CN109542150B - A method for adjusting the influent load of rural domestic sewage treatment facilities - Google Patents

Abstract

The invention discloses an adjusting method of inlet water load of rural domestic sewage treatment facilities, which comprises the steps of selecting rural domestic sewage treatment facilities, sampling sewage in an inlet water adjusting tank, detecting the concentration and the conductivity of pollutants in a sample, obtaining a linear relation between the conductivity and the pollutant concentration according to detection data, installing a conductivity meter and a liquid level meter in the inlet water adjusting tank of each rural domestic sewage treatment facility, calculating the conductivity value and the water level height to obtain the concentration and the total amount of pollutants in the inlet water adjusting tank, and determining the starting time of a lifting pump according to the pollutant volume load or the pollutant surface load of a sewage treatment device so as to adjust the inlet water load of the rural domestic sewage treatment facilities.

Description

A method for adjusting the influent load of rural domestic sewage treatment facilities

technical field

The invention relates to the technical field of wastewater treatment, in particular to a method for adjusting the influent load of rural domestic sewage treatment facilities.

Background technique

In recent years, the number of rural domestic sewage treatment facilities in my country has increased dramatically. Taking Zhejiang as an example, the rural domestic sewage treatment facilities have basically achieved full coverage of villages and households, and the number of facilities in a county can reach hundreds of thousands, and the geographical location is highly dispersed. These facilities are large in number and wide in area, and currently mainly rely on manual operation and maintenance management. However, using the national standard method to monitor water quality indicators, sampling and water quality testing in the supervision process is costly, the cycle is long, and the workload is large, which is not only difficult to real-time In addition, it is difficult to timely respond to the problems of large changes in the quality of rural domestic sewage and large fluctuations in the pollution load of treatment facilities during the operation of the facility, which affects the performance of the facility.

At present, rural domestic sewage treatment facilities are mainly divided into biological treatment processes (such as anaerobic-anoxic-aerobic (A ² O) combined process, anaerobic-aerobic (AO) combined process, sequencing batch reactor and anaerobic , aerobic treatment alone) and ecological treatment (most commonly constructed wetlands). The composition of various rural sewage treatment facilities is generally relatively simple. The equipment involved in biological treatment facilities are mainly influent lifting pumps, return pumps, and fans, while the equipment involved in ecological treatment facilities is generally only influent lifting pumps. The automatic control of the operation of the facility is currently mainly reflected in the control of the water inflow by controlling the start and stop of the lift pump through the electric control cabinet, and the aeration volume by controlling the start and stop and frequency of the fan. In addition, due to the large changes in the quality and quantity of rural sewage, there is generally a conditioning tank at the front end of the treatment facility, with a water inlet at one end and a lift pump at the other end. , The water outlet pipe of the lift pump is provided with a return pipe, which is used to return the sewage to the adjustment tank, so as to control the flow of sewage into the anaerobic tank or constructed wetland.

In order to improve the operation and maintenance effect of facilities, some regions have developed and established a remote monitoring platform for facility operation and maintenance. Through the remote monitoring platform, the operation status of pumps and fans can be monitored in real time. O&M track and O&M record.

For example, the invention patent application with publication number CN105717859A discloses a remote monitoring method for the whole-process management of decentralized rural sewage treatment facilities. The management server stores and processes the collected data information, and transmits the analysis results to the remote operation equipment. The user adjusts the operating parameters of the sewage treatment facility in real time through the platform of the remote operation equipment, and the adjusted data is transmitted back to the sewage treatment facility through the wireless communication network. , to adjust the field equipment operation status monitor and data acquisition instrument to realize the distributed management of sewage treatment facilities. Among them, the collected data includes real-time monitoring images, operating status of pumps or fans, sewage inflow and outflow flow, COD concentration, BOD concentration, pH value and ammonia nitrogen concentration.

However, due to financial constraints, it is impossible for rural sewage treatment facilities to use a large number of online monitoring technologies to systematically monitor and manage the water quality and biochemical reaction parameters of incoming and outgoing water like urban sewage plants. Supervision is a difficult problem in the operation and maintenance of rural sewage treatment facilities.

