Small sewage treatment hydrolysis and gas-stripping and precipitation technique method

Abstract

The invention provides a small sewage treatment hydrolysis and gas-stripping and precipitation technique method which comprises the following steps of: underground sewage, integrated anaerobic hydrolysis acidifying adjustment lift pump pond, integrated sewage treatment pond for Z type gas-stripping reflux two-stage precipitation, and up-to-standard emission. The anaerobic hydrolysis acidifying adjustment lift pump pond is adopted to replace various conventional and non-conventional comprehensive pretreatment procedures, the integrated sewage treatment pond for Z type gas-stripping reflux two-stage precipitation is adopted to replace procedures of a fine-rack girt chamber, an A/O biochemical reaction basin, a nitration liquid internal-reflux pump basin, a secondary precipitation basin, a sludge internal-reflux pump basin, a sludge external-reflux pump basin, a coagulation-flocculation reaction basin and an inclined-tube precipitation basin, a contact sterilization basin and the like in an A/O activated sludge method. The method has the advantages of being small in occupied space, less in investment and medicine consumption and sludge discharge, low in energy consumption and cost, stable and controllable in water quality, simple and convenient to run and manage, especially suitable for high-efficiency and compact treatment of nitrogen and phosphorus removal of sewage of ten thousand tonnage/per day and below.

Description

technical field [0001] The invention relates to a miniaturized sewage treatment process, in particular to a small-scale sewage treatment hydrolysis, air-lift, and sedimentation process for high-efficiency denitrification and phosphorus removal and a compact design by using the principles of hydrolysis, air lift and two-stage precipitation at the same time. 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 e...

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Problems solved by technology

[0003] The above-mentioned already very complex conventional process is added with the function of denitrification and phosphorus removal, so the overall process becomes extremely complicated, the process is longer, and there are more structures to be treated

For large-scale sewage treatment, it is acceptable; for small-scale, it is neither economical nor reasonable to copy the above-mentioned practices. Therefore, it is necessary to find a new process for nitrogen and phosphorus removal by activated sludge method suitable for small-scale sewage treatment.

[0004] For small-scale sewage treatment, the invention patent "Double-sided Diversion Biological Sewage Treatment Technology and Sewage Treatment Equipment" (application number ZL98121863.6, hereinafter referred to as prior art 1), the equipment consists of buffer tank, aeration tank, Settling tank and other components, the equipment is a deep cone-shaped 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 per day, but also can only remove organic pollution The operating principle of this equipment determines that it cannot remove nitrogen (total nitrogen) and cannot remove phosphorus. The nitrogen and phosphorus indicators of the effluent water quality do not meet the current national discharge standards in my country, so it is not a process for nitrogen and phosphorus removal of sewage.

[0005] 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; the 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; the ultraviolet sterilizer is also difficult to build together with the conical hydraulic circulation clarifier; Yes, this method uses a conventional sludge thickening tank and a conventional plate-and-frame filter press, and the moisture content of the sludge after dehydration does not meet the new national sludge moisture content disposal standards

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 denitrification and phosphorus removal of small-scale sewage at this stage and in the future.

[0006] 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 scale up the device and method to 1,600-10,000 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 the sewage itself, and it can only rely on the anoxic denitrification inside the granular sludge and the anoxic denitrification that lacks carbon sources on the other side of the vertical air lift reflux module, so denitrification There is still room for further improvement of the nitrogen effect; in addition, the chemical flocculation reaction below the sedimentation component is not sufficient and uneven, resulting in a large amount of chemical agent, and the water distribution effect of the lower layer becomes worse after the scale is enlarged, so the phosphorus removal effect and other residual pollutant removal effects are still weak. There is room for further improvement

In addition, there is no agitator in the anaerobic adjustment tank in this method, and the sand particles are easily deposited in the tank, and the return sludge is also easy to settle down, making it difficult to achieve the desired effect of homogeneous water quality and mud-water mixing; Pools, disinfection facilities, and water outlet open channel metering tanks are all built independently. There are four process structures from water inlet to water outlet, which occupy a relatively large area and relatively high investment; this method also lacks sludge as an important component of sewage treatment.

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