technical field

The invention relates to a tilted plate type heavy metal removal device and a manufacturing method of a filter plate, belonging to the field of sewage treatment, especially the field of electroplating wastewater treatment.

background art

After the 1950s, the global population grew rapidly and industry developed rapidly. The global water resource situation is rapidly deteriorating, and the "water crisis" is becoming increasingly serious. At present, the annual discharge of electroplating wastewater in my country has reached 4 billion m3. The heavy metals it contains not only pose a threat to environmental protection and species diversity, but also seriously affect human physical and mental health. Lead in sewage can cause poisoning of fish and aquatic organisms; accumulation in the human body can cause headaches, memory loss, and amnesia. Excessive copper can cause dermatitis and eczema, and high concentrations of copper-containing wastewater can cause skin necrosis. Hexavalent chromium in sewage can also cause harm to human skin and respiratory system, and in severe cases can cause bronchial cancer. Therefore, the treatment of electroplating wastewater is urgent. On the other hand, about 50 million tons of red mud is produced every year in the world, and 1 to 1.8 tons of red mud by-products are produced for every 1 ton of alumina produced. Alkali in red mud can cause the body's acid-base balance and even lead to death; fluoride contained in red mud invades human bone tissue, causing the evacuation or deformation of human bone; a large amount of sodium compounds can cause cell dysfunction, especially brain cell dysfunction, leading to death. Therefore, how to fully and rationally utilize red mud has become the focus of people's attention. China's sewage treatment capacity has not kept up with the rapid expansion of water use, and the construction of supporting facilities such as pipe networks and sludge treatment is seriously lagging behind. On the other hand, there is still a significant gap between China's sewage treatment rate and developed countries, and the load rate of treatment facilities is low. The treatment level of water pollution treatment systems or devices currently being widely used needs to be further improved, the treatment effect is not yet very complete, and the resource utilization efficiency is relatively low. At present, commonly used electroplating wastewater treatment methods include biological treatment methods and chemical treatment methods. Biological treatment method has the advantages of low cost, simple process control, simplicity and practicality, but it is difficult to treat large-flow wastewater containing low concentrations of heavy metals; chemical treatment method has the advantages of less investment and simple operation, but it occupies a large area and requires additional chemical substances. Disclosure of the Invention Aiming at the problems existing in the treatment of electroplating wastewater in industrial production, the invention provides a tilted plate type electroplating wastewater heavy metal removal device and a manufacturing method of the tilted plate. The invention is an effective device based on the combination of a filter plate and heavy metal ions in electroplating wastewater through physical adsorption, chemical precipitation and ion exchange to achieve the removal of heavy metal ions and back-wash and replace the filter plate.

The technical scheme of the invention is as follows:

