Phosphate Recovery from Urban Sewage by the Biofilm Sequencing Batch Reactor Process: Key Factors in Biofilm Formation and Related Mechanisms

Environ Res. 2024 Apr 23:118985. doi: 10.1016/j.envres.2024.118985. Online ahead of print.ABSTRACTThe biofilm sequencing batch reactor (BSBR) technique has been deployed in the laboratory to enrich phosphorus from simulated wastewater, but it is still not clear what its performance will be when real world sewage is used. In this work, the effluent from the multi-stage anoxic-oxic (AO) activated sludge process at a sewage plant was used as the feed water for a BSBR pilot system, which had three reactors operating at different levels of dissolved oxygen (DO). The phosphorus adsorption and release, the biofilm growth, and the extracellular polymeric substances (EPS) components and contents were examined. The microbial communities and the signaling molecules N-acyl-l-homoserine lactones (AHLs) were also analyzed. Gratifyingly, the BSBR process successfully processed the treated sewage, and the biofilm developed phosphorus accumulation capability within 40 days. After entering stable operation, the system concentrated phosphate from 2.59 ± 0.77 mg/L in the influent to as much as 81.64 mg/L in the recovery liquid. Sludge discharge had profound impacts on all aspects of BSBR, and it was carried out successfully when the phosphorus absorption capacity of the biofilm alone was comparable to that of the reactor containing the activated sludge. Shortly after the sludge discharge, the phosphate concentration of the recovery liquid surged from 50 to 140 mg/L, the biofilm thickness grew f...
Source: Environmental Research - Category: Environmental Health Authors: Source Type: research