A new biological denitrification enhanced denitrification device for advanced sewage treatment

Abstract

The invention provides a novel biological denitrification enhanced denitrification device for advanced sewage treatment, which includes a water inlet unit, an enhanced internal electrolysis pretreatment unit, a biological denitrification unit and a water outlet unit arranged sequentially from bottom to top; The electrolytic pretreatment unit is a double-layer cylindrical structure. The inner layer is a cast iron cylinder with metal wires wound on the outer surface. rod; the enhanced internal electrolytic pretreatment unit is provided with an enhanced filter layer, and the enhanced filter layer is a mixture of iron powder and anthracite with a mass ratio of 1:1 to 4:1. The device is compact in structure, small in floor area, easy to use, flexible in operation, and can make full use of the residual organic matter in the effluent of the secondary sedimentation tank. While ensuring the removal effect of total nitrogen, it can better guarantee the overall effluent water quality and significantly reduce the treatment cost. The cost has a good promotion and application prospect.

Description

technical field [0001] The invention belongs to the field of water treatment, in particular to a novel biological denitrification enhanced denitrification device for advanced sewage treatment. Background technique [0002] In recent years, water eutrophication has become one of the important water quality problems in the field of water environment in my country, and the control of nitrogen is the key point. In the current urban sewage treatment, organic matter can be well controlled, phosphorus control is relatively easy to achieve, and nitrogen is relatively difficult to control because its removal effect is limited by the content of organic matter in water. The survey results for the Taihu Lake Basin show that the most difficult thing for urban sewage plants to meet the requirements of Class A in the national "Pollutant Discharge Standards for Urban Sewage Treatment Plants" (GB18918-2002) is the total nitrogen index. [0003] Aiming at the control of total nitrogen index,...

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Problems solved by technology

[0003] Aiming at the control of total nitrogen index, a lot of research has been carried out in the field of advanced treatment of urban sewage plants. The main technologies involved include: First, deep bed filter, which uses the depth of the filter bed to create anoxic conditions for denitrification to achieve Synchronous removal of total nitrogen and suspended solids. However, since most of the organic matter in the effluent of the secondary sedimentation tank is refractory organic matter, the removal effect of total nitrogen is relatively poor, and it is difficult to meet the requirements; secondly, the filter cloth filter is mainly made of stainless steel with different pore sizes. Filter cloth is used to replace the quartz sand filter in the traditional advanced treatment process (coagulation, sedimentation, filtration), which also has poor removal effect on total nitrogen; third, iron-carbon internal electrolysis, as a new advanced sewage treatment process In the experimental research, a good organic matter removal effect has also been achieved. However, due to the limited conditions, the removal effect on total nitrogen is relatively poor, and it is difficult to meet the requirements. Fourth, zero-valent iron is also used for the removal of nitrate in water. Also due to the influence of other water quality parameters and the limitation of self-reducing ability, the removal effect is not ideal, and a large amount of toxic nitrite will appear

Biological denitrification has attracted widespread attention due to its low treatment cost, but the removal effect is not ideal due to the limitation of carbon source in advanced sewage treatment. It is usually necessary to improve the removal effect of nitrate by adding carbon source or supplying hydrogen, such as Add methanol, acetic acid, glucose and other organic carbon sources or hydrogen generated by electrolysis to strengthen the biological denitrification on the activated carbon; analysis of the water quality of the secondary sedimentation tank found that the content of organic matter in the water after the biodegradation process was significantly reduced, but still Contains 50-100mg / L of organic matter (as COD Cr ), but the biodegradability of these organic matter is poor and cannot meet the requirements of heterotrophic denitrification

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