Work

Enhanced Removal of Nitrate and Tetracycline by Bacillus cereus W2 Immobilized on Biochar

Year: 2025

Type: article

Abstract: The co-contamination of nitrate nitrogen (NO3−-N) and tetracycline (TC) in aquaculture water has caused serious environmental and health problems. Bioremediation is a promising approach for the removal of NO3−-N and TC. However, free bacteria are sensitive to environmental variation, limiting its application. In this study, a bacterial strain with high NO3−-N and TC degradation ability, Bacillus cereus W2, was isolated and immobilized on wheat straw biochar by an adsorption method. The effect of immobilization conditions, including biochar dosage, inoculum amount, and immobilization time on NO3−-N and TC removal was explored. The degradation abilities of the biochar-immobilized Bacillus cereus W2 under different nitrate and TC concentrations was investigated. Results showed that the prepared biochar had abundant functional groups such as -COOH, -OH, -C=C-OH, etc., which have good affinity for microbial cell membranes and are conducive to the adhesion and proliferation of microbial cells. The highest NO3−-N and TC removal efficiencies of 99.50% and 78.60% after 24 h were obtained under a biochar dosage of 4 mg·mL−1, microbe inoculation amount of 40%, and immobilization time of 24 h. The immobilized Bacillus cereus W2 performed better NO3−-N and TC removal than the free cells under different initial NO3−-N and TC concentrations. The enhanced removal of NO3−-N by the biochar-immobilized Bacillus cereus W2 may be attributed to the promoted expression level of functional genes involved in denitrification (nirS, norB, and nosZ). The biochar-immobilized Bacillus cereus W2 demonstrates potential for treating various nitrate-antibiotic co-contaminated wastewaters, including those from livestock farming, aquaculture systems, and pharmaceutical industries.

Source: Water

DOI: 10.3390/w17030380

Authors: Jiangpeng Xue, Xinyue Lu, Lianghuan Wei, Xianghao Zha, Wenjie Xu

Institutions: Kashi University, China National Offshore Oil Corporation (China), Nanjing 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: $3,137