The origin of Al(OH)3-rich and Al13-aggregate flocs composition in PACl coagulation

Aluminum speciation of coagulants with low concentration: Analysis by electrospray ionization mass spectrometry

“…amorphous Al(OH) 3 flocs), and total ions decreased. Some researchers indicated that Al 13 species formed Al 13 aggregates at pH 6.0 [11,31]. Thus, salicylic acid can be adsorbed on Al 13 aggregates and formed Al 13 -salicylate aggregates, which resulted in no signals of aluminum species and Al 13 -salicylate complexes in the ESI-MS detection.…”

“…Traditional methods include potentiometric titration [4], Al-Ferron timed spectrophotometric assay [5,6] and 27 Al nuclear magnetic resonance ( 27 Al NMR) spectroscopy [7,8]. In addition, X-ray diffraction [9], Raman spectroscopy [10] and X-ray photoelectron spectroscopy [11] are used as aluminum speciation analysis. Al-Ferron assay and 27 Al NMR spectroscopy were common means to identify aluminum speciation of coagulant.…”

Evaluation of enhanced coagulation coupled with magnetic ion exchange (MIEX) in natural organic matter and sulfamethoxazole removals: The role of Al-based coagulant characteristic

“…Other mechanisms, including interparticle bridging and adsorption might also play significant roles in HA removals. It has been recognized that monomeric Al readily forms a large amount of amorphous aluminum hydroxide [29], and consequently when AS solution, containing most monomeric Al, was dosed into the solution at a sufficiently high concentration (above 4.0 mg/L), organic matters could be efficiently enmeshed in the amorphous precipitates.…”

Effect of aging condition on species transformation in polymeric Al salt coagulants

“…This method has little effect on the transformation of Al species and might represent the original status of Al species in solution. The analysis results of AFM might also help the explanation of Al species obtained with some other methods [22]. Thus, the combination application of several methods might provide more information for Al species in solution.…”