Surface water treatment and recycling system

Abstract

The utility model relates to a kind of surface water treatment recycling system, belong to the industrial circulating cooling water treatment field with surface water as supplementary water.The system includes coagulation zone, flocculation zone, sedimentation zone, sand filter area, water production tank connected in turn;Wherein, surface water inflow is entered coagulation zone after being sterilized by NaClO;In coagulation zone, suspended matter colloidal particles in water are condensed and adsorbed, then flow into flocculation zone by itself;In flocculation zone, promote small alun flocculation increase, then flow into sedimentation zone by itself;After being deposited in sedimentation zone, supernatant produced is treated by sand filter area, enters water production tank and is saved, then is supplied to water point;Part is used to backwash sand filter area;Sludge produced by sedimentation in sedimentation zone is transferred into sludge pool, sludge is stored after being pressed by filter press, and press filtrate enters coagulation zone for treatment.The system is simple in operation, high in automation, saves land occupation, saves investment, low in running cost, stable and reliable, and good in treatment effect.

Description

Technical Field

[0001] This utility model relates to a pretreatment method for surface water with high turbidity and high suspended solids, which is suitable for the treatment and recycling of surface water in production plants and belongs to the field of industrial circulating cooling water treatment using surface water as supplementary water. Background Technology

[0002] Industrial production often uses circulating cooling water systems, which require a large amount of water for replenishment. Currently, the sources of water for replenishing industrial circulating cooling water are diverse, including industrial wastewater, reclaimed water, groundwater, and recycled water. However, these systems have drawbacks such as complex water quality, long treatment processes, large land area requirements, and high operating costs.

[0003] Surface water resources account for a large proportion of the total water volume on the ground and are one of the most widely used water resources by humans. Taking surface water as makeup water for circulating cooling water systems is a relatively economical choice.

[0004] Therefore, it is of great significance to develop a highly automated, space-saving, low-investment, stable and reliable surface water treatment and recycling system to achieve compliant resource utilization in the chemical industry. Summary of the Invention

[0005] In order to overcome the shortcomings of the existing technology, this utility model provides a surface water treatment and recycling system that is simple to operate, highly automated, saves space, saves investment, has low operating costs, is stable and reliable, and has good treatment effect.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows: A surface water treatment and recycling system includes a coagulation zone, a flocculation zone, a sedimentation zone, a sand filtration zone, and a product water tank connected in sequence; wherein, Surface water is sterilized with NaClO before entering the coagulation zone; In the coagulation zone, suspended colloidal particles in the water are coagulated and adsorbed, and then flow by gravity into the flocculation zone; The flocculation zone promotes the growth of small alum flocs, which then flow by gravity into the sedimentation zone. The supernatant produced after sedimentation in the sedimentation zone is treated in the sand filtration zone, stored in the product water tank, and then supplied to the water use points; a portion is used for backwashing the sand filtration zone. The sludge produced by sedimentation in the sedimentation zone is transferred to the sludge tank. The sludge after being filtered by the filter press is stored, and the filtrate enters the coagulation zone for treatment.

[0007] Furthermore, coagulant PAC is added to the coagulation zone, and the suspended colloidal particles in the water are coagulated and adsorbed under the mixing of the agitator.

[0008] Furthermore, the concentration of the coagulant PAC is 5wt%, and the dosage is 10~20mg / L.

[0009] Furthermore, the mixer in the coagulation zone is a paddle type with a rotation speed of 60~80 r / min.

[0010] Furthermore, PAM is added to the flocculation zone, and the mixing in the mixer promotes the growth of small alum flocs.

[0011] Furthermore, the flocculant PAM is prepared at a concentration of 0.1 wt% and the dosage is 2-5 mg / L.

[0012] Furthermore, the agitator in the flocculation zone is a paddle type with a rotation speed of 30~40 r / min.

[0013] Furthermore, the sedimentation zone 3 employs inclined tube sedimentation to achieve solid-liquid separation, with a surface loading of 1~2m. 3 / (m 2 ·h).

[0014] Furthermore, the bottom of the sand filter zone 4 is a water distribution pipe for periodic backwashing, and the upper part is quartz sand filter media.

[0015] Furthermore, the quartz sand filter media has two specifications from bottom to top: a particle size of 0.5-1.2mm and a particle size of 1-2mm, with a filling volume ratio of 7:3.

[0016] Furthermore, the sand filtration system in the sand filtration zone has a filtration rate of 6-8 m / h. Backwashing is performed using a backwash pump for forced backwashing, and is also equipped with compressed air rinsing. The backwashing cycle of the filter tank is 12 hours, and the backwashing time is 5-10 minutes. Compared with the prior art, the beneficial effects of this utility model are as follows: 1. This utility model integrates all the processing units together, including sludge treatment and automatic dosing system, to form a complete surface water treatment and recycling system with zero wastewater discharge function. The system has a high degree of automation, saves space, and has low operating costs.

