Microemulsion Formation and Detergency with Oily Soil: V. Effects of Water Hardness and Builder

The need for deinking mills to reduce their fresh water consumption has resulted in higher loads of various contaminants in the process water. Lower recovered paper quality also leads to higher contamination levels in the mills. This higher load has an influence on achievable target brightness. The objective of the work was to determine and explain the main reasons for relatively poor deinked pulp quality or poor deinking potential based on the influence of recovered paper composition and process water quality. The process water parameters significantly affect the deinking potential of recovered paper. The test results showed the negative effects of increased water hardness. For standard recovered paper mixtures, flotation selectivity is higher with increasing flotation pH-value. Good results were realized for standard recovered paper with low hardness, low surface tension, and high pH-value. The results for recovered paper containing flexo newsprint could be slightly improved with low hardness, low surface tension, and low pH-value. The results of the test program using design of experiments showed interacting effects of pH-value and surface tension on luminosity and flotation selectivity.

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

Aquaculture ◽

10.1016/0044-8486(87)90347-4 ◽

1987 ◽

Vol 64 (2) ◽

pp. 111-118 ◽

Cited By ~ 24

Author(s):

Angelito C. Gonzal ◽

Emiliano V. Aralar ◽

Josefina Ma.F. Pavico

Keyword(s):

Silver Carp ◽

Water Hardness ◽

Hypophthalmichthys Molitrix

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Rapid Water Softening with TEMPO-Oxidized/Phosphorylated Nanopapers

Nanomaterials ◽

10.3390/nano9020136 ◽

2019 ◽

Vol 9 (2) ◽

pp. 136 ◽

Cited By ~ 6

Author(s):

Andreas Mautner ◽

Thawanrat Kobkeatthawin ◽

Florian Mayer ◽

Christof Plessl ◽

Selestina Gorgieva ◽

...

Keyword(s):

Adsorption Capacity ◽

Cellulose Nanofibrils ◽

Water Hardness ◽

Organic Liquids ◽

Oxidized Cellulose ◽

Water Softening ◽

Aqueous Suspensions ◽

Overall Performance ◽

Exchange Resins ◽

Very High

Water hardness not only constitutes a significant hazard for the functionality of water infrastructure but is also associated with health concerns. Commonly, water hardness is tackled with synthetic ion-exchange resins or membranes that have the drawbacks of requiring the awkward disposal of saturated materials and being based on fossil resources. In this work, we present a renewable nanopaper for the purpose of water softening prepared from phosphorylated TEMPO-oxidized cellulose nanofibrils (PT-CNF). Nanopapers were prepared from CNF suspensions in water (PT-CNF nanopapers) or low surface tension organic liquids (ethanol), named EPT-CNF nanopapers, respectively. Nanopaper preparation from ethanol resulted in a significantly increased porosity of the nanopapers enabling much higher permeances: more than 10,000× higher as compared to nanopapers from aqueous suspensions. The adsorption capacity for Ca2+ of nanopapers from aqueous suspensions was 17 mg g−1 and 5 mg g−1 for Mg2+; however, EPT-CNF nanopapers adsorbed more than 90 mg g−1 Ca2+ and almost 70 mg g−1 Mg2+. The higher adsorption capacity was a result of the increased accessibility of functional groups in the bulk of the nanopapers caused by the higher porosity of nanopapers prepared from ethanol. The combination of very high permeance and adsorption capacity constitutes a high overall performance of these nanopapers in water softening applications.

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Behavior of surfactant mixtures in model oily-soil detergency studies

Journal of the American Oil Chemists Society ◽

10.1007/bf02702113 ◽

1983 ◽

Vol 60 (7) ◽

pp. 1333-1339 ◽

Cited By ~ 11

Author(s):

M. P. Aronson ◽

M. L. Gum ◽

E. D. Goddard

Keyword(s):

Oily Soil ◽

Surfactant Mixtures

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Effect of vegetation on limestone solution in a small High Arctic basin

Canadian Journal of Earth Sciences ◽

10.1139/e77-059 ◽

1977 ◽

Vol 14 (4) ◽

pp. 571-581 ◽

Cited By ~ 19

Author(s):

Ming-Ko Woo ◽

Philip Marsh

Keyword(s):

