Lebihan fosforus di dalam air sisa menyebabkan pertumbuhan tidak terkawal alga, ketiadaan oksigen di dalam air dan juga fenomena eutrofikasi. Oleh itu, teknologi penyingkiran fosforus yang cekap seperti technologi penurasan nano dalam industri kertas adalah amat diperlukan. Ujian kebolehtelapan air dan penyingkiran fosforus telah dijalankan dengan menggunakan Sel Teranduk SterlitechTM HP4750. Membran penurasan nano komersial iaitu NF90 telah digunakan untuk mengkaji keupayaan membran penurasa nano yang dipengaruhi oleh parameter-parameter seperti tekanan, kepekatan suapan, pH larutan dan juga kehadiran komponen bersaing dalam penyingkiran fosforus. Keputusan menunjukkan NF270 mempunyai kebolehtelapan air yang paling tinggi berbanding membran NF200 dan NF90. Kajian seterusnya menunjukkan pada tekanan serendah 6 bar, NF90 mampu menyingkirkan fosforus melebihi 90% untuk kepekatan suapan 7.5 dan 10 mg/L. Manakala, kepekatan suapan 2.5 dan 5.0 mg/L mampu menyingkirkan fosforus sebanyak 70 sehingga 88 %. Peratus penyingkiran fosforus semakin bertambah apabila semua kepekatan suapan diubah kepada pH 7. Untuk kajian lanjutan, kepekatan suapan 5 mg/L telah diubah kepada pH 5,7,9, dan 12 di mana mampu meningkatkan lagi peratus penyingkiran tetapi tidak apabila diubah kepada pH 2. Kehadiran asid acetik dan kepekatan asid sulfurik yang tinggi (5.0 g/L) di dalam larutan telah mengurangkan peratusan penyingkiran fosforus. Keputusan yang sebaliknya ditunjukkan apabila penambahan kepekatan asid sulfurik yang rendah, (5.0 mg/L) ke dalam larutan. Pemerhatian- pemerhatian ini boleh di jelaskan melalui kesan Donnan dan Sterik.
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Excess of phosphorus in wastewater may lead to uncontrolled growth of algae, deoxygenation of the water and also phenomena of eutrophication. Therefore, efficient phosphorus removal technology like nanofiltration in pulp and paper mill industry is highly demand. Permeability tests and phosphorus removal experiments were then conducted using dead-end SterlitechTM HP4750 Stirred cell. A commercial nanofiltration membrane, NF90 was used to study the potential of removing phosphorus that influence by the operating pressure, pH of solution, feed concentration, and existence of other components. Results showed that NF270 gives highest permeability compared to NF200 and NF90 membranes. Further studies show that NF90 reject more than 90% of phosphorus from feed solution containing 7.5 mg/L and 10 mg/L of phosphorus at a pressure as low as 6 bar. While for feed solution containing 2.5 to 5.0 mg/L of phosphorus give only 70 to 88% of rejection. The phosphorus rejection turned to increase with pH adjustment to pH 7 and rejection for feed containing 5.0 mg/L of phosphorus has been improved with adjustment to pH 5,7,9 and 12 but decrease when adjusted to pH 2. For existence of other components, result shows that the percentage of phosphorus rejection significantly decreases with increase of acetic acid concentration. Meanwhile, adding only 5 mg/L sulphuric acid had increase the percentage of phosphorus removal. However, the phosphorus rejection generally decreases when a great amount of sulphuric acid (5 g/L) is added to all feed concentration of solution.
These observations can be associated to Donnan and steric effects of NF90.
Phosphorus removal using nanofiltration related to pulp and paper mill_Siti Zawiyah Baharom_K4_2011_NI