CN108046541A - A kind of hilly country rural domestic sewage treatment system - Google Patents

Abstract

The invention relates to the technical field of environmental protection, in particular to a rural domestic sewage treatment system in a hilly area, which includes a water collection system, a grit chamber, a sludge pump, a water pump, a diversion channel, and a treatment unit. After the domestic sewage is collected by the water collection system, it is mixed and settled in the grit chamber, and then enters the treatment unit through the water pump and diversion channel for treatment, so as to achieve standard discharge. The sinkhole, drop weir and bentonite anti-seepage layer set in the treatment unit can effectively avoid the blockage of the packing layer, the generation of odor and the infiltration of sewage. Compared with the prior art, the present invention is based on the existing rural ditches in the hilly areas, and builds a microbial-plant joint restoration system, which not only solves the standard discharge of rural domestic sewage in the hilly areas, but also has the advantages of less investment, good effect, easy maintenance and management, It can beautify the rural environment, and at the same time, it can effectively reduce the odor generated in the process of wastewater treatment, reduce the blockage of constructed wetlands, and reduce the risk of groundwater and soil pollution.

Description

A rural domestic sewage treatment system in a hilly area

technical field

The invention relates to the technical field of environmental protection, in particular to a rural domestic sewage treatment system in a hilly area.

Background technique

Of my country's 1.33 billion population, 930 million live in villages and towns, of which the village population is about 763 million, accounting for 57.4% of the country's total population. The annual discharge of domestic sewage is about 9 billion tons. At the same time, the development of rural domestic sewage treatment technology is seriously lagging behind , the sewage treatment rate is seriously insufficient (less than 10%), so that the discharge of rural water pollutants continues to maintain a high level (accounting for more than 50% of the national water pollutant discharge), which puts great pressure on the rural ecological environment and is critical to the realization of the "Water Ten Measures" There are serious constraints on the treatment goals of the rural domestic sewage. Therefore, the treatment of rural domestic sewage is imminent. Different from the domestic sewage of urban residents, the discharge of rural domestic sewage is more scattered, the water quality fluctuates greatly, and the sewage discharge period is relatively concentrated (the discharge of rural sewage is larger in the morning and evening than in the daytime, and the flow is prone to interruption at night). Bath water, laundry water and kitchen sewage, and the ground hardening rate is low, accompanied by sediment brought by surface runoff, so the main components of rural domestic sewage are COD, BOD, SS, N, P, so the composition of rural domestic sewage is relatively high. Single, the water basically does not contain heavy metals and toxic and harmful substances. In addition to the characteristics of rural domestic sewage in hilly areas, rural domestic sewage has a higher degree of dispersion and is more difficult to collect.

At present, the treatment processes of rural domestic sewage mainly include: 1) Traditional activated sludge method, oxidation ditch method, A/O method, A ² /O method, SBR method, biological filter method, these processes not only require high water treatment The cost of facility construction also requires more investment in the collection of domestic sewage. At the same time, due to the water quality and quantity characteristics of rural domestic sewage, the operation and maintenance costs of these processes are also increased, which reduces the operational stability of the system. 2) Simple ecological treatment methods. Typical ecological technologies include artificial wetland, oxidation pond technology, and soil infiltration method. These technologies reduce the cost of sewage collection and infrastructure construction to a certain extent, but their treatment efficiency is low and the treatment effect is poor. Moreover, In the oxidation pond process and soil infiltration method, the sewage fluidity is poor, and it is easy to produce odor, pollute the air, soil and groundwater, and it is not suitable for popularization and application in today's severe ecological environment. At the same time, we should see that currently rural areas generally have ditches for sewage collection (mostly cover-plate-in-ground ditches or buried-pipe sewage collection systems). Therefore, my country is in urgent need of a domestic sewage treatment process that combines the actual situation in rural areas, makes full use of existing rural infrastructure, has relatively low basic investment, and has stable and reliable treatment effects.

Contents of the invention

The purpose of the present invention is to overcome the above-mentioned technical characteristics, and propose a rural domestic sewage treatment system in the hilly area in combination with the topography and landform characteristics of the hilly area and the existing sewage collection system, which not only realizes the discharge of rural domestic sewage in the hilly area up to the standard, but also has The advantages of low energy consumption, relatively low infrastructure costs, and stable treatment effects.