[0017] 2. This utility model has good sand filtration effect and stable effluent. In addition, the sand filter backwashing adopts a backwash pump for forced backwashing, which has high backwashing intensity and good backwashing effect. The filter media has strong dirt holding and recovery capacity, overcoming the disadvantages of siphon backwashing such as easy clogging of filter media, difficulty in washing out, large backwashing water volume, and poor effluent quality. Attached Figure Description

[0018] Figure 1 This is a system structure diagram of the present invention; In the diagram, 1-coagulation zone, 2-flocculation zone, 3-sedimentation zone, 4-sand filtration zone, 5-product water tank, 6-sludge tank, and 7-filter press. Detailed Implementation

[0019] The technical solution and effects of this utility model will be further described below with reference to the accompanying drawings and specific embodiments, but the protection scope of this utility model is not limited thereto. Example 1

[0020] like Figure 1 As shown, a surface water treatment and recycling system according to this embodiment includes a coagulation zone 1, a flocculation zone 2, a sedimentation zone 3, a sand filtration zone 4, and a product water tank 5 connected in sequence; wherein, Surface water is sterilized with NaClO before entering coagulation zone 1; In the coagulation zone 1, suspended colloidal particles in the water are coagulated and adsorbed, and then flow by gravity into the flocculation zone 2. In flocculation zone 2, the growth of small alum flocs is promoted, and then they flow into sedimentation zone 3 by gravity. The supernatant produced after sedimentation in sedimentation zone 3 is treated in sand filtration zone 4 and stored in product water tank 5 before being supplied to water usage points; a portion is used for backwashing sand filtration zone 4. The sludge produced by sedimentation in sedimentation zone 3 is transferred to sludge tank 6. The sludge after being filtered by filter press 7 is stored, and the filtrate enters coagulation zone 1 for treatment.

[0021] In this embodiment, the concentration of NaClO is 10wt%, and the dosage is 5~10mg / L of wastewater.

[0022] In this embodiment, coagulant PAC is added to coagulate and adsorb suspended colloidal particles in the water under the mixing of a mixer. The concentration of coagulant PAC is 5 wt%, and the dosage is 10-20 mg / L. The mixer is a paddle type with a rotation speed of 60-80 r / min.

[0023] In flocculation zone 2, flocculant PAM is added to promote the growth of small flocs under mixing in a mixer. In this embodiment, the concentration of flocculant PAM is 0.1 wt%, and the dosage is 2~5 mg / L. The mixer is a paddle type, with a rotation speed of 30~40 r / min.

[0024] In this embodiment, the precipitation zone 3 uses inclined tube precipitation to complete solid-liquid separation, with a surface loading of 1~2m. 3 / (m 2 (h) The inclined tube packing is ф50*1000mm, 0.5mm thick, made of PP, and inclined at an angle of 60°. Most of the flocs settle down and are discharged into the sludge hopper, then pumped to the sludge tank 6 by a sludge pump, while the supernatant flows by gravity into the sand filter area 4.

[0025] In this embodiment, the bottom of the sand filter zone 4 is a water distribution pipe for periodic backwashing, and the upper part is quartz sand filter media to further trap residual particles in the water.

[0026] Furthermore, the quartz sand filter media comes in two specifications from bottom to top: 0.5-1.2mm in particle size and 1-2mm in particle size, with a volume ratio of 7:3.

[0027] The sand filtration system in sand filtration zone 4 has a filtration rate of 6-8 m / h. Backwashing is performed by a backwash pump for forced backwashing, and is also equipped with compressed air for air washing. The backwashing cycle of the filter tank is about 12 hours, and the backwashing time is 5-10 minutes.

[0028] Furthermore, the sludge tank 6 is equipped with compressed air agitation. The sludge is pumped to the filter press 7 via a pneumatic diaphragm pump. After dewatering by the filter press, the sludge is stored, and the filtrate is returned to the front-end coagulation zone 1 for further treatment.

[0029] To achieve full automation and to ensure its beneficial effects, the above information is insufficient; a detailed description of the components required for full automation, as well as their complete connections, is needed.

[0030] This embodiment uses surface water from a factory production area as the treatment target. The surface water has a suspended solids content of 100 mg / L, a turbidity of 30 NTU, and a pH value of 7-9.

