CN102674585B - Combined enhanced treatment process for low-turbidity high-alga raw water - Google Patents

Abstract

The invention discloses a low-turbidity and high-algae raw water combination enhanced treatment process. Including: first use flocculation advection sedimentation tank or high-efficiency sedimentation tank for sedimentation, then use air flotation tank to remove algae by air flotation, and the effluent will pass through ultrafiltration membrane group to further remove turbidity and algae, and then pass through the clear water tank for adjustment and storage, and then send it to the water supply pump room Water distribution network. According to the characteristics of low turbidity and high algae in raw water, the present invention optimizes and combines conventional coagulation sedimentation, air flotation, filtration and ultrafiltration processes, and fully considers the utilization of geothermal resources in the plant area to form an enhanced conventional treatment system. The advantages of this combined process are that it can save land, optimize the process, make full use of geothermal resources, simplify production management, and have obvious advantages in ensuring the quality of effluent water.

Description

Combined enhanced treatment process for raw water with low turbidity and high algae

technical field

The present invention is a water treatment combined enhanced process involved in water supply engineering, specifically a combined enhanced treatment process for raw water with low turbidity and high algae, which uses combined and enhanced conventional treatment for raw water with low temperature and low turbidity in winter and high algae in summer to achieve high-efficiency treatment The goal.

Background technique

The quality of surface water varies greatly in my country, and the difficulty of treating low-turbidity and high-algae raw water represented by lakes and large reservoirs is no less than that of high-ammonia nitrogen and high-organic matter micro-polluted water sources. During the low turbidity period in winter, the effect of coagulation and sedimentation is poor, causing the turbidity of the effluent water in the sedimentation tank to sometimes even be higher than that of the influent water, which increases the burden on the filtration process; After the pool, the surface of the filter material is blocked and the filter layer penetrates, causing algae to enter the clean water reservoir and pipe network.

At present, tap water plants with low-turbidity and high-algae raw water as drinking water sources adopt general conventional treatment processes. When the turbidity is around 5 NTU in winter and the temperature is lower than 5°C, and the algae exceeds 1 million per liter in summer, it is difficult to reach the new factory-loaded treatment process. Water quality standards require a combination of intensive conventional treatment measures. Recently, with the improvement of drinking water quality standards, in some areas, the turbidity of factory water has been paid more and more attention as an important control index of factory water quality. The standard of modern water plants in Zhejiang Province has raised the turbidity requirement to below 0.1NTU. It is difficult to achieve such a high water discharge requirement.

Contents of the invention

The purpose of the present invention is to provide a combined enhanced treatment process for low-turbidity and high-algae raw water, which is suitable for the treatment process of low-turbidity and high-algae raw water with a turbidity of about 5 NTU in winter and a temperature lower than 5°C, and an algae exceeding 1 million per liter in summer. Solve the influence of factors such as algae, turbidity and temperature changes on the treatment effect of the whole process.

In order to achieve the above object, the technical solution of the present invention is: a combined enhanced treatment process for raw water with low turbidity and high algae. Under normal conditions, the treatment process includes: first use a flocculation advection sedimentation tank or a high-efficiency sedimentation tank for sedimentation, then use an air flotation tank to remove algae by air flotation, and the effluent will further remove turbidity and algae through an ultrafiltration membrane group, and then pass through a clear water tank to adjust After storage, it is sent to the water distribution pipe network by the water delivery pump room. When the turbidity of the raw water is high or the effect of sedimentation water is poor, it can be filtered by the homogeneous filter material air-water backwash sand filter or security filter after the air flotation in the air flotation tank to remove algae, and then further removed by the ultrafiltration membrane group Turbidity and algae. In order to improve the treatment effect, in the low-temperature and low-turbidity raw water treatment process in winter, the raw water is heated first, and the coagulation and sedimentation treatment effect is improved by increasing the water temperature. The high-efficiency sedimentation tank is used for sedimentation, and then the effluent of the sedimentation is passed through the ultrafiltration membrane group to further remove turbidity and algae. When geothermal resources are available in the factory area, a geothermal heating system is installed to directly use geothermal heat to heat raw water.

According to the characteristics of low turbidity and high algae in raw water, the present invention optimizes and combines conventional coagulation sedimentation, air flotation, filtration and ultrafiltration processes, and fully considers the utilization of geothermal resources in the factory area to form an enhanced conventional treatment system, which is more efficient than existing processes The complete and flexible membrane pretreatment process saves operating costs while ensuring the quality of the effluent. The advantages of this combined process are that it can save land, optimize the process, make full use of geothermal resources, simplify production management, and have obvious advantages in ensuring the quality of effluent water.

Description of drawings

Fig. 1 is a schematic diagram of the low-turbidity and high-algae raw water treatment process under conventional conditions of the present invention.

Figure 2 is a schematic diagram of process improvement under the condition of utilizing geothermal resources.

Figure 3 is a schematic diagram of the geothermal heating system.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings.