The technical solution adopted by the present invention to solve the technical problem is: a rural domestic sewage treatment system in a hilly area, including a water collection system, a grit chamber, a sludge pump, a water pump, a diversion channel, and a treatment unit, wherein:

The water collection system makes full use of the existing ditches and pipelines, spreads all over the rural living areas, fully considers the terrain features of hilly areas, and collects rural domestic sewage in the grit chamber by gravity flow; Sedimentation of suspended particles, water quality mixing and water volume stabilization, the mixed domestic sewage is pressurized by the water pump and then transported to the treatment unit through the diversion channel.

The sediment and larger organic matter deposited in the grit chamber are pumped out by the sludge pump, and can be used as farmyard manure after composting and fermentation, or directly landfilled.

There are rams and flowmeters in the diversion ditch, the rams are used to adjust the flow, and the flowmeters are used to measure the flow and velocity of domestic sewage in the ditch.

The treatment unit is rebuilt from the original ditches according to the terrain, and is divided into slope area, cultivation area, sinkhole and drop weir. Along the direction of water flow, the slope area is symmetrically distributed between the cultivation area, sinkhole and drop weir. sides. Among them, along the direction of the water-passing section, the side slope area from the outside to the inside is the canal side slope, the microbial attachment bag, and the keel, and the keel fixes the microbial attachment bag on the canal side slope. From top to bottom, the cultivation area is matrix layer, bentonite anti-seepage layer, cultivation area, sinkhole, and water drop weir are arranged in sequence, and are periodically distributed along the direction of water flow.

The microbial attachment bag is a bag made of permeable PP non-woven fabric, which has good water permeability, is non-toxic and harmless, and is suitable for microbial attachment and growth; the microbial attachment bag is filled with sepiolite, fly ash, vermiculite , large sand mixture, the diameter of sepiolite and vermiculite should be selected as 1~2cm, the diameter of fly ash and large sand should be 2~5mm, and the diameter of sepiolite, fly ash, vermiculite, large sand The mass ratio should be 1:2:2:3; on the one hand, the filler filled in the microbial attachment bag can play a good role in stabilizing the microbial attachment bag; The growth provides a good growth environment, and the microbial attachment bag and its filler can provide living places for aerobic microorganisms, facultative microorganisms and anaerobic microorganisms at the same time, so that microorganisms can work together to effectively reduce the concentration of pollutants in domestic sewage.

The keel is composed of a prefabricated nylon bandage and a steel braze. The two ends of the nylon bandage have holes, and the steel braze is used to fix the nylon bandage on the side slope of the water channel. The slope of the side slope of the canal is no more than 60°.

Described matrix layer is followed by loam layer, gravel layer, ceramsite layer, zeolite layer, fly ash layer from top to bottom, and wherein the thickness of loam layer is 10～25cm, and the thickness of gravel layer is 10～20cm, and the diameter of gravel particle is preferably The thickness of the ceramsite layer is 10~20cm, and the diameter of the ceramsite should be 3~5cm; the thickness of the zeolite layer is 8~10cm, and the diameter of the zeolite particles should be 1~2cm; the thickness of the fly ash layer is 10~ 15cm. In the substrate layer, according to the location of the project, more than 5 kinds of wetland plants are reasonably selected for mixed planting to keep evergreen in all seasons. The following wetland plants can be selected first: Lythrum salicaria L.; T halia dealbata Fraser; T halia dealbata Fraser ; Arundo donax var. versicolor ; Cyperus alternifolius Linn .; Typha orientalis Presl ; Iris pseudocorus L .; Lotus flower ; Canna indica L .; Eichhornia crassipes.; Nymphoides peltatum (Gmel.) O.Kuntze ; water hyacinth Eichhornia crassipes (Mart.) Solms . Among them, wetland plants can effectively absorb nitrogen and phosphorus elements in domestic sewage, and have a good degradation effect on organic matter. The substrate layer not only provides a stable growth place for wetland plants, reduces the drift of wetland plants, but also can be used in domestic sewage. The pollutants have a very good retention effect, and the wetland plants can continuously absorb organic matter and nitrogen and phosphorus elements in domestic sewage.

