Pengaruh pH NH4OH pada Sintesis Mangan Ferrite (MnFe2O4) Berbasis Pasir Besi Alam dengan Metode Kopresipitasi sebagai Adsorben Ion Logam Berat

Abstract

MnFe2O4 has been synthesized by coprecipitation method with variation of pH NH4OH 11,7; 12,0; dan 12,7. The process of preparation started from mixing of Iron Sand and Mangan Clorida powder with HCl as solvent and NH4OH as setting solution. Sampels were dried and characterization include analyze morphology (SEM), powder density, crystal size and structure (XRD), magnetic properties (VSM) and absorption of heavy metal waste (Pb and Cu) (AAS). The result of SEM showed that MnFe2O4 has been able to aglomeration. The results of XRD showed the higher the pH is given the smaller the crystallite grain size so that the powder more tight. The result of VSM showed that the optimum coercivity was achieved when pH of NH4OH 12,7 with a value of 43,82 Oe, magnetic saturation 62.78 emu/g, remanence 1.96 emu/g. AAS characterization showed that nanoparticles MnFe2O4 were able to absorb heavy metal Pb is bigger than Cu.

Telah dilakukan sintesis MnFe2O4 dengan variasi pH NH4OH 11,7; 12,0; dan 12,7 dengan metode kopresipitasi. Proses preparasi dimulai dari pencampuran serbuk Pasir Besi dan Mangan Clorida dengan pelarut HCl dan larutan pengendap NH4OH. Sampel kemudian dikeringkan dan dikarakterisasi, meliputi analisa morfologi (SEM), kerapatan serbuk (Densitas serbuk), ukuran dan struktur kristal (XRD), sifat magnetik (VSM) dan penyerapan limbah logam berat Pb dan Cu (AAS). Hasil SEM menunjukkan bahwa sampel MnFe2O4 mengalami aglomerasi (penggumpalan). Dari hasil uji XRD, bahwa semakin tinggi pH yang diberikan maka ukuran butir kristal semakin kecil sehingga serbuk semakin rapat. Hasil VSM menunjukkan koersivitas optimum terdapat pada saat pH NH4OH 12,7 dengan nilai koersivitas 43,82 Oe, saturasi magnetik 62,78 emu/g, saturasi remanensi 1,96 emu/g. Hasil penyerapan AAS menunjukkan bahwa nanopartikel MnFe2O4 mampu menyerap limbah logam berat Pb lebih besar dibandingkan dengan Cu.