Fouling-regeneration mechanisms and life time prediction of rice husk-derived low-cost ceramic membranes for pretreatment-asssisted peat water treatment

Peat water treatment is limited by high dissolved organic matter, acidity, colour, and membrane fouling.The fouling-regeneration behaviour and operational lifetime of a rice husk-derived low-cost ceramic membrane used after sequential pretreatment were investigated in this study.The tubular membrane was prepared from natural clay, rice husk activated carbon, and Fe₂O₃ at 82.5 : 15.0 : 2.5 wt.% and sintered at 900 °C.The membrane was characterised by SEM-EDS, elemental mapping, XRD, TGA, image analysis, and Archimedes method.Peat water was pretreated by sedimentation, slow-sand filtration, sponge filtration, and activated-carbon adsorption before membrane filtration at 2 bar.Six filtration-backwashing cycles were performed, and fouling was interpreted by using the classical Hermia models.The membrane showed a heterogeneous porous structure with an average porosity of 47.927% and a high thermal stability.Turbidity, colour, Fe, Mn, and nitrite were removed in 98.87%, 91.05%, 98.00%, 97.10% and 99.92%, respectively, and removal of detectable E. coli as well as total coliform was achieved by the integrated system.Fouling developed from internal pore constriction resulting in cake layer formation and more serious pore blocking.The backwashing hydraulic flow reached 95.60-94.23% of flux recovery ratios.However, the irreversible fouling increased from 4.40 to 5.77%, and the filtration time decreased from 77 to 13 h.Recovered flux followed J n /J 0 = e [-0.0498(n-1)] with R 2 = 0.9958.Membrane lifetime was estimated to be 8.17 cycles or 211 h at 70% end-of-life threshold.The membrane thus provides high quality peat water polishing, but requires increased periodic cleaning to limit the accumulation of irreversible fouling.