CN103449670B - System for treating acidic industrial wastewater - Google Patents

Abstract

The invention discloses a system for treating acidic industrial wastewater, which comprises a sedimentation adjustment tank, a porous concrete reaction tank, an artificial wetland, and a water outlet well. The upper part of the sedimentation adjustment tank and the lower part of the porous concrete reaction tank are connected by a first connecting pipe The upper part of the porous concrete reaction tank is connected with the upper part of the constructed wetland through a second communication pipe, and the lower part of the artificial wetland is connected with the lower part of the outlet well through a third communication pipe. The arrangement heights of the sedimentation regulating tank, the porous concrete reaction tank, the artificial wetland and the outlet wells are successively reduced. The system has high treatment efficiency for acidic industrial wastewater, good ecological benefits, and low maintenance and operation costs.

Description

A system for treating acidic industrial wastewater

technical field

The invention relates to the technical field of sewage treatment, in particular to a system for treating acidic industrial wastewater.

Background technique

Acidic wastewater is a common form of industrial wastewater, mainly from mining, metallurgy, electroplating, tanning and pharmaceutical industries. Extreme acidity, high amounts of toxic metals and rich SO ₄ ^2- content are important characteristics of this type of wastewater. Acidic wastewater will corrode drainage pipes and structures. If it is discharged directly into the environment without treatment, the water quality will gradually acidify, heavy metals will exceed the standard, and endanger crops and aquatic organisms. Therefore, harmless treatment must be carried out before discharge.

At present, there are many methods for treating acidic industrial wastewater, including chemical neutralization, adsorption, and microbial methods. Among them, the chemical neutralization method is a traditional method for treating acidic wastewater, and the neutralizer generally uses lime or limestone. The second is the adsorption method, which uses porous solid substances to make one or more substances in the water be adsorbed on the solid surface to remove them. At present, the commonly used adsorbents mainly include activated carbon, fly ash, red mud, natural slag, artificial zeolite, bentonite and sepiolite, etc. Different adsorbents have different adsorption mechanisms and effects.

The acidic water treatment method that has attracted more attention at home and abroad is the sulfate reducing bacteria (SRB) method. It was first proposed by M. Kate (1997) in the United States, applying the principle of sulfur cycle reaction in nature, using SRB to convert sulfate into sulfide or elemental sulfur and finally remove it, and it also has a good neutralization effect on acidic water .

In addition to methods such as neutralization and precipitation, adsorption and SRB, electrolysis, electrodialysis, resin exchange, ion exchange and solvent extraction are also commonly used in the treatment of acidic wastewater. However, the above-mentioned methods have shortcomings. The dosage of the neutralizing agent in the neutralization method is not easy to control, which makes the pH value of the drainage unstable and the cost is high. The subsequent separation takes a long time and occupies a large area. Activated carbon, the most commonly used adsorbent in the adsorption method, is very expensive, and the treatment efficiency of organic matter is not high. The SRB method is often limited by high concentrations of metal pollution, which also reduces its efficiency. However, methods such as electrolysis, electrodialysis, ion exchange, and solvent extraction generally have defects such as strict process conditions, high processing costs, and incomplete removal of heavy metals.

Therefore, it is an urgent problem to be solved in the treatment of acidic industrial wastewater to find a method that is economical, effective, reliable and easy to popularize and apply.

Contents of the invention

Aiming at the deficiencies of the prior art, the technical problem to be solved by the present invention is to provide a system for treating acidic industrial wastewater, so as to achieve the purpose of high sewage treatment efficiency, good ecological benefit and low operating cost.

In order to solve the above-mentioned technical problems, the technical solution adopted in the present invention is: a system for treating acidic industrial wastewater, including a sedimentation adjustment tank, a porous concrete reaction tank, an artificial wetland, and a water outlet well. The lower part of the concrete reaction tank is connected through the first connecting pipe, the upper part of the porous concrete reaction tank is connected with the upper part of the artificial wetland through the second connecting pipe, and the lower part of the artificial wetland is connected with the lower part of the outlet well through the third connecting pipe. The pipes are connected.

Further, the arrangement heights of the sedimentation regulating tank, porous concrete reaction tank, artificial wetland and outlet wells are successively reduced.

A water outlet weir is arranged in the sedimentation adjustment tank, and one end of the first connecting pipe is connected to the water outlet weir.

The porosity of the porous concrete in the porous concrete reaction tank is 15-30%, and the compressive strength is 2.12-4.58Mpa.

