Work

A sulfur-autotrophic bacterial-algal synergistic system for enhanced nitrogen and phosphorus removal

Year: 2025

Type: article

Abstract: In the study of nitrogen and phosphorus removal technology in aquatic environments, bacteria-algae symbiotic systems have attracted increasing attention for their high efficiency and sustainability. Current research primarily focuses on heterotrophic bacteria-algae systems, which exhibit significant limitations when treating low carbon-to-nitrogen ratio (C/N) wastewater, such as the need for an additional carbon source and maintaining dissolved oxygen levels, leading to increased operational costs. In this study, a sulfur autotrophic bacteria-algae synergistic system was constructed to treat low C/N, high nitrate nitrogen (NO₃⁻-N), and phosphorus (P) wastewater, aiming to enhance nitrogen and phosphorus removal efficiency while reducing operational costs. First, the effects of different operating conditions on nitrogen and phosphorus removal were investigated to determine the optimal parameters. Then, under the optimal conditions, pure bacteria and pure algae systems were set up for comparison to evaluate the treatment efficiency and long-term stability of the sulfur autotrophic bacteria-algae synergistic system. Finally, high-throughput sequencing was used to analyze the microbial community structure within the system. Experimental results showed that the optimal operating conditions were a bacteria-to- algae ratio of 1:1, a light intensity of 5000 Lux, and a light-dark cycle of 12h:12h. Compared with pure algae and pure bacterial systems, the sulfur autotrophic bacteria- algae synergistic system exhibited superior nitrogen and phosphorus removal efficiency and stability, achieving a nitrate nitrogen (NO₃⁻-N) removal rate of 92%-98.6% and a total phosphorus (TP) removal rate of 60%-65%, with no accumulation of nitrite nitrogen (NO₂⁻-N) in the effluent. The dominant bacterial genera in the system were Thiobacillus, Sulfurimonas, and Ferritrophicum, whose abundance increased as the system stabilized over time.

Source: Water Cycle

DOI: 10.1016/j.watcyc.2025.08.001

Authors: Xintong Feng, Jiquan Yin, Ganlu Zhu, Ning Guo, Zhaoliang Zhu

Institutions: Shandong Jianzhu University, Guangdong Technion-Israel Institute of Technology

Language: English

Topic: Wastewater Treatment and Nitrogen Removal

Subfield: Pollution

Field: Environmental Science

Domain: Physical Sciences

SDGs: Clean water and sanitation, Responsible consumption and production

Open Access status: gold

Estimated APC paid: $1,100