Work

An online respirometer based on ammonia oxidizing biofilm for prompt toxicity analysis

Year: 2025

Type: article

Abstract: Wastewater toxicity may significantly disturb the performance of activated sludge processes, the core unit of most wastewater treatment plants, and thus needs to be monitored. The frequently used respirometer with suspended microorganisms is faced with problems of microbial stability and sensitivity. In this study, we designed an online respirometer with ammonia oxidizing biofilm growing in a fixed bed reactor. The toxicity of typical substances (thiourea, 2,4-dichlorophenol, pyridine, Zn 2+ , Co 2+ , Cr 6+ ) was measured with the reduction and the reducing trend of their oxygen uptake rates as a key indicator. The detection limits can be down to 1.25 mg/L for thiourea and 25 mg/L for Zn 2+ with measuring time down to 10 min. The IC 50 of thiourea, 2,4-dichlorophenol, pyridine, Zn 2+ , Co 2+ , Cr 6+ observed at 0.37 mg/L, 7.42 mg/L, 378 mg/L, 168 mg/L, 191 mg/L 733 mg/L, respectively. The toxicity values were in a good linear correlation with the traditional raspatory. Moreover, the regeneration time of biofilm after toxicity measure of 5 mg/L 2,4-dichlorophenol and 100 mg/L Zn 2+ was also evaluated in range of 6-24 h. • An online respirometer based on ammonia oxidizing biofilm. • Thiourea, 2,4-dichlorophenol, pyridine, Zn2+, Co2+, Cr6+ as model toxic substances. • Their measured toxicity linearly correlates with the data from a laboratory respirometer. • The measuring time is decreased from hours down to 10 min.

Source: Water Resources and Industry

DOI: 10.1016/j.wri.2025.100323

Authors: Qiqi Zhang, Haiyang Xu, Jing Lu, Yide He, Anlin Xu, Yongjun Zhang

Institution: Nanjing Tech University

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: $3,613