CN-122010295-A - Culture method of salt-tolerant aerobic granular sludge and degradation method of industrial wastewater

CN122010295ACN 122010295 ACN122010295 ACN 122010295ACN-122010295-A

Abstract

The invention relates to the technical field of environmental biotechnology and wastewater treatment, in particular to a method for culturing salt-tolerant aerobic granular sludge and a method for degrading industrial wastewater, wherein the method for culturing comprises the steps of S1 inoculating initial aerobic granular sludge into a bioreactor, S2 adding acrylamide and an auxiliary carbon source into the bioreactor obtained in the step S1 preliminarily, and then adding the acrylamide and reducing the addition amount of the auxiliary carbon source for domestication to obtain the salt-tolerant aerobic granular sludge. The salt-tolerant aerobic granular sludge cultured by the method can grow and metabolize in an environment with the concentration of sodium chloride not lower than 10g/L by taking acrylamide as a sole carbon source, so that the salt-tolerant aerobic granular sludge has excellent salt tolerance and high-efficiency acrylamide degradation capacity, and can degrade 200mg/L of acrylamide by more than 95% in 6 hours, and meanwhile, the salt-tolerant aerobic granular sludge has regular particle shape, compact structure and good sedimentation performance (the SVI value of sludge index is only 24.0 mL/g).

Inventors

SHENG GUOPING
WANG FEI
LI ZHENGHAO
HE YUNTIAN

Assignees

中国科学技术大学

Dates

Publication Date: 20260512
Application Date: 20260414

Claims (10)

1. The culture method of the salt-tolerant aerobic granular sludge is characterized by comprising the following steps of: s1, inoculating initial aerobic granular sludge into a bioreactor; the initial aerobic granular sludge is aerobic granular sludge with sodium chloride tolerance of more than or equal to 10 g/L; S2, primarily adding acrylamide and an auxiliary carbon source into the bioreactor obtained in the step S1, gradually increasing the acrylamide and reducing the addition amount of the auxiliary carbon source to perform domestication of the initial aerobic granular sludge until the concentration of the acrylamide in the effluent of the bioreactor is stably lower than 10mg/L, and obtaining salt-tolerant aerobic granular sludge; In the domestication process, the acrylamide is added in a mode that the adding amount of the acrylamide is increased by 20-25 mg/L every 7 days until the concentration of the acrylamide in the culture medium is 180-220 mg/L, and the adding mode of the auxiliary carbon source is that the adding amount of the auxiliary carbon source is reduced by 80-120 mg/L every 7 days to 0 compared with the initial concentration of the auxiliary carbon source which is initially added.
2. The culture method according to claim 1, wherein in the step S2, the preliminary addition of acrylamide and the auxiliary carbon source is continued for 14 to 16 days, the addition amount of acrylamide to the bioreactor is 8 to 15 mg/L/day based on a medium composed of acrylamide and the auxiliary carbon source, and the addition amount of the auxiliary carbon source to the bioreactor is 500 to 1000 mg/L/day.
3. The culture method according to claim 1 or 2, wherein in step S2, the auxiliary carbon source includes one or more of glucose, sodium acetate and methanol.
4. The culture method according to claim 1, wherein the initial aerobic granular sludge has a sludge concentration index of 20 to 60mL/g and a particle diameter of 0.5 to 1.0mm.
5. The method according to claim 1 or 4, wherein in step S1, the suspended solid concentration of the primary aerobic granular sludge is 3000 to 6000mg/L.
6. The culture method according to claim 1, wherein the bioreactor is a sequencing batch bioreactor, the sequencing batch bioreactor comprises a water inlet period, an anaerobic period, an aerobic period, a precipitation period and a water outlet period which are sequentially carried out, wherein the time of the water inlet period is 5-15 min, the time of the anaerobic period is 20-40 min, the time of the aerobic period is 240-320 min, the time of the precipitation period is 15-40 min, and the time of the water outlet period is 5-15 min.
7. The culture method according to claim 1, wherein the culture time of the culture method is 130 to 160 days.
8. A degradation method of acrylamide in industrial wastewater comprises the following steps: mixing industrial wastewater and salt-tolerant aerobic granular sludge for degradation; the salt-tolerant aerobic granular sludge is the salt-tolerant aerobic granular sludge cultured by the culture method according to any one of claims 1-7.
9. The degradation method according to claim 8, wherein the industrial wastewater is derived from polyacrylamide production industry, petroleum tertiary oil recovery industry or paper industry, and/or the concentration of sodium chloride in the industrial wastewater is 10-30 g/L and the concentration of acrylamide is 100-300 mg/L.
10. The degradation method according to claim 8, wherein the degradation temperature is 20-30 ℃, and the degradation time is 5-8 hours.

