Effect of the lignocellulolytic substrates and fermentation process parameters on myco-coagulant production for water treatment

Abstract

In the present research, a fungal strain was used to produce a myco-coagulant via solid-state bioconversion to reduce water turbidity. The production of myco-coagulant was achieved using several low-cost lignocellulolytic substrates, namely coco peat, sawdust, palm kernel cake, and rice bran as sources of carbon and nitrogen. This research involves the study of both the effect of lignocellulolytic substrates and the parameters involved in the fermentation process for myco-coagulant production. Coco peat was chosen as a suitable lignocellulolytic substrate to serve as a carbon source for producing myco-coagulant, potentially reducing the turbidity by 84.6% from the kaolin suspension. Sawdust, palm kernel cake, and rice bran showed 33.06%, 30.18, and 21.18 %, respectively. Furthermore, a statistical approach to the Plackett-Burman design was conducted to evaluate the significant parameters that affect the production of myco-coagulant. Eleven fermentation process parameters were selected: concentration of coco peat (2- 4 %), incubation time (5-9 days), temperature (25-35 °C), pH (5-9), glucose (0-2 %), malt extract (1-2 %), yeast extract (0-2%), wheat flour (0-2 %), ammonium sulfate (0-1 %), inoculum size (1-3 %) and potassium dihydrogen phosphate (0-0.5 %). The selected variables were assessed through statistical analysis (main effects) based on their significance. Based on the main effect of each variable on flocculation activity, three variables, namely glucose, malt extract, and pH influenced high levels. On the other hand, the remaining eight variables did not significantly affect the production of myco-coagulant. Furthermore, a deeper study was conducted to further optimize the three effective variables involved in the fermentation process to evaluate these factors' influence on flocculation activity. ABSTRAK: Penyelidikan ini adalah berkenaan strain fungus yang digunakan bagi menghasilkan miko-koagulan melalui penukaran-bio berkeadaan pepejal bagi mengurangkan kekeruhan air. Miko-koagulan dihasilkan dengan menggunakan beberapa substrat lignoselulolitik berkos rendah, iaitu habuk kelapa, habuk papan, hampas kelapa sawit, dan dedak padi sebagai sumber karbon dan nitrogen. Penyelidikan ini mengkaji kesan substrat lignoselulolitik dan faktor-faktor yang terlibat dalam proses fermentasi bagi menghasilkan miko-koagulan. Habuk kelapa dipilih sebagai substrat lignoselulolitik yang sesuai berfungsi sebagai sumber karbon dalam menghasilkan miko-koagulan, berpotensi mengurangkan kekeruhan sebanyak 84.6% daripada ampaian kaolin. Sebaliknya, habuk papan, hampas kelapa sawit, dan dedak padi menunjukkan 33.06%, 30.18, dan 21.18 %, masing-masing. Tambahan pula, pendekatan statistik ke atas reka bentuk Plackett-Burman telah dijalankan bagi menilai parameter penting yang mempengaruhi penghasilan miko-koagulan. Sebelas parameter proses penapaian telah dipilih: kepekatan habuk kelapa (2- 4 %), masa pengeraman (5-9 hari), suhu (25-35 C), pH (5-9), glukosa (0-2 %), ekstrak malt (1-2), tepung gandum (0-2 %), ammonium sulfat (0-1%), saiz inokulum (1-3 %) dan Kalium dihidrogen fosfat (0-0.5 %). Pemboleh ubah yang dipilih dinilai melalui analisis statistik berdasarkan kepentingannya. Berdasarkan kesan utama setiap pemboleh ubah terhadap aktiviti penggumpalan, tiga pemboleh ubah ini adalah glukosa, ekstrak malt, dan pH yang memberi kesan tertinggi. Sebaliknya, lapan pemboleh ubah lain tidak mempengaruhi penghasilan miko-koagulan dengan ketara. Tambahan lagi, kajian yang lebih mendalam telah dijalankan bagi membaiki tiga pemboleh ubah utama yang terlibat dalam proses fermentasi bagi menilai kesan yang mempengaruhi aktiviti penggumpalan.