On the other hand, due to the continuous improvement of rural sewage discharge requirements throughout the country, more and more biological or/and ecological treatment processes are used in rural decentralized sewage treatment facilities. The normal operation of the above-mentioned biological and ecological treatment processes depends not only on pumps and The operation of the fan is more dependent on whether a reasonable hydraulic load and contaminant volume/surface load are maintained in the reactor. Studies have shown that the carbon-nitrogen ratio of rural domestic sewage in my country is generally low. Taking Zhejiang as an example, COD/TN is basically lower than 3, and most of them are lower than 2.0. Among all kinds of rural sewage biological treatment processes, the COD compliance rate is the highest, which is more than 90%; ammonia nitrogen, total nitrogen and total phosphorus are the limiting factors of compliance discharge, and are greatly affected by water inflow.

At present, the main reason that the effluent of rural sewage treatment facilities does not meet the standard is that the concentration of the influent is too high, or the influent load is too large; if online monitoring and adjustment of the influent load can be carried out, it will greatly improve the use of AAO and constructed wetlands. Represents the biological or/and ecological treatment efficiency. Therefore, remote supervision has created an urgent need for low-cost and durable online water quality monitoring equipment suitable for rural sewage.

However, the price of online monitoring instruments such as ammonia nitrogen, total nitrogen, and total phosphorus is relatively high, ranging from tens of thousands to hundreds of thousands of yuan, which obviously cannot adapt to the particularity of monitoring of rural domestic sewage treatment facilities. Therefore, it is necessary to explore new monitoring methods to replace conventional online monitoring instruments such as ammonia nitrogen, total nitrogen, and total phosphorus, so as to effectively realize the efficient monitoring of rural domestic sewage.

SUMMARY OF THE INVENTION

The invention provides a method for adjusting the influent load of rural domestic sewage treatment facilities. The method monitors and manages and controls the influent water quality of the rural domestic sewage treatment facilities by measuring the conductivity of the influent water of the treatment facilities, thereby reducing monitoring costs. Under the circumstance, the efficient adjustment of the influent load of the rural domestic sewage treatment facilities is realized.

The specific technical solutions are as follows:

A monitoring method for rural domestic sewage treatment facilities, comprising the following steps:

(1) Select a number of rural domestic sewage treatment facilities composed of two parts: an influent adjustment tank and a sewage treatment device. The influent adjustment tank is equipped with a lift pump for inputting the sewage in the tank into the sewage treatment device; The sewage in the water conditioning tank is sampled, and the concentration and conductivity of the pollutants in the samples are detected; the rural domestic sewage is composed of kitchen sewage, laundry sewage and fecal sewage treated by the septic tank; the pollutants are total nitrogen , ammonia nitrogen or total phosphorus;

(2) according to the detection data of the sample in step (1), carry out linear regression analysis and equation fitting, obtain the linear relationship between conductivity and pollutant concentration;

Among them, the linear regression equation is: y=ax+b; x is the conductivity, y is the concentration of pollutants, a is the slope, and b is the intercept;

(3) Install a conductivity meter and a liquid level gauge in the influent adjustment tank of each rural domestic sewage treatment facility to monitor the conductivity value and water level of the sewage in the influent adjustment tank respectively, and calculate the concentration of pollutants in the influent adjustment tank and the water level. The total amount, and then according to the volume load of pollutants or the surface load of pollutants in the sewage treatment plant, determine the length of time that the lift pump is turned on, so as to adjust the influent load of rural domestic sewage treatment facilities.

In the present invention, the rural domestic sewage refers to the sewage generated by rural residents, and specifically includes three types of sewage, namely: fecal and urine sewage (treated by septic tanks), kitchen sewage and laundry sewage.

The test found that for the above rural domestic sewage, there is a linear relationship between the conductivity and the concentrations of total nitrogen, ammonia nitrogen and total phosphorus, and the conductivity data can reflect the concentration of total nitrogen, ammonia nitrogen and total phosphorus in rural domestic sewage. , and then reflect the quality of the influent water of rural domestic sewage treatment facilities.

