Method for in-situ recovery of high-purity struvite through microbial electrolytic cell

Abstract

The invention belongs to the field of microbial electrochemistry, and discloses a method for in-situ recovery of high-purity struvite through a microbial electrolytic cell. The method comprises the steps that at least one of phosphorus-containing wastewater and phosphorus-containing sludge is added into the microbial electrolytic cell after microbial acclimation, an external voltage is applied tocarry out a microbial electrolysis reaction for a period of time, and then struvite sediment can be separated out, wherein the external voltage is smaller than the electrolytic voltage of water. According to the method, a microbial electrolytic cell (MEC) technology is utilized, and micro-voltage less than that of electrolytic water is adopted so that the problems that the time for obtaining the struvite through ectopic crystallization is long, the purity is low, particles are small and the sedimentation and separation performance is poor can be effectively solved, and the electric energy consumption is greatly reduced. Moreover, the method is based on an in-situ reaction, on the premise that stirring is not needed, the nucleation rate of struvite crystals is increased, the growth rate ofthe struvite crystals is increased, the limit of the growth of the struvite crystals is broken through, the particle size of the struvite is increased, the purity of the struvite is improved, and in-situ crystallization recovery of the high-purity struvite is achieved.

Description

technical field [0001] The invention belongs to the field of microbial electrochemistry, and more specifically relates to a method for in-situ recovery of high-purity struvite in a microbial electrolytic cell. Background technique [0002] Phosphorus is an element widely used in the earth and one of the essential elements for the growth of organisms. Phosphorus is also a non-renewable resource. In the process of nature and human use, a large amount of phosphorus is discharged into the water body, causing eutrophication of the water body, causing huge economic losses and environmental hazards. At the same time a portion of phosphorus is deposited in ocean and geological formations, reducing the amount of available phosphorus. The recovery of phosphorus from wastewater can not only avoid the eutrophication caused by phosphorus, but also avoid the deposition of phosphorus and increase the cycle of phosphorus in nature to increase the availability of phosphorus. The recovery o...

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Problems solved by technology

[0005] For the above defects or improvement needs of the prior art, the object of the present invention is to provide a method for reclaiming high-purity struvite in situ by a microbial electrolytic cell, wherein the microbial electrolytic cell (i.e. MEC) technology is utilized, and an electrolysis voltage less than water is used The microvoltage can effectively solve the problems of long time-consuming to obtain struvite by ectopic crystallization, low purity, poor separation performance of small particles, and greatly reduce power consumption; moreover, the present invention is based on in-situ reaction and does not require stirring In this way, the nucleation rate of struvite crystals is accelerated and the growth rate of struvite crystals is increased, the limit of struvite crystal growth is broken through, the particle size of struvite is increased and the purity of struvite is increased, and high-purity struvite is realized. In situ crystallization recovery of struvite, thereby solving the technical problems of cumbersome struvite recovery operation, small struvite particles, low purity, and high recovery cost. It can be seen that the present invention utilizes phosphorus-containing wastewater or phosphorus-containing sludge to recycle Struvite breaks through the mass transfer limitation, obtains high-purity struvite, reduces operating steps, and shortens reaction time

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