CN102992552A - Internal carbon source-oxygen enrichment stair combination constructed wetland engineering reactor - Google Patents

Abstract

The invention relates to an internal carbon source-oxygen-enriched cascade combined constructed wetland engineering reactor. The reactor is arranged in a three-stage series connection form, which successively includes: a first-level surface flow artificial wetland (1), a second-level vertical subsurface flow artificial wetland (5) ) and three-stage denitrification horizontal subsurface flow constructed wetland (12); a septum diversion wall (18) is provided between each stage, and the bottom layer of each stage is an anti-seepage layer (2). The invention can effectively realize the graded removal of organic matter and ammonia nitrogen in printing and dyeing wastewater, overcome the shortcomings that a traditional artificial wetland unit is difficult to simultaneously realize aerobic degradation of organic matter, nitrification and denitrification, improve the operation effect of conventional water treatment processes, and enhance water safety. It has a good application prospect.

Description

An internal carbon source-oxygen-enriched cascade combined constructed wetland engineered reactor

technical field

The invention belongs to the field of constructed wetlands, and in particular relates to an engineered wetland reactor with an internal carbon source-oxygen-enriched step combination constructed wetland.

Background technique

Among all wastewater treatment technologies, ecological treatment technology is the cheapest, and the most typical and representative one is artificial wetland technology. The unique advantages of low investment, low energy consumption and easy operation and management of constructed wetland technology have been widely researched and applied in the field of rural sewage treatment. It is used for farmland irrigation and miscellaneous water use, and is very suitable for rural areas where funds and management talents are relatively scarce. However, engineering examples of large-scale application of constructed wetlands in the treatment of industrial wastewater such as printing and dyeing wastewater are still rare, and most of the relevant research reports are laboratory experiments. Refractory printing and dyeing wastewater has achieved better results. However, in actual engineering, it is impossible to use methods such as artificial aeration and oxygenation, and the addition of commercial carbon sources, otherwise it will be difficult to maintain the characteristics of low operating costs of constructed wetlands.

Although the constructed wetland technology meets the current requirements for low-cost treatment of printing and dyeing wastewater, the poor biodegradability of printing and dyeing wastewater has become a potential limiting factor for the use of constructed wetland technology. In addition, the water quality characteristics of printing and dyeing wastewater are not limited to the situation of high organic matter, ammonia nitrogen has gradually become a common pollution indicator, and the artificial wetland technology is difficult to complete the organic matter degradation and denitrification requirements in one unit. Although the characteristics of low cost and low investment of constructed wetlands are more suitable for the treatment and reuse of printing and dyeing wastewater, technical innovation of traditional constructed wetlands is still needed to adapt to the water quality characteristics of high ammonia nitrogen and refractory printing and dyeing wastewater.

Contents of the invention

The technical problem to be solved by the present invention is to provide an internal carbon source-oxygen-enriched cascade combined constructed wetland engineered reactor, which can effectively realize the graded removal of organic matter and ammonia nitrogen in printing and dyeing wastewater, and overcome the difficulty of a traditional constructed wetland unit at the same time It can realize the shortcomings of aerobic degradation of organic matter, nitrification and denitrification, improve the operation effect of conventional water treatment processes, and enhance water safety, so it has a good application prospect.

An internal carbon source-oxygen-enriched cascade combined constructed wetland engineered reactor of the present invention, the reactor is set in a three-stage series connection form, which successively includes: a first-level surface flow artificial wetland, a second-level vertical subsurface flow artificial wetland and a third-level Denitrification horizontal subsurface flow artificial wetland; there is a partition diversion wall between each level, and the bottom layer of each level is an anti-seepage layer.

One side of the first-level constructed wetland is provided with a main water inlet, and the upper water body is constructed with plants, algae, bacterial symbiotic ecosystems and composite reactors, and the lower layer is paved with gravel filler.

The particle size of the gravel filler is 50mm-100mm.

The plant is reed.

The upper water body of the secondary vertical subsurface flow artificial wetland is planted with wetland plants, and the lower layer is provided with gravel and crushed stone beds to form a drainage layer, transition layer, filter material layer and covering layer respectively, and a sprinkler water distribution system is arranged above the wetland plants.

The wetland plant is canna.

