An intelligent water treatment method based on membrane separation

Abstract

The present invention relates to the field of water treatment technology, and in particular to an intelligent water treatment method based on membrane separation, including pre-treating discharge water to obtain secondary water, filtering the secondary water according to a set water pressure, adjusting the water pressure on both sides of the separation membrane according to the thickness growth value of the filter cake layer, and when the thickness of the filter cake layer reaches a preset thickness value, if the filtration amount of the secondary water does not meet the standard, the thickness of the filter cake layer attached to the separation membrane is detected to determine the descaling method, or the water pressure on both sides of the separation membrane is increased. The descaling method includes ultrasonic descaling and adding a membrane antiscalant to descaling. When determining ultrasonic descaling, the ultrasonic power is calculated to determine the parameter to determine the ultrasonic power, and when determining the addition of a membrane antiscalant to descaling, the addition amount is calculated to determine the parameter to determine the addition amount of the membrane antiscalant, or when determining to increase the water pressure on both sides of the separation membrane, the water pressure is calculated to determine the parameter to determine the increased water pressure. The present invention improves the filtration efficiency and the service life of the separation membrane.

Description

Technical Field

[0001] The present invention relates to the technical field of water treatment, and in particular to an intelligent water treatment method based on membrane separation. Background Art

[0002] At present, membrane technology has been widely used in the treatment of domestic sewage, industrial wastewater from power plants, oily wastewater, recycled wastewater, etc. due to its advantages of high treatment efficiency and low resource loss. Membrane technology is generally divided into low-pollution membranes, ultra-low pressure membranes, positively charged reverse osmosis membranes and high-temperature resistant food-grade reverse osmosis membranes.

[0003] Osmotic membrane vaporization separation technology is currently the fastest-growing membrane technology, mainly used in the treatment of petrochemical, pharmaceutical, power plant wastewater, etc.; forward osmosis is composed of a semipermeable membrane, an extractant liquid and a raw material liquid, and is often used in industrial wastewater treatment, such as power plant desulfurization wastewater, coal chemical wastewater, etc.; reverse osmosis mainly isolates and treats impurities in industrial wastewater through a filtration system; nanofiltration membranes are widely used in water treatment and wastewater recovery due to their good water permeability, water-salt selective separation and low working pressure.

[0004] Chinese patent publication number CN113574022B discloses a membrane separation method, the main purpose of which is to provide a membrane separation method that can inhibit the activity of microorganisms in the biofilm existing on the reverse osmosis membrane and continuously perform water treatment in a long-term and stable manner. The invention is a method for performing membrane separation treatment by intermittently adding a combined chlorine agent containing an aminosulfonic acid compound to the treated water supplied to the reverse osmosis membrane separation device, and the intermittent addition is repeatedly performed during the intermittent addition water supply period of adding the combined chlorine agent at a concentration that inhibits the activity of microorganisms in the biofilm to the treated water and supplying water to the reverse osmosis membrane separation device and the non-addition water supply period of supplying water to the reverse osmosis membrane separation device without adding the combined chlorine agent.

[0005] During the water treatment process of membrane separation, a filter cake layer will grow attached to the separation membrane. The existence of the filter cake layer will not only improve the filtration effect of the separation membrane, but also protect the separation membrane to a certain extent and extend the service life of the separation membrane. However, if the thickness of the separation membrane exceeds the set standard, the filtration efficiency of the separation membrane will be reduced. The filter cake layer can be removed by ultrasonic means or by adding membrane antiscalants. However, if the thickness of the filter cake layer is not monitored in real time, the growth of the filter cake layer may be destroyed, or if the filter cake layer is removed when it is too thick, the broken filter cake layer will damage the separation membrane, resulting in a reduction in the service life of the separation membrane. Summary of the invention

[0006] To this end, the present invention provides an intelligent water treatment method based on membrane separation, so as to overcome the problem in the prior art that the thickness of the filter cake layer is not monitored in real time, resulting in a reduction in the service life of the separation membrane.

