Microalgal cultivation open pond runoff heavy metal interception kit and method

Abstract

The application discloses a microalgae culture open pool runoff heavy metal interception kit and method, relates to the field of microalgae culture wastewater treatment, and the heavy metal interception treatment unit comprises a treatment unit outer cylinder, a central water collecting pipe, an annular filler cavity and a plurality of independent coaxial annular gap filler modules; a cyclone water distributor is arranged at the water inlet end of the heavy metal interception treatment unit; a distribution valve core is installed in the central water collecting pipe and is driven by a rotary driving motor, and is used for changing the series connection, parallel connection or bypass relationship among the coaxial annular gap filler modules. The application adopts the annular filler cavity and coaxial annular gap filler module structure, cooperates with the distribution valve core and the rotary driving motor, can adjust the series connection, parallel connection or bypass relationship of the filler modules in real time according to the effluent heavy metal concentration, realizes dynamic matching of the residence time and the treatment load, increases the series connection number when the load is high to ensure the removal effect, and reduces the series number when the load is low to reduce the flow resistance and operation energy consumption.

Description

Technical Field

[0001] This invention relates to the field of microalgae culture wastewater treatment technology, and in particular to a kit and method for intercepting heavy metals in runoff from open microalgae culture ponds. Background Technology

[0002] During operation, open microalgae cultivation ponds are affected by factors such as fluctuations in source water quality, atmospheric deposition, leaching of pond materials, and runoff from surrounding areas. Consequently, the cultivation water often contains heavy metal ions such as cadmium, lead, copper, and zinc. The accumulation of heavy metals within algal cells not only inhibits photosynthesis and growth rates, reducing biomass, but also enters downstream industries with algal products, posing risks to food safety and the ecological environment. Therefore, heavy metal interception treatment is necessary before runoff from open microalgae cultivation ponds is discharged.

[0003] Existing runoff treatment methods for open microalgae cultivation ponds mostly employ single filters or fixed-bed adsorption devices, which have the following shortcomings:

[0004] The fixed series connection of filtration and adsorption units makes it impossible to adjust the treatment path and residence time according to fluctuations in the influent heavy metal concentration. Under high load, the effluent fails to consistently meet standards, while under low load, high flow resistance leads to energy waste. Water distribution is mostly direct-flow through straight pipes, resulting in uneven water distribution within the packing chamber, short-circuit flow, and dead zones, leading to low packing efficiency. Adsorption packing is often integrally packed, requiring shutdown and evacuation for replacement, resulting in long maintenance cycles and impacting continuous operation. The lack of linkage between effluent quality monitoring and treatment path switching poses a risk of direct discharge of substandard water and prevents closed-loop purification.

[0005] To address the aforementioned issues, there is an urgent need to develop a microalgae cultivation open pond runoff heavy metal interception kit that features adjustable treatment paths, uniform water distribution, convenient packing material replacement, and closed-loop control of effluent water quality. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention provides a kit and method for intercepting heavy metals in runoff from open microalgae cultivation ponds. The technical solution adopted is as follows:

[0007] A heavy metal interception kit for runoff from open microalgae cultivation ponds includes a shell, a contaminant filter, a heavy metal interception and treatment unit, an emission unit, and a controller.

[0008] The housing is sequentially equipped with an impurity filter, a heavy metal interception and treatment unit, and an emission unit.

[0009] The heavy metal interception and treatment unit includes an outer cylinder, a central water collection pipe, an annular packing chamber, and several independent coaxial annular packing modules. The annular packing chamber is divided into coaxial annular packing modules by radial partitions and annular partitions. Each coaxial annular packing module is detachably equipped with a heavy metal trapping packing module. A vortex distributor is located at the inlet end of the heavy metal interception and treatment unit. A distribution valve core is installed in the central water collection pipe and is driven by a rotary drive motor to change the series, parallel, or bypass relationship between the coaxial annular packing modules.

