Titanium xerogel coagulant (TXC) worked better than titanium tetrachloride (TC) and polytitanium chloride (PTC) in a wider pH/dose range for the removal of turbidity. However, the underlying mechanisms were not comprehensively understood. In this work, the better coagulation performance of TXC than TC and PTC was systematically elucidated from the following aspects: the physicochemical properties of the three coagulants, the removal of turbidity and organic matter, and the complexation reactions in coagulation. The results demonstrate that the merits of TXC were attributable to the following characteristics: (1) the higher surface charge density/total surface site concentration/isoelectric point of TXC hydrolysates, (2) the formation of TXC hydrolysates with a net-work structure, and (3) the strong binding affinity of TXC hydrolysates to organic matter caused by the bonded acetylacetone in the TXC framework. In short, the hydrolysis behavior of TXC significantly differed from both its precursor, TC, and the prehydrolyzed PTC. The difference in the hydrolysis of TXC was derived from the gelation process, which led to the polymerization of Ti in a way different from prehydrolyzation. The elucidation of the hydrolysis mechanisms is useful for the better application of Ti-based coagulants and may shed light on the preparation of other metal salts.

钛干凝胶凝结剂（TXC）在较宽的pH /剂量范围内比四氯化钛（TC）和聚氯化钛（PTC）更好地去除了浊度。但是，尚未全面了解其潜在机制。在这项工作中，从以下方面系统地阐明了TXC比TC和PTC更好的混凝性能：三种混凝剂的理化性质，浊度和有机物的去除以及混凝中的络合反应。结果表明，TXC的优点归因于以下特征：（1）TXC水解产物的表面电荷密度/总表面位点浓度/等电点较高，（2）具有网络结构的TXC水解产物的形成，（3）TXC水解产物对有机物的强结合亲和力，该结合物是由TXC骨架中键合的乙酰丙酮引起的。简而言之，TXC的水解行为与它的前体TC和预水解的PTC显着不同。TXC水解的差异源自凝胶化过程，这导致Ti聚合的方式与预水解不同。阐明水解机理有助于更好地应用Ti基凝结剂，并可能有助于其他金属盐的制备。从而导致钛以不同于预水解的方式聚合。阐明水解机理有助于更好地应用Ti基凝结剂，并可能有助于其他金属盐的制备。从而导致钛以不同于预水解的方式聚合。阐明水解机理有助于更好地应用Ti基凝结剂，并可能有助于其他金属盐的制备。