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Results for “Water Softening”

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At least 19 recordsLinked to original sources
PubMed2004

Heterotrophic plate count and consumer's health under special consideration of water softeners.

The phenomenon of bacterial growth in water softeners is well known since years. To upgrade the hygienic safety of water softeners, the German DIN Standard 19636 was developed, to assure that the distribution system could not be contaminated by these devices and that the drinking water to be used in the household still meets the microbiological standards according to the German drinking water guidelines, i.e. among others heterotrophic plate count (HPC) below 100 CFU/ml. Moreover, the standard for the water softeners includes a test for contamination with Pseudomonas aeruginosa which has to be disinfected during the regeneration phase. This is possible by sanitizing the resin bed during regeneration by producing chlorine. The results of the last 10 years of tests of water softeners according to DIN 19636 showed that it is possible to produce water softeners that comply with that standard. Approximately 60% of the tested models were accepted. P. aeruginosa is used as an indicator for potentially pathogenic bacteria being able to grow also in low nutrient conditions which normally prevail in drinking water. Like other heterotrophs, the numbers of P. aeruginosa increase rapidly as stagnation occurs. Normally P. aeruginosa is not present in the distributed drinking water. However, under certain conditions, P. aeruginosa can be introduced into the drinking water distribution system, for instance, during construction work. The occurrence of P. aeruginosa is shown in different cases in treatment plants, public drinking water systems and in-house installations. The compliance with DIN 19636 provides assurance that a water softener will not be a constant source of contamination, even if it is once inoculated with a potentially pathogenic bacterium like P. aeruginosa.

Bacteria↗
PubMed2005

Ion exchange with natural zeolites: an alternative for water softening?

Possibility of using natural zeolites for water softening was investigated. Quantitative data regarding separation of calcium from water at various levels of hardness through ion exchange with the ammonium selective natural zeolite clinoptilolite is reported. Capacity of the zeolite towards calcium removal in the presence of ammonium at low concentrations and calcium at higher concentrations, and breakthrough characteristics are presented. The results have revealed that removal of calcium, and hence hardness, through ion exchange with clinoptilolite under those circumstances is a promising alternative, with surface capacities reaching 11 mg calcium/g clinoptilolite.

Calcium↗
PubMed2004

Use of water 'softening and conditioning systems' significantly increases the risk of periodontitis: smoking considerations.

BACKGROUND: The role of water in the etiology of periodontal disease is poorly understood. OBJECTIVES: The objective of this study was to examine the association amongst water softness, risk for periodontitis, and smoking status. METHODS: We examined the association between use of water 'softening and conditioning systems' and the risk for periodontal disease in smokers and non-smokers, using adult participants (18+ years), from the third National Health and Nutrition Examination Survey (NHANES III) data. Zero to 33 per cent (0-33%) of sites with periodontal attachment loss > or = 3 mm was considered a healthy periodontium, and > 33% of sites with periodontal attachment loss > or = 3 mm was defined as periodontitis. Soft water users were divided into 'yes' or 'no' using the question, 'Does your home have a "softening or conditioning system?".' Smoking subjects were divided into groups as follows: current smokers (had smoked > or = 100 cigarettes in their lifetime and currently smoked), former smokers (had smoked > or = 100 cigarettes in their lifetime, not currently smoking), or never smokers (had not smoked > or = 100 cigarettes in their lifetime). Data was analyzed by univariate analyses using SPSS. The 5% level of statistical significance was adopted throughout. RESULTS: Subjects that answered the question 'yes' to soft water use had a significantly higher risk of periodontitis (p < 0.05), adjusting for confounders. When mineral intake from foods was added to the model, the significance of periodontitis risk remained the same for the non-smoking, soft water-using subjects, whereas for the smoking, soft water-using subjects the risk for periodontitis increased significantly (p < 0.05) in most cases. CONCLUSIONS: Thus, use of water 'softening and conditioning systems' significantly increased the risk for periodontitis, and smoking increased this risk.

Adult↗
PubMed1996

Effect of water softening and heating on microbial contamination of dental unit systems.

This study regards the quality of the water used in 4 types of dental units making use of softened and heated water, softened but non-heated water, non-softened but heated water and non-softened and non-heated water. The samples were taken from the incoming tap water, from oral rinsing cup, the air-water syringe and the ultrasound descaling hand-piece. The results showed how the water underwent a notable growth in bacteria during its passage within the circuits of the units, reaching heterotrophic total counts greatly exceeding the guidelines set down by Italian laws regarding drinking water. While the influence of softening was evident, the bacteria in the samples taken from descaling handpiece, where there is more stagnation, found excellent growing conditions also at high temperatures. In the softened and heated waters a notable growth of Pseudomonas aeruginosa was found and it is likely that this was encouraged by the combined effect of the softening and heating. As far as the origin of the contamination is concerned, the bacteria present in the water systems seem to have come from the incoming water.

Bacteria↗
PubMed1968

[Water softeners].

Explore the source record for details and available documents.

Water Softening↗
PubMedDate not supplied

Effect of water softening on the colour intensity of routine haematoxylin and eosin stain.

Haematoxylin and eosin (H&E) is the most popular routine stain used in pathology laboratories for highlighting cellular structures. To study the effect of tap water'softening' (i.e. calcium extraction) on H&E stains, 5 sets of slides from 30 different paraffin-embedded human pathologic tissue blocks were prepared in the same way except for washing with 5 different types of water. Slides washed in untreated tap water showed the best results concerning differentiation and colour intensity, while slides washed with softened or other treated water showed poorer degrees of differentiation and colour intensity. The worst results were obtained from slides washed with water containing sodium bicarbonate. Low calcium and magnesium ions and high sodium ions in soft water adversely affect the results of routine H&E stain.

Calcium↗
PubMedDate not supplied

A multi-purpose system for water purification and sea-water softening.

A novel technique that can be used for reacting toxic carbon dioxide (CO2) emissions from power plants and other combustion wastes with sea water is described. A chemical interaction between CO2 and the cations in sea water, with the pH electrolytically regulated, can precipitate almost all the calcium and magnesium ions, as well as some sodium and potassium ions, as carbonates and bicarbonates. The carbonates and bicarbonates thus prepared can then be mixed with ash to yield a building material. Sulfur ions will be neutralized with calcium and magnesium, and the remaining ions can be removed using reverse osmosis or some other method. The technology and equipment for purification are based on modules that can be used for industrial waste-water, sea water, solutions, and otherwise. The module for separation of sand and suspended coarse substances consists of a tank for flocculation, coagulation, and precipitation of solid particles; and a low-pressure hydrocyclone. The module for purification from oil and fine suspensions is based on column flotation, flotation with a special ejector, and adhesion flotation. The module for ions and colloids consists of an absorbing filter with zeolite, fly ash, and other absorbing materials. Using a laboratory model consisting of a special mini-plant, we processed 10 L of factory-waste water containing more than 20 g/L organic content (compare with the upper limit of 0.02 g/L allowed by the Ministry of Environmental Protection in Israel). After the experimental solution was treated and evaporated to a small bulk, the water obtained was almost clear. On the basis of the results in the model, we present a scaled-up process for the design, development, and production of equipment for and the assembly of a large installation for drainage and water purification.

Seawater↗