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CN-121975872-A - Application of Cu/Zn-ZIF material in strengthening anaerobic digestion of organic waste

CN121975872ACN 121975872 ACN121975872 ACN 121975872ACN-121975872-A

Abstract

The invention discloses an application of a Cu/Zn-ZIF material in strengthening anaerobic digestion of organic waste, which is characterized in that a bionic metal organic framework material Cu/Zn-ZIF with Cu (II)/Zn (II) bimetal active centers is added into an anaerobic digestion system of the organic waste, so that a catalysis mechanism of natural copper-zinc superoxide dismutase is simulated, excessive active oxygen induced by exogenous disturbance factors and endogenous factors in the anaerobic digestion process is directionally cleared, the oxidative stress mediated by the active oxygen is reduced, the activity and metabolic stability of key functional microorganisms such as methanogenic archaea are maintained, the tolerance of the anaerobic digestion system to exogenous impact is remarkably improved, and the methane yield and the stability of the anaerobic digestion system are synergistically improved. The invention has simple operation, low operation cost and strong applicability, is suitable for the stable operation of newly built anaerobic digestion facilities, is also suitable for the impact resistance strengthening transformation of the existing device, and has good environmental benefit and economic value.

Inventors

  • XIE BING
  • WANG WENYUE
  • ZHAN MIN

Assignees

  • 华东师范大学

Dates

Publication Date
20260505
Application Date
20260209

Claims (10)

  1. The application of Cu/Zn-ZIF materials in strengthening anaerobic digestion of organic wastes.
  2. 2. The use according to claim 1, wherein the anaerobic digestion of the organic waste is performed by inoculating anaerobic sludge in the organic waste to form an anaerobic digestion system, and the strengthening is a Cu/Zn-ZIF material to promote the oxidation stress resistance of the anaerobic sludge.
  3. 3. The use according to claim 1 or 2, wherein the anaerobic digestion system comprises one of the following two anaerobic digestion systems: I. The total solid content TS of the anaerobic digestion system is less than or equal to 10 percent, and the anaerobic digestion system contains exogenous disturbance factors which comprise any one or a combination of a plurality of micro-plastics, nano-plastics, antibiotics and heavy metals, preferably, the exogenous disturbance factors comprise micro-plastics and/or nano-plastics; II. The total solid content TS of the anaerobic digestion system is in the range of 10% < TS < 20%.
  4. 4. The use according to claim 3, wherein the ratio of the mass of the exogenous turbulence factor to the total solid mass of the anaerobic digestion system is 10-300 mg:1 g.
  5. 5. The use according to claim 1 or 2, wherein the organic waste is one or a combination of several of municipal sludge, kitchen waste and kitchen waste.
  6. 6. The use according to claim 1 or 2, characterized in that the Cu/Zn-ZIF material is a metal organic framework material with Cu/Zn bimetallic active centers.
  7. 7. The method for preparing the Cu/Zn-ZIF material according to claim 6, wherein the method comprises the step of adding 2-methylimidazole, zn 2+ and Cu 2+ into methanol for reaction.
  8. 8. The use according to claim 7, wherein Zn 2+ and Cu 2+ are added to the methanol as Zn (NO 3 ) 2 ·6H 2 O and Cu (NO 3 ) 2 ·3H 2 O), respectively, and the mass ratio of 2-methylimidazole, zn (NO 3 ) 2 ·6H 2 O and Cu (NO 3 ) 2 ·3H 2 O) is (1-2): 1 (23-24).
  9. 9. The use according to claim 3, wherein when the anaerobic digestion system is anaerobic digestion system I, the ratio of the addition amount of the Cu/Zn-ZIF material to the total solid mass of the anaerobic digestion system is 0.1 to 0.5 mg:1 g.
  10. 10. The use according to claim 3, wherein when the anaerobic digestion system is anaerobic digestion system II, the ratio of the addition amount of the Cu/Zn-ZIF material to the total solid mass of the anaerobic digestion system is 1 to 5 mg:1 g.