[0007] To achieve the above object, the present invention provides an intelligent water treatment method based on membrane separation, comprising:

[0008] Pre-treating the discharged water to obtain secondary water;

[0009] The secondary water is filtered through the separation membrane according to the set water pressure;

[0010] Periodically detect the thickness of the filter cake layer attached to the separation membrane, and adjust the water pressure on both sides of the separation membrane based on the thickness growth value of the filter cake layer in the current period;

[0011] When the thickness of the filter cake layer reaches a preset thickness value, if the filtration amount of secondary water per unit time does not meet the standard, the thickness of the filter cake layer attached to the separation membrane is detected to determine the descaling method, or the water pressure on both sides of the separation membrane is increased; the descaling method includes ultrasonic descaling and descaling by adding a membrane antiscalant;

[0012] When determining ultrasonic descaling, the ultrasonic power is calculated to determine the parameter to determine the ultrasonic power; when determining the addition of membrane antiscalant for descaling, the addition amount is calculated to determine the parameter to determine the addition amount of membrane antiscalant;

[0013] Or when determining to increase the water pressure on both sides of the separation membrane, the water pressure determination parameter is calculated to determine the increased water pressure.

[0014] Further, the thickness of the filter cake layer attached to the separation membrane is periodically detected, the thickness growth value of the filter cake layer in the current period is calculated, and the water pressure on both sides of the separation membrane is adjusted based on the thickness growth value of the filter cake layer in the current period;

[0015] The thickness growth value of the filter cake layer in the current cycle is the difference between the detection value of the thickness of the filter cake layer in the current cycle and the detection value of the thickness of the filter cake layer in the previous cycle.

[0016] Furthermore, a thickness growth curve of the filter cake layer is preset, and the thickness growth value of the filter cake layer within a preset time period is compared with the standard thickness growth value of the filter cake layer corresponding to the growth curve to determine the adjustment method of the water pressure on both sides of the separation membrane.

[0017] Further, adjusting the water pressure on both sides of the separation membrane according to the thickness growth value includes:

[0018] If the thickness growth value of the filter cake layer within the preset time period is greater than (1+α) times the standard thickness growth value at the corresponding time, the water pressure on both sides of the separation membrane is increased;

[0019] If the thickness growth value of the filter cake layer within the preset time period is less than (1-α) times the standard thickness growth value at the corresponding moment, the water pressure on both sides of the separation membrane is reduced.

[0020] Otherwise, the water pressure on both sides of the separation membrane is not adjusted.

[0021] Furthermore, when the thickness of the filter cake layer reaches a preset thickness value, the filtration amount of secondary water per unit time is monitored in real time. If the filtration amount is less than the preset standard filtration amount, the thickness of the filter cake layer attached to the separation membrane is detected to determine the descaling method.

[0022] Further, the detecting the thickness of the filter cake layer attached to the separation membrane to determine the descaling method comprises:

[0023] If the thickness of the filter cake layer is greater than a preset first thickness comparison value and less than or equal to a preset second thickness comparison value, ultrasonic descaling is started;

[0024] If the thickness of the filter cake layer is greater than the second thickness comparison value, a membrane antiscalant is added to the filter tank for descaling.

[0025] Further, when it is determined that ultrasonic descaling needs to be started, an ultrasonic power determination parameter is calculated, and the power of the ultrasonic wave is determined based on the ultrasonic power determination parameter;

[0026] The ultrasonic power determination parameter is the difference between the thickness of the filter cake layer and the first thickness comparison value.

[0027] Further, when it is determined that a membrane antiscalant needs to be added for descaling, an addition amount determination parameter is calculated, and an addition amount of the membrane antiscalant is determined based on the addition amount determination parameter;

[0028] The parameter for determining the amount of addition is the difference between the thickness of the filter cake layer and the second thickness comparison value.

[0029] Furthermore, the thickness of the filter cake layer attached to the separation membrane is detected, and if the thickness of the filter cake layer is less than the first thickness comparison value, it is determined that the water pressure on both sides of the separation membrane is increased.

[0030] Further, when it is determined that the water pressure on both sides of the separation membrane needs to be increased, a water pressure determination parameter is calculated, and the increased water pressure is determined based on the water pressure determination parameter;

[0031] The water pressure determination parameter is the difference between the filtration volume of secondary water per unit time and a preset standard filtration volume.

