KR20050083048A - Apparatus for control of supply of water with acidity - Google Patents

Abstract

The present invention removes the heavy metals contained in the acid drainage by using the composition of the wetlands and the red mud powder by acidic drainage discharged from the pit after the tunnel construction passing through the mountainous terrain, without affecting the existing environment and the surrounding ecosystem. The present invention relates to an acid drainage treatment apparatus capable of satisfying more than a standard.

The present invention, limestone drain to remove the sediment contained in the runoff flowing out of the pit during mountainous highway construction; A storage tank for storing the treated water discharged from the limestone drain, but discharged when a predetermined amount is introduced in consideration of the case where a large amount of groundwater flows out due to rainy season or hydrogeological site conditions (aquifer); And a reaction tank for mixing the red mud powder with the discharge water discharged from the storage tank to treat the heavy metal concentration included in the acid drainage at the level of the drinking water quality standard.

Description

Apparatus for Control of Supply of Water with acidity

The present invention relates to an apparatus for treating acidic drainage contained in effluent flowing out of a gang during road construction passing through mountainous terrain.

The mountainous terrain of Korea has a lot of rocks containing various harmful heavy metals, the road construction through the mountainous terrain having such a geological layer, a sufficient treatment for the adverse effects of acidic drainage is required.

Particularly, in the case of the rock containing heavy metals generated in the cut slope and the ground due to the excavation of the ground or tunnel, minerals including sulfur react with dissolved oxygen dissolved in groundwater or rainwater, and the sulfuric acid is mineralized. Strong acidic water is dissolved by dissolving various heavy metals contained in it, and this strong acidic water flows into rivers along the incline due to rainfall, causing not only bad effects on aquatic ecosystems, but also threatening the lives of nearby residents. Appropriate treatment measures are required. Therefore, the highway contractor basically blocks the contact between the rock block and the groundwater generated in the tunnel excavation, and the groundwater generated in the tunnel is discharged to the outside of the tunnel with the strong acidic water. It must be processed.

In general, acid mine drainage (AMD) is water with a pH of 6.0 or less and total acidity above total alkalinity, in areas where open pits have been performed, running or It can be defined as an outflow from an abandoned mine, and acidic water leaches if exposed to air in the formation of road slope cuts and tunnel excavations, or in the underground subway tunnels containing pyrite or marcasite. Comes out.

The treatment of acidic drainage uses physicochemical methods to maximize the precipitation effect of harmful heavy metals by neutralizing the acidity in water with alkaline agents and injecting flocculant into neutralized acidic leachate, and chemical and biological reactions occurring in nature. It can be largely divided into biological methods that are naturally purified and currently introduced and operated in several places in Korea.

The former method of physicochemical treatment is a technology to purify wastewater by using chemicals (for example, acid neutralizers) and mechanical power as in general acid wastewater treatment methods. It is composed of treatment processes such as agglomeration / sedimentation method, limestone drainage method, grouting, and the like.

This treatment method has a problem that requires a constant operating costs, chemicals, and labor costs.

In the physicochemical treatment method, agglomeration / precipitation method is chemical treatment of particles in water as a first step, and becomes cohesive or unstable, and in the second step, particles which become unstable are brought into contact with each other to form agglomerates. By eliminating by, there is a problem that the continuous operation is required and the accompanying costs are high.

Next, the Limestone Drains method is a method of converting acidic wastewater into alkaline water by contacting limestone with acidic mine drainage. There is a problem.

The grouting is a method to fundamentally block the drainage discharged from the groundwater outflow point, and the purpose is to reduce the drainage rather than the concept of purification, which must be preceded by the characterization in the rock when the acidic drainage through the grouting is closed. In order to prevent water leakage, it is necessary to precisely investigate the ground, select the appropriate grouting material, and thoroughly construct it.

Biological methods include the Successive Alkalinity Producing System (SAPS), the marsh land method, and the drainage method.

First, the treatment method using SAPS is used when it is difficult to treat mine drainage with an existing treatment system that supplies ALD (Anoxic Limestone Drains) or Alkalinity due to high acidity of mine drainage and high concentration of trivalent iron.

Next, the marsh land method is a natural purification treatment technology for purifying acidic drainage by the biochemical action of microorganisms to artificially form marshes (bogs) to purify the mine drainage through biochemical reactions inside the marsh land. Compared with the physicochemical method, the marsh land method is difficult to control the purification efficiency and is limited by seasonal factors in operation. However, physicochemical wastewater treatment is continuously used in the waste mine area because operating and maintenance costs are continuously required, but natural purification formula requires minimum maintenance costs.

Next, the drainage method is a kind of natural purification method that removes neutralization or contaminants while installing a drainage layer with a purification material, that is, limestone, in a tunnel or a mine drainage passage. Although the drainage method is inexpensive and simple in construction, there is a problem in that the purification efficiency is lowered due to the drainage layer coating with iron oxide or the like over time.

Therefore, the present invention has been proposed to solve the above problems, by removing the heavy metal contained in the acid drainage using the composition of the marsh and red mud powder to acid drainage discharged from the pit after the tunnel construction passing through the mountain terrain. Its purpose is to provide a treatment system for acidic wastewater that can satisfy a predetermined water quality standard without affecting the existing environment and surrounding ecosystem.