However, other types of sewage do not have the above rules, for example: the electrical conductivity in urban sewage (urban domestic sewage and urban production sewage) does not have a good linear relationship with the concentrations of total nitrogen, ammonia nitrogen and total phosphorus; and Other indicators in rural domestic sewage, such as: COD, SS concentration, etc., also have no linear relationship with the concentration of total nitrogen, ammonia nitrogen and total phosphorus; There is also no linear relationship between the electrical conductivity of brewing sewage or farmhouse discharge sewage and the concentrations of total nitrogen, ammonia nitrogen and total phosphorus. Even whether the fecal and urine sewage in rural domestic sewage has been treated by septic tanks also affects the linear relationship between its electrical conductivity and the concentrations of total nitrogen, ammonia nitrogen and total phosphorus. The conductivity in the wastewater has only a weak linear correlation with ammonia nitrogen, and the linear relationship with total nitrogen and total phosphorus does not hold.

The rural domestic sewage treatment facility of the present invention is composed of two parts: an inflow regulating tank and a sewage treatment device; the lift pump is located in the influent regulating tank, and the influent of the rural domestic sewage treatment facility refers to the influent regulating tank (or the regulating tank) The effluent of rural domestic sewage treatment facilities refers to the effluent treated by the sewage treatment device. The pollutant volume load or pollutant surface load that the sewage treatment device of the present invention can bear refers to the total nitrogen, ammonia nitrogen and total phosphorus that various sewage treatment devices can bear in a unit time that has been determined at the time of installation. quantity.

Since the conductivity value is related to the water temperature, the conductivity value at a water temperature of 20°C is generally used as a reference for calibration in this field, and conventional conductivity meters are generally automatically calibrated, so the conductivity value described in the present invention is actually corrected. The conductivity value when the water temperature is 20°C.

The time, frequency, and method of sampling can affect the accuracy of the linear relationship between conductivity and contaminant concentration. Preferably, in step (1), three water samples are taken in the morning, noon and evening of the sampling day, and the average value of the pollutant concentration and conductivity in the three water samples is used as the final sampling result.

As preferably, in the step (3), the conductivity meter is an online monitoring conductivity meter, and the probe of the conductivity meter is fixed on the inner wall of the regulating pond by a bracket, 20-50cm from the inner wall of the regulating pond, below the low liquid level. ~30cm and at the outlet of the return line.

Fixing the probe by the bracket can prevent the probe from colliding with the well wall with the flow of water in the adjustment tank, causing the probe to be damaged; the probe is placed 0-30cm below the low liquid level to ensure that the conductivity meter is always immersed in the water body; At the outlet of the return pipe, the irregular automatic cleaning of the probe by the return liquid can be realized.

There are high liquid level and low liquid level in the adjustment tank, and the specific value is set according to the actual situation; controlling the switch of the lifting pump through the liquid level is one of the conventional adjustment methods of rural domestic sewage treatment facilities. The existing adjustment method It is: when the actual liquid level is higher than the high liquid level, the lift pump starts, and starts to pump water from the regulating tank to the anaerobic tank or constructed wetland. When the actual liquid level is lower than the low liquid level, the lift pump is turned off and stops pumping.

Preferably, a protective sleeve is fixed on the outside of the probe. The protective sleeve is a perforated PVC pipe, which is used to avoid the contact and collision of large debris in the adjustment tank and the probe, and also to avoid the possibility of direct collision and contact between the probe and the well wall.

The linear relationship between the electrical conductivity and the concentrations of total nitrogen, ammonia nitrogen and total phosphorus has nothing to do with the specific treatment process of rural domestic sewage. Therefore, theoretically, the rural domestic sewage treatment facilities currently available in this field, such as ^: AO, SBR, anaerobic-aerated biological filter and anaerobic-constructed wetland, etc., are all applicable to the method of the present invention.

Preferably, in step (1), a rural domestic sewage treatment facility using the same sewage treatment device is selected for unified adjustment; the sewage treatment device is an A ² O facility or an anaerobic-constructed wetland facility.

Further, in step (3), the lift pump is set to the circulation mode, the lift pump is turned on every 3 to 8 hours, and the duration of the lift pump on is calculated according to the pollutant volume load that the sewage treatment device can bear.