The constructed wetland is a vertical flow constructed wetland, and the matrix of the vertical flow constructed wetland is: sand layer, gravel layer, and pebble layer in order from top to bottom, and a water distribution pipe connected with the second connecting pipe is arranged in the sand layer.

Wetland plants are planted on the artificial wetland, and the wetland plants are one of reed, Artemisia betel, calamus and water onion, or a combination of several plants.

The matrix thickness of the constructed wetland is 0.8-1.0m.

The gravel layer is divided into upper and lower layers, and the particle size of the gravel in the upper layer is smaller than that of the gravel in the lower layer.

The first communicating pipe, the second communicating pipe, the third communicating pipe and the water distribution pipe are all PVC pipes.

The surrounding retaining walls and the bottom of the porous concrete reaction tank and the artificial wetland are all provided with an anti-seepage layer.

Compared with the prior art, the present invention has the following advantages:

1. Treat acidic industrial wastewater through the combination of porous concrete and constructed wetland, and use physical, chemical and biological methods to achieve the purpose of efficient treatment of acidic wastewater;

2. No need to add chemicals, rely on gravity to maintain operation, less power consumption, low maintenance and operation costs;

3. The sewage is absorbed and decomposed by wetland plants in the wetland, and the wetland plants can also play a role in greening and beautiful, and purifying the environment;

4. The acid industrial wastewater treatment system belongs to the category of ecological treatment, and has good ecological benefits.

Description of drawings

The following is a brief description of the content expressed in the drawings of this manual and the marks in the drawings:

Fig. 1 is a schematic layout diagram of the system for treating acidic industrial wastewater according to the present invention.

Fig. 2 is a schematic structural diagram of the system for treating acidic industrial wastewater according to the present invention.

In the figure: 1. Sedimentation adjustment tank, 11. Outlet weir, 2. Porous concrete reaction tank, 21. Porous concrete, 3. Constructed wetland, 31. Water distribution pipe, 32. Wetland plants, 33. Sand layer, 34. Gravel layer , 35. Cobblestone layer, 4. Outlet well.

Detailed ways

The specific implementation manner of the present invention will be described in further detail below by describing the embodiments with reference to the accompanying drawings.

As shown in Figure 1 and Figure 2, the ecological system used to treat acidic industrial wastewater does not need to add chemicals. The system includes a sedimentation adjustment tank 1, a porous concrete reaction tank 2, a constructed wetland 3, and a water outlet well connected in sequence through connecting pipes. 4; Specifically, the upper part of the sedimentation adjustment tank 1 is connected to the lower part of the porous concrete reaction tank 2 through the first connecting pipe, and the upper part of the porous concrete reaction tank 2 is connected to the upper part of the constructed wetland 3 through the second connecting pipe. The lower part of 3 communicates with the lower part of outlet well 4 through a third communication pipe.

The heights of the sedimentation regulating tank 1, the porous concrete reaction tank 2, the constructed wetland 3, and the outlet well 4 are successively lowered. Acidic industrial wastewater passes through the sedimentation adjustment tank, porous concrete reaction tank, and artificial wetland in sequence, and circulates by gravity, with less power consumption and low maintenance and operation costs.

A water outlet weir 11 is arranged in the sedimentation adjustment tank 1 , and one end of the first communication pipe is connected to the water outlet weir 11 . The acidic industrial wastewater settles and stays in the sedimentation adjustment tank for a certain period of time to remove larger suspended matter, some organic matter and floating matter. The sedimentation time is 2.0-3.0 hours to complete the initial sedimentation; The pipe flows into the porous concrete reaction tank 2.

The surrounding retaining walls and the bottom of the porous concrete reaction tank 2 are all provided with an anti-seepage layer, and square or circular porous concrete 21 is arranged in the porous concrete reaction tank. The porosity of the porous concrete 21 is 15-30%. 2.12-4.58Mpa, the water inlet on one side of the porous concrete reaction tank is 10cm above the bottom, and the water outlet on the other side of the porous concrete reaction tank is 30cm above the porous concrete. The influent water is clear water flowing out from the outlet weir 11 in the sedimentation adjustment tank, and the influent water stays in the porous concrete reaction tank for 8-12 hours, and is discharged through the outlet after completing acid-base neutralization, adsorption of some heavy metals, and adsorption and degradation of organic matter. The two connecting pipes flow into the constructed wetland.