[0032] Compared with the prior art, the beneficial effect of the present invention is that, in the process of water treatment by membrane separation, the present invention will attach the separation membrane to grow a filter cake layer. The existence of the filter cake layer will not only improve the filtering effect of the separation membrane, but also protect the separation membrane to a certain extent and extend the service life of the separation membrane. However, if the thickness of the separation membrane exceeds the set standard, the filtering efficiency of the separation membrane will be reduced. The filter cake layer can be removed by ultrasonic means or by adding a membrane scale inhibitor. However, if the thickness of the filter cake layer is not monitored in real time, the growth of the filter cake layer may be destroyed, or the filter cake layer may be removed when the thickness of the filter cake layer is too thick, and the broken filter cake layer may damage the separation membrane. The present invention presets the thickness growth curve of the filter cake layer and detects the thickness growth value of the filter cake layer in real time to adjust the water pressure on both sides of the separation membrane, thereby ensuring the growth and filtering efficiency of the filter cake layer. When the filter cake layer reaches the standard thickness, the filtration amount of secondary water per unit time is detected to ensure the filtering efficiency. When it is determined that descaling is required, the descaling method is determined according to the thickness of the filter cake layer, thereby ensuring the filtering efficiency and the safety of the filter cake layer, and improving the service life of the separation membrane.

[0033] Furthermore, when the water pressure set on both sides of the separation membrane is relatively large, the filtration effect is high, but the growth of the filter cake layer is relatively slow. When the water pressure set on both sides of the separation membrane is relatively small, the filtration effect is low, but the growth of the filter cake layer is relatively fast. The present invention detects the thickness of the filter cake layer in real time and calculates the thickness growth value of the filter cake layer to adjust the water pressure on both sides of the separation membrane, thereby ensuring the growth of the filter cake layer while ensuring the filtration efficiency.

[0034] Furthermore, when the filter cake layer exceeds the standard by a small amount, ultrasonic method is used for descaling. The ultrasonic method is relatively gentle and will not cause damage to the filter cake layer. In addition, the power of the ultrasonic wave is determined according to the ultrasonic power parameter, thereby improving the descaling efficiency while protecting the filter cake layer.

[0035] Furthermore, when the filter cake layer exceeds the standard by a large margin, descaling is performed by adding a membrane antiscalant. This method is relatively fast, and the amount of membrane antiscalant added is determined according to the parameters of the added amount. While descaling quickly, the safety of the filter cake layer is protected. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a flow chart of an intelligent water treatment method based on membrane separation according to an embodiment of the present invention;

[0037] Figure 2 This is a flow chart of step S4 in the intelligent water treatment method based on membrane separation according to an embodiment of the present invention;

[0038] Figure 3 This is a flow chart of step S3 in the intelligent water treatment method based on membrane separation according to an embodiment of the present invention;

[0039] Figure 4This is a flow chart of step S42 in the intelligent water treatment method based on membrane separation in an embodiment of the present invention. DETAILED DESCRIPTION

[0040] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0041] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0042] It should be pointed out that the data in this embodiment are obtained by comprehensive analysis of historical experimental data and corresponding data from previous water treatment processes using the membrane separation-based intelligent water treatment method of the present invention. Those skilled in the art will appreciate that the membrane separation-based intelligent water treatment method of the present invention can determine a single parameter by selecting the value with the highest proportion as the preset standard parameter based on data distribution, as long as the present invention can clearly define different specific situations in the single determination process through the acquired values.

[0043] See also Figures 1 to 4 As shown, an embodiment of the present invention provides an intelligent water treatment method based on membrane separation, comprising:

[0044] Step S1, pre-treating the discharged water to obtain secondary water;

[0045] Step S2, periodically detecting the thickness of the filter cake layer attached to the separation membrane, and adjusting the water pressure on both sides of the separation membrane based on the thickness growth value of the filter cake layer in the current period;

[0046] Step S3, adjusting the water pressure on both sides of the separation membrane according to the thickness growth value of the filter cake layer attached to the separation membrane within a preset time period;

[0047] Step S4, when the thickness of the filter cake layer reaches a preset thickness value, if the filtration amount of secondary water per unit time does not meet the standard, the thickness of the filter cake layer attached to the separation membrane is detected to determine the descaling method, or the water pressure on both sides of the separation membrane is increased; the descaling method includes ultrasonic descaling and descaling by adding a membrane antiscalant;

[0048] Wherein, step S4 comprises:

[0049] Step S41, when determining ultrasonic descaling, calculating the ultrasonic power determination parameter to determine the ultrasonic power, and when determining the addition of membrane antiscaling agent for descaling, calculating the addition amount determination parameter to determine the addition amount of the membrane antiscaling agent;

[0050] Step S42, when determining to increase the water pressure on both sides of the separation membrane, calculate the water pressure determination parameter to determine the increased water pressure.