The three-stage denitrification horizontal subsurface flow artificial wetland includes a water inlet area and an outlet area. The upper water body is planted with wetland plants, and the bottom is a crushed stone bed filter material layer; in addition, a water outlet main pipe is also provided on one side.

The wetland plant is cattail.

The anti-seepage layer is anti-seepage concrete.

The invention adopts three-stage artificial wetlands in series, including first-stage surface flow artificial wetlands, second-stage vertical subsurface flow artificial wetlands and third-stage denitrification horizontal underflow artificial wetlands, and the bottom layer of each stage is made of anti-seepage concrete to form an anti-seepage layer. In the first-level surface flow artificial wetland, the upper water body is used to construct a symbiotic ecosystem of plants, algae, and bacteria and a composite reactor, in which the dead algae can be used as an internal carbon source to supplement the subsequent denitrification needs, and the algae produced in the process of growth and metabolism Oxygen can supplement the oxygen demand for the oxidation of organic matter, and can supplement the alkalinity required for subsequent denitrification. In the first-level surface flow artificial wet base layer, a certain thickness of gravel filler is laid to form a submerged biofilm carrier. In an anoxic environment at the bottom, the biodegradability of refractory organic matter in printing and dyeing wastewater can be improved after hydrolysis and acidification. In the primary surface flow constructed wetland, the biodegradability and dissolved oxygen of printing and dyeing wastewater are improved, and the carbon source of subsequent denitrification is supplemented to a certain extent. In addition, the surface flow constructed wetland itself is a large-area advection sedimentation tank, which can effectively remove suspended solids in printing and dyeing wastewater. As a subsequent pretreatment of the subsurface flow constructed wetland, it can ensure that the wetland does not become clogged. The effluent from the primary surface flow constructed wetland enters the secondary subsurface flow constructed wetland. In the secondary vertical subsurface flow artificial wetland, a gravel bed is set up. The water distribution system abandons the traditional perforated pipe water distribution system, and adopts a spray water distribution system with better aeration and oxygenation effects to form an aerobic biofilm, so that the dissolved oxygen can basically reach The oxygen enrichment level of the sewage aerobic bioreactor creates good dissolved oxygen conditions for aerobic nitrification and organic matter oxidation. In order to further increase the denitrification carbon source, the plants produced in the constructed wetland are used as the carbon source in the biomass, without adding commercial carbon sources such as low-molecular carbohydrates. Adding plant biomass can also improve the biodegradability of printing and dyeing wastewater. The effluent from the secondary vertical subsurface flow constructed wetland enters the tertiary horizontal subsurface flow constructed wetland, and this unit does not adopt any artificial oxygenation measures. At the bottom of the gravel bed in the three-level horizontal subsurface flow constructed wetland, an anoxic environment is formed to denitrify and denitrify NO ₃ ^- and NO ₂ ^- in the influent.

Beneficial effect

The invention can effectively realize the graded removal of organic matter and ammonia nitrogen in printing and dyeing wastewater, overcome the shortcomings that a traditional artificial wetland unit is difficult to simultaneously realize aerobic degradation of organic matter, nitrification and denitrification, improve the operation effect of conventional water treatment processes, and enhance water safety. It has a good application prospect.

Description of drawings

Fig. 1 is a flow chart of the present invention;

Fig. 2 is a schematic diagram of the structure of the present invention.

Detailed ways

Below in conjunction with specific embodiment, further illustrate the present invention. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the teachings of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of the present application.

Example 1

As shown in Figure 2, an internal carbon source-oxygen-enriched cascade combined constructed wetland engineered reactor provided in this embodiment, the constructed wetland is set in a three-stage series connection form, and the first-level constructed wetland 1 is provided with a water inlet main pipe 16. Plant (reed), algae, bacterial symbiotic ecosystem and composite reactor 4 in the upper water body, and gravel packing 3 in the lower layer; in the secondary constructed wetland 5, wetland plants (canna) 10 are planted in the upper water body, and gravel gravel beds are set in the lower layer The drainage layer 6, the transition layer 7, the filter material layer 8, and the covering layer 9 are respectively formed. The water distribution system adopts the spray water distribution system 11 with better aeration and oxygenation effects; the third-level constructed wetland 12 includes the water inlet area 13 and the water outlet area. In zone 15, no artificial oxygenation measures are adopted, wetland plants (cattails) 14 are planted in the upper water body, and the bottom of the gravel bed filter material layer 8 forms an anoxic environment. In addition, the three-level constructed wetland 12 is equipped with a water outlet main pipe 17, and a partition diversion wall 18 is set between each level, and the bottom layer of each level is made of anti-seepage concrete to form an anti-seepage layer 2. Before entering the constructed wetland, printing and dyeing wastewater undergoes biochemical pretreatment, that is, it enters the constructed wetland after passing through the hydrolytic acidification tank, anoxic tank, contact oxidation aerobic tank and sedimentation tank in sequence.

