Recycling process for synchronously enhancing anaerobic acid production and phosphorus recovery of sludge

A phosphorus recovery and resource utilization technology, applied in the field of sludge resource utilization, can solve the problems of increasing Fe-P, low phosphorus release efficiency, and limited popularization and application, so as to promote the hydrolysis of organic matter, strengthen the anaerobic fermentation of sludge to produce acid, Effect of Strengthening Anaerobic Phosphorus Release from Sludge

Active Publication Date: 2021-07-09
TONGJI UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, as one of the most commonly used sludge treatment methods in the world, anaerobic digestion technology has the problem of low phosphorus release efficiency
In recent years, studies have found that the sulfur ions generated by sulfate radicals under the action of sulfate-reducing bacteria can effectively increase the dissolution of Fe-P, so the addition of sulfate radicals can significantly improve the anaerobic digestion of sludge. release of phosphorus in the process, but the inhibitory effect on methanogenesis limits the popularization and application of this technology

Method used

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  • Recycling process for synchronously enhancing anaerobic acid production and phosphorus recovery of sludge
  • Recycling process for synchronously enhancing anaerobic acid production and phosphorus recovery of sludge
  • Recycling process for synchronously enhancing anaerobic acid production and phosphorus recovery of sludge

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Effect test

Embodiment 1

[0035] The sludge used in this example is the mixed sludge of the activated sludge of biological phosphorus removal in a certain sewage treatment plant in Suzhou and the chemical sludge of iron salt enhanced phosphorus removal, and its total solids (TS) and volatile solids (VS) are respectively 2.51% and 1.59%, VS / TS=63.34%; the domesticated inoculum slime has the ability to stably reduce sulfate radical, among which TS=2.50%, VS / TS=44.51%.

[0036] Add 0.125mmol / gTS sodium persulfate to the sludge, at this time the molar ratio S:Fe=0.5, shake in a high-temperature shaker at 80°C for 2 hours, cool to room temperature, the pH of the sludge drops from 6.8 to 5.4, and use 1M NaOH was used to adjust the sludge pH to 7.0. The pre-oxidized sludge and inoculum sludge were mixed into the anaerobic fermentation tank according to the TS mass ratio of 2:1, and batch experiments were carried out under the conditions of 37 °C water bath and 100 r / min stirring conditions.

[0037] The cont...

Embodiment 2

[0045] The sludge used in the experiment is the primary sludge of a sewage treatment plant for iron-salt enhanced phosphorus removal, in which TS=2.46%, VS=1.53%, VS / TS=62.20%; the domesticated seed sludge has the ability to stably reduce sulfate , where TS=2.50%, VS / TS=44.51%.

[0046] Add 0.3mmol / g TS sodium persulfate to the sludge. At this time, the molar ratio S:Fe=2. Shake in a high-temperature shaker at 80°C for 2 hours, cool to room temperature, and the sludge is reduced from 6.5 to 4.5. Use 1M NaOH was used to adjust the sludge pH to 7.0. The pre-oxidized sludge and inoculum sludge were mixed into the anaerobic fermentation tank according to the TS mass ratio of 2:1, and batch experiments were carried out under the conditions of 37 °C water bath and 100 r / min stirring conditions.

[0047] The contents of volatile fatty acids (VFAs) and dissolved phosphorus were measured daily during the experiment.

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Abstract

The invention relates to a recycling process for synchronously strengthening anaerobic acid production and phosphorus recovery of sludge. The process comprises the following steps: (1) pretreating residual sludge by adopting a thermal activation persulfate pre-oxidation process; (2) cooling the pretreated sludge obtained in the step (1) to room temperature, adjusting the pH value, and carrying out anaerobic fermentation to produce acid; (3) carrying out solid-liquid separation on the anaerobic fermentation sludge obtained in the step (2); and (4) adding magnesium salt into the filtrate obtained in the step (3), adjusting the pH value, conducting filtering to obtain struvite crystal precipitate, carrying out phosphorus recovery, and backflowing the residual filtrate as a carbon source to a sewage treatment plant. Compared with the prior art, the method provided by the invention overcomes the defect that various existing technologies cannot simultaneously meet the requirements of high-efficiency release and high-added-value recovery of phosphorus in the anaerobic recycling process of the sludge; the peroxysulphate pre-oxidation can strengthen the anaerobic phosphorus release of the sludge; and the sludge can be cracked, and anaerobic fermentation and acid production of the sludge are enhanced.

Description

technical field [0001] The invention relates to the technical field of sludge resource utilization, in particular to a resource utilization process for synchronously strengthening sludge anaerobic acid production and phosphorus recovery. Background technique [0002] Phosphorus is one of the essential nutrients for all living things. Global population growth and intensive farming methods have led to an average annual growth rate of more than 2% in the consumption of phosphate rock. As a non-renewable resource, the long-term stable supply of phosphate rock has become one of the issues worthy of human attention. my country is a populous country. As of 2020, my country's phosphate rock reserves are only 3.2 billion tons, which is less than 5% of the world's reserves. However, the annual phosphate rock consumption reaches 50% of the world level. The uneven distribution of resources and the huge demand for mining make the shortage of phosphorus resources imminent in my country,...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C02F11/04C02F11/06C02F11/00C02F11/127C02F11/122C01B25/45
CPCC02F11/04C02F11/06C02F11/00C02F11/12C01B25/451C02F2209/18C02F2209/06C02F2209/08
Inventor 戴晓虎丁燕燕武博然
Owner TONGJI UNIV
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