The bentonite in the bentonite anti-seepage layer is naturally pulverized bentonite particles with a thickness of 10-15 cm. Due to the high flow velocity in hilly areas, the bentonite anti-seepage layer can effectively prevent the infiltration of domestic sewage and reduce the pollution of soil and groundwater. At the same time, the bentonite anti-seepage layer has the characteristics of low cost, convenient construction and good anti-seepage effect.

For the sinking pit and the falling water weir, the length of the cultivation area set in the middle should be 100-500m, the depth of the sinking pit should be 80-100cm, and the falling water drop of the sinking weir should be 30-80cm. The drop weirs are all reinforced concrete prefabricated components, the sinkhole should be designed as an inverted trapezoid, and the drop weir should be designed as an inverted "L" shape. In order to ensure the stability of the drop weir, support holes are reserved for the drop weir, and It is equipped with pillar accessories, and the pillars can be made on-site from galvanized steel pipes according to the conditions of the ditch. The sinkhole can effectively remove the sediment brought by water erosion, further reducing the risk of blockage of the substrate layer in the cultivation area, and the drop weir can effectively supplement the dissolved oxygen in the domestic sewage, ensuring a stable treatment effect, and can effectively reduce the life. Odor caused by insufficient dissolved oxygen during sewage treatment.

A treatment process of a rural domestic sewage treatment system in a hilly area includes the following steps:

1) The water collection system throughout the rural living areas collects domestic sewage in the grit chamber;

2) Domestic sewage in the grit chamber realizes sedimentation, water quality mixing and water volume stabilization, and then is pumped to the diversion channel;

3) The domestic sewage in the diversion channel is regulated by the ram, and enters the treatment unit after being measured by the flow meter;

4) In the treatment unit, the domestic sewage is discharged up to the standard under the joint treatment of aerobic microorganisms, facultative microorganisms, anaerobic microorganisms and aquatic plants.

The beneficial effects of the present invention are: the present invention is based on the existing rural ditches in hilly areas, and builds a microbial-plant joint restoration system, which not only solves the standard discharge of rural domestic sewage in hilly areas, but also has the advantages of less investment, good effect, and easy maintenance. The advantages of management and beautification of the rural environment, as well as the technical advantages of effectively reducing the odor generated during wastewater treatment, reducing the blockage of constructed wetlands, and reducing the risk of groundwater and soil pollution.

Description of drawings

Accompanying drawing 1 is the processing flowchart schematic diagram of the present invention.

Accompanying drawing 2 is the cross-sectional schematic view of the treatment unit of the present invention.

Accompanying drawing 3 is the schematic diagram of sinkhole and drop weir of the present invention.

Accompanying drawing 4 is the schematic diagram of keel structure and assembly of the present invention.

Accompanying drawing 5 is the immobilization schematic diagram of the microorganism attachment bag of the present invention.

Accompanying drawing 6 is the layout schematic diagram of matrix layer of the present invention.

Accompanying drawing 7 is the schematic diagram of sinkhole and drop weir of the present invention.

Accompanying drawing 8 is the figure of influence of different drop heights on domestic sewage dissolved oxygen concentration in the present invention.

Accompanying drawing 9 is the influence diagram of sinkhole of the present invention to water body turbidity of different velocity.

Accompanying drawing 10 is the change figure of the microbial population quantity in the microbial attachment bag of the present invention with time.

Detailed ways:

Below in conjunction with accompanying drawing 1～7, the present invention is described in detail below.

As shown in Figures 1 to 7, the present invention includes: a water collection system 1, a grit chamber 2, a diversion channel 3, a water pump 4, a processing unit 5, a sludge pump 21, a gate 31, a flow meter 32, and a slope area 51. Cultivation area 52, keel 53, sinking pit 54, water drop weir 55, canal slope 511, microbial attachment bag 512, matrix layer 521, bentonite anti-seepage layer 522, nylon bandage 531, steel brazing 532, pillar 551, Loam layer 5211 , gravel layer 5212 , ceramsite layer 5213 , zeolite layer 5214 , and fly ash layer 5215 .