A tilted plate type electroplating wastewater heavy metal removal device comprises a water distribution device, a tilted plate reaction device, a washing device, an effluent collection device, and a precipitate collection device. Among them, the water distribution device comprises a water collection tank 1 and a water distribution tank 3, a water distribution plate 4 is arranged between the water distribution tank 3 and the inclined plate reaction device 6, and a water distribution hole 5 is arranged at the bottom of the water distribution plate 4 to communicate with the water distribution tank 3 and the inclined plate reaction device 6; The main body of the inclined plate reaction device 6 is a box reactor with an open upper part. There are three groups of filter plates 9 placed obliquely in the reactor. Two adjacent groups of filter plates are perpendicular to each other. There is an overflow tank 11 on one side of the upper part of the reactor. The wall of the overflow tank is provided with a water outlet 12 connected to an outlet water collection device 13; the bottom of the box reactor is a precipitation collection device 7 to enrich sludge falling off the surface of the filter plates. The angle between the inclination direction of the filter plate and the horizontal direction is 50-60 degrees, which is opposite to the water inlet direction. Since the inclined plate is tilted to the left based on the vertical direction, the water entering is from left to right, so it is opposite to the water entering direction. This is also an important technical condition for the diversion of wastewater entering the reactor. The inclined filter plate not only absorbs the incoming wastewater but also plays a role of diversion; the upper and lower ends of the filter plate 9 are inserted into the clamping grooves 8 on the wall of the reactor to fix the filter plate. 15-20 Each filter plate is parallel to each other in a group. The filter plate is made of a net-like mud hanger made of iron wire as a skeleton, and red mud pulverized coal adsorbent is sintered on it. The mud hanger can be replaced. The flushing device is a jet pipe 10 arranged above the filter plate; when the device is not working, the jet pipe can comprehensively flush the filter plate 9 to ensure high efficiency of the reaction and prevent passivation of the reactor. Preferably, a jet pipe is arranged above each filter plate to facilitate rinsing of each filter plate. A peristaltic pump 2 with a flowmeter is arranged on the pipeline between the water collecting tank 1 and the water distributing tank 3. Wastewater flows from bottom to top by peristaltic pump 2. The sedimentation collecting device is preferably a conical body, and the bottom is provided with a drop-off sludge discharge outlet. During use, electroplating wastewater enters the water distribution tank 3 from the water collection tank 1 under the action of the peristaltic pump 2, and enters the inclined plate reaction device 6 through the water distribution holes 5 below the water distribution plate 4. The wastewater is guided through the inclined filter plates under the action of gravity difference, flows in the inclined direction of the filter plates, flows in a baffled manner between the three inclined filter plates and fully contacts the filter plates, so that the heavy metal ions in the wastewater react with the adsorbent on the filter plate 9. The treated wastewater passes through the upper overflow tank 11 and is connected to the outlet water collection device 13 through the water outlet 12. The sludge falling off the surface of the filter plate is enriched and uniformly removed in the sedimentation collection device 7 at the bottom of the reactor. According to the above-mentioned technical scheme of the invention, the manufacturing method of the filter plate is as follows: (1) respectively crushing red mud and coal powder, passing through a 100-mesh sieve, weighing 70 - 80 parts of red mud, 10 - 20 parts of coal powder and 1-3 parts of expansion agent according to parts by weight, evenly mixing, adding 5-10 parts of water to make a slurry;(2) Take 5 - 10g of the slurry prepared in step (1) and evenly coat it on a (15 - 20)cm×(10 - 14)cm mesh mud hanger made of iron wire, and dry it to prepare a raw mud filter plate; (3) Place the raw mud filter plate prepared in step (2) in a muffle furnace for sintering at a sintering temperature of 300 - 350℃ for 20 - 30 minutes. Preferably, the expansion agent in step (1) is aluminum powder. Preferably, the size of the mesh mud hanger made of iron wire in step (2) is 18cm×12cm.

Results Advantages:

1. The heavy metal removal device of the present invention is of inclined plate precipitation type, in which the raw materials needed for making the filter plate mainly use red mud and coal powder, and no special materials are needed. It has the advantages of low production cost and simple process, and truly achieves low cost and low energy consumption in the sewage treatment process;

2. The inclined filter plate of wastewater entering the reactor realizes a baffled flow. The inclined filter plate not only adsorbs the incoming wastewater but also plays a diversion role; during the wastewater treatment process, physical adsorption, chemical precipitation and ion exchange methods work together to treat heavy metal ions in sewage quickly, simply, thoroughly and effectively;

3. The device of the present invention is equipped with a jet pipe that can be used for flushing, which can be used for flushing the inclined plate device when the device is not working, so that the red mud pulverized coal adsorbent adsorbed on the surface will fall to form a new surface. In addition, the red mud pulverized coal adsorbent filter plate can also be replaced, which not only extends the service life of the device, but also improves the sewage treatment effect.

4. The device of the invention provides an effective and environmentally friendly detoxification device for the treatment of electroplating wastewater and promotes industrial production. The new inclined plate heavy metal detoxification device disclosed by the invention not only uses the industrial by-product red mud as the raw material, which solves the problem of the outlet of the red mud, but also has the advantages of lower load rate, more thorough treatment effect, far lower production cost than other sewage treatment equipment, and high resource utilization rate.