Description

Culture method of salt-tolerant aerobic granular sludge and degradation method of industrial wastewater Technical Field The disclosure relates to the technical fields of environmental biotechnology and wastewater treatment, in particular to a method for culturing salt-tolerant aerobic granular sludge and a method for degrading industrial wastewater. Background Acrylamide (AM) is a water-soluble vinyl monomer, and is widely used as an important raw material for producing polyacrylamide in various industrial fields such as petroleum exploitation, papermaking, mining, etc. However, acrylamide is a known neurotoxic, genotoxic and carcinogenic substance that can pose a serious threat to the ecological environment and human health. During the production and use of polyacrylamide, industrial waste water containing residual acrylamide monomer is inevitably produced. Particularly in the industries of chemical industry, oil and gas exploitation (such as polymer oil displacement technology) and the like, the generated wastewater not only contains high-concentration acrylamide, but also is usually accompanied by extremely high salinity (the concentration of sodium chloride can reach 10-30 g/L). The high water solubility of the acrylamide makes the acrylamide extremely easy to migrate and diffuse in a water body, and causes persistent pollution to surface water and underground water. Currently, treatment techniques for wastewater containing acrylamide mainly include physicochemical and biological methods. Although the physical and chemical method (such as adsorption, advanced oxidation and the like) can effectively remove the acrylamide, the method has the problems of high cost, easy secondary pollution and the like, and the biological method is considered to be the most potential treatment technology due to low cost and environmental friendliness. Studies have shown that some microorganisms are capable of metabolizing acrylamide as a carbon or nitrogen source, and that the degradation pathway is mainly by hydrolyzing acrylamide to acrylic acid and ammonia by amidase (amidase), and thus are utilized by the microorganism. However, the traditional activated sludge process faces great challenges in treating such wastewater, firstly, acrylamide has a strong toxicity inhibition effect on common microorganisms, and secondly, the high salinity environment commonly existing in the wastewater can generate strong osmotic stress, so that microbial cells are dehydrated, enzyme activity is reduced, and even death is caused, and the whole biological treatment system is low in efficiency, unstable in operation and even crashed. The aerobic granular sludge (Aerobic Granular Sludge, AGS) technology is a novel biological wastewater treatment technology developed in recent years. AGS is a dense granular biological aggregate formed by self-aggregation of microorganisms under specific hydraulic conditions. Compared with the traditional flocculent activated sludge, the AGS has the advantages of compact structure, good sedimentation performance, high biomass, strong impact load resistance, capability of simultaneously performing nitrification and denitrification and the like, and is considered as an ideal choice for treating high-concentration, toxic and nondegradable industrial wastewater. Attempts have been made to treat high-salinity wastewater with AGS, but the cultivation process usually requires domestication of salinity gradients of up to several months, and the process is long and unstable. Meanwhile, the existing research on salt-tolerant AGS is mainly focused on the removal of conventional organics, the degradation problem of specific toxic pollutants such as acrylamide is not solved pertinently, and a special microbial community culture technology capable of simultaneously tolerating high salinity and efficiently degrading acrylamide is lacking. Moreover, few researches on the degradation of acrylamide by salt-tolerant aerobic granular sludge are carried out, and a special microbial community culture technology capable of simultaneously tolerating high salinity and efficiently degrading acrylamide is lacking. Therefore, there is an urgent need to develop an aerobic granular sludge and a rapid culture method thereof, which can simultaneously endure high salt and acrylamide toxicity and can efficiently degrade acrylamide, so as to solve the problem of treating industrial wastewater containing salt and acrylamide. Disclosure of Invention The technical problem solved by the disclosure is to provide a method for culturing salt-tolerant aerobic granular sludge, which is the aerobic granular sludge with salt-tolerant and acrylamide degradation functions, and can realize high treatment efficiency, high stability and short-period degradation of industrial wastewater of high-salt and high-concentration acrylamide. In view of the above, the application provides a method for culturing salt-tolerant aerobic granular sludge, which comprises the