Salt inhibition kinetics in Anaerobic Sequencing Batch Biofilm (ASBBR) treating mustard tuber wastewater at low temperature

摘要

Mustard tuber wastewater is of high organic content (COD =4000 ± 100 L-l),high salinity ([Cl-1] =18～23 g L-1) and biodegradability (BOD5/COD ≈ 0.5).The Anaerobic Sequencing Batch Biofilm Reactor (ASBBR) pretreatment was employed to reduce much of the organics in mustard tuber wastewater.In this study the substrate removal performance and salt inhibition kinetics at low temperature and saline environment were investigated by ASBBR.The result indicated that at low temperature,an aerobic polishing step is necessary to degrade organics in hypersaline wastewater.The maximum specific substrate utilization rate (d-l) k and substrate saturation constant (mg L-1) Ks could be expressed as a function of salinity,Ks =24.19 salinity + 691.21 and k =-0.0004 salinity + 0.0251,respectively.Thus effluent COD concentration could be predicted,this may have some applications for ASBBR design and selection.