Kinetics of organics removal in swine wastewater treatment using anaerobic moving bed biofilm reactor

In Vietnam, livestock production, especially pigs, plays an important role in the agriculture sector. The number of livestock farms in Vietnam is more than 19,000 with 28 million pigs. However, swine wastewater mainly directed to biogas is finally discharged to ponds and lakes, causing serious environmental problems. This research applied the high-rate anaerobic moving bed biofilm reactor (AnMBBR) to treat swine wastewater. A lab-scale reactor with a working volume of 12 L in which 4 L wheel-shaped polyethylene carrier materials (PE) and 4 L anaerobic inoculum were added. This reactor operated continuously at 35 degrees C +/- 2 degrees C in 185 d under the volumetric loading rate with 12.2 kg-COD/m(3) d. The average total chemical oxygen demand (COD) removal efficiency was 60% with a methane conversion efficiency of about 54%. A kinetic model referred from Anaerobic Digestion Model No. 1 was used to simulate reasonably the methane production, total COD, total suspended solids as well as the effluent compositions in terms of carbohydrate, protein, lipid, propionate, acetate, and ammonium nitrogen. In regression analysis, linear correlation showed that the simulation results almost corresponded with the experiment results. The model could be employed to design the AnMBBR at a pilot scale for the removal of organic matters in swine wastewater.