[0051] The pretreatment includes but is not limited to screen filtration, aerobic oxidation, sedimentation, biological treatment, etc. of the discharged water.

[0052] The membrane antiscalant can be selected according to the type of separation membrane used, such as OSM352, SP-600 and ME220, etc., and is not specifically limited in this embodiment.

[0053] In the water treatment process of membrane separation, a filter cake layer will be attached to the separation membrane to grow. The existence of the filter cake layer will not only improve the filtering effect of the separation membrane, but also protect the separation membrane to a certain extent and extend the service life of the separation membrane. However, if the thickness of the separation membrane exceeds the set standard, the filtering efficiency of the separation membrane will be reduced. The filter cake layer can be removed by ultrasonic means or by adding a membrane scale inhibitor. However, if the thickness of the filter cake layer is not monitored in real time, the growth of the filter cake layer may be destroyed, or the filter cake layer may be removed when the thickness is too thick, and the broken filter cake layer may damage the separation membrane. The present invention presets the thickness growth curve of the filter cake layer and monitors the thickness growth value of the filter cake layer in real time to adjust the water pressure on both sides of the separation membrane, thereby ensuring the growth and filtering efficiency of the filter cake layer. When the filter cake layer reaches the standard thickness, the filtration amount of secondary water per unit time is detected to ensure the filtering efficiency. When it is determined that descaling is required, the descaling method is determined according to the thickness of the filter cake layer, thereby ensuring the filtering efficiency and the safety of the filter cake layer, and improving the service life of the separation membrane.

[0054] Specifically, step S3 includes:

[0055] Step S31, periodically detecting the thickness of the filter cake layer attached to the separation membrane, calculating the thickness growth value of the filter cake layer in the current period, and adjusting the water pressure on both sides of the separation membrane based on the thickness growth value of the filter cake layer in the current period;

[0056] The thickness growth value of the filter cake layer in the current cycle is the difference between the detection value of the thickness of the filter cake layer in the current cycle and the detection value of the thickness of the filter cake layer in the previous cycle.

[0057] Specifically, the period for detecting the growth value of the filter cake layer thickness is preferably set to 10 days to 15 days.

[0058] When the water pressure set on both sides of the separation membrane is relatively large, the filtering effect is high, but the growth of the filter cake layer is relatively slow. When the water pressure set on both sides of the separation membrane is relatively small, the filtering effect is low, but the growth of the filter cake layer is relatively fast. The present invention detects the thickness of the filter cake layer in real time and calculates the thickness growth value of the filter cake layer to adjust the water pressure on both sides of the separation membrane, thereby ensuring the growth of the filter cake layer while ensuring the filtering efficiency.

[0059] Step S32, preset a thickness growth curve of the filter cake layer, compare the thickness growth value of the filter cake layer within a preset time period with the standard thickness growth value of the filter cake layer corresponding to the growth curve, so as to determine the adjustment method of the water pressure on both sides of the separation membrane.

[0060] When drawing the thickness growth curve of the filter cake layer, the thickness growth value of the filter cake layer in different time periods is set according to the thickness of the filter cake layer and the filtration efficiency of the secondary water. It is necessary to take into account the growth of the thickness of the filter cake layer and the filtration efficiency of the secondary water, and at the same time ensure the safe use of the separation membrane. Therefore, when the thickness of the filter cake layer reaches the preset thickness value, the thickness of the filter cake layer should gradually increase, and the thickness growth value should gradually decrease. The thickness growth curve of the filter cake layer should be an arc curve with a gradually decreasing slope.

[0061] Specifically, adjusting the water pressure on both sides of the separation membrane according to the thickness growth value includes:

[0062] If the thickness growth value of the filter cake layer within the preset time period is greater than (1+α) times the standard thickness growth value at the corresponding time, the water pressure on both sides of the separation membrane is increased;

[0063] If the thickness growth value of the filter cake layer within the preset time period is less than (1-α) times the standard thickness growth value at the corresponding moment, the water pressure on both sides of the separation membrane is reduced.

