Drinking water treatment device for strengthening turbidity pretreatment and disinfection

Abstract

The invention belongs to the technical field of water treatment, and relates to a drinking water treatment device for enhancing turbidity pretreatment and disinfection, which comprises a high-density coagulative precipitation tank, an activated carbon aeration biological composite filter tank and a peracetic acid contact tank, wherein the high-density coagulative precipitation tank consists of a coagulating tank, a folded plate flocculation tank and an inclined tube precipitation tank which are communicated in sequence; the activated carbon biological aerated filter consists of a biological aerated filter and a sand filter which are communicated in sequence; the peracetic acid contact tank is formed by communicating a first water tank, a second water tank and a third water tank, the first / second water tank is filled with suspended balls containing active matters, and the active matters are iron and nitrogen doped biochar materials. Through a cooperative technology, the adaptability and purification capacity of the water purification device to water quality and water quantity changes of a water source are effectively improved, the settling speed is high, and the purification efficiency is high. The treatment device disclosed by the invention is high in integration level, and is particularly suitable for treating rural drinking water sources.

Description

Technical Field

[0001] The present invention belongs to the technical field of water treatment, relates to drinking water treatment, and particularly relates to a drinking water treatment device for enhancing turbidity pretreatment and disinfection. Background Art

[0002] Due to their relatively remote geographical locations and insufficient protection measures, rural drinking water sources are extremely vulnerable to interference from external environmental factors. Floods, droughts, agricultural activities, etc. can all lead to unstable water quality and quantity, manifested as increased turbidity of source water and easy contamination of raw water. In some rural areas, due to economic conditions and technical limitations, the early water supply projects such as slow sand filters and reservoirs have relatively low design standards and low treatment efficiency, making it difficult to effectively deal with high-turbidity source water and sudden pollution incidents. In this case, not only are pollutants likely to penetrate the filter layer, but in the subsequent disinfection process, the residual pollutants react with disinfectants (such as chlorine), possibly generating harmful disinfection by-products to human health such as trihalomethanes and haloacetic acids.

[0003] Therefore, in order to promote the high-quality development of rural water supply, how to carry out the transformation of the front-end high-turbidity source water enhanced turbidity removal pretreatment technology and the research and development of the supporting technology for in-depth disinfection control on the basis of conventional processes has become a technical problem urgently to be solved in the industry. Summary of the Invention

[0004] Aiming at the rural high-turbidity source water and sudden pollution incidents in the prior art, the purpose of the present invention is to disclose a drinking water treatment device for enhancing turbidity pretreatment and disinfection.

[0005] Technical Solution

[0006] A drinking water treatment device for enhancing turbidity pretreatment and disinfection includes a high-density coagulation sedimentation tank, an activated carbon aerated biological composite filter tank, and a peracetic acid contact tank; wherein,

[0007] The high-density coagulation sedimentation tank is composed of a coagulation tank, a folded plate flocculation tank, and an inclined tube sedimentation tank that are connected in sequence. The unclosed pool wall of the coagulation tank separates it from the folded plate flocculation tank, and a stirrer is arranged inside. The raw water flows into the coagulation tank through the coagulation tank inlet pipe and is fully mixed with the coagulant pumped by the dosing pump. The mixed raw water is slowly pushed to the folded plate flocculation tank to form large flocs, and then the flocs are removed through the inclined tube sedimentation tank. The sludge at the bottom of the inclined tube sedimentation tank is pumped out of the tank by a recovery pump;

[0008] The activated carbon aerated biological composite filter is composed of an aerated biological filter and a sand filter connected in sequence. A pebble support layer is evenly laid at the bottoms of the aerated biological filter and the sand filter. An activated carbon layer is laid on top of the pebble support layer in the aerated biological filter, which is used to adsorb heavy metals, organic matters, and nitrogen and phosphorus pollutants in the water body. An aeration pipe is partially buried in the activated carbon layer for aerating the aerated biological filter. A sand filter layer is laid on top of the pebble support layer in the sand filter, which is used to intercept sludge in the water and the microbial film washed out from the aerated biological filter.

