title: Effect of microwave pretreatment in presence of NaOH on mesophilic anaerobic digestion of thickened waste activated sludge.
abstract: This work experimentally determined the effect of microwave irradiation with NaOH pretreatment on anaerobic digestion of thickened waste activated sludge in semi-continuous mesophilic digesters at hydraulic retention times (HRT) of 15, 10, 7, and 5 days. The degree of substrate solubilization was 18 times higher in pretreated sludge (53.2%) than in raw sludge (3.0%). Removal efficiency of volatile solid in digesters fed with raw (control) and pretreated sludges (PD) decreased as HRT reduced. The highest relative improvement of properties compared with the control occurred at 5 day HRT. Improvements in biogas production compared with the control increased in the PD as HRT was reduced to 5 days (205% higher at 5 days). However, digested sludges in the control and PD increased capillary suction time compared with raw sludge. The results show that microwave irradiation combined with alkali pretreatment is effective in increasing mesophilic anaerobic biodegradability of sewage sludge.
authors: Department of Environmental Engineering, College of Engineering, Kangwon National University, Chuncheon, Gangwon 200-701, Republic of Korea.
authors: Joo-Hyun
authors: JH
authors: Jang
authors: Johng-Hwa
authors: JH
authors: Ahn
mesh_terms: D001421:Bacteria, Anaerobic / Q000378:metabolism* / Q000528:radiation effects; D001673:Biodegradation, Environmental; D008872:Microwaves; D011829:Radiation Dosage; D012037:Refuse Disposal / Q000379:methods*; D012722:Sewage / Q000737:chemistry* / Q000382:microbiology*; D012972:Sodium Hydroxide / Q000737:chemistry* / Q000528:radiation effects
chemical_list: D012722:Sewage; D012972:Sodium Hydroxide