EFEKTIVITAS ZEOLIT ALAM-TiO2/Fe2O3 DAN IRRADIASI ULTRAVIOLET DALAM PENURUNAN KONSENTRASI CAMPURAN METILEN BIRU DAN Cr(VI) - Darmawan, D. P.; Simpen, I N.; Sudiarta, I W. (Jurnal Kimia (Journal of Chemistry); Vol. 19 Issue 2, Juli 2025DO - 10.24843/JCHEM.2025.v19.i02.p23, 2025)
Industri tekstil merupakan salah satu penghasil limbah cair yang mengandung berbagai zat warna sintetik dan logam yang sulit terurai seperti halnya metilen biru dan Cr(VI), sehingga dapat mengganggu ekosistem perairan. Penurunan konsentrasi campuran metilen biru dan Cr(VI) menggunakan zeolit alam-TiO 2 /Fe 2 O 3 dengan irradiasi ultraviolet dilakukan dalam penelitian ini. Penelitian ini bertujuan untuk mengetahui konsentrasi, waktu penyinaran, dan pH optimum terhadap penurunan konsentrasi campuran metilen biru dan Cr(VI) dengan zeolit alam-TiO 2 /Fe 2 O 3 . Zeolit alam-TiO 2 /Fe 2 O 3 yang disintesis dikarakterisasi luas permukaan spesifik secara BET, gugus fungsi dengan FTIR, dan jumlah situs aktif permukaan secara titrasi asam-basa. Karakteristik optimum diperoleh luas permukaan spesifik zeolit alam-TiO 2 /Fe 2 O 3 (3:1) sebesar 16,902 m 2 /g, dan jumlah situs aktif sebesar 7,7171×19 20 situs/gram. Hasil analisis gugus fungsional zeolit alam-TiO 2 /Fe 2 O 3 menunjukkan adanya puncak khas yang teridentifikasi untuk zeolit alam pada bilangan gelombang 3636,56 cm -1 ; 1654,47 cm -1 ; dan 1055,10 cm -1 , puncak spesifik TiO 2 pada 797,60 cm -1 dan Fe 2 O 3 pada 496,69 cm -1 . Hasil penelitian menunjukkan bahwa konsentrasi optimum diperoleh pada perbandingan konsentrasi 1:1, waktu irradiasi 10 menit, dan pH 8 dan 4. Efektivitas penurunan konsentrasi metilen biru dan Cr(VI) 50 ppm menggunakan irradiasi sinar ultraviolet yaitu sebesar 99,98% dan 99,60%. Zeolit alam-TiO 2 /Fe 2 O 3 dikategorikan efektif dalam menurunkan konsentrasi campuran metilen biru dan Cr(VI). K ata kunci : Cr(VI), metilen biru, irradiasi ultraviolet, zeolit alam-TiO 2 /Fe 2 O 3 ABSTRACT            Textiles are one of the producers of liquid waste that contains synthetic dyes and metals, such as methylene blue and Cr(VI), which are difficult to decompose and can disrupt aquatic ecosystems. This research investigated the reduction of a mixture of methylene blue and Cr(VI) using natural zeolite-TiO 2 /Fe 2 O 3 with ultraviolet irradiation. This research aimed to determine the optimum concentration, irradiation time, and pH for reducing the concentration of a mixture of methylene blue and Cr(VI) with natural zeolite-TiO 2 /Fe 2 O 3 . The specific surface area of the synthesized natural zeolite-TiO 2 /Fe 2 O 3 was characterized by BET, the functional groups by FTIR, and the number of surface-active sites using acid-base titration. The optimum characteristics of the synthesized natural zeolite-TiO 2 /Fe 2 O 3 (3:1) were the specific surface area of 16.902 m 2 /g, and the number of surface-active sites of 7.7171×1920 sites/gram. The results of the functional groups analysis showed that a typical peak was identified for natural zeolite at a wave number of 3636.56 cm -1 , 1654.47 cm -1 , and 1055.10 cm -1 , respectively, and the specific peaks of TiO 2 at 797.60 cm -1 and Fe 2 O 3 at 496.69 cm -1 . The research results showed that the optimum concentration was obtained at a concentration ratio of 1:1, irradiation time of 10 minutes, and pH of 8 and 4. The effectiveness of reducing the concentration of methylene blue and Cr(VI) of 50 ppm using ultraviolet irradiation was 99.98% and 99.60%, respectively. Natural zeolite-TiO 2 /Fe 2 O 3 was categorized as effective in reducing the concentration of a mixture of methylene blue and Cr(VI). Keywords : Cr(VI), methylene blue, ultraviolet irradiation, natural zeolte-TiO 2 /Fe 2 O 3