[0009] The peracetic acid contact tank is formed by connecting a first water tank, a second water tank, and a third water tank. A wind stirring device is provided in each of them. The water tanks are separated by grids. A disinfectant dosing pipe is provided below the side wall of the first water tank. Suspension balls containing active substances are filled in the first water tank and the second water tank. An outlet pipe is provided above the side wall of the third water tank, and a backwash pipe is provided below. The active substance is an iron and nitrogen-doped biochar material.

[0010] In a preferred disclosed example of the present invention, a coagulation tank inlet is provided at the bottom of the coagulation tank. The mixer is arranged at the top of the coagulation tank, and there are three groups of stirring paddles on it.

[0011] In a preferred disclosed example of the present invention, a dosing pipe is connected to the inlet pipe, and a dosing pump is installed on the dosing pipe to pump the coagulant into the coagulation tank.

[0012] In a preferred disclosed example of the present invention, same-wave folding plates are provided in the folded plate flocculation tank. The angle of the same-wave folding plates is 60°, and the material is stainless steel. Further, the same-wave folding plates are vertical flow type.

[0013] In a preferred disclosed example of the present invention, a triangular weir is provided at the top of the inclined tube sedimentation tank, and a collecting trough is provided on the side of the inclined tube sedimentation tank. The clarified water overflows through the triangular weir into the collecting trough. The outlet pipe of the inclined tube sedimentation tank is arranged at the bottom of the collecting trough.

[0014] In a preferred disclosed example of the present invention, a sludge discharge pipe is further provided at the bottom of the inclined tube sedimentation tank, and a recovery pump is installed on the sludge discharge pipe.

[0015] In a preferred disclosed example of the present invention, a partition is provided at the connection between the folded plate flocculation tank and the inclined tube sedimentation tank, which is used to prevent the coagulated water and the sedimented sludge from flowing back. Further, the inclined tubes are arranged at an angle of 60° for sedimenting sludge.

[0016] In a preferred disclosed example of the present invention, the inlet pipe of the aerated biological filter is arranged at the bottom of the activated carbon aerated biological composite filter, and a water distribution branch pipe is installed on it. Filter heads are also provided correspondingly for flushing sludge impurities in the filter. The bottom of the sand filter is provided with a sand filter outlet pipe. A check valve is provided between the inlet pipe of the aerated biological filter and the outlet pipe of the sand filter.

[0017] In a preferred disclosure example of the present invention, an aeration pipe is provided in the activated carbon layer, and the aeration pipe is connected to an aeration pump.

[0018] In a preferred disclosure example of the present invention, a drain trough is provided inside the sand filter, and a V-shaped trough is obliquely provided on the inner side of the edge of the sand filter. The V-shaped troughs are connected by perforated pipes for uniform water distribution in the sand filter.

[0019] In a preferred disclosure example of the present invention, the influent pipe of the biological aerated filter, the effluent pipe of the sand filter, and the backwash pipe are the same pipeline.

[0020] In a preferred disclosure example of the present invention, the disinfectant dosing pipe is connected beside the effluent pipe of the sand filter through a disinfectant dosing pump, and a backwash pump is installed on the backwash pipe.

[0021] In a preferred disclosure example of the present invention, the disinfectant is peracetic acid. The grille is used to intercept the suspension balls. The diameter of the suspension balls is larger than the distance between two adjacent grid bars of the grille. The material is polymer with holes on the surface. The density in the water tank is 10 - 100 pieces / m 3 。

[0022] In a preferred disclosure example of the present invention, the iron and nitrogen-doped biochar material (Fe / N-BC) is synthesized in two steps by hydrothermal synthesis - pyrolysis method, with a particle size of 2 - 5 mm (for the preparation method, see Ruyan Ning et al., Fe-N co-doped biochar derived from biomass waste triggers peracetic acid activation for efficient water decontamination; Journal of Hazardous Materials 470 (2024) 134139).

[0023] The purification device disclosed by the present invention is particularly applied to the treatment of rural drinking water sources.

