Work

Aerobic granular sludge treating tannery wastewater and particle size control

Year: 2025

Type: article

Abstract: Aerobic granulation of tannery wastewater was achieved in sequencing batch reactors (with R1 using a conventional aeration head and R2 using a spiky-type aeration head). The short settling time (5 min) and the influent (rich in elements such as Ca, Mg, P, and Fe) played important roles in the formation of aerobic granules. The results showed that the granules were cultivated in R1 and R2 on day 36 and day 40, respectively. On the 60th day of operation, the average particle size of R1 and R2 reached 469.6±31.4 μm and 390.3±22.8 μm, respectively, while the SVI5 values were 43.6 mL/g and 46.2 mL/g. The spiky-type aeration head effectively prevented the increase in particle size by continuously cutting the granular sludge. Throughout the whole granulation process, both systems exhibited improved pollutant degradation capabilities (reaching removal efficiency of approximately 85% for COD, 80% for NH4+-N, 70% for TN, and 60% for TP after operating for 60 days). Significant changes were observed in EPS and microbial communities, with a significant increase in the relative abundance of Proteobacteria (from 46.45% in the inoculum sludge to 80.98% in R1 and 75.86% in R2), playing a crucial role in the granulation process.

Source: AIP Advances

DOI: 10.1063/5.0255163