Wherein, the sludge pump 21 is arranged in the grit chamber 2; the gate 31 and the flowmeter 32 are installed in the diversion channel 3 in sequence along the water flow direction. The processing unit 5 is composed of a slope area 51, a cultivation area 52, a sinking pit 54, and a water drop weir 55, wherein the slope area 51 is distributed on both sides of the cultivation area 52, the sinking pit 54, and the water drop weir 55. Area 52, sinking pit 54, and water drop weir 55 are arranged in sequence and distributed periodically along the direction of water flow; among them, microbial adhesion bags 512 are stacked on the side slope 511 of the canal, and are fixed on the side slope 511 of the canal using keel 53, wherein the keel 53 is made of nylon Composed of bandage 531 and steel braze 532, water channel slope 511, microbial attachment bag 512, keel 53 together constitute slope area 51; cultivation area 52 is formed by substrate layer 521 and bentonite anti-seepage layer 522, wherein, substrate layer 521 is from top to bottom The bottom layer is a loam layer 5211 , a gravel layer 5212 , a ceramsite layer 5213 , a zeolite layer 5214 and a fly ash layer 5215 .

As shown in Figures 1 to 7, the rural domestic sewage is collected by the water collection system 1 and then enters the grit chamber 2. In the grit chamber 2, the domestic sewage realizes the sedimentation and large particle suspension in the grit chamber 2. The mixing of water quality and the stability of water quantity, and the precipitation of sediment and large suspended solids can effectively reduce the blockage of constructed wetlands and enhance the operation stability of constructed wetlands. The mixing of water quality and stable water quantity is conducive to ensuring the stable operation of constructed wetlands. After the grit chamber 2 has been in operation for a certain period of time, the deposited silt and organic matter are discharged through the sludge pump 21 for subsequent composting or landfill treatment. The evenly mixed domestic sewage in the grit chamber 2 enters the diversion channel 3 after being pressurized by the water pump 4, and is transported to the treatment unit 5 for combined microorganism-plant restoration. After the domestic sewage enters the treatment unit 5, on the one hand, the microbial adhesion bag 512 And its fillers provide habitats for aerobic microorganisms, facultative microorganisms and anaerobic microorganisms. COD, BOD, ammonia nitrogen, and P in domestic sewage provide nutrients for the growth of microorganisms, and realize partial degradation of pollutants in domestic sewage. The microbial attachment bag 512 is fixed on the ditch slope 511 by the keel 53, so that the microbial attachment bag 512 has good stability and erosion resistance; Decomposition further reduces the concentration of COD, BOD, ammonia nitrogen, and P in the wastewater. Some pollutants will also be adsorbed and fixed by the matrix layer 521 in the cultivation area 52, and the growth of plants will provide nutrients when the water is dry at night or when the flow is cut off, so as to realize the purification of wastewater. 24/7 processing. With the extension of the cultivation area 52, the pollutants in the domestic sewage are continuously degraded, absorbed and utilized by plants and microorganisms to achieve water purification and finally meet the discharge standard or irrigation water standard. On the one hand, due to the large hydraulic drop in hilly areas and the low ground hardening rate in rural areas, sediment is likely to be brought in during the collection and transportation of domestic sewage. Generally, due to the existence of aquatic plants in the cultivation area 52, it will cause The retention of silt in the sewage will lead to the uplift of the cultivation area 52 after long-term operation, and even the blockage of the matrix layer 521, which will affect the stable operation of the sewage treatment system. In the present invention, after the domestic sewage is treated at the cultivation area 52 for a certain distance, the Entering the sinkhole 54, the sinkhole 54 is equivalent to a small settling tank, which can settle the sediment brought by the sewage in the collection and transportation process, and at the same time, the sediment deposited in the sinkhole 54 is easy to clean and maintain , is essential to the stable operation of the water treatment system. On the other hand, the concentration of dissolved oxygen in the domestic sewage itself is relatively low, coupled with the long-term transportation and treatment of sewage in the constructed wetland, the concentration of dissolved oxygen in the water is further reduced, resulting in The death of aerobic microorganisms not only reduces the sewage treatment effect, but also causes the death of the fibrous roots of aquatic plants, and even causes the death of aquatic plants in severe cases. Water drop occurs in the weir 55, which effectively supplements the dissolved oxygen in the wastewater, improves the wastewater treatment effect, reduces the odor caused by the action of anaerobic bacteria, the death of roots, and the death of aerobic microorganisms in the process of water treatment, and reduces the Air pollution generated during sewage treatment. Below the matrix layer 521, a bentonite anti-seepage layer 522 is laid, which can effectively avoid infiltration of domestic sewage and soil and groundwater pollution.