Further, when the sewage treatment device is an A ² O facility, the calculation formula for the opening time of the lift pump is as follows:

Among them, t is the time when the lift pump is turned on, the unit is h; L _TN is the volume load of TN in the A ² O facility, L _NH3-N is the volume load of NH ₃ -N in the A ² O facility, and L _TP is A The volumetric load of TP in the ² O facility, the unit is g/m ³ d; V _effective is the effective volume of the A ² O facility, the unit is m ³ ; n is the number of water inflows per day, 3-8 times/d; x is the electrical conductivity , the unit is mS/cm; q is the rated flow of the lift pump, the unit is m ³ /h; a is the slope of the linear regression equation between conductivity and pollutant concentration; b is the linear regression equation between conductivity and pollutant concentration intercept.

The pollutant volume load of A ² O facility is generally: L _TN is 150-600g/m ³ d; L _NH3-N is 80-500g/m ³ d; L _TP is 50-200g/m ³ d.

Further, when the sewage treatment device is an anaerobic-constructed wetland facility, the calculation formula for the opening time of the lift pump is as follows:

Among them, t is the time when the lift pump is turned on each time, the unit is h; L _TN is the surface load of the anaerobic-constructed wetland facility TN, L _NH3-N is the surface load of the anaerobic-constructed wetland facility NH ₃ -N, and L _TP is the surface load of the anaerobic-constructed wetland facility TP, in g/m ² d; S is the _effective area of the constructed wetland facility, in m ² ; n is the number of water inflows per day, 4-12 times/d; x is the electrical conductivity, in mS/cm; q is the rated flow of the lift pump, in m ³ /h; a is the slope of the linear regression equation between electrical conductivity and pollutant concentration; b is the relationship between electrical conductivity and pollutant concentration The intercept of the linear regression equation.

The pollutant surface load of anaerobic-constructed wetland facilities is generally: L _TN is 5-15g/m ² d, L _NH3-N is 2-10g/m ² d, and L _TP is 0.5-5g/m ² d.

Further, the electrical conductivity value is the average value of electrical conductivity from 0 to 15 minutes before the lift pump is turned on.

The conductivity online monitor in the method of the present invention can transmit the signal to the electric control box by analog signal or other means, and then transmit to the platform, so as to realize the real-time online monitoring of the conductivity of the water in and out of the facility.

Compared with the prior art, the present invention has the following beneficial effects:

(1) The present invention monitors and controls the influent water quality of the rural domestic sewage treatment facilities by measuring the conductivity of the influent water of the treatment facilities, and realizes the efficient regulation of the influent load of the rural domestic sewage treatment facilities under the condition of reducing the monitoring cost. .

(2) The present invention calculates the concentration and total amount of total nitrogen, ammonia nitrogen and total phosphorus in the water inlet regulating tank respectively according to the real-time data of electrical conductivity and water level data, and then according to the total nitrogen, ammonia nitrogen and total phosphorus that the sewage treatment device can bear Calculate the minimum value of the total amount of sewage pumped into the sewage treatment device by the lift pump from the water inlet adjustment tank, and then determine the ON time of the lift pump when the flow rate per unit time of the lift pump is known, so as to provide the existing rural life Sewage treatment facilities provide a new quantitative influent load regulation method.

Description of drawings

Fig. 1 is a graph showing the relationship between the electrical conductivity and TN concentration of the 87 rural domestic sewage treatment facilities in the influent conditioning tanks in Example 1 and Example 2, wherein the abscissa represents the conductivity of sewage, the unit (mS/cm), the vertical axis The coordinates represent the TN concentration in units (mg/L).

Fig. 2 is a graph showing the relationship between the conductivity and NH ₃ -N concentration of the 87 rural domestic sewage treatment facilities in the influent conditioning pools in Example 1 and Example 2, wherein the abscissa represents the conductivity of sewage, the unit (mS/cm ), and the ordinate represents the NH ₃ -N concentration, unit (mg/L).

Figure 3 is a graph showing the relationship between the electrical conductivity and TP concentration of the influent conditioning tanks of 87 rural domestic sewage treatment facilities in Example 1 and Example 2, wherein the abscissa represents the conductivity of sewage, the unit (mS/cm), the The coordinates represent the TP concentration in units (mg/L).

FIG. 4 shows the results of ammonia nitrogen removal rates using the method of Example 1 and the method of Comparative Example 1 in Comparative Example 1.

