Integrated thermophilic enzyme-immobilized reactor and high-rate biological reactors for treatment of palm oil-containing wastewater without sludge production.

Bacillus pumilus, the thermophilic microorganism, was used to biosynthesise lipase of specific activity 5173 U. The purified lipase was highly stable in the pH range from 1 to 7 and temperature at 50 °C. The functionalized nanoporous activated carbon matrix was used for the immobilization of lipase at the optimum conditions and was used for the hydrolysis of palm oil-containing wastewater at optimum time, 3 h, pH 7, and at temperature 50 °C. The hydrolyzed palm oil wastewater was treated in an upflow anaerobic reactor for the removal of soluble COD at hydraulic retention time (HRT) of 3 days. The anaerobic-treated wastewater was applied to the fluidized immobilized carbon catalytic oxidation (FICCO) reactor at HRT of 16 h to reduce the soluble COD. The FICCO-treated wastewater was further treated in chemo-autotrophic activated carbon oxidation (CAACO) reactor to reduce the COD less than 100 mg/L.