Optimization of Kapok Fiber Adsorption in Integrated Electocoagulation and Moving Bed Biofilm Reactor for Treating Palm Oil Mill Effluent

Abstract

The integrated Electrocoagulation (EC) and Moving Bed Biofilm Reactor (MBBR) system still faces limitations in effectively removing Oil and Grease (O&G) from Palm Oil Mill Effluent (POME). This study aimed to enhance O&G removal efficiency by incorporating chemically modified kapok fiber (KF) as an adsorbent medium. The fibers were treated using tetraethyl orthosilicate (TEOS) and trimethylchlorosilane (TMCS), followed by pyrolysis at 300°C and 400°C. The research involved four stages: media preparation, reactor assembly, biomass seeding and acclimatization, and performance evaluation. The best result was achieved using KF (1:1)/300, with an O&G removal efficiency of 90.45%. The Redlich–Peterson isotherm model provided a more accurate prediction of adsorption parameters compared to the Langmuir model. Additionally, the modified EC–MBBR unit successfully reduced TSS by 78%, sCOD by 66%, and increased the pH from acidic to neutral–alkaline conditions. It is recommended to replace kapok media periodically and explore further chemical modifications to prevent the final-stage rise in sCOD levels.

Kinerja integrasi Elektrokoagulasi (EC) dan Moving Bed Biofilm Reactor (MBBR) masih kurang optimal dalam mengurangi kandungan minyak dan lemak (oil and grease/O&G) pada limbah cair kelapa sawit (POME). Penelitian ini bertujuan meningkatkan efisiensi penyisihan O&G dengan menambahkan media adsorpsi berupa serat kapuk yang telah dimodifikasi secara kimia menggunakan TEOS dan TMCS, kemudian dipirolisis pada suhu 300°C dan 400°C. Penelitian dilakukan melalui empat tahap, yaitu persiapan media, perakitan reaktor, proses seeding dan aklimatisasi, serta pengujian kinerja reaktor. Hasil terbaik diperoleh pada variasi kapuk (1:1)/300 dengan efisiensi penyisihan O&G mencapai 90,45%. Model isoterm Redlich–Peterson terbukti lebih akurat dalam memprediksi parameter adsorpsi dibandingkan model Langmuir. Selain itu, unit EC–MBBR juga berhasil menurunkan kadar TSS sebesar 78%, sCOD sebesar 66%, serta meningkatkan pH dari kondisi asam menjadi netral–basa. Media kapuk disarankan diganti secara berkala dan dilakukan eksplorasi modifikasi kimia lanjutan untuk mengatasi peningkatan sCOD pada akhir proses.