V-shape air-stripping technology for removing nitrogen and phosphorus of large and medium-sized sewage processing

Abstract

The invention provides a V-shape air-stripping technology for removing nitrogen and phosphorus of large and medium-sized sewage processing. The technology comprises following steps: introducing sewage, subjecting the sewage to go through a coarse screen to remove the slag, then adding water, lifting by a sewage pump, subjecting the sewage to a fine screen, transporting the sewage to a sand settling pool, transporting the sewage to a hydrolysis acidification pool, transporting the sewage to an integral processing pool of V-shape air stripping reflux and two-grade precipitation, transporting the sewage to a disinfecting pool and finally discharging the sewage if the quality of the sewage meets the standard. In the technology, the integral sewage processing pool of V-shape air stripping reflux and two-grade precipitation substitutes the biochemical reaction pool of A / A / O activated sludge process, the nitrated liquid internal reflux pump pool, the secondary precipitation pool, the sludge internal influx and external influx pump pool, the coagulation reaction pool and the inclined tube precipitation pool, and thus the high efficiency and compactness of removing nitrogen and phosphorus in sewage are achieved. Compared to the conventional processing technology, the V-shape air-stripping technology has the advantages of small occupied area, low investment, little drug consumption, little sludge discharge, low energy consumption, low cost, stable and controllable water quality, and convenient operation management.

Description

technical field [0001] The invention relates to a large and medium-sized sewage treatment process, in particular to a sewage treatment method which simultaneously utilizes the principle of air lift, anaerobic / anoxic / aerobic and two-stage sedimentation to realize high-efficiency denitrification and phosphorus removal and a compact design. Background technique [0002] Conventional sewage treatment methods are mainly biochemical methods, namely activated sludge method and biofilm method. Among them, activated sludge method is the most widely used secondary biological treatment process in various countries in the world. The earlier activated sludge process was mainly to remove organic pollutants, and now it has fully entered the process stage of not only removing organic pollutants, but also removing nitrogen and phosphorus. The principles of activated sludge denitrification and phosphorus removal processes are basically similar, but there are many forms of expression. At prese...

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Problems solved by technology

[0005] Invention patent "Double-sided diversion biological sewage treatment technology and its sewage treatment equipment" (public number CN1223972A, publication date 1999.7.28, hereinafter referred to as prior art 1), the equipment consists of a buffer tank, an aeration tank, a sedimentation tank etc., the equipment is in the shape of a deep conical bucket, the width ratio is insufficient, limited by the structural shape and the slope of the cone bottom, not only cannot be enlarged to the commonly used small scale of 100-10,000 tons / day, but also cannot be enlarged to 10,000 tons / day Moreover, this technology and equipment can only remove organic pollutants and ammonia nitrogen. Its operating principle determines that it cannot remove nitrogen (total nitrogen) and cannot remove phosphorus. The nitrogen and phosphorus indicators of the effluent quality do not meet my country's current national discharge standards, so It is not a process for denitrification and dephosphorization of sewage

[0006] Invention patent "Double-sided diversion hydraulic circulation clarification sewage treatment method" (application number ZL200610124503.5, hereinafter referred to as prior art 2), this method has many structures and equipment, and the process is long, the sewage needs two-stage lifting, and the sludge There are many pumps, the sludge needs to be pumped from the pool, the energy consumption of the system is high, and the sludge discharge effect is poor; the water level of the water inlet adjustment pool should usually be located at a lower place under the ground, and the water level difference between the adjustment pool and the double-sided diversion pool is actually large , so the joint construction of the two pools is relatively unreasonable in engineering; the double-sided diversion pool used in prior art 2 is the technology and equipment of prior art 1 (see the penultimate 4th line on page 1 of the main text of prior art 2); Subsequently, prior art 2 applied for the improvement of its own double-sided diversion pool and was approved for an invention patent "Forced Backflow Double-sided Diversion Sewage Treatment Pool" (application number ZL200610125119.7, hereinafter referred to as prior art 3), The treatment effect is still unsatisfactory. The effluent of the sewage treatment pool is not clear and transparent. After the pool is improved, a filter layer is installed at the end for further filtration. However, the filter layer will be blocked soon during operation, and there is no backwash of the filter layer. In actual use, the blockage cannot be cleared and it is difficult to operate normally; in addition to the above, the sewage treatment method and the subsequent improved pool type all lack the sand setting process, which easily leads to the deposition of sand particles in the sewage system and brings equipment wear and siltation and other adverse effects; this sewage treatment method also lacks the function of biological phosphorus removal, and completely relies on the diatomite treatment agent to absorb and remove phosphorus, so the dosage is large; in addition, this method uses conventional sludge thickening tanks and conventional plate-and-frame pressure filter, the water content of the sludge after dehydration does not meet the new national sludge water content disposal standard

Therefore, the above-mentioned various defects lead to the actual treatment effect, system engineering investment, and operation cost of the method and its main sewage treatment tank, which are difficult to meet the actual needs of small-scale sewage denitrification and phosphorus removal at this stage and in the future, let alone large and medium-sized The actual needs of wastewater denitrification and phosphorus removal

[0007] Invention patent application "An integrated device, system and process for sewage biochemical treatment" (publication number CN102923908A, publication date 2013.2.13), can basically meet the needs of small-scale sewage denitrification and phosphorus removal of 1500 tons / day and below, but the It is difficult to continue to expand the device to more than 1,600 tons / day, let alone to more than 10,000 tons / day, and the effect of nitrogen and phosphorus removal needs to be further improved

The main reason is that after the device continues to be enlarged, the oblique guide partition will be further extended obliquely upwards, resulting in the sludge farther away lacking horizontal power and difficult to reach the vicinity of the vertical air lift return component, resulting in insufficient sludge return. Problems such as sludge deactivation and floating, anaerobic gas production or death and corrosion brought about in time will seriously affect the water quality of the effluent; at the same time, due to the small size of the device, all one side of the vertical air lift return component is an aerated biochemical zone. There is no pre-anoxic denitrification zone that can use the carbon source of sewage itself, and there is no integrated anaerobic zone. It can only rely on the anoxic denitrification inside the granular sludge and the carbon-deficient post-positioning on the other side of the vertical air lift return module. Anoxic denitrification of the source, so there is room for further improvement in the denitrification effect and phosphorus removal effect; in addition, the chemical flocculation reaction under the sedimentation component is not sufficient and uneven, resulting in a large amount of chemical agent, and the water distribution effect becomes worse after scale-up. Therefore, there is still room for further improvement in the removal of phosphorus and other residual pollutants

This method also lacks sludge as an important component of sewage treatment

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