PL
 |
EN
Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników
Powiadomienia systemowe
  • Sesja wygasła!
  • Sesja wygasła!
  • Sesja wygasła!

Znaleziono wyników: 6

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
Wyszukiwano:
w słowach kluczowych:  związki wapnia
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
1
Content available Analysis of the breakthrough phenomena during heavy metal elution from a column packed with municipal waste incineration ash
Zhang W., Yang Y., Suganuma H., Kato S., Suzuki S., Kojima T.
Environment Protection Engineering
|
2018
|
Vol. 44, nr 3
63--78
EN
At some point during acid leaching column tests of heavy metals from municipal waste incineration ash, sudden and rapid elution of harmful elements was observed which was called the breakthrough (BT) phenomena. The mechanism was elucidated from the results of measurement of elemental and particle size distribution in the column and batch leaching tests as follows. At the first stage of experimental runs, CaCO3 was dissolved in acidic solution and pH profile along the bed is formed. Some of the minor elements of Zn and Al dissolved by acid at the upper part of the column are precipitated at bottom of the column, leading to the reduction of flow rate of the leachate solution. After leachate pH becomes low by the termination of dissolution of Ca, these deposits are dissolved and thus, the flow rate increases. Most of the trace elements behave as such, which causes the increase of harmful element concentrations in the eluate. Some drastic concentration increase of harmful elements in leachate may occur even after the long period of pseudo stable dissolution behavior in the land-fill site.
2
Content available remote The influence of gamma-Al2O3 and Na2O on the formation of calcium silicate hydrates in the CaO-quartz-H2O system
Baltakys K., Siauciunas R.
Materials Science Poland
|
2007
|
Vol. 25, No. 1
185--198
EN
The influence of gamma-Al2O3 and Na2O additives on the formation and sequence of calcium silicate hydrates in the CaO-quartz-H2O system with CaO/SiO2 (C/S) molar ratio equal to 0.66 was determined. The synthesis was carried out in unstirred suspensions. The molar ratios of the primary mixtures were CaO/(SiO2 + Al2O3) = 0.66 and Al2O3/(SiO 2 + Al2O3) = 0 or 0.025. The amount of NaOH, corresponding to 5% of Na2O in the mass of dry material, was added in the form of solution. Due to the low solubility rate of quartz in the CaO-quartz-H2O system with C/S = 0.66 in the temperature range 150-200°C, low-base calcium silicate hydrates (Z-phase, gyrolite, pectolite, and others) do not form even after 72 hours of hydrothermal curing. It has been proved that gamma-Al2O3 and Na2O additives change the reaction mechanisms and composition of intermediate (final) products. In mixtures with Na2O, gyrolite starts to form already at 175°C. It should be noted that in the temperature range 175-200°C the final products are gyrolite and pectolite, and the intermediate compounds are C-S-H(l) and Z-phase. The formation of low-base calcium silicate hydrates in the CaO-quartz-Na2O-H2O system is slowed down when Al 2O3 is added because Al3+ ions stimulate the formation of tobermorite and prevent the formation of pectolite and Z-phas
3
Content available Wpływ procesów biochemicznych i substancji humusowych na stężenie związków wapnia i magnezu w wodach
Kolanek A., Kowalski T.
Ochrona Środowiska
|
2002
|
nr 1
9-12
EN
The results of laboratory tests showed that biochemical oxidation, as well as concomitant biocoagulation phenomena, brought about a change of the calcium and magnesium concentration in the water. This led to the establishment of a new calcium-magnesium equilibrium in the humic substances, which were present in the water. As a result, calcium concentration in the investigated water samples underwent some variations (but not substantial changes). The said processes exerted an indirect effect on the concentration of magnesium. When following addition of a sewage portion the value of the Ca/Mg molar ratio fell below that of the Ca-Mg equilibrium in the humic substances, the concentration of magnesium decreased in the course of biochemical degradation. When the Ca/Mg ratio value exceeded the Ca-Mg equilibrium value, magnesium concentration increased. The decrement or increment of magnesium was BOD5-dependent and averaged 0.045 val/gO2. Statistical analysis of the relationship between calcium and magnesium concentration variations for 8 rivers and 24 cross-sections substantiated the results of laboratory tests. Over 92% of instances showed a positive annual [Mg] = f([Ca]/[Mg]) relation with a coefficient of determination greater than 0.6. A positive annual [Ca] = f([Ca]/[Mg]) relation was detected in 6% of instances.
4
Content available remote Badania nad odzyskiem związków fosforu ze ścieków pochodzących z Zakładów Chemicznych "Alwernia"
Kijkowska R., Pawłowska-Kozińska D., Jodko M., Wzorek Z., Gorazda K.
Czasopismo Techniczne. Chemia
|
2002
|
R. 99, z. 3-Ch
21--32
EN
This paper presents the method for treatment of industrial wastewater detained during STPP and phosphoric acid production in "Alwernia" Chemical Works. The potential recovery of phosphorus and its use as a substitute of natural raw materials in feed phosphate production is presented too.
5
Content available Wpływ procesów biochemicznych na stężenia związków wapnia i magnezu w wodach
Kolanek A., Kowalski T.
Ochrona Środowiska
|
2001
|
nr 1
17-21
EN
Biochemical oxidation and concomitant biocoagulation phenomena were found to produce loss of calcium and magnesium cations in treated water, thus contributing to the stabilization Ca-Mg equilibrium in the double layer of the humus complex. As a result, calcium concentration in the investigated water varied only negligibly. The effect of biochemical processes on magnesium concentration was an indirect one. If after sewage addition the Ca/Mg molar ratio value stabilized below the Ca-Mg equilibrium in the humus complex, magnesium concentration decreased in the course of the biochemical degradation process. If the said ratio value was greater than the equilibrium value, magnesium concentration increased.
6
Content available Zawartość związków wapnia i magnezu w wybranych wodach i osadach ściekowych Górnego Śląska
Bodzek D., Janoszka B., Tyrpień K., Wielkoszyński T.
Ochrona Środowiska
|
1998
|
nr 4
18-19
EN
Magnesium and calcium ion concentrations were determined in drinking water and wastewater sludge samples coming from the industrialized Upper Silesian Region and ( for comparative purposes ) from different non- industrialized bockground areas.Mg2+ Ca2+ concentrations in water samples were measured by spectrophotometry ( Mg2+ concentration in the reaction with the Mann and Yoe agent,and Ca2+ concentration in reaction with metalphthalein). In wastewater sludge, Mg2+ and Ca2+ content was determined by AAS.The concentration of Mg2+ in the water samples was generally below the concentrations of both the ions were noticeably high,thus making the investgated sludge snitable for agricultural uses,provided that the concentration of heavy metals is within the range of permissible values.
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.