The retaining walls and the bottom of the artificial wetland 3 are provided with anti-seepage layers. The constructed wetland is a vertical flow constructed wetland, and the thickness of the matrix of the constructed wetland is 0.8-1.0m. The matrix of the vertical flow constructed wetland from the top to the bottom is: sand layer 33, gravel layer 34, pebble layer 35, connected to the second connecting pipe The common water distribution pipe 31 is placed in the deep sand layer of 5 cm. Wherein, the gravel layer 34 is divided into upper and lower layers, and the particle size of the gravel in the upper layer is smaller than that of the gravel in the lower layer. The thickness of the sand layer is 15cm, with a particle size of 5-10mm; the thickness of the upper layer of gravel is 25cm, with a particle size of 10-20mm; the thickness of the lower layer of gravel is 25cm, with a particle size of 30-50mm; And wetland plants 32 are planted on the constructed wetland, and the wetland plants 32 are one of reed, Artemisia betel, calamus, water onion, or a combination of several plants.

The water inflow to the constructed wetland is the effluent from the porous concrete reaction tank, and the water is distributed through the water distribution pipes with uniform through-hole distribution; the constructed wetland passes through the comprehensive reaction process of physics, chemistry, biology and plants to dispose of settleable solids, colloidal substances, and BOD in the water. , N, P, heavy metals, refractory organic matter, bacteria and viruses, etc., with powerful multifunctional purification capabilities. Finally, the effluent is collected by the pebble layer and flows into the effluent well outside the constructed wetland connected to the bottom of the constructed wetland. The clean water comes from After the effluent well flows out, it is discharged up to the standard.

The first communication pipe, the second communication pipe, the third communication pipe and the water distribution pipe 31 are all PVC pipes, which reduces the system cost.

The present invention has been exemplarily described above in conjunction with the accompanying drawings. Obviously, the specific implementation of the present invention is not limited by the above methods, as long as various insubstantial improvements are made using the concept and technical solutions of the present invention, or the present invention will be If the concept and technical solutions of the present invention are directly applied to other occasions, they all fall within the protection scope of the present invention.

Claims (8)

1. the system for the treatment of acidic industrial effluent, it is characterized in that: comprise sedimentary adjustive pool (1), cellular concrete reaction tank (2), artificial swamp (3), wet well (4), be connected by the first communicating pipe between described sedimentary adjustive pool (1) top with cellular concrete reaction tank (2) bottom, described cellular concrete reaction tank (2) top is connected by the second communicating pipe with between artificial swamp (3) top, be connected by third connecting pipe between described artificial swamp (3) bottom with wet well (4) bottom, the height that described sedimentary adjustive pool (1), cellular concrete reaction tank (2), artificial swamp (3), wet well (4) are arranged reduces successively, be provided with effluent weir (11) in described sedimentary adjustive pool (1), first communicating pipe one end link in effluent weir (11).

2. as claimed in claim 1 for the treatment of the system of acidic industrial effluent, it is characterized in that: the porosity of the cellular concrete (21) in described cellular concrete reaction tank (2) is 15-30%, ultimate compression strength is 2.12-4.58Mpa.

3. as claimed in claim 1 for the treatment of the system of acidic industrial effluent, it is characterized in that: described artificial swamp (3) is vertical current constructed wetland, the matrix of vertical current constructed wetland is down followed successively by from top: layer of sand (33), gravel bed (34), pebbles layer (35), is provided with the water distributor (31) be connected with the second communicating pipe in layer of sand (33).

4. as claimed in claim 3 for the treatment of the system of acidic industrial effluent, it is characterized in that: wetland plant (32) that described artificial swamp (3) has been planted, described wetland plant (32) is reed, beach wormwood wormwood artemisia, calamus, Scirpus tabernaemontani one wherein, or the combination of several plant.

5. as claimed in claim 3 for the treatment of the system of acidic industrial effluent, it is characterized in that: the stromal thickness of described artificial swamp (3) is 0.8-1.0m.

6. as claimed in claim 3 for the treatment of the system of acidic industrial effluent, it is characterized in that: described gravel bed (34) is divided into two-layer up and down, the particle diameter of upper strata gravel is less than the particle diameter of lower floor's gravel.

7. as described in any one of claim 3 to 6 for the treatment of the system of acidic industrial effluent, it is characterized in that: described first communicating pipe, the second communicating pipe, third connecting pipe and water distributor (31) are pvc pipe.

8. as described in any one of claim 1 to 6 for the treatment of the system of acidic industrial effluent, it is characterized in that: surrounding barricade and the bottom of described cellular concrete reaction tank (2) and artificial swamp (3) are equipped with impervious barrier.