[0024] The specific working principle and usage process are as follows:

[0025] After the raw water is dosed with a coagulant, the colloidal particles that are quickly mixed and destabilized under the action of a stirrer are initially coagulated; the mixed water generates micro-vortices in a corrugated plate flocculation tank with a certain angle under the action of plug flow, promoting the collision of flocculation particles to form large flocs; the large and dense flocs circulate up and down through the partition plate and then enter the inclined tube for sedimentation, effectively preventing the backflow of settled sludge; the sludge separated by the inclined tube forms dense flocs under the action of cyclic extrusion and rotation and settles to the bottom of the tank, and is recovered by a sludge recovery pump.

[0026] The clear water treated by the high-density coagulation sedimentation tank enters the composite filter tank from the bottom of the collecting tank. The activated carbon aerated biological composite filter tank includes an activated carbon aerated biological filter tank and a sand filter tank that are connected in sequence. A filter media support layer is provided below the aerated biological filter tank and the sand filter tank. The filler in the aerated biological filter tank is activated carbon, which is used to adsorb heavy metals, organic matters, and nitrogen and phosphorus pollutants in the water body. An air pipe is provided in the activated carbon filler. After micro-aeration by an aeration pump, the biological contact oxidation effectively removes the organic matters in the water. A sand filter layer is provided in the sand filter tank to further intercept suspended solids and the biological film shed from the aerated biological filter tank.

[0027] An anti-flushing pipe is provided at the bottom of the activated carbon aerated biological composite filter tank, which shares the inlet pipe and the outlet pipe connected through a check valve. When the composite filter tank is working normally, under the action of the check valve, the water flows through the aerated biological filter tank and overflows to the V-shaped groove, and is evenly distributed to the sand filter tank through the perforated pipe, and then flows out through the bottom outlet pipe. When the composite filter tank is being backwashed, the backwashing water flows through the outlet pipe of the sand filter tank and the inlet pipe of the aerated biological filter tank in sequence, and different intensities of backwashing are carried out on the aerated biological filter tank and the sand filter tank according to the weight of the filter media. The aeration pump operates normally for the air-water backwashing of the aerated biological filter tank.

[0028] The clear water treated by the activated carbon aerated biological composite filter tank and peracetic acid disinfectant enter the peracetic acid contact tank together. Under the action of the wind stirring device, the disinfectant makes full contact with the suspended balls filled with active substances, and the generated free radicals such as HO· and CH3C(=O)O· efficiently and continuously remove pathogenic microorganisms and inorganic pollutants in the water. A grille is provided between each water tank to intercept the suspended balls filled with active substances.

[0029] Beneficial effects

[0030] The present invention effectively improves the adaptability of the water purification device to changes in the water quality and quantity of the water source through the collaborative technologies of the high-density sedimentation tank, the activated carbon aerated biological composite filter tank, and the peracetic acid contact tank. At the same time, it improves the water quality purification ability, with a fast sedimentation speed, high purification efficiency, and high integration degree of the treatment device. The present invention combines the activated carbon aerated biological filter tank and the sand filter tank. While the activated carbon adsorbs heavy metals, nitrogen, phosphorus, and organic matters, the organic matters in the water are further removed through aeration. In addition, the sand filter tank filters the suspended solids in the water and the biological film shed from the aerated biological filter tank. The inlet and outlet pipes at the bottom of the filter tank share the anti-flushing pipe, which facilitates the backwashing operation and greatly reduces the pipeline cost. The present invention further efficiently removes pathogenic microorganisms and refractory inorganic pollutants in the water through the free radicals such as HO· and CH3C(=O)O· generated by activating peracetic acid with active substances, improving the water quality of the effluent. A wind stirring device is provided in the peracetic acid contact tank, which uses wind for stirring, saving electricity costs while promoting the full contact between peracetic acid and active substances. Description of the drawings

[0031] Figure 1. Structural schematic diagram of a drinking water treatment device for enhanced turbidity pretreatment and disinfection;

[0032] Figure 2 . Structural schematic diagram of a high-density sedimentation tank;

[0033] Figure 3 . Structural schematic diagram of an activated carbon aerated biological composite filter;

[0034] Figure 4 . Structural schematic diagram of a peracetic acid contact tank;