FIG. 5 is the result of ammonia nitrogen removal rate using the method of Example 2 and the method of Comparative Example 2 in Comparative Example 2.

Figure 6 is a graph showing the relationship between the electrical conductivity and the TN concentration of the 12 urban sewage treatment plants in Comparative Example 3, where the abscissa represents the conductivity of the sewage, in mS/cm, and the ordinate represents the TN concentration, in mg /L).

Fig. 7 is a graph showing the relationship between the electrical conductivity and the NH ₃ -N concentration of the 12 urban sewage plant conditioning tanks in Comparative Example 3, wherein the abscissa represents the conductivity of the sewage, in mS/cm, and the ordinate represents the NH ₃ -N N concentration, unit (mg/L).

Figure 8 is a graph showing the relationship between the electrical conductivity and the TP concentration of the 12 urban sewage plant conditioning tanks in Comparative Example 3, where the abscissa represents the sewage conductivity, in mS/cm, and the ordinate represents the TP concentration, in mg /L).

FIG. 9 is a graph showing the relationship between the conductivity and the COD concentration of the influent conditioning tank of the rural domestic sewage treatment facility in Comparative Example 4. FIG.

FIG. 10 is a graph showing the relationship between the conductivity and the SS concentration of the influent conditioning tank of the rural domestic sewage treatment facility in Comparative Example 5.

FIG. 11 is a graph showing the relationship between the conductivity and the TN concentration of the influent conditioning tank of the rural domestic sewage treatment facility in Comparative Example 6. FIG.

FIG. 12 is a graph showing the relationship between the electrical conductivity and the NH ₃ -N concentration of the influent conditioning tank of the rural domestic sewage treatment facility in Comparative Example 6. FIG.

FIG. 13 is a graph showing the relationship between the conductivity of the influent conditioning tank of the rural domestic sewage treatment facility and the TP concentration in Comparative Example 6. FIG.

Detailed ways

The present invention will be further described below in conjunction with specific embodiments, the following are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto.

Since the linear relationship between conductivity and pollutant concentration is not affected by the type of process adopted by rural domestic sewage treatment facilities, the linear relationship diagrams between conductivity and pollutant concentration in Example 1 and Example 2 are the same .

Example 1A ² O Process Rural Domestic Sewage Treatment Facility

A monitoring method for rural domestic sewage treatment facilities, comprising the following steps:

(1) 87 rural domestic sewage treatment facilities were randomly selected in Jiaxing City, Zhejiang Province, and the rural domestic sewage in the conditioning tanks of the 87 stations was sampled, and the concentrations and conductivity of TN, NH ₃ -N and TP in the samples were detected; Three water samples were taken in the morning, noon and evening of the sampling day, and the average value of pollutant concentration and electrical conductivity in the three water samples was taken as the final sampling result.

(2) according to the detection data of the sample in step (1), carry out linear regression analysis and equation fitting, obtain the linear relationship between the electrical conductivity and the concentration of TN, NH ₃ -N, TP;

Wherein, the linear regression equation is: y=ax+b; x is conductivity, y is TN, NH ₃ -N or TP;

Based on the conductivity x to predict the pollutant concentration y in rural domestic sewage, a prediction model is established:

TN: y=0.0723x-31.228 (R2= ^0.7745 );

NH3-N: y=0.0712x-34.516 (R ² =0.785);

TP: y=0.0059x-2.6007 (R ² =0.7468);

The correlation coefficient (R ² ) of the model is high, indicating that the electrical conductivity has a good correlation with the concentrations of TN, NH ₃ -N and TP, and the model is in good agreement.

(3) Taking an A ² O process treatment facility with an effective volume of 15m ³ as an example, the sewage is collected in a regulating tank, and is lifted by a lift pump and flows through an anaerobic tank, an anoxic tank, and an aerobic tank for treatment. The volume loads of total nitrogen, ammonia nitrogen and total phosphorus of the above facilities are 180, 100, and 50 g/m ³ d, respectively. The standard flow rate of the lift pump is 3 t/h. The lift pump is turned on every 4 hours and 6 times a day.

