Underground ecological sewage treatment system and method using gravel as medium

Abstract

The invention discloses a buried ecological sewage treatment system using gravel as a medium. The system comprises a pretreatment unit and an inter-gravel contact oxidation unit which are sequentially connected, wherein the inter-gravel contact oxidation unit comprises a gravel-filled inter-gravel aeration region, an inter-gravel non-aeration region and a sludge storage tank; the inter-gravel aeration region communicates with the inter-gravel non-aeration region through an aeration pipe; the aeration pipe is connected with a blast blower; the aeration pipe is provided with an aeration region valve and a non-aeration region valve; the inter-gravel non-aeration region communicates with the sludge storage tank through a water outlet pipe; and the water outlet pipe is provided with a water outlet valve and a sludge discharge valve. The invention also discloses a sewage treatment method. The system has the advantages of simple technical process and low engineering investment (only 2 / 3 of the investment of the traditional sewage treatment method). The system also has the advantages of strong adaptability to sewage quality / quantity fluctuations, and high pollutant removal efficiency (the removal rate for ammonia nitrogen, BOD (biochemical oxygen demand) and SS (suspended sediment)) can reach 90%. By adopting the inter-gravel buried type, the system reduces the land occupation, and is ecological and environment-friendly.

Description

technical field [0001] The invention belongs to an ecological sewage treatment method, which uses gravel as a carrier and achieves the purpose of reducing organic matter, suspended matter, ammonia nitrogen and other pollutants in sewage through the action of biofilm attached to the gravel. It is mainly used in the water purification of the rainy season overflow water of the confluence system pipeline, the initial rainwater or dry flow water of the diversion system rainwater pipeline, and the intercepted water of the river. Background technique [0002] Sewage treatment refers to the process of purifying sewage to meet the water quality requirements that can be discharged into a certain water body or reused. Conventional sewage treatment methods mainly include activated sludge method and biofilm method. Conventional sewage treatment methods have the advantages of high removal efficiency, mature technology and stable operation for the treatment of highly polluted sewage such a...

AI Technical Summary

Problems solved by technology

[0003] However, for the rainy season overflow water of the combined system pipeline, the initial rainwater or dry flow water of the separate system rainwater pipeline, and the intercepted river water, due to the low concentration of pollutants, if the activated sludge method is used, the activated sludge system is difficult to maintain and the overall investment Disadvantages such as too high and large land occupation; if the conventional biofilm method is used, there are disadvantages such as complicated pretreatment, difficulty in biofilm formation and difficult disposal of excess sludge

[0004] In the case of serious water pollution in our country's river basins, it is difficult to meet the needs of improving the water environment in river basins only by relying on sewage treatment plants.

Especially in rainy days, a large amount of overflow water from combined pipelines that cannot be treated by sewage treatment plants in rainy seasons and initial rainwater from diverted rainwater pipelines will pollute the water environment of the river if they are not treated and directly discharged into the river.

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