[0035] Each mark in the attached drawings is respectively: 1. High-density coagulation sedimentation tank; 11. Coagulation tank; 12. Folded plate flocculation tank; 13. Inclined tube sedimentation tank; 111. Water inlet pipe; 112. Chemical dosing pipe; 113. Chemical dosing pump; 114. Coagulation tank water inlet; 115. Stirring paddle; 116. Mixer; 121. Same-wave folded plate; 131. Recycling pump; 132. Sludge discharge pipe; 133. Sludge; 134. Partition board; 135. Inclined tube; 136. Water collection tank; 137. Triangular weir; 138. Inclined tube sedimentation tank outlet pipe; 2. Activated carbon aerated biological composite filter; 21. Aerated biological filter; 211. Aerated biological filter water inlet pipe; 212. Distribution branch pipe; 213. Filter head; 214. Check valve; 215. Cobblestone supporting layer; 216. Activated carbon layer; 217. Drainage tank; 218. Aeration pipe; 219. Aeration pump; 22. Sand filter; 221. Sand filter layer; 222. V-shaped groove; 223. Perforated pipe; 224. Sand filter outlet pipe; 3. Peracetic acid contact tank; 31. Disinfectant dosing pipe; 311. Disinfectant dosing pump; 32. First water tank; 321. Suspended ball of nano zero-valent iron; 322. Grille; 323. Wind stirring device; 33. Second water tank; 34. Third water tank; 341. Peracetic acid contact tank outlet pipe; 342. Backwashing pipe; 343. Backwashing pump. Detailed implementation manners

[0036] The technical solutions and advantages of the present invention will be further elaborated below in combination with specific examples. However, the following examples are only a part of the examples of the present invention. All other examples obtained by those of ordinary skill in the art based on the examples in the present invention without making creative efforts fall within the protection scope of the present invention.

[0037] Example 1

[0038] A drinking water treatment device for enhanced turbidity pretreatment and disinfection, including a high-density coagulation sedimentation tank 1, an activated carbon aerated biological composite filter 2 and a peracetic acid contact tank 3; wherein,

[0039] The high-density coagulation sedimentation tank 1 is composed of a coagulation tank 11, a folded plate flocculation tank 12, and an inclined tube sedimentation tank 13 that are connected in sequence. The unenclosed pool wall of the coagulation tank 11 separates it from the folded plate flocculation tank 12, and a mixer 116 is provided therein. The raw water flows into the coagulation tank 11 through the coagulation tank inlet pipe 111 and is fully mixed with the coagulant pumped by the chemical dosing pump 113. The mixed raw water is slowly pushed to the folded plate flocculation tank 12 to form large flocs, and then the flocs are removed through the inclined tube sedimentation tank 13. The sludge 133 at the bottom of the inclined tube sedimentation tank 13 is pumped out of the tank by the recycling pump 131;

[0040] The activated carbon aerated biological composite filter 2 is composed of an aerated biological filter 21 and a sand filter 22 that are connected in sequence. The pebble support layer 215 is evenly laid at the bottoms of the aerated biological filter 21 and the sand filter 22. The activated carbon layer 216 is laid on top of the pebble support layer 215 in the aerated biological filter 21 for adsorbing heavy metals, organic matters, and nitrogen and phosphorus pollutants in the water body. The aeration pipe 218 is partially buried in the activated carbon layer 216 for aerating the aerated biological filter 21. The sand filter layer 221 is laid on top of the pebble support layer 215 in the sand filter 22 for intercepting the sludge in the water and the microbial film washed out from the aerated biological filter 21;

[0041] The peracetic acid contact tank 3 is formed by connecting a first water tank 32, a second water tank 33, and a third water tank 34. Wind stirring devices 323 are provided therein. Each water tank is separated by a grid 322. A disinfectant dosing pipe 31 is provided below the side wall of the first water tank 32. Suspension balls 321 containing active substances are filled in the first water tank 32 and the second water tank 33. An outlet pipe 341 is provided above the side wall of the third water tank 34, and a backwash pipe 342 is provided below.

