School of Environmental and Safety Engineering, Changzhou University, Changzhou, 213164, China.
Environ Sci Pollut Res Int. 2023 Feb;30(7):18285-18295. doi: 10.1007/s11356-022-23448-0. Epub 2022 Oct 8.
Titanium xerogel coagulant (TXC) is a new type of coagulant that has attracted much attention in recent years. However, the tetracycline removal performance of TXC was not satisfactory because low isoelectric point (pH) inhibited the electrical neutralization efficiency of TXC in an alkaline environment. To overcome this shortcoming, a composite xerogel coagulant (titanium-aluminum xerogel composite coagulant) was prepared. The removal of tetracycline and turbidity was used as evaluation indexes. It was proved that the combination of aluminum (III) and titanium (IV) enhanced the resistance of TXC to pH. The synthesized titanium-aluminum xerogel composite coagulant (TXAC) has an excellent removal ability of tetracycline in a wide pH range (pH = 5-10). At pH 8.8, the dosage required to remove 80% tetracycline from water decreased from 93 (TXC) to 35 mg/L (TXAC). The reason for this improvement could be attributed to (i) aluminum (III) enhanced the electric neutralization of TXC to negatively charged pollutants in an alkaline environment; (ii) the complexing ability of organic matter and aluminum (III) was enhanced. This work provides a feasible scheme for the pretreatment of tetracycline in water to meet the pretreatment requirements of special water.
钛硅凝胶凝结剂（TXC）是近年来备受关注的新型凝结剂。然而，由于低等电点（pH）抑制了 TXC 在碱性环境中的电中和效率，TXC 的四环素去除性能并不令人满意。为了克服这一缺点，制备了一种复合硅凝胶凝结剂（钛铝硅凝胶复合凝结剂）。以去除四环素和浊度为评价指标。结果表明，铝（III）和钛（IV）的结合增强了 TXC 对 pH 的抵抗力。合成的钛铝硅凝胶复合凝结剂（TXAC）在很宽的 pH 范围内（pH=5-10）对四环素具有优异的去除能力。在 pH 8.8 时，从水中去除 80%四环素所需的剂量从 93（TXC）mg/L 降低到 35 mg/L（TXAC）。这种改进的原因可能是（i）铝（III）增强了 TXC 在碱性环境中对带负电荷污染物的电中和；（ii）增强了有机物和铝（III）的络合能力。这项工作为水中四环素的预处理提供了一种可行的方案，以满足特殊水的预处理要求。
