CN-121974469-A - Nutrient recovery process switching method for cultivation sewage

CN121974469ACN 121974469 ACN121974469 ACN 121974469ACN-121974469-A

Abstract

The invention discloses a culture sewage nutrient recovery process switching method, in particular relates to the technical field of culture sewage recycling recovery, and aims to solve the problems that in the existing culture sewage nutrient recovery process, process switching timing is inaccurate and operation is unstable after switching due to large water quality fluctuation and difficulty in timely eliminating residual disturbance of front and rear process paths. The recovery condition fingerprints are constructed by collecting multiple items of condition information of the aquaculture sewage in the continuous observation window, the entering qualification, the maintaining qualification and the forbidden qualification of the phosphorus recovery path and the nitrogen recovery path are respectively judged based on the recovery condition fingerprints, the switching conditions are restrained by combining the inheritance disturbance indexes, and switching candidates are generated and buffer transition treatment is executed when the switching precondition is met, so that the purposes of improving the process switching judgment accuracy and reducing the interference of misoperation switching, hysteresis switching and improper switching on the nutrient recovery process are achieved.

Inventors

DU LIANZHU
WANG MENGYA
ZHANG KEQIANG
ZHANG MINGYE
LIANG JUNFENG

Assignees

农业农村部环境保护科研监测所

Dates

Publication Date: 20260505
Application Date: 20260409

Claims (9)

1. The method for switching the nutrient recovery process of the culture sewage is characterized by comprising the following steps of: S1, collecting ammonia nitrogen concentration, phosphate concentration, pH value, alkalinity, calcium and magnesium concentration, suspended matter concentration, temperature, flow and current running path state of the culture sewage in a continuous observation window, and constructing a recovery working condition fingerprint; s2, respectively judging the entering qualification, maintaining qualification and forbidden qualification of the phosphorus recovery path and the nitrogen recovery path according to the recovery condition fingerprint to obtain a target path qualification result; S3, calculating an inheritance disturbance index when the current running path is switched to the target path according to the current running path state and the target path qualification result; S4, when the exiting qualification of the current running path is met, the entering qualification of the target path is met, and the inheritance disturbance index meets the switching constraint, generating a switching candidate and executing buffer transition processing; s5, cutting into the target path after the buffer transition processing, collecting the recovery state parameters of the target path in the verification window, and judging the stable forming state of the target path; And S6, locking the target path when the stable forming state of the target path is established, executing rollback processing and reconstructing the recovery working condition fingerprint when the stable forming state of the target path is not established.
2. The method for switching a nutrient recovery process of culture sewage according to claim 1, wherein S1 comprises: Collecting ammonia nitrogen concentration, phosphate concentration, pH value, alkalinity, calcium and magnesium concentration, suspended matter concentration, temperature, flow and current running path state in a continuous observation window, wherein the calcium and magnesium concentration comprises a calcium ion concentration record value and a magnesium ion concentration record value; performing time alignment on the original record, supplementing the missing record in time sequence, and marking the unavailable record; and forming a current value, a median value in the window, a fluctuation amplitude in the window and a continuous out-of-range time based on the effective record, and generating a recovery working condition fingerprint record.
3. The method for switching a nutrient recovery process of culture sewage according to claim 1, wherein S2 comprises: respectively judging the entering qualification, the maintaining qualification and the forbidden qualification according to the entering qualification rule set, the maintaining qualification rule set and the forbidden qualification rule set corresponding to the phosphorus recovery path and the nitrogen recovery path respectively; Firstly judging the forbidden qualification of the phosphorus recovery path, then judging the forbidden qualification of the nitrogen recovery path, then judging the maintenance qualification corresponding to the current running path, and finally judging the entry qualification of the phosphorus recovery path and the nitrogen recovery path; And generating a target path qualification result.
4. A nutrient recovery process switching method for aquaculture wastewater according to claim 3, wherein qualification of the phosphorus recovery path is based on the phosphate concentration, pH, calcium ion concentration, magnesium ion concentration, suspended matter concentration and current operating path state, and qualification of the nitrogen recovery path is based on the ammonia nitrogen concentration, pH, alkalinity, temperature, flow rate, suspended matter concentration and current operating path state.
5. The method for switching a nutrient recovery process of culture sewage according to claim 1, wherein S3 comprises: forming a subentry record of residual medicament deviation, residual liquid level ratio, residual solid load, flow passage blocking degree and short-time fluctuation degree before switching according to the current running path state and the target path qualification result; Converting each sub-item record into a sub-item grade value; and forming an inherited disturbance index value based on the accumulation of the subtended grade values according to preset weights in the rule version, and forming an inherited disturbance index record based on the inherited disturbance index value.
6. The method for switching a nutrient recovery process of culture sewage according to claim 1, wherein S4 comprises: generating a switching candidate record when the current running path exit qualification is met, the target path entry qualification is met and the inheritance disturbance index meets the switching constraint; Executing buffer transition processing according to the action sequence bound with the path combination in the rule version; And generating a buffer transition processing result record.
7. The method for switching a nutrient recovery process of culture sewage according to claim 6, wherein the action sequence comprises load reduction, stop adding, flow dividing, emptying, liquid stabilizing and pre-conducting; When the former action is not finished, the latter action cannot be started; all enabled actions in the sequence of actions are completed, no buffer transition processing abort record is generated, and the total consumption time does not exceed the allowed execution time limit, then the buffer transition processing is completed.
8. The method for switching a nutrient recovery process of culture sewage according to claim 1, wherein S5 comprises: Collecting target path inlet flow, target path circulation flow, target path liquid level, target path PH value, target path temperature, addition record value corresponding to the target path, target path recovery product state quantity and target path equipment state quantity in a verification window; Judging a continuous operation boundary, an inlet continuous liquid inlet boundary, a liquid level stability boundary, a pH value stability boundary, a temperature stability boundary, an addition continuity boundary and a recovered product formation boundary of the equipment according to a fixed sequence; and thereby determining the stable forming state of the target path.
9. The method for switching a nutrient recovery process of culture sewage according to claim 1, wherein S6 comprises: When the stable forming state of the target path is established, locking the target path, writing the target path into the current running path state record, and generating a target path locking record; And executing rollback processing when the stable forming state of the target path is not established, and reconstructing the recovery working condition fingerprint after the rollback processing is completed.

