The study of C P determination of hydrotalcite intercalated with heavy metal ions

Abstract

In this work, the influence of adsorption temperature on heavy metal ions intercalation and their effect on hydrotalcite specific heat capacity were examined. The hydrotalcite samples were prepared via hydrothermal synthesis (200 °C; 3 h) in stirred suspensions, when the primary mixture molar ratio (Mg/Al) was equal to 2. It was determined that the simultaneous adsorption temperature as well as the nature of heavy metals had a significant influence on the uptake of Cu2+, Co2+ and Cr3+ ions. The selectivity sequence of adsorption of hydrotalcite (according to the total amount of adsorbed ions) under all experimental conditions can be represented as: Cr3+ > Cu2+ > Co2+. However, the highest adsorption capacity of the latter compound for heavy metal ions was achieved at 25 °C. It should be noted that, after 30 min of the latter process at 35 °C, a partial destruction of hydrotalcite was observed, while at higher temperature, together with hydrotalcite other LDHs with intercalated NO3 − anions were identified. It was observed that both the presence of Cu2+, Co2+ and Cr3+ ions into the structure of the latter compound and the adsorption temperature, played an important role on specific heat capacity of hydrotalcite.