An online monitoring conductivity meter is installed in the adjustment tank of each rural domestic sewage treatment facility. The probe of the conductivity meter is fixed on the inner wall of the adjustment tank through a bracket, 35cm away from the inner wall of the adjustment tank, 15cm below the low liquid level, and located in the return pipe the exit. The outside of the probe is provided with a protective sleeve, which is a perforated PVC pipe.

Measure the conductivity value (the average value of 15 minutes before the lift pump is turned on), and control and adjust the time when the lift pump is turned on in the pool according to the obtained conductivity value;

From the 1st to the 6th time on a certain day, the average value of the measured conductivity is 891, 1230, 1005, 985, 1206, 1065 mS/cm.

The formula for calculating the opening time of the lift pump is as follows:

Among them, t is the time when the lift pump is turned on, the unit is h; L _TN is the volume load of TN in the A ² O facility, L _NH3-N is the volume load of NH ₃ -N in the A ² O facility, and L _TP is A The volumetric load of TP in the ² O facility, in g/m ³ d; V _effective is the effective volume of the A ² O facility, in m ³ ; n is the number of water inflows per day, in times/d; x is the electrical conductivity, The unit is mS/cm; q is the rated flow of the lift pump, and the unit is m ³ /h.

Calculated according to the A ² O facility formula

Comparative Example 1

Take two groups of A ² O facilities with an effective volume of 15m ³ and similar operating conditions as examples, one group operates with the supervision method of Example 1, and the other group operates with the conventional method (ie: when the liquid level is higher than the high water level) , lift the sewage in the adjustment tank into the anaerobic tank of the facility at one time, until the liquid level is lower than the low water level).

At 8:00, 14:00, and 20:00 every day, the sewage in the adjustment tank of the facility and the effluent from the outlet well were sampled 3 times to test the ammonia nitrogen concentration for 10 days, and the daily average removal rate of ammonia nitrogen was calculated.

The results are shown in Figure 4: the ammonia nitrogen removal rate of the facility operated by the supervision method of Example 1 was significantly higher than that of the conventional facility, and the removal effect was more stable.

Example 2 Rural Domestic Sewage Treatment Facility of Anaerobic-Constructed Wetland Process

(1) 87 rural domestic sewage treatment facilities were randomly selected in Jiaxing City, Zhejiang Province, and the rural domestic sewage in the conditioning tanks of the 87 stations was sampled, and the concentrations and conductivity of TN, NH ₃ -N and TP in the samples were detected; Three water samples were taken in the morning, noon and evening of the sampling day, and the average value of pollutant concentration and electrical conductivity in the three water samples was taken as the final sampling result.

(2) according to the detection data of the sample in step (1), carry out linear regression analysis and equation fitting, obtain the linear relationship between the electrical conductivity and the concentration of TN, NH ₃ -N, TP;

Wherein, the linear regression equation is: y=ax+b; x is conductivity, y is TN, NH ₃ -N or TP;

Based on the conductivity x to predict the pollutant concentration y in rural domestic sewage, a prediction model is established:

TN: y=0.0723x-31.228 (R2= ^0.7745 );

NH3-N: y=0.0712x-34.516 (R2= ^0.7985 );

TP: y=0.0059x-2.6007 (R ² =0.7468);

The correlation coefficient (R ² ) of the model is high, indicating that the electrical conductivity has a good correlation with the concentrations of TN, NH ₃ -N and TP, and the model is in good agreement.

( ³ ) Take an anaerobic + vertical flow constructed wetland treatment facility with an effective area of 40m2 as an example. The facility is mainly composed of a regulating pool and a constructed wetland. The main equipment is a lift pump. The sewage collected in the regulating pool flows into the lift pump through the lift pump. Constructed wetlands are treated. The standard flow rate of the lift pump of the above facilities is 3t/h. The surface loads of total nitrogen, ammonia nitrogen and total phosphorus in the above facilities are 10, 8 and 2 g/m ² d, respectively. The standard flow rate of the lift pump is 3 t/h. The lift pump is turned on every 4 hours and 6 times a day.

An online monitoring conductivity meter is installed in the adjustment tank of the rural domestic sewage treatment facility. The probe of the conductivity meter is fixed on the inner wall of the adjustment tank through a bracket, 35cm away from the inner wall of the adjustment tank, 15cm below the low liquid level, and located in the return pipe the exit. The outside of the probe is provided with a protective sleeve, which is a perforated PVC pipe.