The invention is a combined enhanced treatment process for low-turbidity and high-algae raw water. Under normal conditions, the raw water 1 is first settled in the flocculation advection sedimentation tank 2 or the high-efficiency sedimentation tank 3, and then the air flotation tank 4 is used to remove algae. After being stored, it is sent to the water distribution pipe network 10 by the water delivery pump house 9 . When the turbidity of the raw water is high or the effect of sedimentation water is poor, after the algae removal by air flotation in the air flotation tank 4, it can be filtered by the homogeneous filter material air-water backwashing sand filter 5 or the security filter 6, and then filtered by the ultrafiltration membrane Group 7 further removes turbidity and algae, and the effluent is sent to the water distribution pipe network 10 by the water delivery pump room 9 after being regulated and stored in the clear water pool 8 . In winter, in order to improve the treatment effect, a heating device can be added before the flocculation advection sedimentation tank 2 or the high-efficiency sedimentation tank 3. When geothermal resources are available in the factory area, a geothermal heating system 11 is installed to directly use geothermal heat to heat the raw water. If If not, the raw water can be heated by other means. The specific treatment process can be optimized as follows: the raw water is first heated to raise the water temperature to 5~15°C, then enters the flocculation advection sedimentation tank 2 or the high-efficiency sedimentation tank 3 for sedimentation, and then uses the air flotation tank 4 to remove algae by air flotation, and then enters the homogeneous filter material gas The water is filtered by the backwash sand filter 5 or the security filter 6 , and then the turbidity and algae are further removed by the ultrafiltration membrane group 7 . Of course, when the turbidity of raw water is low or the effect of sedimentation effluent is better, it can also surpass the air flotation tank 4 and the homogeneous filter material air-water backwash sand filter 5 or security filter 6, and directly connect the sedimentation effluent to the ultrafiltration membrane group 7 to process.

In the process combination, chlorine or chlorine dioxide 12, potassium permanganate (composite salt) 13, powdered activated carbon 14, alum 15 and coagulation aid 16 (generally high manganese Potassium acid and powdered activated carbon can be determined according to the raw water quality test, and the rest of the chemicals need to be added. The reference dosage: the dosage of chlorine is about 2mg/l, and the dosage of chlorine dioxide is about 1mg/l. l, the dosage of potassium permanganate is about 1~2mg/l, the dosage of powdered activated carbon is about 5~10mg/l, the dosage of alum is about 20~30mg/l, and the coagulation aid can be PAM. The dosage is about 0.1～0.2mg/l); the filter aid 17 is added before the homogeneous filter material air-water backwash sand filter 5 or the security filter 6 (the filter aid can be polyaluminum chloride, the dosage About 3~5mg/l); Dosing chlorine or chlorine dioxide 12 before the clear water pool 8 for disinfection. (The dosage of chlorine is about 2~3mg/l, and the dosage of chlorine dioxide is about 1~2mg/l).

When geothermal resources are available in the factory area, the geothermal heating system consists of water inlet pipe 18, heat exchange pipe 19, water outlet pipe 20, water inlet cut-off valve 21, water outlet cut-off valve 22, flushing water inlet valve 23 and flushing water outlet valve 24. The specific structure is: the geothermal heating system includes a multi-channel heat exchange pipe 19 buried underground, one end of the multi-channel heat exchange pipe 19 is connected to the water inlet pipe 18, and the other end of the multi-channel heat exchange pipe is connected to the In the flocculation advection sedimentation tank or high-efficiency sedimentation tank, a water inlet isolation valve 21 is provided between the water inlet pipe 18 and each heat exchange pipe 19, and an outlet water isolation valve 22 is provided between the outlet pipe 20 and each heat exchange pipe 19. One end of each heat exchange pipe 19 is connected to external pressurized water through a flushing water inlet valve 23, and the other end of each heat exchange pipe 19 is provided with a flushing water outlet valve 24 to drain water. The working method is: the outlet water of the sedimentation tank is divided into multiple heat exchange pipes 19 on the water inlet pipe 18, and the heat exchange pipes 19 are buried underground to fully absorb geothermal heat to increase the water temperature in the pipes, and after being collected by the outlet pipes 20, they enter the subsequent flocculation advection sedimentation tank 2 or high-efficiency sedimentation Pond 3: When single heat exchange pipe 19 needs to be flushed, close the water inlet shutoff valve 21 and the water outlet shutoff valve 22, open the flushing water inlet valve 23 and the flushing water outlet valve 24 and add pressure water to flush and drain.

The rest of the flocculation advection sedimentation tank, high-efficiency sedimentation tank, air flotation tank, homogeneous filter material air-water backwash sand filter, security filter, ultrafiltration membrane group, clear water tank and water delivery pump room are all existing technologies, and will not be described in detail .

Claims (4)

1. one kind low turbid algae concentrated feeding water combination strengthening treatment process, it is characterized in that when former water turbidity in winter at about 5NTU and temperature lower than under the normal condition of 5 DEG C, treatment process comprises: former water enters flocculation and sedimentation tank after first improving water temperature by heat riser or efficient sedimentation tank precipitates, then air flotation pool air floatation alga removing is used, water outlet removes turbidity and algae further by ultra-filtration membrane group, the distribution system of water supply is sent into by Water-supply station after being regulated and stored by clean water basin again, heat riser is underground heat temperature elevation system, directly adopts underground heat to heat former water.

2. technique as claimed in claim 1, after it is characterized in that air flotation pool air floatation alga removing, after being filtered by homogeneous filtering material air-water backwashing sand filter or cartridge filter, then is accessed ultra-filtration membrane group and processes.

3. technique as claimed in claim 2, it is characterized in that this underground heat temperature elevation system comprises the multichannel heat exchanger tube being embedded in underground, one end of this multichannel heat exchanger tube is connected with water inlet pipe, and the other end of this multichannel heat exchanger tube is connected to flocculation and sedimentation tank or efficient sedimentation tank by rising pipe.

4. technique as claimed in claim 2, adds chlorine or dioxide peroxide, potassium permanganate, powder activated carbon, alum and coagulant aids before it is characterized in that flocculation and sedimentation tank or efficient sedimentation tank; Flocculating aids is added before homogeneous filtering material air-water backwashing sand filter or cartridge filter; Chlorine or disinfection by chlorine dioxide is added before clean water basin.