Influence of pH on the synthesis of layered double hydroxides for adsorption of ectoparasiticide

Influence of pH on the synthesis of layered double hydroxides for adsorption of ectoparasiticide

• Autor
• POLLYANNA VANESSA DOS SANTOS LINS
• Co-autores
• Rafaela Gabriel , Ícaro Mychel Gomes Leite de Sá , Lucas Meili
• Resumo

• In this work, layered double hydroxides, ZnAl, were synthesized in a molar ratio of 3:1, by the coprecipitation method at increasing pH, with synthesis 1 and synthesis 2 being completed at pH equal to 8 and 12, respectively. According to the characterizations performed, the LDH was synthesized satisfactorily. The XRD showed reflections that corroborate these materials, presenting an interesting difference in the crystallite size between the materials produced. Through SEM, it was possible to observe that the adsorbents have platelet, hexagonal and layered morphologies. The adsorbents produced were used to adsorb malachite green from aqueous solutions, with adjusted pH values. Confirming that since VM is cationic, the adsorptive process is favored in conditions in which the adsorbent is negatively charged, that is, at pH above the pH_PCZ, as occurs in both materials. Furthermore, it was possible to observe that in S2 the material presented better crystallinity, a more ordered structure, a more uniform distribution of charges on the surface, in addition to offering a greater number of active sites, when compared to S1, important characteristics for a good adsorbent, a fact confirmed in the affinity tests, where for the VM solutions at pH 3 the removal percentage increases from 5.43% in S1 to 59.19% in S2 and for the VM solutions at pH 9 it increases from 12.96% in S1 to 70.68% in S2, evidencing the influence of the final pH 12 on the synthesis of LDHs.

• Palavras-chave
• Malachite green, adsorption, LDH, synthesis
• Área Temática
• Adsorção aplicada ao meio ambiente