Basicity of titanium-based coagulants matters in the treatment of low-turbidity water

Acetylacetone promoted high-efficiency coagulation toward arsenite through a synchronous photooxidation process

“…Different from organic matter, turbidity cannot coordinate with the metal hydrolysates and compete for the active sites. 42 The main inhibition stemming from its effect on AA photooxidation is by obstructing the transmission of light. It is worth noting that the turbidity was removed simultaneously, especially at a high turbidity load (Fig.…”

“…The O 1s spectra of the two flocs exhibited three O 1s components, including O 2− (530.1 eV), OH − (531.3/531.5 eV), and O in the water molecule (533.0/ 533.3 eV). 41,42 Compared with the flocs generated in the UV + TS system, the UV/AA + TS sample had an increased O 2− content but decreased proportion of OH − , which was because more arsenic immobilized on its surface. Thus, based on these results, it can be concluded that arsenic was mainly removed by coordination adsorption with the Ti-OH bond in the coagulated flocs, whereas AA only exhibited an oxidation function and did not promote the immobilization of arsenic.…”

Insighting the interaction mechanism of zirconium xerogel coagulants with humic acid: the protective effect of acetylacetone

“…4b). 15,34 The Cl2p spectrum was composed of two Zr-Cl peaks (199.7 eV and 198.3 eV) (Fig. 4c), which originated from incompletely hydrolyzed Cl in the structure.…”

“…14 This type of coagulants offer the advantages of lower dosage requirements, lower residual turbidity, and wider pH application range, which have made the acetylacetone-regulated sol-gel method receive special attention in the field of developing new coagulants. 15,16 In this study, zirconium xerogel coagulants (ZXC) were prepared by using acetylacetone regulation, which resulted in stronger turbidity removal ability, improved organic load resistance, higher hydrolysis stability and desirable effluent pH values. Then, the effects of acetylacetone on the microscopic and structural morphology of ZXC were investigated by FTIR, XRD, TEM, SEM and UV-vis spectrophotometry.…”

“…14 This type of coagulants offer the advantages of lower dosage requirements, lower residual turbidity, and wider pH application range, which have made the acetylacetone-regulated sol–gel method receive special attention in the field of developing new coagulants. 15,16…”