Measure the conductivity value (the average value of 15 minutes before the lift pump is turned on), and control and adjust the time when the lift pump is turned on in the pool according to the obtained conductivity value;

From the 1st to the 6th time on a certain day, the measured conductivity values were 1056, 1125, 975, 859, 1352, and 1248 mS/cm.

When the sewage treatment device is an anaerobic-constructed wetland facility, the calculation formula for the opening time of the lift pump is as follows:

Among them, t is the time when the lift pump is turned on each time, and the unit is h; LTN is the surface load of the constructed wetland facility _TN , _LNH3 -N is the surface load of _{NH3-N in} the sewage treatment device, and LTP is the constructed wetland facility. Surface load of TP, the unit is g/m ² d; S _effective is the effective area of the constructed wetland facility, the unit is m ² ; n is the number of water inflows per day, the unit is times/d; x is the electrical conductivity, the unit is mS/ cm; q is the rated flow of the lift pump, in m ³ /h.

Calculated according to the formula of anaerobic + vertical flow constructed wetland

Comparative Example 2

Taking ² groups of constructed wetland facilities with an effective area of 40m2 and similar operating conditions as examples, 1 group is operated by the supervision method of Example 2, and the other group is operated by the conventional method (when the liquid level is higher than the high water level, once The sewage in the conditioning tank is lifted into the anaerobic tank of the facility until the liquid level is lower than the low water level).

At 8:00, 14:00, and 20:00 every day, the sewage in the adjustment tank of the facility and the effluent from the outlet well were sampled 3 times to test the ammonia nitrogen concentration for 10 days, and the daily average removal rate of ammonia nitrogen was calculated.

The results are shown in Figure 5: the ammonia nitrogen removal rate of the facility operated by the supervision method in Example 2 was significantly higher than that of the conventional facility, and the removal effect was more stable.

Comparative Example 3

Investigate the influent data of 12 urban sewage treatment plants, and also sample in the adjustment tank, the sampling method is the same as that of Example 1, and then test the values of total nitrogen, ammonia nitrogen, total phosphorus and electrical conductivity.

The results showed (Figures 6-8): the relationship between electrical conductivity and the concentrations of total nitrogen, ammonia nitrogen, and total phosphorus did not show a linear correlation similar to that of rural domestic sewage.

Comparative Example 4

In this comparative example, the concentration of COD in rural domestic sewage was measured, and the sampling method was the same as that of Example 1. The analysis data found that (Figure 9): the linear relationship between COD concentration and electrical conductivity in rural domestic sewage is not good: the linear correlation coefficient R ² is only 0.259 .

Comparative Example 5

In this comparative example, the concentration of SS in rural domestic sewage was measured, and the sampling method was the same as that of Example 1. The analysis data found that (Fig. 10): the linear relationship between SS concentration and electrical conductivity in rural domestic sewage is not good: the linear correlation coefficient R ² is only 0.0007 .

Comparative Example 6

30 rural domestic sewage treatment facilities were randomly selected in Jiaxing City, Zhejiang Province. The influent of this rural domestic sewage treatment facility comes from three streams of sewage, namely: fecal and urine sewage (without septic tank treatment), kitchen sewage and laundry sewage . Sampling was also taken in the conditioning tank, and the sampling method was the same as that of Example 1, and then the values of total nitrogen, ammonia nitrogen, total phosphorus and electrical conductivity were tested. The results show (Figures 11 to 13): the relationship between the electrical conductivity and the concentrations of total nitrogen, ammonia nitrogen and total phosphorus does not show a linear correlation as good as the rural domestic sewage in Example 1 and Example 2.

