Preparation Of Hydrotalcite-like Absorbent Material Based On Oil Shale Ash And Application In Removal Of Heavy Metal Ions

With the rapid economic development of the modern industry, we have made a great progress and the consequent environmental problems become increasingly serious. Especially the contamination of heavy metals caused the attention of people. So it is worth to develop a method to prepare high-performance adsorbent material by oil shale ash which called industrial hazardous waste about research and application.In this paper, Huadian oil shale ash which came from thermal power plant area and magnesium nitrate were used as the main raw material to explore an effective method of preparing Oil shale ash-based hydrotalcite-like compound（OSA-HTLc） for the adsorption of Cu²⁺, Pb²⁺ and Cd²⁺ metal ions in wastewater.The results show:1. When the reaction temperature is 80°C and p H=11.5, the synthesis of Oil shale ash-based hydrotalcite-like compound（OSA-HTLc） owe best crystallinity. The XRD, XPS, SEM, TEM, FT-IR, TG-DSC and other test results of the analysis proved characterization results indicate that the prepared samples have a structure hydrotalcite-like compound, OSA-HTLc mesoporous crystalline form present in the state material into a layered form, having a large specific surface area and pore volume, which will help OSA-HTLc adsorption of heavy metal ions.2. The affecting factors of the adsorption study showed that: OSA-HTLc for Cu²⁺adsorption optimum p H was 6, when the reaction temperature below 35℃, as the temperature rises, the removal rate tended to increase gradually over 35℃ removal basic no longer increased, and the removal rate was high, when the oil shale ash-based hydrotalcite-like（OSA-HTLc） adsorbent dosage<0.1g, with the increase of OSA-HTLc dosage, Cu²⁺ removal significantly enhanced. When the amount of adsorbent in the OSA-HTLc>0.1g, adsorption capacity remained almost constant. So the 0.1g OSA-HTLc adsorbent dosage is the optimal amount of adsorbent.3. Oil shale ash-based hydrotalcite-like（OSA-HTLc） metal ion adsorption and coincide with Langmuir isotherm model and pseudo-second adsorption kinetics equa-tion, OSA-HTLc of Pb²⁺, Cu²⁺ and Cd²⁺ balance adsorption capacities 120.92mg·g^-1,120.34mg·g^-1,114.94mg·g^-1, further study of OSA-HTLc thermodynamic characteristics of adsorption of heavy metal ions, indicating that the adsorption process is a spontaneous process.4. Oil shale ash-based hydrotalcite-like（OSA-HTLc） metal ions adsorption mechanism for the use of a single molecular layer OSA-HTLc laminates of regulated metal cation adsorption.