Sisa pertanian yang berpotensi dimanfaatkan untuk penyediaan karbon teraktif untuk penyingkiran pencelup daripada larutan akuas. Untuk ujikaji ini, karbon teraktif berasaskan biji longan (KTBL) dan kulit pistachios (KTKP) telah disediakan mengunakan kaedah pengaktifan fiki-kimia yang terdiri daripada jerap isi kalium hidroksida (KOH), penggasan CO2 dan penyinaran gelombang mikro. Prestasi KTBL dan KTKP dinilai dengan menjalankan kajian penjerapan kelompok untuk menyingkirkan pencelup metilena biru (MB) and remazol biru berkilau R (RBBR). Dengan menggunakan rekabentuk komposit pusat, keadaan optimum penyediaan bagi kuasa penyinaran, masa penyinaran dan nisbah jerap isi (NJI) telah ditentukan untuk KTBL (330 watt, 2.0 min dan 0.7) dan KTKP (440 watt, 2.07 min dan 1.0), di mana masing-masing telah menghasilkan penyingkiran MB dan RBBR sebanyak 77.0% dan 80.9% dan hasilan sebanyak 22.1% and 21.7%. KTBL dan KTKP mempunyai luas permukaan yang tinggi (>847 m2/g), isipadu liang (> 0.49 cm3/g) dan kandungan karbon tetap (>76%) dan mempunyai taburan saiz liang jenis heterogen dan berliang meso. Kesan kepekatan awal pencelup (25-300 mg/L), masa sentuh (0-24 jam) dan suhu larutan telah dinilai. Penjerapan pencelup oleh KTBL dan KTKP meningkat apabila kepekatan awal pencelup dan masa sentuh meningkat. Untuk data keseimbangan bagi penjerapan kedua-dua pencelup ke atas KTBL dan KTKP adalah sesuai dipadankan oleh model Freundlich. Manakala, data kinetik adalah terbaik diwakili oleh model pseudo tertib pertama. Untuk kedua-dua pencelup, proses penjerapan oleh KTBL dan KTKP masing-masing adalah endotermik dan eksotermik dan semua proses penjerapan yang dikaji dikawal oleh mekanisma serapan-filem.
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Potential of agrowastes were harnesses for preparation of activated carbon (AC) for dyes removal from aqueous solution. In this study, longan seed based activated carbon (LSAC) and pistachios shell based activated carbon (PSAC) were prepared using physiochemical activation consisting of potassium hydroxide (KOH) impregnation, CO2 gasification and microwave irradiation. The performance of the LSAC and PSAC were evaluated by conducting a batch adsorption study for methylene blue (MB) and remazol brilliant blue R (RBBR) removal. By using central composite design (CCD), the optimum preparation conditions of radiation power, radiation time and IR were determined for LSAC (440 watt, 2.0 min and IR 0.7) and PSAC (440 watt, 2.07 min and 1.0), which resulted MB removal of 77.0% and 80.9%, respectively; RBBR removal of 59.4% and 69.8%, respectively and yield of 22.1% and 21.7%, respectively. LSAC and PSAC have high surface area (>847 m2/g), pore volume (> 0.49 cm3/g) and fixed carbon content (>76%). The LSAC and PSAC have heterogeneous type pore size in mesoporous region. The effect of initial dye concentrations (25-300 mg/L), contact times (0-24 hours) and solution temperatures (30-60oC) were evaluated. The MB and RBBR adsorption by LSAC and PSAC were increased as the initial dye concentration and contact time increased. The adsorption equilibrium data for both dyes onto LSAC and PSAC were best fitted by Freundlich model. Meanwhile, the kinetic data was best represented by the pseudo first-order kinetic model. For both dyes, the adsorption of LSAC and PSAC were respectively endothermic and exothermic processes. All the adsorption processes were mainly governed by the film-diffusion controlled mechanism.
Activated carbon from longan seed and pistachios shell prepared via microwave irradiated for dye removal_Siti Zawiyah Baharom_K4_2017_MYMY