Biojisim magnet berliang merupakan bahan mesra alam penyahtoksik yang lebih cekap bila digunakan untuk membuang pewarna dan logam berat daripada larutan akueus. Penjerapan asid violet 7 (AV7) oleh penjerap magnetik kulit bawang merah (PMKBM) telah dikaji dalam proses kelompok. Kulit bawang merah (KBM) telah menjalani proses magnetik, dimana KBM telah direndam dalam larutan 1.0 mol/L besi (III) klorida hexahidrat dan dikacau selama lapan jam bagi menghasilkan PMKBM. Ciri-ciri fizikal dan kimia bagi PMKBM telah disiasat menggunakan spektrometer inframerah pengubahan Fourier (FTIR). PMKBM mengandungi kumpulan berfungsi logam oksida, kumpulan Si-O-Si, bengkok C-C dan benzena. Kesan kepekatan awal pewarna (20-150mg/L), masa kacau (0-60 minit), dos penjerap (0.2-1.5 g) dan kelajuan penggoncang (50-250 rpm) turut telah dinilai. Didapati bahawa model Langmuir adalah paling berpadanan untuk data garis sesuhu AV7 diterkapasiti penjerapan monolapisan 3.03 mg/g. Manakala, untuk analisa kinetik, didapati bahawa model pseudo-tertib-pertama adalah paling sesuai digunakan untuk menentukan mekanisme penjerapan AV7.
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Magnetized porous biomass is an eco-friendly detoxification material which is highly efficient when used to remove dye and heavy metals from aqueous solutions. The adsorption of acid violet 7 (AV7) dye onto magnetic onion peel adsorbent (MOA) were investigated in a batch process. Onion peel (OP) undergoes magnetic process, where the OP was soaked into 1.0 mol/L Iron(III) chloride hexahydrate solution and stirred for eight hours to prepared MOA. The physical and chemical properties of MOA was investigated using Fourier transform infrared spectroscopy (FTIR). The MOA contained of metal oxide group, Si-O-Si group, C-C bending and benzene functional group. The effect of initial dye concentration (20-150mg/L), agitation time (0-60 minutes), adsorbent dosage (0.2-1.5 g) and shaker speed (50-300 rpm) were also evaluated through. The obtained equilibrium data for MB dye was best fitted by Langmuir model with monolayer adsorption capacity of 3.03 mg/g. Meanwhile, the kinetics data was best represented by the pseudo first-order model.