[0042] Example 2

[0043] A drinking water treatment device for enhancing turbidity pretreatment and disinfection includes a high-density coagulation sedimentation tank 1, an activated carbon aerated biological composite filter 2, and a peracetic acid contact tank 3; wherein,

[0044] The high-density coagulation sedimentation tank 1 is composed of a coagulation tank 11, a folded plate flocculation tank 12, and an inclined tube sedimentation tank 13 that are connected in sequence. The unenclosed pool wall of the coagulation tank 11 separates it from the folded plate flocculation tank 12, and a mixer 116 is provided inside; a coagulation tank water inlet 114 is provided at the bottom of the coagulation tank 11, the mixer 116 is arranged on the top of the coagulation tank 11, and there are three groups of stirring paddles 115 on it; a chemical dosing pipe 112 is connected to the water inlet pipe 111, and a chemical dosing pump 113 is installed on the chemical dosing pipe 112 to pump the coagulant into the coagulation tank 11; the folded plate flocculation tank 12 is provided with same-wave folded plates 121, the angle of the same-wave folded plates is 60°, and the material is stainless steel; a triangular weir 137 is provided at the top of the inclined tube sedimentation tank 13, a collecting trough 136 is provided on the side of the inclined tube sedimentation tank 13, and the clarified water overflows through the triangular weir 137 into the collecting trough 136; an inclined tube sedimentation tank water outlet pipe 138 is provided at the bottom of the collecting trough 136; the raw water flows through the coagulation tank water inlet pipe 111 into the coagulation tank 11 and is fully mixed with the coagulant pumped by the chemical dosing pump 113, and the mixed raw water is slowly pushed to the folded plate flocculation tank 12 to form large flocs, and then the flocs are removed through the inclined tube sedimentation tank 13, and the sludge 133 at the bottom of the inclined tube sedimentation tank 13 is pumped out of the tank by a recovery pump 131;

[0045] The activated carbon aerated biological composite filter 2 is composed of an aerated biological filter 21 and a sand filter 22 that are connected in sequence. A pebble support layer 215 is evenly laid at the bottoms of the aerated biological filter 21 and the sand filter 22, and an activated carbon layer 216 is laid on the pebble support layer 215 inside the aerated biological filter 21 for adsorbing heavy metals, organic matters, and nitrogen and phosphorus pollutants in the water body. An aeration pipe 218 is partially buried in the activated carbon layer 216 for aerating the aerated biological filter 21; a sand filter layer 221 is laid on the pebble support layer 215 inside the sand filter 22 for intercepting sludge in the water and the microbial film washed out from the aerated biological filter 21; an aerated biological filter water inlet pipe 211 is provided at the bottom of the activated carbon aerated biological composite filter 2, a water distribution branch pipe 212 is installed on it, and filter heads 213 are also provided correspondingly for flushing sludge impurities in the filter; a sand filter water outlet pipe 224 is provided at the bottom of the sand filter 22; a check valve 214 is provided between the aerated biological filter water inlet pipe 211 and the sand filter water outlet pipe 224; a drainage trough 217 is provided inside the sand filter 22, and a V-shaped groove 222 is obliquely provided on the inner side of the edge of the sand filter 22, and the V-shaped groove 222 is connected through an opening pipe 223 for evenly distributing water in the sand filter 22;

[0046] The peracetic acid contact tank 3 is formed by connecting a first water tank 32, a second water tank 33, and a third water tank 34. A wind stirring device 323 is provided inside each of them. The water tanks are separated by a grille 322. A disinfectant dosing pipe 31 is provided below the side wall of the first water tank 32. Suspension balls 321 containing active substances are filled in the first water tank 32 and the second water tank 33. An outlet pipe 341 is provided above the side wall of the third water tank 34, and a backwash pipe 342 is provided below. The disinfectant dosing pipe 31 is connected beside the outlet pipe 224 of the sand filter tank via a disinfectant dosing pump 311. A backwash pump 343 is installed on the backwash pipe 342.