Carbon Dioxide ◽

Partial Pressure ◽

Soil Water ◽

Water Hardness ◽

Late Summer ◽

Arctic Basin ◽

The Arctic ◽

Total Hardness ◽

Equilibrium Partial Pressure ◽

Biogenic Carbon

To evaluate the effect of tundra vegetation on limestone solution processes, the present study was carried out in a small basin in southwestern Ellesmere Island, N.W.T. A test reach was selected along the stream, and water samples were collected at regular intervals from a seepage point entering the reach, a soil water pit at the bottom of a vegetated slope along the test reach, and from the stream at the outlet of the reach. Hydrochemical characteristics of the samples were described by several measured and calculated variables including water temperature, pH, calcium and total hardness, bicarbonate concentration, equilibrium partial pressure of carbon dioxide, and indices of saturation with respect to calcite and dolomite. Throughout the growing season of 1975, all samples indicated higher concentrations in water hardness and in bicarbonate than those reported in nonvegetated areas of the Arctic. A rising trend was apparent in these data, with the concentrations reaching a seasonal maximum in late summer. These phenomena are attributed to the production of biogenic carbon dioxide, which increased the aggressiveness of the water. The partial pressure of carbon dioxide in soil water was directly increased by this process, while the addition of soil water to the stream caused noticeable downstream increase in partial pressure of carbon dioxide and a corresponding reduction in saturation with respect to calcite and to dolomite. The influence of vegetation was therefore very marked in both surface and in subsurface flows.

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Assessment of the drinking water quality for planning endogenic prevention of dental caries

Стоматология детского возраста и профилактика ◽

10.33925/1683-3031-2021-21-2-88-93 ◽

2021 ◽

Vol 21 (2) ◽

pp. 88-93

Author(s):

A. B. Shashmurina ◽

O. L. Mishutina ◽

V. R. Shashmurina

Keyword(s):

Drinking Water ◽

Dental Caries ◽

Water Supply ◽

Fluoride Concentration ◽

Water Hardness ◽

Drinking Water Supply ◽

Ion Concentration ◽

Normal Range ◽

Hydrogen Ion Concentration ◽

Normal Limits

Relevance. Dental caries is a leading dental disease in children. Aim – to study the quality of drinking water in Smolensk and its region to provide evidence for implementing dental caries preventive measures in children.Materials and methods. We took tap water samples from ten water intake points in seven districts of Smolensk and six Smolensk regions. An accredited testing laboratory of the Center for Hygiene and Epidemiology in the Smolensk Region carried out water chemical analysis. The study analyzed standard parameters of drinking water quality: pH 6.5-8.5, fluoride content 0.60-1.2 mg/l; water hardness 7.0-9.0 (Sanitary Regulations and Standards 2.1.4.1116-02). The parameter was considered normal if its 95% confidence interval was within the reference range.Results. In Smolensk, the hydrogen ion concentration in centralized drinking water supply systems is within normal limits and amounts to 7.39 (95% CI: 7.32-7.46; р < 0,05) pH units. The mean fluoride concentration in the Smolensk water is 0.19 (95% CI: 0.14-0.23; р < 0,05) mg/l, which is below the normal range. In most Smolensk districts, water hardness is within normal limits, 8.21 mmol/l (95% CI: 7.03-9.39; р < 0,05). However, the upper limit of the confidence interval of 9.39 mg/l and the maximum of 12.0 mg/l exceed the normal range. In the Smolensk region cities, the hydrogen ion concentration is 7.2 (95% CI: 7.02-7.38; р < 0,05) pH units in the centralized drinking water supply. The fluoride concentration in the Smolensk region water is 0.45 mg/l (95% CI: 0.23-0.68; р < 0,05), which demonstrates the fluoride deficiency in water. In the Smolensk region cities, mean water hardness is 6.66 mmol/l (95% CI: 6.00-7.03; р < 0,05), which is below the normal values. However, the CI upper limit of 7.03 mmol/l and the maximum of 7.05 mmol/l are within normal limits.Conclusions. The water of the centralized drinking water supply system in Smolensk and the Smolensk region is low in fluorides. Urgent community and individual preventive measures should be taken to expose children to fluoride.

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