CN-122013201-A - Polymeric lanthanum titanium-based flocculant and preparation method and application thereof

Abstract

The invention belongs to the technical field of material chemistry, and provides a polymeric lanthanum titanium-based flocculant, a preparation method and application thereof. The invention adopts the electrochemical method to prepare the lanthanum titanium composite flocculant, and has the advantages of simple and convenient operation and controllable process. The composite flocculant has obvious synergistic effect on pollutant removal efficiency, has particularly outstanding removal rate of organic matters, phosphate and UV 254 in water, reduces the problem of high cost of a single lanthanum flocculant, simultaneously provides strong phosphorus precipitation capability for lanthanum, and solves the problem of insufficient efficiency of titanium salt under the condition of low phosphorus.

Inventors

• ZHAO YANXIA
• YAN LU
• ZHANG XINYI
• Mou Junli
• SHI YAGE
• LIU BEIBEI
• SUN CHUNYI
• TIAN CHANG
• YAN LIANGGUO

Assignees

• 济南大学

Dates

Publication Date

20260512

Application Date

20260205

Claims (10)

1. 1. The electrochemical process of preparing polymerized lanthanum-titanium coagulant includes the steps of mixing titanium salt solution with lanthanum salt solution as the reaction liquid for electrodialysis to produce anionic OH - through semi-permeable membrane and reaction liquid; the mol ratio of lanthanum ions to titanium ions in the reaction liquid is (0.05-0.3): 1.
2. 2. The method of claim 1, wherein the electrodialysis is performed under conditions of 0.02A to 0.05A constant current electrodialysis, and the dialysis time is 1 to 8 h.
3. 3. The method according to claim 1, wherein the concentration of cations in the reaction solution is 0.5-10 mol/L and the concentration of the catholyte or anolyte is 0.1-1 mol/L.
4. 4. The method according to claim 1, wherein the molar ratio of lanthanum ions to titanium ions in the reaction solution is 0.3:1, the electrodialysis time is 1-2 h, and the catholyte or anolyte concentration is 0.1-0.5 mol/L.
5. 5. The method according to claim 1, wherein the titanium salt is selected from any one of titanium tetrachloride or titanium sulfate, and the lanthanum salt is selected from any one of lanthanum chloride, lanthanum nitrate or lanthanum sulfate; the catholyte is selected from sodium chloride or potassium chloride, and the anolyte is selected from sodium sulfate or potassium sulfate.
6. 6. The method according to claim 1, characterized in that the catholyte, anolyte are stirred during electrodialysis.
7. 7. A polymeric lanthanum titanium coagulant prepared by the method of any one of claims 1-6 and a water treatment agent prepared therefrom.
8. 8. The use of the polymeric lanthanum titanium coagulant or water treatment agent according to claim 7 in water treatment.
9. 9. A water treatment method, characterized by comprising a step of adding the polymeric lanthanum titanium coagulant or the water treatment agent according to claim 7 to water to be treated.
10. 10. The method for treating water according to claim 9, wherein the addition amount is 2.5-50 mg-Ti/L, preferably 10-40 mg-Ti/L.

Description

Polymeric lanthanum titanium-based flocculant and preparation method and application thereof Technical Field The invention belongs to the technical field of material chemistry, and particularly relates to a polymeric lanthanum titanium-based flocculant and application thereof. Background Lanthanum (La) is a rare earth element with abundant and low cost, has good biocompatibility and strong chemical reactivity, and has fast hydrolysis rate and small influence by temperature. Meanwhile, lanthanum has larger electron radius, outer layer electrons are in an unfilled state, coordination is active, and metal lanthanum has strong specific affinity to oxygen atoms in phosphate groups, so that insoluble lanthanide complexes are easy to form, and excellent dephosphorization performance is shown. The coagulation effect is little affected by water quality. The single lanthanum salt coagulant has the problems of high cost, high residual lanthanum metal, narrow pH application range, large pH change range of effluent, influence on the stable performance of the subsequent process and the like when being directly used. Proved by researches, titanium salt (such as TiCl 4) can be hydrolyzed in the water treatment process to generate polynuclear hydroxy titanium complex (such as Ti 4(OH)84+), and the complex has the core characteristics of high charge density and rapid hydrolysis, can adsorb negative charges of colloid particles in water body through electric neutralization, and can wrap suspended impurities through combination of net capturing and rolling sweeping, thereby realizing high-efficiency removal of turbidity and organic matters of the water body. The titanium salt coagulant has less hydrolysis residue, small influence on a lower-stage treatment unit, and the flocculation growth rate, the flocculation size and the sedimentation speed in the coagulation process are high, so that the time required by coagulation-sedimentation is greatly shortened. In addition, the titanium salt coagulant has other advantages such as no toxicity, excellent settling property of the generated flocs and capability of preparing TiO 2 by calcining and recycling chemical sludge generated after treatment. Thanks to the above advantages, titanium salt coagulants have been widely studied in the aspects of drinking water treatment, wastewater treatment, sludge dewatering, pre-membrane pretreatment, and the like. However, the single titanium salt coagulant has limited effect of removing low-concentration phosphorus due to easy saturation of adsorption points, and is difficult to meet the requirement of deep phosphorus removal, and secondly, the titanium salt coagulant is easy to be influenced by pH value fluctuation in the process of coagulating treatment, and the pH value of an effluent solution is too low, so that the stability is insufficient in a complex water environment. In conclusion, the single titanium salt or lanthanum salt coagulant cannot meet the requirements of high-efficiency dephosphorization, wide pH adaptation, rapid sedimentation and turbidity removal and organic matter removal at the same time, so that the poly-lanthanum-titanium composite coagulant is invented to realize complementary advantages of the two, and becomes a necessary direction for solving phosphorus pollution of surface water. Disclosure of Invention Aiming at the phenomenon that the current sewage treatment requirements are continuously improved and the problem of urban water phosphorus pollution, the invention provides the electrochemical preparation method of the poly lanthanum titanium composite coagulant, and the coagulation effect is compared, so that the advantages of high-efficiency phosphorus removal, wide pH adaptation, rapid sedimentation and high-efficiency turbidity and organic matter removal of the poly lanthanum titanium composite coagulant are reflected. In order to achieve the above purpose, the present invention adopts the following technical scheme. The electrochemical process of preparing polymerized lanthanum-titanium coagulant includes the following steps: mixing titanium salt solution and lanthanum salt solution as reaction liquid of electrodialysis, and enabling anion OH - generated by the catholyte and the anolyte to permeate through a semipermeable membrane to react with the reaction liquid to obtain the product; The molar ratio of lanthanum ions to titanium ions in the reaction liquid is (0.05-0.3): 1, preferably 0.3:1. The electrodialysis condition is constant current electrodialysis under the condition of 0.02A-0.05A, the electrodialysis time is 1-8 h, the electrodialysis time has little influence on the effect of removing organic matters of the coagulant, and the electrochemical method for preparing the flocculant is actually a prehydrolysis process, namely under the pushing of an external direct current power supply, OH - and metal cations in a reaction chamber are polymerized to generate hydroxyl polymers. The increase of electrod