[0047] Example 3

[0048] A drinking water treatment device for enhancing turbidity pretreatment and disinfection includes a high-density coagulation sedimentation tank 1, an activated carbon aeration biological composite filter tank 2, and a peracetic acid contact tank 3. Among them,

[0049] The high-density coagulation sedimentation tank 1 is composed of a coagulation tank 11, a folded plate flocculation tank 12, and an inclined tube sedimentation tank 13 connected in sequence. The unclosed pool wall of the coagulation tank 11 separates it from the folded plate flocculation tank 12, and a stirrer 116 is provided inside. A coagulation tank inlet 114 is provided at the bottom of the coagulation tank 11. The stirrer 116 is arranged at the top of the coagulation tank 11, and there are three groups of stirring paddles 115 on it. A dosing pipe 112 is connected to the inlet pipe 111, and a dosing pump 113 is installed on the dosing pipe 112 to pump the coagulant into the coagulation tank 11. The folded plate flocculation tank 12 is provided with coaxial folded plates 121, the angle of the coaxial folded plates is 60°, and the material is stainless steel. A triangular weir 137 is provided at the top of the inclined tube sedimentation tank 13, and a collecting trough 136 is provided on the side of the inclined tube sedimentation tank 13. The clarified water overflows through the triangular weir 137 into the collecting trough 136. The outlet pipe 138 of the inclined tube sedimentation tank is arranged at the bottom of the collecting trough 136. The inclined tubes 135 are arranged at an angle of 60° for sedimenting sludge. A sludge discharge pipe 132 is also provided at the bottom of the inclined tube sedimentation tank 13, and a recovery pump 131 is installed on the sludge discharge pipe 132. A partition 134 is provided at the connection between the folded plate flocculation tank 12 and the inclined tube sedimentation tank 13, and the partition 134 is used to prevent the coagulated water and the sedimented sludge from flowing back. The raw water flows through the coagulation tank inlet pipe 111 into the coagulation tank 11 and is fully mixed with the coagulant pumped by the dosing pump 113. The mixed raw water is slowly pushed to the folded plate flocculation tank 12 to form large flocs, and then the flocs are removed through the inclined tube sedimentation tank 13. The sludge 133 at the bottom of the inclined tube sedimentation tank 13 is pumped out of the tank by the recovery pump 131.

[0050] The activated carbon aerated biological composite filter 2 is composed of an aerated biological filter 21 and a sand filter 22 connected in sequence. A pebble support layer 215 is evenly laid at the bottoms of the aerated biological filter 21 and the sand filter 22. An activated carbon layer 216 is laid on top of the pebble support layer 215 in the aerated biological filter 21, which is used to adsorb heavy metals, organic matters and nitrogen and phosphorus pollutants in the water body. An aeration pipe 218 is partially buried in the activated carbon layer 216 for aerating the aerated biological filter 21. The aeration pipe 218 is connected to an aeration pump (219); A sand filter layer 221 is laid on top of the pebble support layer 215 in the sand filter 22, which is used to intercept sludge in the water and the microbial film washed out from the aerated biological filter 21; An aerated biological filter inlet pipe 211 is arranged at the bottom of the activated carbon aerated biological composite filter 2, on which a water distribution branch pipe 212 is installed, and filter heads 213 are also correspondingly provided for flushing sludge impurities in the filter; A sand filter outlet pipe 224 is arranged at the bottom of the sand filter 22; A check valve 214 is arranged between the aerated biological filter inlet pipe 211 and the sand filter outlet pipe 224; A drainage trough 217 is arranged inside the sand filter 22, and a V-shaped trough 222 is obliquely arranged on the inner side of the edge of the sand filter 22. The V-shaped trough 222 is connected through an opening pipe 223 for uniform water distribution of the sand filter 22; The aerated biological filter inlet pipe 211, the sand filter outlet pipe 224 and the backwashing pipe 342 are the same pipeline;

[0051] The peracetic acid contact tank 3 is formed by connecting a first water tank 32, a second water tank 33 and a third water tank 34. A wind stirring device 323 is arranged in each of them. Each water tank is separated by a grid 322. A disinfectant dosing pipe 31 is arranged below the side wall of the first water tank 32. Suspended balls 321 containing active substances are filled in the first water tank 32 and the second water tank 33. An outlet pipe 341 is arranged above the side wall of the third water tank 34, and a backwashing pipe 342 is arranged below; The disinfectant dosing pipe 31 is connected beside the sand filter outlet pipe 224 through a disinfectant dosing pump 311, and a backwashing pump 343 is installed on the backwashing pipe 342.

