PENURUNAN KONSENTRASI ZAT WARNA BIRU METILENA DALAM AIR DENGAN MENGGUNAKAN ADSORBEN LIMBAH STYROFOAM SULFONAT TERMODIFIKASI MAGNETIT

EARLY ZAHWA A, Prof. Dr. Endang Tri Wahyuni, M.S.,; Suherman, S.Si., M.Sc., Ph.D.

2020 | Skripsi | S1 KIMIA

Dalam rangka penurunan zat warna biru metilena (MB) dalam air sekaligus pemanfaatan limbah styrofoam, pada penelitian ini telah dilakukan modifikasi limbah styrofoam menjadi adsorben yang mampu menyerap kation MB dan dapat dipisahkan secara praktis oleh medan magnet. Penelitian ini terdiri dari sulfonasi dan magnetisasi styrofoam membentuk adsorben styrofoam-sulfonat termagnetisasi (styrofoam-SO3/Fe3O4), karakterisasi adsorben, dan uji aktivitas adsorben tersebut untuk penghilangan MB dalam air. Proses sulfonasi dan magnetisasi limbah styrofoam dilakukan menggunakan asam sulfat dan larutan Fe(II)/Fe(III) dalam kondisi basa membentuk styrofoam-SO3/Fe3O4. Pada preparasi adsorben styrofoam-SO3/Fe3O4, fraksi Fe3O4 dibuat bervariasi. Karakterisasi adsorben dilakukan dengan alat FTIR, XRD, dan SEM. Pada adsorpsi MB secara batch dilakukan evaluasi pengaruh fraksi Fe3O4 dalam adsorben terhadap kapasitas adsorpsi dan efektivitas pemisahan. Selain itu, dilakukan optimasi pH, waktu, dan konsentrasi awal MB, serta penentuan kinetika dan isoterm adsorpsi. Hasil karakterisasi menunjukkan bahwa melalui sulfonasi dan magnetisasi pada limbah styrofoam telah diperoleh adsorben styrofoam-SO3/Fe3O4 yang mampu secara efektif mengadsorpsi kation MB dan mudah dipisahkan oleh batang magnet. Fraksi Fe3O4 dalam styrofoam-SO3/Fe3O4 sebesar 50,00% menunjukkan kemampuan adsorpsi dan separabilitas yang tinggi. Kondsi optimum adsorpsi MB 10 mg/L dalam 40 mL larutan oleh adsorben styrofoam-SO3/Fe3O4 50,00% adalah, massa adsorben 15 mg, waktu kontak 45 menit, pH larutan sebesar 7 dengan efektivitas adsorpsi sebesar 93,11%. Adsorpsi MB mengikuti orde dua semu dengan konstanta laju 0,065 g/mg.menit dan isoterm adsorpsi mengikuti model isoterm Langmuir dengan kapasitas adsorpsi 46,51 mg/g.

In order to decrease methylene blue (MB) dye concentration in the water and utilize styrofoam solid waste, in this present research a modification of the styrofoam waste to form an adsorbent that can remove MB and practically separated by magnetic field has been performed. This research consisted of sulfonation and magnetization of the styrofoam waste, characterization of the adsorbent, and adsorption study of the adsorbent for MB removal. The sulfonation and magnetization were performed by using sulfuric acid and Fe(II)/Fe(II) in base solution of the styrofoam waste to form magnetized styrofoam-sulfonate (styrofoam-SO3/Fe3O4). In the preparation step, Fe3O4 fraction was varied. Characterization of the adsorbent prepared was conducted by FTIR, XRD, and SEM, instruments. In the adsorption process by batch technique, the influence of Fe3O4 fraction on the adsorption capacity and separable effectiveness was evaluated. Additionally, pH, time, and the MB initial concentration were optimized. In addition, kinetic and isotherm adsorption were also determined. The characterization results indicated that by sulfonation and magnetization toward styrofoam waste, it has been obtained an adsorbent that was able to adsorb MB effectively and to be separated practically by magnetic rod. The Fe3O4 fraction of 50.00% in the adsorbent gave compromisingly good adsorption capacity and separability. The optimum condition of the adsorption of MB 10 mg/L in 40 mL solution by styrofoam-SO3/Fe3O4 50.00% was found as 15 mg of the adsorbent mass, 45 min of the contact time, pH solution of 7, with the effectiveness as ca. 93.11 %. The adsorption kinetic best fitted to pseudo-second order with adsorption rate constant as 0.065 g/mg.min, and it was well described by Langmuir isotherm model with adsorption capacity of 46.51 mg/g.

Kata Kunci : adsorben, biru metilena, Fe3O4, styrofoam, sulfonasi/adsorbent, Fe3O4, methylene blue, styrofoam, sulfonation.