Automatic regulating device and method for backflow amount of mixed liquid in small purification tank

Abstract

The invention discloses an automatic regulating device and method for the backflow amount of a mixed liquid in a small purification tank. According to the automatic adjusting device, an ultrasonic liquid level detection device is arranged in a water inlet groove, a plurality of electromagnetic valves are installed at the groove bottom, located above an aerobic nitrification area, of a mixed liquidbackflow groove side by side, and the ultrasonic liquid level detection device and the electromagnetic valves are connected through a controller. A PLC reads the inner water depth, detected by the ultrasonic liquid level detection device, in the water inlet groove at regular time, calculates the average water depth in a continuous period of time, and controls opening and closing of the electromagnetic valves in a delayed mode according to the ratio of the average water depth to a designed water depth; and when the ratio of the average water depth to the designed water depth is changed, the opening and closing of the electromagnetic valves can be controlled by the PLC in a delayed manner, so that the water amount of the mixed liquid flowing back to an anoxic denitrification region is automatically adjusted. The backflow amount of the mixed liquid can be automatically adjusted according to the actual water inlet amount of the small purification tank, meanwhile, dissolved oxygen in an anoxic zone is controlled, anoxic conditions are provided for denitrification, and the denitrification efficiency of the purification tank is improved.

Description

technical field [0001] The invention relates to a sewage treatment device, in particular to an automatic adjustment device and an adjustment method for the return flow of mixed liquid in a small purification tank. Background technique [0002] As China continues to promote the implementation of the new urban-rural integration and rural revitalization strategies, the treatment of rural domestic sewage has become a very important part of the improvement of the rural living environment. Compared with urban domestic sewage, the discharge of rural domestic sewage is relatively scattered, the collection is difficult, the treatment process is also different from that of urban domestic sewage, and the amount of funds required for treatment is large, resulting in a low treatment rate of rural domestic sewage in my country. It is very urgent to improve the rural living environment and improve the quality of village water environment. [0003] In the treatment of domestic sewage in rur...

AI Technical Summary

Problems solved by technology

However, due to the large time-varying coefficient of water inflow to small and medium-sized purification tanks in actual operation, that is, the inflow flow rate varies greatly, and the air-lift return flow rate of the purification tank is usually determined according to the design water volume, and cannot be adjusted with the actual water flow rate. Real-time adjustment; on the other hand, although the opening degree of the air lift valve can be adjusted, when the actual water inflow is less than the design flow, if the gas volume used for the gas lift of the mixed liquid is reduced according to the demand for the return flow, there will be gas volume in the actual operation. Unstable, frequently interrupted reflow conditions

Due to the above two reasons, the actual return flow of small purification tanks is usually much greater than the return flow required for denitrification and denitrification. Excessive return flow carries too much dissolved oxygen, which leads to high dissolved oxygen in the anoxic denitrification area and damages The denitrification conditions are not met, resulting in very low denitrification and denitrification efficiency of the small purification tank. Key Factors for Nitrogen Efficiency

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