Hydrogen production and struvite recovery method for sludge by adopting FNA (free nitrous acid) reinforced microbial electrolysis

A microbial electrolysis and nitrite technology is applied in the field of using free nitrite to strengthen microbial electrolysis sludge for hydrogen production and recovery of struvite, which can solve the problem of low utilization rate of sludge organic matter, low recovery rate of high value-added nutrients, and low recovery rate of high value-added nutrients. Problems such as difficulty in breaking the wall of sludge flocs

Active Publication Date: 2017-03-08
TAIYUAN UNIV OF TECH
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  • Abstract
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Problems solved by technology

[0004] The purpose of the present invention is to solve the technical problems of the difficulty in breaking the wall of sludge flocs, the low utilization rate of sludge organic matter and the low recovery rate

Method used

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  • Hydrogen production and struvite recovery method for sludge by adopting FNA (free nitrous acid) reinforced microbial electrolysis
  • Hydrogen production and struvite recovery method for sludge by adopting FNA (free nitrous acid) reinforced microbial electrolysis
  • Hydrogen production and struvite recovery method for sludge by adopting FNA (free nitrous acid) reinforced microbial electrolysis

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specific Embodiment approach 1

[0018] Specific implementation mode 1: In this implementation mode, free nitrite is used to strengthen the hydrogen production of microbial electrolytic sludge and recover struvite, specifically according to the following steps:

[0019] 1. Sludge pretreatment: Settling the remaining sludge naturally at a temperature of 4 °C, the settling time is 24 h ~ 30 h (optional 24 h, 26 h, 28 h, 30 h), and then drain the supernatant liquid to obtain sludge samples; prepare NaNO 2 Stock solution, so that the concentration of FNA in the reactor reaches 2.13 mgN / L, the rotation speed is 102 rpm / min ~108 rpm / min (102 rpm / min, 104 rpm / min, 106 rpm / min, 108 rpm / min can be selected), and the treatment is 24 h ;

[0020] 2. Preliminary anaerobic fermentation of sludge: After driving oxygen and nitrogen into the reaction bottle for 10 minutes, seal the reaction bottle and put it in an air bath shaker at 100 rpm / min~110rpm / min (100rpm / min, 102rpm / min, 104 rpm / min, 106rpm / min, 108rpm / min, 110rpm...

specific Embodiment approach 2

[0024] Embodiment 2: The difference between this embodiment and Embodiment 1 is that the pH should be adjusted to 5.5 ± 0.1 using 1.0M NaOH and HCl in step 1, and phosphate buffer solution is added to keep the pH. Others are the same as Embodiment 1. same.

specific Embodiment approach 3

[0025] Specific embodiment three: this embodiment is different from one of specific embodiments one to two in that: the VSS of sludge anaerobic fermentation in step two should be more than 10 g / L, and the sludge after FNA pretreatment should be 1: A ratio of 9 was added to the new inoculated sludge. Others are the same as one of the specific embodiments 1 to 2.

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Abstract

The invention discloses a hydrogen production and struvite recovery method for sludge by adopting FNA (free nitrous acid) reinforced microbial electrolysis, aims to realize utmost synchronous recovery of C, N and P by coupling FNA pretreatment and an electrochemical system to solve the problem of incomplete recycling of C, N and P in sludge at present. The method comprises the following steps: 1, FNA pretreatment of residual sludge; 2, anaerobic preliminary fermentation of the sludge; 3, MEC (microbial electrolysis cell) starting and functional microbial acclimation; 4, MEC step utilization of fermented 4d sludge; 5, synchronous N and P recovery adopting struvite. FNA pretreatment for the residual sludge is a novel sludge pretreatment method, has the advantages of being low in cost, free of secondary pollution and the like compared with the traditional pretreatment method, and the cell breaking rate can reach 80% or higher. Anaerobic treatment and the MEC are used for step utilization of FNA pretreated sludge for hydrogen production, N and P in a sludge digestion liquid are recovered with a struvite precipitation method, and C, N and P in the sludge are synchronously recovered.

Description

technical field [0001] The method relates to a method for using free nitrite to enhance hydrogen production from microbial electrolysis sludge and recover struvite. Background technique [0002] Surplus sludge is an associated product in the process of urban sewage treatment. With the gradual expansion of sewage plant construction and scale, its output has also increased rapidly. Excess sludge contains a large amount of toxic and harmful substances, but at the same time, the organic matter, nitrogen and phosphorus contained in it can be further recycled to realize the reduction, harmlessness and resource utilization of sludge. As a new type of sludge pretreatment method, free nitrite can inactivate 80% of microorganisms, effectively realize sludge disintegration, realize sludge reduction, and do not introduce new pollutants and cause secondary pollution. The nitrogen introduced into the system is subsequently recycled by the struvite method. [0003] The traditional anaero...

Claims

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Application Information

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IPC IPC(8): C02F11/12C02F11/04C02F11/00C01B25/45C12P3/00
CPCC01B25/45C02F11/006C02F11/04C02F11/12C02F2303/06C12P3/00Y02P20/129
Inventor 周爱娟张家广岳秀萍刘芝宏汪素芳
Owner TAIYUAN UNIV OF TECH
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