As shown in Figure 1, the process of rural domestic sewage treatment in hilly areas includes the following steps:

1) The water collection system 1 throughout the rural living areas collects domestic sewage in the grit chamber 2;

2) Domestic sewage in the grit chamber 2 realizes sedimentation, water quality mixing and water volume stabilization, and then is transported to the diversion channel 3 by the water pump 4;

3) The domestic sewage in the diversion channel 3 is regulated by the ram 31, measured by the flow meter 32, and enters the treatment unit 5;

4) In the treatment unit 5, domestic sewage is discharged up to standard through the joint treatment of aerobic microorganisms, facultative microorganisms, anaerobic microorganisms and aquatic plants.

The present invention utilizes the existing rural drainage ditches in hilly areas to carry out plant-microbial joint restoration of pollutants such as COD, BOD, ammonia nitrogen, and P in rural domestic sewage in hilly areas. The water treatment micro-environment where aerobic microorganisms, facultative microorganisms and anaerobic microorganisms coexist improves the effect of microorganisms on domestic sewage treatment; secondly, by rationally laying out sinkholes in the cultivation area, it avoids serious water erosion in hilly areas and ground The problem of ditch siltation and matrix layer blockage caused by low hardening rate; thirdly, the problem of odor caused by low dissolved oxygen concentration in wastewater was solved by rationally laying out weirs in the cultivation area; finally, the bottom of the matrix layer was laid There is a bentonite anti-seepage layer, which can effectively avoid soil pollution and groundwater pollution caused by the infiltration of domestic sewage. The invention has the advantages of low investment, good effect, easy maintenance and management, can beautify the rural environment, and can effectively reduce the pollution of air, soil and groundwater during the water treatment process.

Example 1: The impact of water drop height on the concentration of dissolved oxygen in domestic sewage

Taking the sewage at the water inlet of the urban sewage treatment plant in Hanzhong City as the treatment object, by designing different water drop heights, the water drop heights are 10cm, 20cm, 30cm, 40cm, 50cm, 60cm, 70cm, 80cm, 90cm, before and after the water drop weir Dissolved oxygen concentration, found the impact of water drop height on the concentration of dissolved oxygen in wastewater.

Example 2: Effects of sinkholes on water turbidity at different flow rates

Under the condition of stirring at a stirring speed of 1200r/s, wastewater with an initial turbidity of 260NTU enters an open channel with a sinkhole with a depth of 15cm. Use a turbidimeter to measure the turbidity of wastewater before and after the sinkhole. The effect on the turbidity of wastewater reflects the removal effect of the sinkhole on the sediment in the wastewater.

Embodiment 3: the variation of the microbial population quantity in the microbial attachment bag over time

Select the microorganism attachment bag that diameter is 25cm, the diameter of sepiolite, vermiculite is selected as 2cm, the diameter of fly ash, large sand is selected as 3mm, the mass ratio of sepiolite, fly ash, vermiculite, large sand The ratio is 1:2:2:3; after bagging, immerse in flowing domestic sewage, take a sample at the center of the microbial attachment bag, take 1g of filler, wash with 10ml of deionized water, and the liquid obtained by washing is separated in bacteria, fungi, and liner Counted after 72 h of cultivation on bacterial culture medium.

Claims (8)