Description

Application of Cu/Zn-ZIF material in strengthening anaerobic digestion of organic waste Technical Field The invention belongs to the technical field of organic solid waste recycling treatment, and particularly relates to an application of a Cu/Zn-ZIF material in strengthening anaerobic digestion of organic wastes. Background The organic solid waste is widely derived from municipal sludge, kitchen waste and the like due to high organic matter content and complex composition, and the content of organic components in dry matters can reach 60-80% generally. If the disposal is improper, the organic solid waste is easy to release a large amount of greenhouse gases in the natural degradation or landfill process, and the environment is continuously influenced. According to related researches, the organic solid waste treatment process accounts for about 8-10% of the global greenhouse gas emission, so that the reduction, stabilization and resource utilization of the organic solid waste treatment process have important environmental and energy significance. Anaerobic digestion technology is widely used in the fields of sludge, kitchen waste and kitchen waste treatment because of being capable of converting organic solid waste into biogas and synchronously realizing reduction and stabilization treatment. However, during actual engineering operation, anaerobic digestion systems are highly sensitive to operating conditions and feed composition, and are susceptible to a variety of exogenous disturbances and endogenous operational imbalance factors, thereby inducing system performance fluctuations, and even destabilizing or collapsing the digestion process. For example, excessive loading of the feed, fluctuations in feed composition, and accumulation of toxic and harmful substances may disrupt the metabolic balance and energy conversion efficiency of microorganisms within an anaerobic system. The existing anaerobic digestion enhancement technology is mainly focused on improving the degradation rate of a substrate or the yield of methane by adding metal salts, conductive materials or metal organic framework Materials (MOFs) to promote the hydrolysis of organic matters, electrons or proton transfer. For example, MOF-808 and like materials improve reaction kinetics during anaerobic digestion, primarily by accelerating the intermediate conversion process. However, the technology generally aims at regulating and controlling the substrate conversion efficiency or the electron transfer process, and ignores the problem of redox imbalance possibly occurring in an anaerobic digestion system under the condition of exogenous pollutant disturbance (such as micro/nano plastic, heavy metal, antibiotic residues) or endogenous high organic load operation, especially the excessive accumulation of active oxygen in the system and the toxic effect of the active oxygen on key functional microorganisms such as methanogenic archaea. Recent studies have shown that in addition to the conventionally focused acidification inhibition, nutrient imbalance and toxic substance accumulation, redox imbalance and the resulting abnormal accumulation of active oxygen in the anaerobic digestive system have gradually become one of the important intrinsic mechanisms leading to system destabilization. Although the anaerobic digestion process is entirely in a reducing environment, after high organic load operation, feed upsets, or the entry of exogenous contaminants (e.g., emerging contaminants such as microplastic, nanoplastic, etc.) into the system, environmentally persistent free radicals can be induced and further promote the production of reactive oxygen species (e.g., O 2·- and H 2O2). The active oxygen has stronger oxidation activity, and when excessive active oxygen is accumulated in an anaerobic digestion system, DNA damage, lipid peroxidation and protein structure damage in microbial cells can be caused, and obvious toxic effects on key functional microbial groups such as methanogenic archaea are shown, so that methanogenesis pathways are inhibited, and the accumulation of volatile fatty acids, the reduction of gas production efficiency and even the collapse of fermentation process are caused. Thus, the accumulation of excess active oxygen has been considered as one of the important contributors to performance degradation and operational instability of the anaerobic digestion system under a variety of impact conditions. However, in existing engineering practices and regulatory strategies, there is still limited interest in the mechanism of active oxygen production within the anaerobic digestion system and its regulatory pathways. Aiming at the problems of performance reduction or operation instability of an anaerobic digestion system, the prior art mainly adopts means such as process parameter regulation and control, chemical additive intervention or biological reinforcement and the like for repairing. For example, by adjusting the feed mode, pH, temperat