[0064] Otherwise, the water pressure on both sides of the separation membrane is not adjusted.

[0065] It can be understood that α is an interval parameter, preferably 0.1 to 0.3.

[0066] Specifically, for increasing or decreasing the water pressure on both sides of the separation membrane, the water pressure after increasing or decreasing can be determined by setting the adjustment coefficient, such as setting three adjustment coefficients of 0.8, 0.85 and 0.9. When the water pressure needs to be increased, the adjustment coefficient can be selected according to the difference between the thickness growth value of the filter cake layer within the preset time and the standard thickness growth value at the corresponding moment × (1+α), and the water pressure after increasing is the current water pressure × (2-adjustment coefficient). Similarly, when the water pressure needs to be reduced, the adjustment coefficient can be selected according to the difference between the thickness growth value of the filter cake layer within the preset time and the standard thickness growth value at the corresponding moment × (1-α), and the water pressure after reducing is the current water pressure × adjustment coefficient. This embodiment also provides another specific implementation method, which can determine the water pressure after increasing or decreasing by setting an increment.

[0067] Specifically, when the thickness of the filter cake layer reaches a preset thickness value, the filtration amount of secondary water per unit time is monitored in real time. If the filtration amount is less than the preset standard filtration amount, the thickness of the filter cake layer attached to the separation membrane is detected to determine the descaling method.

[0068] In this embodiment, the filtration amount of the secondary water per unit time is detected, wherein the filtration amount is the flow rate of the secondary water filtered per unit time.

[0069] It is understood that the preset thickness of the filter cake layer is determined according to the type of separation membrane and historical test values ​​to ensure the filtration effect, filtration efficiency and service life of the separation membrane. Separation membranes include but are not limited to microfiltration membranes (MF), ultrafiltration membranes (UF), nanofiltration membranes (NF), reverse osmosis membranes (RO), etc.

[0070] It is understandable that the preset standard filtration volume is set according to the requirements for actual filtration efficiency, such as daily water discharge volume, daily water treatment volume, etc., and this embodiment does not make specific restrictions.

[0071] Specifically, the method of detecting the thickness of the filter cake layer attached to the separation membrane to determine the descaling method includes:

[0072] If the thickness of the filter cake layer is greater than a preset first thickness comparison value and less than or equal to a preset second thickness comparison value, ultrasonic descaling is started;

[0073] If the thickness of the filter cake layer is greater than the second thickness comparison value, a membrane antiscalant is added to the filter tank for descaling.

[0074] In this embodiment, the preset thickness value is less than the first thickness comparison value and less than the second thickness comparison value. When setting the first thickness comparison value and the second thickness comparison value, the filtration volume per unit time detected in the historical experiment and the thickness of the filter cake layer corresponding to the time when the filtered water quality meets the standard are selected. The thickness of the filter cake layer is taken as a random variable, and the random variable obeys the probability density function. Then, a normal distribution curve can be constructed according to the probability density function, and the 95% confidence interval of the normal distribution curve can be determined. The thickness value of the filter cake layer corresponding to the midpoint of the 95% confidence interval is determined as the first thickness comparison value, and the thickness value of the filter cake layer corresponding to the lower limit of the 95% confidence interval is determined as the second thickness comparison value. Constructing a probability density function and constructing a normal distribution curve based on the probability density function are commonly used technical means in statistics, which will not be repeated here.

[0075] Specifically, when it is determined that ultrasonic descaling needs to be started, an ultrasonic power determination parameter is calculated, and the power of the ultrasonic wave is determined based on the ultrasonic power determination parameter;

[0076] The ultrasonic power determination parameter is the difference between the thickness of the filter cake layer and the first thickness comparison value.

[0077] Specifically, when determining the ultrasonic power, it can be determined by setting the adjustment coefficient, such as setting three adjustment coefficients of 0.82, 0.88 and 0.94, and selecting the adjustment coefficient according to the ultrasonic power determination parameter, and calculating the difference between 2 and the selected adjustment coefficient, then the adjusted ultrasonic power is the product of the ultrasonic set power value and the calculated difference. The ultrasonic set power value is set according to the actual situation.

