Affiliation:
1. Anhui Provincial Engineering Laboratory for Rural Water Environment and Resources, School of Civil and Hydraulic Engineering Hefei University of Technology Hefei China
2. Anhui Provincial Academy of Eco‐Environmental Science Research Hefei China
3. CAS Key Laboratory of Crust‐Mantle Materials and the Environments, School of Earth and Space Sciences University of Science and Technology of China Hefei China
4. Mass Spectrometry Lab, Hefei National Laboratory for Physical Sciences at Microscale University of Science and Technology of China Hefei China
Abstract
AbstractIn the present study, magnetic coagulation was used to treat dredged water and the response surface method was used to optimize process parameters. The dissolved organic matter (DOM) removal characteristics were characterized by three‐dimensional fluorescence spectrometry and ultra‐high resolution mass spectrometry. During the magnetic coagulation process, the suspended solids (SS) removal rate increased initially and then decreased under conditions of increasing magnetic powder dosage and stirring rate. After magnetic coagulation and precipitation for 20 min, the contents of SS, ammonia nitrogen, chemical oxygen demand, and total phosphorus in the treated dredged water met the requirements of the discharge standard (GB8978–1996, China). Three‐dimensional fluorescence results showed that magnetic coagulation selectively removed fulvic acids and humic acid substances. After magnetic coagulation with precipitation for 10 min and 20 min, the total relative content of lignins, tannins, proteins, lipids, aminosugars, unsaturated hydrocarbons, condensed aromatic structures, and carbohydrates decreased by 26.3% and 39.4%, respectively. After magnetic coagulation, the distribution range of small molecule DOM shifted to the low H/C and high O/C regions. This study provides a novel perspective for studies on the removal of DOM in dredged water by magnetic coagulation.Practitioner Points
SS and DOM removal were significantly enhanced by the use of magnetic coagulation.
SS removal efficiency was affected by stirring rate and magnetic powder dosage.
Magnetic coagulation selectively removed fulvic acids and humic acid substances.
DOM molecule shifted to low H/C and high O/C regions after magnetic coagulation.
Funder
National Natural Science Foundation of China