Claims (9)

1. a method for regulating the influent load of a rural domestic sewage treatment facility, is characterized in that, comprises the following steps: (1) Select a number of rural domestic sewage treatment facilities composed of two parts: an influent adjustment tank and a sewage treatment device. The influent adjustment tank is equipped with a lift pump for inputting the sewage in the tank into the sewage treatment device; The sewage in the water conditioning tank is sampled, and the concentration and conductivity of the pollutants in the samples are detected; the rural domestic sewage is composed of kitchen sewage, laundry sewage and fecal sewage treated by the septic tank; the pollutants are total nitrogen , ammonia nitrogen or total phosphorus; (2) according to the detection data of the sample in step (1), carry out linear regression analysis and equation fitting, obtain the linear relationship between conductivity and pollutant concentration; Among them, the linear regression equation is: y=ax+b; x is the conductivity, y is the concentration of pollutants, a is the slope, and b is the intercept; (3) Install a conductivity meter and a liquid level gauge in the influent adjustment tank of each rural domestic sewage treatment facility to monitor the conductivity value and water level of the sewage in the influent adjustment tank respectively, and calculate the concentration of pollutants in the influent adjustment tank and the water level. The total amount, and then according to the volume load of pollutants or the surface load of pollutants in the sewage treatment plant, determine the length of time that the lift pump is turned on, so as to adjust the influent load of rural domestic sewage treatment facilities. 2. the adjustment method of the influent load of rural domestic sewage treatment facility as claimed in claim 1, it is characterized in that, in step (1), take three water samples respectively in the morning, noon and evening of the sampling day, with three water samples The average value of the pollutant concentration and the average value of the electrical conductivity were taken as the final sampling result. 3. the adjustment method of the influent load of rural domestic sewage treatment facility as claimed in claim 1, is characterized in that, in step (3), described conductivity meter is on-line monitoring conductivity meter, and the probe of conductivity meter passes through support It is fixed on the inner wall of the adjustment tank, 20-50cm away from the inner wall of the adjustment tank, 0-30cm below the low liquid level, and located at the outlet of the return pipe. 4. The method for adjusting the influent load of a rural domestic sewage treatment facility according to claim 3, wherein a protective sleeve is provided on the outside of the probe. 5. The method for adjusting the influent load of a rural domestic sewage treatment facility as claimed in claim 1, wherein in step (1), a rural domestic sewage treatment facility using the same sewage treatment device is selected for unified adjustment; the sewage The treatment device is an A ² O facility or an anaerobic-constructed wetland facility. 6. The method for adjusting the influent load of rural domestic sewage treatment facilities as claimed in claim 1, wherein in step (3), the lift pump is set to a circulation mode, and the lift pump is turned on every 3 to 8 hours, According to the volume load of pollutants or the surface load of pollutants that the sewage treatment device can bear, calculate the time when the lift pump is turned on. 7. The method for adjusting the influent load of a rural domestic sewage treatment facility as claimed in claim 6, wherein when the sewage treatment device is an A ² O facility, the calculation formula of the lift pump opening time is as follows:

Among them, t is the time that the lift pump is turned on each time, the unit is h; L _TN is the volume load of TN in the A ² O facility, L _NH3-N is the volume load of NH ₃ -N in the A ² O facility, and L _TP is The volume load of TP in the A ² O facility, the unit is g/m ³ d; V _effective is the effective volume of the A ² O facility, the unit is m ³ ; n is the number of water intakes per day, 3-8 times/d; x is the conductance rate, in mS/cm; q is the rated flow of the lift pump, in m ³ /h; a is the slope of the linear regression equation between conductivity and pollutant concentration; b is the linear regression between conductivity and pollutant concentration The intercept of the equation. 8. The method for adjusting the influent load of rural domestic sewage treatment facilities as claimed in claim 6, wherein when the sewage treatment device is an anaerobic-constructed wetland facility, the calculation formula of the lift pump opening duration is as follows:

Among them, t is the time when the lift pump is turned on each time, the unit is h; L _TN is the surface load of the constructed wetland facility TN, L _NH3-N is the surface load of NH ₃ -N in the sewage treatment device, and L _TP is the constructed wetland facility TP. The surface load is g/m ² d; S is the _effective area of the constructed wetland facility, the unit is m ² ; n is the number of water inflows per day, 4-12 times/d; x is the conductivity, the unit is mS/ cm; q is the rated flow of the lift pump, in m ³ /h; a is the slope of the linear regression equation between conductivity and pollutant concentration; b is the intercept of the linear regression equation between conductivity and pollutant concentration. 9 . The method for adjusting the influent load of rural domestic sewage treatment facilities according to claim 1 , wherein the conductivity value described in step (3) is the average value of the conductivity of 0-15min before the lift pump is turned on. 10 .

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