CN-121974497-A - Biochar denitrification and dephosphorization composite material based on quorum sensing signal molecule slow release and metal modification, and preparation method and application thereof

Abstract

The invention discloses a biochar denitrification and dephosphorization composite material based on quorum sensing signal molecule slow release and metal modification, and a preparation method and application thereof, and relates to the technical field of water treatment. The preparation method comprises three steps of preparing the metal modified biochar, preparing the AHL@PLGA microcapsule and carrying out composite granulation. According to the invention, through the synergistic effect of metal active site adsorption and AHL slow-release induced biodegradation, the deep purification of nitrogen and phosphorus in the water body is realized, no additional biological microbial agent and chemical phosphorus removing agent are required to be added, the operation is simple, the operation cost is low, and no environmental ecological and sanitary potential safety hazard exists. The composite material can be directly used as a filler for water treatment systems such as artificial wetlands, ecological ditches and the like, is suitable for deep denitrification and dephosphorization of surface water and tail water of sewage treatment plants, and has good practical application value and popularization prospect.

Inventors

• GUO YANBING
• GAO HUAN
• WU YAN
• LUO ZHU
• SUN LAN

Assignees

• 华中师范大学
• 武汉光化学技术研究院

Dates

Publication Date

20260505

Application Date

20260318

Claims (10)

1. 1. A biochar denitrification and dephosphorization composite material based on quorum sensing signal molecule slow release and metal modification is characterized in that biochar is taken as a carrier, and metal nano particles and slow release microcapsules for embedding quorum sensing signal molecules are loaded on the carrier; the metal of the metal nano-particles is at least two selected from calcium, magnesium and lanthanum, and the quorum sensing signal molecules are N-acyl homoserine lactones.
2. 2. The quorum sensing signaling molecule slow release and metal modification based biochar denitrification and dephosphorization composite material as claimed in claim 1, wherein the N-acyl homoserine lactone is one or two of C 6 -HSL and C 10 -HSL.
3. 3. The quorum sensing signal molecule slow release and metal modification based biochar denitrification and dephosphorization composite material as claimed in claim 1, wherein the wall material of the slow release microcapsule is polylactic acid-glycolic acid copolymer.
4. 4. The quorum sensing signal molecule slow release and metal modification based biochar denitrification and dephosphorization composite material as claimed in claim 1, wherein the loading amount of the metal nano particles is 5-20 wt% of the mass of the biochar.
5. 5. The quorum sensing signal molecule slow release and metal modification based biochar denitrification and dephosphorization composite material as claimed in claim 1, wherein the load of the slow release microcapsule in the composite material is 30-50 mug/g.
6. 6. The quorum sensing signal molecule slow release and metal modification based biochar denitrification and dephosphorization composite material as claimed in claim 1, wherein the coating rate of the slow release microcapsule on the N-acyl homoserine lactone is 80-95%.
7. 7. The method for preparing the biochar denitrification and dephosphorization composite material based on quorum sensing signal molecule slow release and metal modification as claimed in any one of claims 1 to 6, which is characterized by comprising the following steps: (1) Soaking biomass in a metal salt solution, washing to neutrality, and calcining to obtain metal nanoparticle modified biochar; (2) Embedding N-acyl homoserine lactone into the polylactic acid-glycolic acid copolymer by a multiple emulsion solvent volatilization method to form an AHL@PLGA microcapsule; (3) And (3) compounding and granulating the metal nanoparticle modified biochar and the AHL@PLGA microcapsule through an adhesive to obtain the biochar denitrification and dephosphorization composite material based on quorum sensing signal molecule slow release and metal modification.
8. 8. The method according to claim 7, wherein the calcination is carried out in a protective atmosphere at 400-700 ℃ for 1-3 h hours, wherein the inner aqueous phase of the multiple emulsion solvent volatilization method is a dimethyl sulfoxide solution of N-acyl homoserine lactone, the oil phase is a methylene dichloride solution of polylactic acid-glycolic acid copolymer, and the outer aqueous phase is a polyvinyl alcohol aqueous solution.
9. 9. The method of claim 7, wherein the molar ratio of divalent metal to trivalent metal in the metal salt solution is 3:1.
10. 10. The use of the quorum sensing signal molecule slow release and metal modification based biochar denitrification and dephosphorization composite material as claimed in any one of claims 1 to 6 in sewage denitrification and dephosphorization treatment.