Description

Nutrient recovery process switching method for cultivation sewage Technical Field The invention relates to the technical field of recycling and recovery of culture sewage, in particular to a nutrient recovery process switching method of culture sewage. Background The existing culture sewage nutrient recovery technology is mostly developed around phosphorus recovery, nitrogen recovery or a combination of the phosphorus recovery and the nitrogen recovery, and commonly adopts crystallization recovery, absorption recovery or corresponding combined technology to realize resource utilization according to the conditions of nitrogen, phosphorus and acid and alkali in sewage after front end liquid separation. From the prior art, the related scheme can complete nutrient extraction and recovery under certain conditions, but most technical emphasis is still placed on the recovery efficiency of a single path, the medicament adding control, the equipment structure optimization or the fixed process flow configuration, and a plurality of water quality indexes reach a set range to be used as starting or switching basis. For a continuous operation production line, the mode can meet basic operation requirements when the liquid-supply condition is relatively stable, but in an actual scene of the cultured sewage, the mode is influenced by the cultured batch, the discharge rhythm, the front-end separation state and the reflux working condition, the sewage components and the operation state often show the characteristic of continuous fluctuation, and influence factors such as liquid retention, medicament residues, particle deposition, loop disturbance and the like also exist between the front treatment path and the rear treatment path, so that path selection is carried out only according to a single index or an instantaneous state, and whether the current process has the switching condition is difficult to be truly reflected. Further, the prior art generally focuses more on "whether to switch" in the process path switching link, and considers the "when to switch", "whether the current path residual disturbance is released before switching" and "whether the target path can form a stable recovery state after switching". Especially, when the phosphorus recovery path and the nitrogen recovery path are continuously switched, if the switching is directly performed only according to the water quality value or the equipment state at a certain moment, the situation that the liquid remains in the previous path, the medicament is added, the suspended particles or the short-time fluctuation enters the next path is easy to occur, so that the unstable operation, the fluctuation of the recovery state and the abnormal load of the equipment are caused after the switching, and even the condition that the target path is just cut into is needed to be adjusted or withdrawn again is caused. The existing scheme can describe the running conditions of various recovery processes, but is generally lack of uniform and refined judging mechanisms suitable for continuous production lines for continuous connection before and after path switching, disturbance transfer and state confirmation after switching. Therefore, aiming at the existing culture sewage nutrient recovery technology, in the continuous running process of the culture sewage, the prior art lacks a mode capable of continuously judging and connecting and controlling around the whole path switching process in the face of coexistence of fluctuation of incoming liquid water quality, residual disturbance of front and rear paths and equipment state change, so that the process switching time is not easy to accurately grasp, the stability of a target path after switching is insufficient, and the continuity and reliability of the nutrient recovery process are further affected. This problem is not the inability of the single recovery path itself to operate, but rather the insufficient handling of the links between the path switch preconditions, switch transitions, and post-switch state confirmations in the prior art, which also constitutes a targeted problem that the following summary needs to further address. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a cultivation sewage nutrient recovery process switching method, which aims to solve the problems in the background art. In order to achieve the purpose, the invention provides the following technical scheme that the nutrient recovery process switching method for the culture sewage comprises the following steps: S1, collecting ammonia nitrogen concentration, phosphate concentration, pH value, alkalinity, calcium and magnesium concentration, suspended matter concentration, temperature, flow and current running path state of the culture sewage in a continuous observation window, and constructing a recovery working condition fingerprint; s2, respectively judging the entering qualification, maintaining qualification and