|
ИСТИНА |
Войти в систему Регистрация |
Интеллектуальная Система Тематического Исследования НАукометрических данных |
||
The behavior of strontium and zinc during crystallization of Fe(III) Hydroxideтезисы доклада Тезисы
- Авторы: Karaseva O.N., Lakshtanov L.Z., Ivanova L.I.
- Сборник: Goldschmidt Abstracts
- Том: 71
- Тезисы
- Год издания: 2007
- Первая страница: 463
- Аннотация: Oxides and hydroxides of Fe (III) are common components of the soil environment and can have a significant role in toxic metal mobility and retention. Sorption of many elements, among them heavy and earth metal, on Fe hydroxides is enough well understood. However, practically it is not known about influence of ageing and transformation Fe hydroxides on ions sorption from a solution. The alteration of Fe hydroxide specific surface during crystallization and the dynamics of interactions between toxic metal (Zn and Sr) and Fe hydroxide were studied at 250 C with experimental method, representing a combination of potentiometric acid-base titration and metal uptake experiments. As it has been noted the surface of ferric hydroxide was significantly reduced during first day after the initial coprecipitation. In previous study (1) the acid-base properties of the hematite surface-solution interface has been evaluated. Assuming the similarity of acid-base properties of hematite and Fe hydroxide surfaces we calculated the specific surface of Fe hydroxide depending on aging time. The values of the specific surface after one hour, one and ten days after the initial coprecipitation consist 570, 450 and 420 m2/g, respectively. Our results show a significant difference in the behavior of strontium and zinc during hydroxide transformation. Solubility of Sr increases while the hydroxide surface and, consequently, site density decrease. At increasing of aging time from 2 hours to 10 days Sr adsorption falls on 15 % approximately. The fundamental reason leading to reduction of strontium concentration in a solution is the adsorption on the surface of iron hydroxide. In the case of Zn, as our results indicate, even at low pH sorption of Zn on the iron hydroxide consists above 40 % increasing during mineral transformation. This indicates the predominance of co-precipitation process of Zn with Fe hydroxide. Such mechanism of metal uptake is more effective as the absorbed component can be release in a solution at dissolution of a solid phase only.
- Добавил в систему: Карасева Ольга Николаевна