[0031] The process of treating surface water using this system is as follows: 1) Surface water is first sterilized with sodium hypochlorite before entering the coagulation zone; 2) A double-layer paddle coagulation mixer with a speed of 60 r / min is configured in the coagulation zone. By adding coagulant PAC and mixing, the suspended colloidal particles in the water are coagulated and adsorbed to form small flocs, which then flow into the flocculation zone by gravity. 3) A double-layer paddle flocculation mixer with a speed of 30 r / min is configured in the flocculation zone. By adding flocculant PAM and stirring, the small flocs are promoted to increase in size and then flow into the inclined tube sedimentation zone by gravity. 3) The design surface load of the sedimentation zone is 1.5 m. 3 / (m 2 ·h), the inclined tube sedimentation method is used to complete the solid-liquid separation. Most of the flocs settle down and are discharged into the sludge hopper. An electric valve is installed on the sludge discharge pipe and an ultrasonic level gauge is installed in the sludge tank to realize automatic sludge discharge. That is, the sludge in the sludge hopper can be periodically pumped to the sludge tank by a sludge pump, while the supernatant flows into the sand filter area by gravity. 4) The bottom of the sand filter area has a water distribution pipe for periodic backwashing, and the upper part is filled with quartz sand filter media. The quartz sand filter media comes in two specifications: 0.5-1.2mm and 1-2mm in particle size, with a volume ratio of 7:3. The system is equipped with a sand filter backwash water pump, a product water electric valve, and a backwash electric valve. The backwash water pump is set with periodic start-up and running times. After the set period is reached, the backwash program is started, thereby realizing the automatic operation of the system.

[0032] The sand filtration zone has a filtration rate of 8 m / h, and backwashing is performed using a forced backwash pump with a flushing intensity of 10 L / (m). 2 It is equipped with compressed air washing, and the backwashing cycle of the filter tank is 12 hours, with a backwashing time of 8 minutes.

[0033] The incoming water is further filtered to remove residual particulate matter. The suspended solids in the sand-filtered water are reduced to below 10 mg / L, the turbidity to below 5 NTU, and the pH value to 7-9, meeting the requirements of the "Design Code for Industrial Circulating Cooling Water Treatment" (GB / T 50050-2017). The treated water finally enters the product water tank and is then pumped to the point of use via an external water supply pump.

[0034] 5) The sludge tank is equipped with compressed air agitation, and the sludge is pumped to the filter press via a pneumatic diaphragm pump. The pneumatic diaphragm pump is equipped with an inlet solenoid valve, which is interlocked with the ultrasonic level gauge in the sludge tank and the pressure transmitter at the filter press inlet to realize automatic start and stop of the sludge pressing. After dewatering by filtration, the sludge is stored, and the filtrate is returned to the front-end coagulation zone for further treatment.

[0035] This surface water treatment and recycling system achieves fully automated operation, is simple to operate, has low operating costs, and produces stable and qualified effluent.

[0036] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A surface water treatment and recycling system, characterized in that, The system comprises a coagulation zone, a flocculation zone, a sedimentation zone, a sand filtration zone, and a product water tank, connected in sequence; wherein, Surface water is sterilized with NaClO before entering the coagulation zone; In the coagulation zone, suspended colloidal particles in the water are coagulated and adsorbed, and then flow by gravity into the flocculation zone; The flocculation zone promotes the growth of small alum flocs, which then flow by gravity into the sedimentation zone. The supernatant produced after sedimentation in the sedimentation zone is treated in the sand filtration zone, stored in the product water tank, and then supplied to the water use points; a portion is used for backwashing the sand filtration zone. The sludge produced by sedimentation in the sedimentation zone is transferred to the sludge tank, which is equipped with compressed air agitation. The sludge is pumped to the filter press by a pneumatic diaphragm pump. After dewatering by filter press, the sludge is stored, and the filtrate is returned to the front-end coagulation zone for further treatment. The coagulant PAC is added to the coagulation zone, and the colloidal particles of suspended matter in the water are coagulated and adsorbed under the mixing of the agitator. PAM is added to the flocculation zone, and the mixture in the agitator promotes the growth of small alum flocs.

2. The system according to claim 1, characterized in that, The coagulant PAC is prepared at a concentration of 5wt% and the dosage is 10~20mg / L.

3. The system according to claim 1, characterized in that, The mixer in the coagulation zone is a paddle type with a rotation speed of 60~80 r / min.

4. The system according to claim 1, characterized in that, The flocculant PAM is prepared at a concentration of 0.1 wt% and the dosage is 2-5 mg / L.

5. The system according to claim 1, characterized in that, The agitator in the flocculation zone is a paddle type with a rotation speed of 30~40 r / min.

6. The system according to claim 1, characterized in that, The sedimentation zone employs inclined tube sedimentation to achieve solid-liquid separation, with a surface loading of 1~2m. 3 / (m 2 ·h).

7. The system according to claim 1, characterized in that, The bottom of the sand filtration zone is a water distribution pipe for periodic backwashing, and the upper part is quartz sand filter media.

8. The system according to claim 7, characterized in that, The quartz sand filter media consists of two specifications from bottom to top: a particle size of 0.5-1.2 mm and a particle size of 1-2 mm, with a filling volume ratio of 7:3.

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