The present invention for achieving the above object is, limestone drain to settle and remove the sludge contained in the outflow water flowing out of the gangway during mountainous highway construction; A storage tank for storing the treated water discharged from the limestone drain, but discharged when a predetermined amount is introduced in consideration of the case where a large amount of groundwater flows out due to rainy season or hydrogeological site conditions (aquifer); And a reaction tank for mixing the red mud powder with the discharged water discharged from the storage tank to treat the acidic drainage on the basis of drinking water quality standards.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a configuration diagram of an acid drainage treatment apparatus according to an embodiment of the present invention, and shows an acid drainage treatment apparatus using red mud.

As shown in the figure, this embodiment is a method of forming a marsh land of a suitable size based on the groundwater outflow amount in the gang, storage acidic drainage therein, and then simply spraying the red mud powder Is a neutralization / stabilization / solidification technique that neutralizes acid and prevents heavy metal elements from adsorbing after they are adsorbed to the heavy metal removal material.

The acid drainage treatment apparatus using the red mud technique according to the present invention, the limestone drain 210 for sedimentation and removal of sludge contained in the outflow water flowing out of the gang during the construction of the mountain terrain; The treated water discharged from the limestone drain 210 is stored, but a storage tank 220 is discharged when a predetermined amount is introduced in consideration of a large amount of groundwater flowing out due to the rainy season or hydrogeological site conditions (aquifer). Wow; It includes a reaction tank 230 to mix the red mud powder in the discharge water discharged from the storage tank 220 to remove the heavy metals to treat the heavy metal concentration to the level of drinking water quality standards.

Hereinafter, the acidic wastewater treatment process by each configuration will be described in detail.

The limestone drain 210 converts the acid drainage into alkaline water by neutralizing the pH by contacting the acid mine drainage with limestone and performing a pretreatment step of removing some suspended solids (suspension) having good settling properties. The storage tank 220 performs a process of sedimenting and removing the suspended solids and heavy metals attached to the suspended substances in the storage of the acidic drainage. The reactor 230 is filled with red mud powder to remove heavy metals by passing the influent containing the thick metal with little turbidity after the flocculation / precipitation process.

Herein, the red mud powder will be described in more detail. The red mud powder is a by-product generated in the process of producing aluminum hydroxide or alumina as bauxite ore and is used for neutralizing acid drainage and stabilizing heavy metals. The red mud has a high alkalinity and acts as a flocculant to neutralize acids and adsorb toxic heavy metal elements so that they do not dissociate. Typically, the acid neutralization capacity of the red mud is 3.5 to 7.5 moles of acid / kg, and variously charged particles may bind additional hydrogen ions, and if the acidity of the pore water is less than 5, about 14 to 20 moles / kg. Acid can be neutralized.

Heavy metal treatment in the reactor 230 is to neutralize the acid by the intrinsic alkalinity of the red mud powder, and to aggregate the toxic heavy metal elements so as not to dissociate. Accordingly, the heavy metal concentration contained in the acidic wastewater passed through the reaction tank 230 may be treated to the level of drinking water quality standards.

The storage tank 220 and the reaction tank 230 has a structure in which both side walls and the bottom are made of cement walls by simple excavation.

According to the present embodiment configured as described above, it is not necessary to add chemicals such as neutralizing agents, no subsequent process such as adding a flocculant, can increase the degree of heavy metal treatment up to drinking water quality standards, maintenance is not required It is easy to

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes are possible in the art without departing from the technical spirit of the present invention. It will be clear to those of ordinary knowledge.

As described above, according to the present invention, the heavy metal concentration contained in the acid drainage discharged from the pit during or after the road construction passing through the mountainous terrain is treated by using a reaction tank filled with marsh land and red mud powder to the existing environment and the surrounding ecosystem. It has the effect of making acid drainage water above certain water quality standards without adversely affecting it. In addition, it is easy to manage and can adjust the operation time of the plant in consideration of the capacity of the storage tank and the operating conditions of the site, there is another effect that can reduce the cost of treating the acidic drainage.

Figure 1 is an embodiment configuration of the acid wastewater treatment apparatus according to the present invention.

* Explanation of symbols for the main parts of the drawings

210: limestone drain 220: reservoir

230: reactor

Claims (3)

Limestone drain for sedimentation and removal of sludge contained in the runoff flowing out of the pit during mountainous highway construction; A storage tank for storing the treated water discharged from the limestone drain, but discharged when a predetermined amount is introduced in consideration of the case where a large amount of groundwater flows out due to rainy season or hydrogeological site conditions (aquifer); And A reaction tank for removing heavy metals contained in the acid drainage by mixing red mud powder with the discharge water discharged from the storage tank. Acid drainage treatment apparatus comprising a. The method of claim 1, The storage tank and the reaction tank, The acid drainage treatment apparatus, characterized in that the simple sidewall and the bottom and both side walls and the bottom is composed of a cement wall. The method according to claim 1 or 2, The storage tank is an acidic wastewater treatment apparatus, characterized in that to perform the function of sedimenting and removing the suspended solids and heavy metals attached to the suspended solids contained in the acidic drainage.