[0052] The disinfectant is peracetic acid. The grid 322 is used to intercept the suspended balls 321. The diameter of the suspended balls 321 is larger than the distance between two adjacent grid bars of the grid 322. The material is polymer and the surface is perforated. The density of the filling in the water tank is 10 - 100 pieces / m 3 。

[0053] The active substance is an iron and nitrogen doped biochar material (Fe / N-BC), which is synthesized by a two-step method of hydrothermal synthesis - pyrolysis, and its particle size is 2 - 5 mm.

[0054] Water treatment test comparison

[0055] Table 1 Analysis of the water purification efficiency of different devices

[0056]

[0057] As can be seen from Table 1, compared with the conventional rural drinking water treatment device - "coagulation - sedimentation - filtration - disinfection", the flocculation effect and filtration and disinfection functions of this device have been greatly improved: when the turbidity of the raw water reaches more than 1000 NTU, after being treated by this device, the turbidity of the water after sedimentation drops to 8.44 NTU, and finally the turbidity of the filtered water is 0.15 NTU; the Mn COD value drops from 3.57 mg / L to 0.32 mg / L, and the removal rate is as high as over 90%; the total number of colonies drops from 2432 CFU / ml to 8 CFU / ml. It can be seen that the high - density sedimentation tank of this device can efficiently treat raw water with high turbidity, further reduce the turbidity in the water. At the same time, by combining the activated carbon aerated biological filter and the sand filter, while the activated carbon adsorbs nitrogen, phosphorus and organic matter, the organic matter in the water is further removed through aeration. In addition, the free radicals such as HO· and CH3C(=O)O· generated by the activation of peracetic acid by the active substance in this device can further efficiently remove pathogenic microorganisms and refractory inorganic pollutants in the water, improving the quality of the effluent water.

[0058] The above has described in detail one embodiment of the present invention, including the basic principle, main features and advantages of the present invention. However, the content is only the preferred embodiment of the present invention. For those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and deformations can be made to these embodiments without departing from the principle and spirit of the present invention, and these changes and improvements should still fall within the scope covered by the patent of the present invention.

Claims

1. A drinking water treatment device for enhancing turbidity pretreatment and disinfection, comprising a high-density coagulation sedimentation tank (1), an activated carbon aerated biological composite filter (2) and a peracetic acid contact tank (3); characterized in that: The high-density coagulation sedimentation tank (1) is composed of a coagulation tank (11), a folded plate flocculation tank (12) and an inclined tube sedimentation tank (13) connected in sequence. The unclosed pool wall of the coagulation tank (11) separates it from the folded plate flocculation tank (12). A stirrer (116) is arranged inside it. The raw water flows into the coagulation tank (11) through the coagulation tank inlet pipe (111) and is fully mixed with the coagulant pumped by the dosing pump (113). The mixed raw water is slowly pushed to the folded plate flocculation tank (12) to form large alum flowers, and then the alum flowers are removed through the inclined tube sedimentation tank (13). The sludge (133) at the bottom of the inclined tube sedimentation tank (13) is pumped out of the tank by the recovery pump (131); The activated carbon aerated biological composite filter (2) is composed of an aerated biological filter (21) and a sand filter (22) connected in sequence. The pebble support layer (215) is evenly laid at the bottoms of the aerated biological filter (21) and the sand filter (22). The activated carbon layer (216) is laid on the pebble support layer (215) inside the aerated biological filter (21) for adsorbing heavy metals, organic matters and nitrogen and phosphorus pollutants in the water body. The aeration pipe (218) is partially buried in the activated carbon layer (216) for aerating the aerated biological filter (21); The sand filter layer (221) is laid on the pebble support layer (215) inside the sand filter (22) for intercepting the sludge in the water and the microbial film washed out from the aerated biological filter (21); The peracetic acid contact tank (3) is formed by connecting a first water tank (32), a second water tank (33) and a third water tank (34). A wind stirring device (323) is arranged inside each of them. Each water tank is separated by a grid (322). A disinfectant dosing pipe (31) is arranged below the side wall of the first water tank (32). Suspension balls (321) containing active substances are filled in the first water tank (32) and the second water tank (33). An outlet pipe (341) is arranged above the side wall of the third water tank (34), and a backwashing pipe (342) is arranged below it. The active substance is an iron and nitrogen doped biochar material.