The gravel filled inside the constructed wetland is made of pebbles or natural zeolite (or local materials), with a particle size of 50mm-100mm. The effective volume of the primary surface flow constructed wetland is 195m ³ , and the hydraulic retention time is 0.98d. The effluent from the primary surface flow constructed wetland enters the secondary subsurface flow constructed wetland. The effective volume of the secondary canna horizontal subsurface flow constructed wetland is 288m ³ , and the hydraulic retention time is 9 days. The wetland adopts an automatic oxygenation type subsurface flow constructed wetland. The upper part is equipped with ventilation pipes, built-in porous oxygenation pipes, water distribution pipes and porous water collection pipes. The effluent from the second-level vertical subsurface flow constructed wetland enters the third-level horizontal subsurface flow constructed wetland. The effective volume of the third-level cattail vertical subsurface flow constructed wetland is 288m ³ , and the hydraulic retention time is 2.9d. The wetland adopts the upper perforated pipe water distribution system and the bottom perforated pipe water collection system. .

Claims (9)

1. An internal carbon source-oxygen-enriched cascade combined constructed wetland engineered reactor, characterized in that: the reactor is set in a three-stage series connection, which successively includes: a first-level surface flow artificial wetland (1), a second-level vertical Subsurface flow constructed wetland (5) and three-stage denitrification horizontal subsurface flow constructed wetland (12); a septum diversion wall (18) is provided between each stage, and the bottom layer of each stage is an anti-seepage layer (2). 2. An internal carbon source-oxygen-enriched cascade combined constructed wetland engineered reactor according to claim 1, characterized in that: a water inlet main pipe (16) is provided on one side of the first-level constructed wetland (1), The upper water body is constructed with plants, algae, bacterial symbiotic ecosystems and composite reactors (4), and the lower layer is laid with gravel fillers (3). 3. The internal carbon source-oxygen-enriched cascade combined constructed wetland engineered reactor according to claim 2, characterized in that: the particle size of the gravel filler (3) is 50mm-100mm. 4. The internal carbon source-oxygen-enriched cascade combined constructed wetland engineered reactor according to claim 2, characterized in that: the plants are reeds. 5. The internal carbon source-oxygen-enriched cascade combined constructed wetland engineering reactor according to claim 1, characterized in that wetland plants (10) are planted in the upper water body of the secondary vertical subsurface flow constructed wetland (5) ), the lower layer is set with gravel and gravel beds to form the drainage layer (6), transition layer (7), filter material layer (8) and cover layer (9), and the sprinkler water distribution system (11) is set above the wetland plants (10) ). 6 . The internal carbon source-oxygen-enriched cascade combined constructed wetland engineered reactor according to claim 5 , characterized in that: the wetland plant ( 10 ) is canna. 7. The internal carbon source-oxygen-enriched cascade combined constructed wetland engineered reactor according to claim 1, characterized in that: the three-stage denitrification horizontal subsurface flow constructed wetland (12) includes a water inlet area (13) And the water outlet area (15), the upper water body is planted with wetland plants (14), and the bottom is a crushed stone bed filter material layer (8); in addition, a water outlet main pipe (17) is also provided on one side. 8. The internal carbon source-oxygen-enriched cascade combined constructed wetland engineered reactor according to claim 5, characterized in that: the wetland plant (14) is cattail. 9. The internal carbon source-oxygen-enriched cascade combined constructed wetland engineered reactor according to claim 1, characterized in that: the anti-seepage layer (2) is anti-seepage concrete.

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