Sains Malaysiana 49(9)(2020): 2311-2322

http://dx.doi.org/10.17576/jsm-2020-4909-28

Treatment of Palm Oil Mill Effluent by Poly(L-Lactic Acid)-Poly(Ethylene Glycol)/Silica Membrane

(Rawatan Efluen Kilang Sawit menggunakan Membran Poli(L-Asid Laktik)-Poli(Etilena Glikol)/Silika)

FATIMAH ZAHRAH MOHD KAMIL¹, NORILYANI IZZATI HASANUDDIN¹, RIZAFIZAH OTHAMAN^1,2 & FARAH HANNAN ANUAR^1,2*

¹Department of Chemical Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor Darul Ehsan, Malaysia

²Polymer Research Centre (PORCE), Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor Darul Ehsan, Malaysia

Diserahkan: 15 Oktober 2019/Diterima: 8 Mei 2020

ABSTRACT

Biodegradable membrane technology has received an increasing interest in many fields of applications exclusively to preserve the earth. A renewable polymer such as poly(L-lactic acid) (PLLA) often being introduced with reinforcement material to improve the characteristics of membranes itself. Herein, this study highlights the development of membrane from poly(L-lactic acid)-poly(ethylene glycol) (PLLA-PEG) copolymer with silica (SiO₂) in the treatment of palm oil mill effluent (POME) wastewater. We hypothesized that the incorporation of SiO₂ as a nanofiller promoted PLLA-PEG/SiO₂ membrane to have a porous and higher number of pores on the membrane surface. Therefore, the effect of silica amount added in the PLLA-PEG copolymer membrane was also investigated and examined by using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). Based on FTIR analysis, the presence of the urethane (-NHCOO-) functional group indicated the formation of PLLA-PEG copolymer and SEM micrographs showed porous surface on the membranes with increasing pores size in a favor of SiO₂ amount added. Also, the surface wettability of membranes was evaluated through water contact angle which render hydrophilic characteristics. These membranes were subsequently applied for POME filtration where the test resulted in significant discolouration of POME. Furthermore, the high percentage removal efficiency of biochemical oxygen demand (BOD), chemical oxygen demand (COD) and total suspended solid (TSS) up to 99.5% empowers the treated POME wastewater to be within the range set by the Malaysian Department of the Environment.

Keywords: Copolymer; membrane; poly(ethylene glycol); poly(lactic acid); POME

ABSTRAK

Pada masa kini, teknologi membran terbiodegradasi semakin mendapat perhatian dalam pelbagai bidang aplikasi khususnya untuk menjaga kesejahteraan bumi. Polimer yang berasaskan sumber keterbaharuan seperti poli(asid laktik) selalunya ditambah baik dengan bahan penguat bagi meningkatkan ciri membran tersebut. Oleh itu, kajian ini memfokuskan kepada perkembangan membran berasaskan kopolimer poli(L-asid laktik)-poli(etilena glikol) (PLLA-PEG) dengan penambahan silika bagi rawatan air sisa buangan efluen minyak kelapa sawit. Kami menjangkakan bahawa penambahan silika sebagai pengisi di dalam membran PLLA-PEG/SiO₂ menjadikan permukaannya berliang dan mampu meningkatkan bilangan liang. Oleh itu, kesan penambaan berat silika ke dalam membran kopolimer PLLA-PEG dikaji menggunakan FTIR, SEM dan EDX. Berdasarkan analisis FTIR, pembentukan kopolimer PLLA-PEG telah dibuktikan dengan kehadiran kumpulan berfungsi uretana (-NHCOO-) dan mikrograf SEM menunjukkan permukaan berliang yang terdapat pada membran selain terdapat peningkatan dari segi saiz liang selepas penambahan berat silika. Seterusnya, kebolehbasahan permukaan membran telah dinilai melalui analisis sudut sentuhan air kerana telah memperlihatkan ciri-ciri kehidrofilikan. Kesemua membran ini telah diaplikasikan bagi rawatan POME yang telah menunjukkan perubahan penyahwarnaan yang signifikan. Tambahan lagi, kadar peratusan penyingkiran yang tinggi bagi BOD, COD dan TSS sehingga 99.5% telah membuatkan air sisa POME yang terawat berada dalam had pengeluaran yang telah dikeluarkan oleh Jabatan Alam Sekitar Malaysia.

Kata kunci: Kopolimer; membran; poli(etilena glikol); poli(L-asid laktik); POME

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*Pengarang untuk surat-menyurat; email: farahhannan@ukm.edu.my