Kewujudan fluorida dalam kuantiti yang melebihi had dibenarkan adalah perkara
yang perlu diambil perhatian serius. Kandungan fluorida yang tinggi akan
mengganggu kesihatan dan menyebabkan penyakit fluorosis. Beberapa bahan
penjerap yang digunakan untuk menyingkirkan fluorida dari air telah dikaji. Alumina
nanoparticles digunakan dalam kajian ini untuk menyingkirkan fluorida. Ujikaji
secara kelompok dijalankan untuk mengkaji keberkesanan alumina nanoparticles
dalam penyingkiran fluorida dari air. Kajian terhadap pengaruh pH, masa tindakbalas,
kepekatan awal fluorida dan dos bahan penjerap ke atas penyingkiran fluorida
dilakukan. Pergantungan penjerapan fluorida terhadap nilai pH larutan dikaji untuk
mendapatkan nilai pH yang optimum. Kadar penjerapan yang maksimum diperolehi
apabila nilai pH adalah 2.5. Analisa ke atas masa tindakbalas menunjukkan peratusan
penyingkiran fluorida pada mulanya meningkat dan beransur-ansur menjadi malar
dengan peningkatan masa. Ini menunjukkan bahawa proses penjerapan telah
mencapai keseimbangan. 120 minit adalah masa tindakbalas yang sesuai. Dalam
kajian kinetik, model Tertib Kamiran Kedua adalah lebih sesuai digunakan untuk
menyatakan kinetik penjerapan fluorida. Kajian terhadap dos bahan penjerap
menunjukkan kecekapan penyingkiran fluorida meningkat dengan penambahan dos
bahan penjerap. Kecekapan alumina nanoparticles pada dos 2, 4, 6, 8, dan 10g/l
adalah 15, 24.80, 33.87, 41.33, dan 48.53% masing-masing. Isoterma penjerapan
dimodelkan dengan menggunakan persamaan Langmuir dan Freundlich dan nilai
pemalar untuk kedua-dua isoterma dikira. Kedua-dua model tersebut sesuai digunakan
untuk menghuraikan penjerapan fluorida ke atas alumina nanoparticles. Kapasiti
alumina nanoparticles adalah 4.4033 mg/g.
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The presence of fluoride in drinking water, in quantities in excess of permissible
limits is a serious matter of concern from a public health point of view. High
concentration of fluoride can lead to fluorosis. Various adsorbents for removing
fluoride from drinking water have been studied in the past. In this research, alumina
nanoparticles was proposed for the removal of fluoride from drinking water. Batch
experiments were conducted to determine the efficacy of alumina nanoparticles in
fluoride removal from water. The fluoride removal performance was investigated as a
function of pH, contact time, initial fluoride concentration and adsorbent dosage. The
dependence of the adsorption of fluoride on the pH of the solution has been studied to
achieve the optimum pH value. It was found that the maximum adsorption takes place
at pH 2.5. Contact time analysis revealed that the percent fluoride removal increases
initially as contact time increases, but then it gradually approaches a more or less
constant value, indicating that the equilibrium has been attained. The experiments
showed that 120 minutes was the suitable contact time. In kinetic study, the Second
Order Integral model was found to express the sorption kinetics of fluoride better.
Study on the influence of adsorbent dosage showed that the efficiency of the fluoride
removal increases with the increase of adsorbent dosage. The removal efficiency for
2, 4, 6, 8, and 10 g/l of alumina nanoparticles is 15, 24.80, 33.87, 41.33, and 48.53 %
respectively. Adsorption isotherms have been modeled by Langmuir and Freundlich
equations and isotherm constants for both isotherms were calculated. In isotherms
studies, both models were found to be suitable to describe the adsorption of fluoride
onto the alumina nanoparticles. The capacity of alumina nanoparticles is 4.4033 mg/g
which can be obtained from the Langmuir isotherm.
Fluoride removal using alumina nanoparticles / Ecrolien Liberty Lopog