2. The drinking water treatment device for enhanced turbidity pretreatment and disinfection according to claim 1, characterized in that: The bottom of the coagulation tank (11) is provided with a coagulation tank inlet (114). The stirrer (116) is arranged on the top of the coagulation tank (11), and there are three groups of stirring paddles (115) on it; The dosing pipe (112) is connected to the inlet pipe (111), and the dosing pump (113) is installed on the dosing pipe (112) to pump the coagulant into the coagulation tank (11).

3. The drinking water treatment device for enhanced turbidity pretreatment and disinfection according to claim 1, wherein: The folded plate flocculation tank (12) is provided with same-wave folded plates (121), and the angle of the same-wave folded plates is 60°, and the material is stainless steel; Further, the same-wave folded plates (121) are vertical flow type.

4. The drinking water treatment device for enhanced turbidity pretreatment and disinfection according to claim 1, characterized in that: At the top of the inclined tube sedimentation tank (13), there is a triangular weir (137). On the side of the inclined tube sedimentation tank (13), there is a water collection tank (136). The clarified water overflows through the triangular weir (137) into the water collection tank (136). The outlet pipe (138) of the inclined tube sedimentation tank is arranged at the bottom of the water collection tank (136). At the bottom of the inclined tube sedimentation tank (13), there is also a sludge discharge pipe (132), and the recycling pump (131) is installed on the sludge discharge pipe (132).

5. The drinking water treatment device for enhanced turbidity pretreatment and disinfection according to claim 1, characterized in that: At the connection between the folded plate flocculation tank (12) and the inclined tube sedimentation tank (13), there is a partition plate (134), and the partition plate (134) is used to prevent the coagulated water and sedimented sludge from flowing back. Further, the inclined tubes (135) are arranged at an angle of 60° for sedimenting sludge.

6. The drinking water treatment device for enhanced turbidity pretreatment and disinfection according to claim 1, wherein: The inlet pipe (211) of the aerated biological filter is arranged at the bottom of the activated carbon aerated biological composite filter (2). A water distribution branch pipe (212) is installed thereon, and filter nozzles (213) are also provided correspondingly for flushing the sludge impurities in the filter. At the bottom of the sand filter (22), there is an outlet pipe (224) of the sand filter. A check valve (214) is arranged between the inlet pipe (211) of the aerated biological filter and the outlet pipe (224) of the sand filter. In the activated carbon layer (216), there is an air distribution pipe (218), and the air distribution pipe (218) is connected to an air pump (219).

7. The drinking water treatment device for enhanced turbidity pretreatment and disinfection according to claim 1, characterized in that: Inside the sand filter (22), there is a drainage trough (217). On the inner side of the edge of the sand filter (22), a V-shaped groove (222) is obliquely arranged. The V-shaped grooves (222) are connected through an open-hole pipe (223) for uniform water distribution in the sand filter (22). The inlet pipe (211) of the aerated biological filter, the outlet pipe (224) of the sand filter, and the backwashing pipe (342) are the same pipeline.

8. The drinking water treatment device for enhanced turbidity pretreatment and disinfection according to claim 1, characterized in that: The disinfectant dosing pipe (31) is connected beside the outlet pipe (224) of the sand filter through a disinfectant dosing pump (311). A backwashing pump (343) is installed on the backwashing pipe (342).

9. The drinking water treatment device for enhanced turbidity pretreatment and disinfection according to claim 1, wherein: The disinfectant is peracetic acid. The grille (322) is used to intercept the suspension balls (321). The diameter of the suspension balls (321) is greater than the distance between two adjacent grid bars of the grille (322). The material is polymer and the surface is perforated. The pool is filled with a density of 10 to 100 pieces / m 3 .

10. An application of the device according to any one of claims 1-9, characterized in that: It is applied to the treatment of rural drinking water sources.

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