Treatment of fresh leachate by anaerobic membrane bioreactor
This study proposed fresh leachate treatment with AnMBR based on the on-site investigation of the characteristics of fresh leachate. Temperature-related profiles of the fresh leachate properties and a high ratio of BOD5/COD (0.462 ~ 0.719) were observed. In addition, AnMBR achieved a high COD removal of 98.6% with a maximum organic loading rate (OLR) of 19.27 kg-COD/m3/d at the shortest HRT of 1.5 d, significantly higher than those by other anaerobic processes for fresh leachate treatment, such as UASB and EGSB. The microbial analysis implied that the abundant protein and carbohydrate degraders (e.g., Thermovirga and Petrimonas) as well as syntrophic bacteria, such as Syntrophomonas, ensured the effective adaptation of AnMBR to the reduced HRTs. However, an excessive OLR at 36.55 kg-COD/m3/d at HRT of 1 d resulted in a sharp decrease in key microbes, such as archaea (from 37% to 15%), finally leading to the deterioration of AnMBR.