In:
Water, MDPI AG, Vol. 15, No. 9 ( 2023-05-06), p. 1782-
Abstract:
Coagulation can effectively recover substances from wastewater; however, there is a lack of efficient coagulants for simultaneous recovery of organic matter, nitrogen, and phosphorus. We prepared a composite polysilicate metal (CSM) flocculant by combining Fe3+ and Mg2+ ions in polysilicic acid (PSiA). According to the results of scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR), the CSM exhibited a larger amorphous phase along with new compounds, including Mg3Fe2(SiO4)3 and hydroxyl metals. The CSM demonstrated a higher coagulation efficiency than PSiA and polymeric ferric sulfate, particularly for PO43−-P and NH4+-N removal. The metal/silicate molar ratio substantially influenced the structure and composition of the CSM, along with the coagulation efficiency, with an optimal ratio of 3:1. Additionally, we proposed a novel preparation strategy to achieve an optimum CSM basicity (B*) for coagulation by adjusting the initial pH of PSiA (pHInitial) without adding an alkali agent. The results demonstrated that the optimum B* can be obtained by adjusting pHInitial to 0.5 or 1. The overall optimum coagulation performance for the simultaneous removal of organic matter, PO43−P, and NH4+-N from wastewater was 68.5%, 99%, and 17.5%, respectively. This study provides a feasible approach for synchronous pollutant recovery from wastewater.
Type of Medium:
Online Resource
ISSN:
2073-4441
Language:
English
Publisher:
MDPI AG
Publication Date:
2023
detail.hit.zdb_id:
2521238-2
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