished specimens at levels similar to those for the heavy duty liquid detergent.

The effects of water hardness on the hatching and viability of silver carp ( Hypophthalmichthys molitrix) eggs

An investigation was conducted to establish water hardness concentration for optimum hatching of silver carp ( Hypophthalmichthys molitrix) eggs. Eggs were incubated for 19 h at 26.5°C at six levels of water hardness: 100, 200, 300, 400, 500 and 600 mg/l CaCO 3. Water absorption at 100–200 mg/l CaCO 3 caused eggs to burst prematurely and minimal water absorption occurred at 600 mg/l CaCO 3. Chloride concentration at 0 and 6 h post-fertilization was significantly related to egg hatchability. Total ammonia-nitrogen at 6 h, pH at 6 h, magnesium hardness at 18 h and chlorides at 18 h significantly influence viability of larvae. A water hardness of 300–500 mg/l CaCO 3 is recommended for the successful hatching of silver carp eggs.

An approach to formulating cold‐water laundry products

AbstractTrilinear plots showing the performance of linear alkylbenzene (LAS), alcohol ether sulfate (ES) and alcohol sulfate (AS) mixtures are used to optimize surfactant active composition for maximum cold‐water detergency. Superimposition of cost lines allows for estimating cost/performance. Results show that the composition of the optimally performing LAS/ES/AS mixture depends strongly on temperature, water hardness and cloth type. Under most conditions at low water hardness levels, optimum cost/performance is obtained by an all‐LAS active composition. When water hardness exceeds the hardness removal capability of the builder, an LAS/ES blend is best.

Influence of water hardness on fluoride toxicity to rainbow trout

AbstractStatic bioassays were conducted to determine effects of water hardness on toxicity of sodium fluoride to rainbow trout (Salmo gairdneri). Ninety‐six hour LC50 values increased from 51 to 193 mg/L [F] as water hardness levels rose from 17 to 385 mg/L CaCO3. Tests of chronic toxicity at different water hardness levels are needed before fluoride standards for aquatic life, such as fish, can be set.

INFLUENCE OF WATER HARDNESS ON FLUORIDE TOXICITY TO RAINBOW TROUT

Static bioassays were conducted to determine effects of water hardness on toxicity of sodium fluoride to rainbow trout (Salmo gairdneri). Ninety-six hour LC50 values increased from 51 to 193 mg/L [F] as water hardness levels rose from 17 to 385 mg/L CaCO3. Tests of chronic toxicity at different water hardness levels are needed before fluoride standards for aquatic life, such as fish, can be set.

Cold water detergency studies using radiolabeled soils

AbstractThe effects of single and multiple washing and of resoiling‐rewashing of cotton and synthetic fabrics have been studied in Tergotometer tests at various levels of temperature, detergent concentration and water hardness. The soiling mixture consisted of a seven component sebum tagged with tritium and carbon‐14; in some tests gammaray emitting Kaolinite clay was also used. Linear primary alcohol ethoxylate (LAEO) and linear alkylbenzene sulfonate (LAS) were used for surfactant type comparisons. In single wash tests in both hot and cold water, LAEO was generally more effective than LAS in removing sebum. This was particularly noticeable at low product concentration where insufficient sodium tripolyphosphate was present to sequester the water hardness. A 1/1 blend of the two surfactants approached LAEO in performance. The nonpolar sebum fraction was more readily removed from Dacron or nylon in cold water; otherwise, detergency was generally better at high temperatures. In rewash tests, using labeled lube oil, cholesterol and clay, a progressive increase in soil removal was found during five wash cycles. The nonpolar lube oil component was the most difficult to remove from permanent press Dacron‐cotton (PP), but was more readily removed from cotton. The more polar cholesterol and especially the clay were more easily removed from PP. LAEO gave better detergency both hot and cold than LAS, especially in hard water. On cotton swatches resoiled with sebum after each wash the residual sebum content was still increasing after five cycles. With PP in soft water, a steady state was reached after three to five cycles. Soil buildup was greater as hardness increased and as wash temperature and active matter concentration decreased, and was generally greater on cotton than on PP. LAEO allowed appreciably less soil buildup than did LAS especially at low concentration in hard water, indicating a reduced requirement for sodium tripolyphosphate.

Lithium in the drinking water and atherosclerotic heart death; epidemiologic argument for protective effect.

Voors, A. W. (School of Public Health, Univ. of North Carolina, Chapel Hill, N. C. 27514). Lithium in the drinking water and atherosclerotic heart death: epidemiologic argument for protective effect. Amer. J. Epid., 1970, 92: 164–171.—Age-adjusted rates of mortality for atheroscleratic heart disease and from all causes combined were compared with the logarithmic transformations of hardness and lithium contents of the municipal water supplies for some 100 largest U.S.A. cities. This was done separately for each sex and race. It was found that the wellknown negative correlation between water hardness and atherosclerotic heart mortality can be explained almost entirely by the geologically determined, highly positive correlation between water hardness and lithium level. The thus seemingly more fundamental negative correlation between lithium level and atherosclerotic heart mortality may indicate the beneficial pharmacological influence of lithium on five risk factors predisposing to the disease, and its protection against the adrenergic stimulation which is likely to mediate the influence of Selyean stress on these risk factors. Research implications towards possible future health measures are suggested.