[0078] In a specific implementation, when selecting the adjustment coefficient according to the ultrasonic power determination parameter, two reference values ​​can be selected according to historical data, a first ultrasonic power comparison parameter and a second ultrasonic power comparison parameter, the first ultrasonic power comparison parameter is less than the second ultrasonic power comparison parameter, the calculated ultrasonic power determination parameter is compared with the first ultrasonic power comparison parameter and the second ultrasonic power comparison parameter, respectively, and the adjustment coefficient is selected according to the comparison result;

[0079] When the ultrasonic power determination parameter is less than the first ultrasonic power comparison parameter, the adjustment coefficient is selected as 0.94;

[0080] When the ultrasonic power determination parameter is greater than or equal to the first ultrasonic power comparison parameter and less than the second ultrasonic power comparison parameter, the adjustment coefficient is selected as 0.88;

[0081] When the ultrasonic power determination parameter is greater than or equal to the second ultrasonic power comparison parameter, the adjustment coefficient 0.82 is selected.

[0082] In a specific implementation, when determining the first ultrasonic power comparison parameter and the second ultrasonic power comparison parameter, several calculated ultrasonic power determination parameters in the historical data can be obtained, and the ultrasonic power determination parameters are taken as random variables. The random variables obey the probability density function, and then a normal distribution curve can be constructed according to the probability density function, and the 95% confidence interval of the normal distribution curve is determined. The ultrasonic power determination parameter value corresponding to the midpoint of the 95% confidence interval is determined as the first ultrasonic power comparison parameter, and the ultrasonic power determination parameter value corresponding to the lower limit of the 95% confidence interval is determined as the second ultrasonic power comparison parameter. Constructing a probability density function and constructing a normal distribution curve based on the probability density function are commonly used technical means in statistics, which will not be repeated here.

[0083] It can be understood that in this embodiment, when determining the selected adjustment coefficient, the above method can be used to determine the corresponding comparison parameter, and the selected adjustment coefficient can be determined according to the determined comparison parameter.

[0084] When the filter cake layer exceeds the standard by a small amount, ultrasonic method is used for descaling. The ultrasonic method is relatively gentle and will not cause damage to the filter cake layer. In addition, the power of the ultrasonic wave is determined according to the parameters to protect the filter cake layer while improving the descaling efficiency.

[0085] Specifically, when it is determined that a membrane antiscalant needs to be added for descaling, an addition amount determination parameter is calculated, and an addition amount of the membrane antiscalant is determined based on the addition amount determination parameter;

[0086] The parameter for determining the amount of addition is the difference between the thickness of the filter cake layer and the second thickness comparison value.

[0087] Specifically, when determining the amount of membrane antiscalant to be added, the amount of membrane antiscalant to be added is determined as the basic amount of membrane antiscalant added × the parameter for determining the amount of addition. The basic amount of membrane antiscalant added is the amount of membrane antiscalant required to remove a unit thickness of the filter cake layer. The amount of addition is in terms of mass.

[0088] When the filter cake layer exceeds the standard by a large margin, descaling is performed by adding membrane antiscalants. This method is relatively fast, and the amount of membrane antiscalants added is determined based on the parameters of the added amount. While descaling quickly, the safety of the filter cake layer is protected.

[0089] The step S42 comprises:

[0090] Step S421, detecting the thickness of the filter cake layer attached to the separation membrane, and if the thickness of the filter cake layer is less than the first thickness comparison value, determining to increase the water pressure on both sides of the separation membrane.

[0091] Step S422, when it is determined that the water pressure on both sides of the separation membrane needs to be increased, calculating the water pressure determination parameter, and determining the increased water pressure based on the water pressure determination parameter;

[0092] The water pressure determination parameter is the difference between the filtration volume of secondary water per unit time and a preset standard filtration volume.

[0093] Specifically, when determining the water pressure that needs to be increased, it can be determined by setting the adjustment coefficient, such as setting three adjustment coefficients of 0.7, 0.8 and 0.9, and selecting the adjustment coefficient based on the water pressure determination parameter, and calculating the difference between 2 and the selected adjustment coefficient. The increased water pressure is the product of the current water pressure and the calculated difference.