Description

Biochar denitrification and dephosphorization composite material based on quorum sensing signal molecule slow release and metal modification, and preparation method and application thereof Technical Field The invention relates to the technical field of water treatment, in particular to a biochar denitrification and dephosphorization composite material based on quorum sensing signal molecule slow release and metal modification, and a preparation method and application thereof. Background As the quality standard of the surface water environment becomes stricter (for example, GB 3838-2002 requires class II water TP less than or equal to 0.1mg/L, TN less than or equal to 0.5 mg/L), the deep denitrification and dephosphorization of sewage becomes a core challenge in the field of water treatment. The traditional biological denitrification and dephosphorization process generally faces the double restriction of sludge age conflict and carbon source competition that nitrifying bacteria need to maintain activity for a long sludge age (> 15 days), phosphorus accumulating bacteria need to ensure dephosphorization efficiency for a short sludge age (about 3 days), so that synchronous denitrification and dephosphorization efficiency is insufficient when the process is in compromise operation, denitrifying bacteria and phosphorus accumulating bacteria have strong competition for carbon source volatile fatty acid in low-C/N sewage, and high-concentration nitrate in return sludge can have an inhibition effect on the phosphorus accumulating bacteria, so that the unbalanced problem of nitrogen and phosphorus removal is further aggravated. To break through this bottleneck, modified filler technology is widely studied. Biochar is considered as a filler matrix with great potential because of wide sources, strong environmental sustainability, abundant functional groups and developed pore structures, but biochar has weak adsorption selectivity on phosphorus and limited adsorption capacity. While the metal-loaded biochar material can improve the dephosphorization capability through physical and chemical adsorption, but cannot synchronously strengthen the biological denitrification effect, the typical quorum sensing signal molecule N-acyl homoserine lactone (N-acyl-homoserine lactones, AHLs) is introduced, and can induce microorganisms to gather to form a biological film and improve the biological denitrification efficiency, the AHLs have half-life in a water phase of less than 24 hours and are easy to diffuse and degrade, so that frequent addition is required in practical application, the utilization rate is lower, and low-cost long-acting regulation and control are difficult to realize. The prior related technology has the main defects that firstly, functional materials are in synergistic deficiency, physical and chemical phosphorus removal materials (such as metal oxide load carriers) often inhibit microbial activity, biological nitrogen removal fillers (such as sulfur autotrophic denitrification media) are in deficiency of phosphorus removal capability, integrated materials capable of achieving synchronous deep nitrogen and phosphorus removal are not yet developed, secondly, AHL application stability is insufficient, AHL directly added into a water body is easy to hydrolyze and is easy to degrade by acyl hydrolase (AiiA) due to ester bonds, effective concentration cannot be maintained on the surfaces of the fillers, so that biofilm formation is slow and denitrification efficiency fluctuates, thirdly, system operation sustainability is poor, traditional fillers are required to be replaced or chemically regenerated after adsorption saturation, secondary pollution is easy to generate, and the denitrification process relies on external addition of a carbon source, so that operation cost is remarkably increased. Although patents and papers have attempted to use metal modified biochar or hydrogels embedding biochar and AHL for removing nitrogen or phosphorus in water, these techniques have failed to solve the problem of stable co-loading of metal components with AHL, and have not achieved space-time synergy of denitrification and dephosphorization functions. Disclosure of Invention The invention aims to provide a biochar denitrification and dephosphorization composite material based on quorum sensing signal molecule slow release and metal modification, and a preparation method and application thereof, so as to solve the problems in the prior art. In order to achieve the above object, the present invention provides the following solutions: The invention provides a biochar denitrification and dephosphorization composite material based on quorum sensing signal molecule slow release and metal modification, which takes biochar as a carrier, wherein metal nano particles and slow release microcapsules for embedding quorum sensing signal molecules are loaded on the carrier; the metal of the metal nano-particles is at least two selected from ca