The suitability of titanium salts in coagulation removal of micropollutants and in alleviation of membrane fouling.
In: Water Research, Jg. 205 (2021-10-15), S. N.PAG
academicJournal
Zugriff:
• Superior floc properties and low residues were the main merits of TXC. • TXC overperformed TiCl 4 and PTC for toxic oxysalts and antibiotics removal. • TXC pre-coagulation could effectively alleviate ultrafiltration membrane fouling. • The diketone moieties make TXC less sensitive to coordination reactions with organics. Coagulation is a conventional method in water treatment. In recent decades, with the rapid development of membrane filtration, the use of coagulation is facing some new challenges. How to minimize the membrane fouling became a leading-edge topic in the study of coagulation. Here, the performances of three types of titanium coagulants were evaluated in terms of both the coagulation removal of toxic micropollutants and the alleviation of membrane fouling. Three oxysalts and two antibiotics were taken as representatives of inorganic and organic micropollutants. As compared with titanium tetrachloride (TiCl 4) and polytitanium chloride (PTC), titanium xerogel (TXC) with a higher polymerization degree showed much better performances in direct coagulation removal of oxysalts and antibiotics and in pre-coagulation for mitigating membrane fouling in both coagulation-sedimentation-ultrafiltration (CSUF) and in-line coagulation-ultrafiltration (CUF) processes. In the CSUF system, the membrane permeate flux with TXC pre-coagulation (89.5%) was much higher than those of TiCl 4 (56.1%) and PTC (57.4%). After a 5 day continuous operation, the transmembrane pressure in the CUF system with TXC coagulation was increased only to 4.9 kPa, while those of PTC and TiCl 4 were 12.2 and 18.5 kPa, respectively. The results here demonstrate that TXC is a promising coagulant for pollutant removal and membrane fouling alleviation, due to the following merits: better floc properties, weaker pH-dependence, and higher resistance to coordination with organic pollutants. The observation shed new lights on the fabrication and application of coagulants in a wide variety of scenarios. [Display omitted] [ABSTRACT FROM AUTHOR]
Titel: |
The suitability of titanium salts in coagulation removal of micropollutants and in alleviation of membrane fouling.
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Autor/in / Beteiligte Person: | Gan, Yonghai ; Zhang, Li ; Zhang, Shujuan |
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Zeitschrift: | Water Research, Jg. 205 (2021-10-15), S. N.PAG |
Veröffentlichung: | 2021 |
Medientyp: | academicJournal |
ISSN: | 0043-1354 (print) |
DOI: | 10.1016/j.watres.2021.117692 |
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