1. a kind of hilly country rural domestic sewage treatment system, including collecting system（1）, setting pot（2）, sludge pump（21）、 Water pump（4）, diversion channel（3）, processing unit（5）, which is characterized in that wherein：Collecting system（1）Make full use of existing irrigation canals and ditches, pipe Road is dispersed throughout life in the countryside area, by rural domestic sewage collection in setting pot（2）；Sanitary sewage is in setting pot（2）Middle realization mud The stabilization of husky and bulky grain suspended matter precipitation, water quality mixing and water, mixed sanitary sewage is through water pump（4）It is passed through after pressurization Diversion channel（3）It is delivered to processing unit（5）；Diversion channel（3）It is interior to be equipped with flashboard（31）And flowmeter（32）, flashboard（31）For flowing The adjusting of amount, flowmeter（32）For measuring the flow of sanitary sewage, flow velocity in irrigation canals and ditches；Processing unit（5）According to physical features by original Irrigation canals and ditches are reconstructed and obtained, and are divided into side slope area（51）, cultivation area（52）, heavy puddle（54）With drop weir（55）, along water (flow) direction, side slope Area（51）It is symmetrically distributed in cultivation area（52）, heavy puddle（54）With drop weir（55）Both sides；It is described along cross-section of river direction Side slope area（51）Water channel side slope is followed successively by from outside to inside（511）, microorganism adhesion bag（512）, keel（53）, the keel （53）By the microorganism adhesion bag（512）It is fixed on water channel side slope（511）On；The cultivation area（52）From top to bottom according to Secondary is hypothallus（521）, bentonite impervious barrier（522）；The cultivation area（52）, heavy puddle（54）, drop weir（55）Successively It sets, along water (flow) direction periodic distribution.

2. a kind of hilly country rural domestic sewage treatment system according to claim 1, it is characterised in that：Described is micro- Biological attachment bag（512）For sack made of permeable PP non-woven fabrics, the microorganism adhesion bag（512）In be filled with Hai Pao Stone, flyash, vermiculite, great Sha mixtures, sepiolite, the diameter of vermiculite are preferably elected as 1 ~ 2cm, and flyash, the diameter of great Sha are suitable It elects as 2 ~ 5mm, sepiolite, flyash, vermiculite, the mass ratio of great Sha are preferably 1:2:2:3.

3. a kind of hilly country rural domestic sewage treatment system according to claim 1, it is characterised in that：The dragon Bone（53）By prefabricated nylon bandage（531）And drill rod（532）Composition, nylon bandage（531）There is hole at both ends, and use drill rod （532）By nylon bandage（531）It is fixed on water channel side slope（511）On.

4. a kind of hilly country rural domestic sewage treatment system according to claim 1, it is characterised in that：The base Matter layer（521）Loam layer is followed successively by from top to bottom（5211）, gravel layer（5212）, haydite layer（5213）, zeolite layer（5214）, powder Soot layer（5215）, medium loam layer（5211）Thickness be 10 ~ 25cm, gravel layer（5212）10 ~ 20cm of thickness, gravel particle Diameter is preferably 5 ~ 6cm；Haydite layer（5213）Thickness is 10 ~ 20cm, and the diameter of haydite is preferably 3 ~ 5cm；Zeolite layer（5214）Thickness For 8 ~ 10cm, the diameter of zeolite granular is preferably 1 ~ 2cm；Flyash Layer（5215）Thickness is 10 ~ 15cm.

5. a kind of hilly country rural domestic sewage treatment system according to claim 1, it is characterised in that：Described is swollen The native impervious barrier of profit（522）In bentonite for nature crush after bentonite clay particle, thickness be 10 ~ 15cm.

6. a kind of hilly country rural domestic sewage treatment system according to claim 1, it is characterised in that：Described is heavy Puddle（54）For precast member for reinforcing bar concrete, inverted trapezoidal is preferably designed as, depth is preferably 80 ~ 100cm.

7. a kind of hilly country rural domestic sewage treatment system according to claim 1, it is characterised in that：Described falls Mill weir（55）For precast member for reinforcing bar concrete, inverted "L" shape is preferably designed as, drop drop is preferably 30 ~ 80cm, the drop weir （55）Supported hole is reserved with, equipped with branch column fitting.

8. a kind of hilly country rural domestic sewage treatment system according to claim 1, it is characterised in that：Sanitary sewage The flow of processing includes the following steps：

1）The collecting system in life in the countryside area is dispersed throughout by Domestic sewage collecting in setting pot（2）In；

2）Sanitary sewage is in setting pot（2）It is middle realize silt precipitation, water quality mixing and water stabilization, after through water pump（4） It is delivered to diversion channel（3）；

3）Diversion channel（3）In sanitary sewage through flashboard（31）It adjusts, flowmeter（32）Enter processing unit after metering（5）；

4）Sanitary sewage is in processing unit（5）In, in aerobic microbiological, facultative microbe, anaerobe and water plant Qualified discharge is realized under Combined Treatment.