[0094] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

[0095] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An intelligent water treatment method based on membrane separation, characterized in that: include: Pre-treating the discharged water to obtain secondary water; The secondary water is filtered through the separation membrane according to the set water pressure; Periodically detect the thickness of the filter cake layer attached to the separation membrane, and adjust the water pressure on both sides of the separation membrane based on the thickness growth value of the filter cake layer in the current period; When the thickness of the filter cake layer reaches a preset thickness value, if the filtration amount of secondary water per unit time does not meet the standard, the thickness of the filter cake layer attached to the separation membrane is detected to determine the descaling method, or the water pressure on both sides of the separation membrane is increased; the descaling method includes ultrasonic descaling and descaling by adding a membrane antiscalant; Wherein, when determining ultrasonic descaling, the ultrasonic power determination parameter is calculated to determine the ultrasonic power, and when determining the addition of membrane antiscalant for descaling, the addition amount determination parameter is calculated to determine the addition amount of the membrane antiscalant; or when determining to increase the water pressure on both sides of the separation membrane, calculating the water pressure determination parameter to determine the increased water pressure; Periodically detecting the thickness of the filter cake layer attached to the separation membrane, calculating the thickness growth value of the filter cake layer in the current cycle, and adjusting the water pressure on both sides of the separation membrane based on the thickness growth value of the filter cake layer in the current cycle; The thickness growth value of the filter cake layer in the current cycle is the difference between the detection value of the thickness of the filter cake layer in the current cycle and the detection value of the thickness of the filter cake layer in the previous cycle; Preset a thickness growth curve of the filter cake layer, compare the thickness growth value of the filter cake layer within a preset time with the standard thickness growth value of the filter cake layer corresponding to the growth curve, so as to determine the adjustment method of the water pressure on both sides of the separation membrane; Adjusting the water pressure on both sides of the separation membrane according to the thickness growth value includes: If the thickness growth value of the filter cake layer within the preset time period is greater than (1+α) times the standard thickness growth value at the corresponding time, the water pressure on both sides of the separation membrane is increased; If the thickness growth value of the filter cake layer within the preset time period is less than (1-α) times the standard thickness growth value at the corresponding moment, reducing the water pressure on both sides of the separation membrane; Otherwise, the water pressure on both sides of the separation membrane is not adjusted.

2. The intelligent water treatment method based on membrane separation according to claim 1 is characterized in that: When the thickness of the filter cake layer reaches a preset thickness value, the filtration amount of secondary water per unit time is monitored in real time. If the filtration amount is less than the preset standard filtration amount, the thickness of the filter cake layer attached to the separation membrane is detected to determine the descaling method.

3. The intelligent water treatment method based on membrane separation according to claim 2 is characterized in that: The step of detecting the thickness of the filter cake layer attached to the separation membrane to determine the descaling method comprises: If the thickness of the filter cake layer is greater than a preset first thickness comparison value and less than or equal to a preset second thickness comparison value, ultrasonic descaling is started; If the thickness of the filter cake layer is greater than the second thickness comparison value, a membrane antiscalant is added to the filter tank for descaling.

4. The intelligent water treatment method based on membrane separation according to claim 3 is characterized in that: When it is determined that ultrasonic descaling needs to be started, an ultrasonic power determination parameter is calculated, and the power of the ultrasonic wave is determined based on the ultrasonic power determination parameter; The ultrasonic power determination parameter is the difference between the thickness of the filter cake layer and the first thickness comparison value.

5. The intelligent water treatment method based on membrane separation according to claim 4 is characterized in that: When it is determined that a membrane antiscalant needs to be added for descaling, an addition amount determination parameter is calculated, and an addition amount of the membrane antiscalant is determined based on the addition amount determination parameter; The parameter for determining the amount of addition is the difference between the thickness of the filter cake layer and the second thickness comparison value.

6. The intelligent water treatment method based on membrane separation according to claim 5, characterized in that: The thickness of the filter cake layer attached to the separation membrane is detected, and if the thickness of the filter cake layer is less than the first thickness comparison value, it is determined that the water pressure on both sides of the separation membrane is increased.

7. The intelligent water treatment method based on membrane separation according to claim 6 is characterized in that: When it is determined that the water pressure on both sides of the separation membrane needs to be increased, a water pressure determination parameter is calculated, and the increased water pressure is determined based on the water pressure determination parameter; The water pressure determination parameter is the difference between the filtration volume of secondary water per unit time and a preset standard filtration volume.

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