[0010] The discharge unit is used to receive the water from the central water collection pipe and monitor the water quality and level. The outlet of the central water collection pipe is connected to the discharge unit. One path of the discharge unit is connected to the qualified water outlet, and the other path is connected to the upstream of the impurity filter or the external microalgae cultivation open pool.

[0011] The controller is connected to the actuator and rotary drive motor in the discharge unit. The controller controls the rotary drive motor to rotate the distribution valve core according to the concentration of heavy metals in the effluent to change the number of series stages of the coaxial annular packing module. When the concentration of heavy metals in the effluent exceeds the limit, the controller controls the discharge unit to perform closed-loop circulation. When the concentration is lower than the limit and the liquid level is lower than the warning level, the controller controls the discharge unit to discharge.

[0012] Optionally, the impurity filter includes a filter screen and a filter screen support; the filter screen is a multi-layer stainless steel filter screen with a pore size of 0.5mm to 5mm; the filter screen support is detachably installed in the water inlet end of the housing.

[0013] Optionally, the heavy metal trapping packing module includes a modular mesh cage, lifting lugs, and modified biochar-iron-manganese oxide composite packing; the modular mesh cage is a corrosion-resistant mesh cage, filled with modified biochar-iron-manganese oxide composite packing; the lifting lugs are fixed to the top of the modular mesh cage; a detachable top cover is provided on the top of the shell, and the detachable top cover is aligned with the lifting path of the modular mesh cage.

[0014] Optionally, the vortex distributor has a tangential inlet structure and is located on the upper part of the outer cylinder of the treatment unit, so that the water enters tangentially along the annular packing cavity and forms a vortex, which enhances the contact with the heavy metal capture packing module.

[0015] Optionally, the distribution valve core is a rotary valve core with multiple opening groups, each opening group being connected to the inlet and outlet of the corresponding coaxial annular packing module; the rotary drive motor changes the series, parallel, or bypass relationship between the coaxial annular packing modules by rotating the distribution valve core.

[0016] Optionally, the discharge unit includes an effluent monitoring chamber, a discharge valve, a return pipe, a return pump, an online heavy metal monitoring sensor, and a liquid level sensor; the outlet of the central water collection pipe is connected to the effluent monitoring chamber; one path of the effluent monitoring chamber is connected to the compliant effluent outlet via the discharge valve, and the other path is connected to the inlet upstream of the impurity filter or the return outlet of the external microalgae cultivation open tank via the return pipe and the return pump; the online heavy metal monitoring sensor and the liquid level sensor are installed in the effluent monitoring chamber; the discharge valve is an electric valve; and the return pump is a variable frequency pump.

[0017] Optionally, the controller includes a signal acquisition module, a threshold comparison module, a path switching module, and an actuator drive module; the signal acquisition module is connected to the heavy metal online monitoring sensor and the liquid level sensor in the emission unit; the actuator drive module is connected to the rotary drive motor and the emission valve and the return pump in the emission unit.

[0018] A method for controlling a heavy metal interception kit for runoff in an open microalgae culture pond, characterized by comprising the following steps:

[0019] Step 1: The controller collects the concentration of heavy metals from the online monitoring sensors in the emission unit in real time. And the liquid level H of the liquid level sensor;

[0020] Step 2, the controller simultaneously determines With emission limits The relationship between size, liquid level H and warning liquid level Size relationship;

[0021] Step 3, if And the liquid level H < The controller controls the rotary drive motor to rotate the valve core, increases the number of series stages of the coaxial annular packing module, and extends the residence time;

[0022] Step 4, re-collect data ,like Still greater than If the discharge valve in the control discharge unit is closed, the return pump is started to return the effluent through the return pipe to the upstream of the impurity filter or the external microalgae cultivation open tank for closed-loop circulation.

[0023] Step 5, if ≤ And the liquid level H < If so, the discharge valve will be opened to discharge the pollutant;

[0024] like ≤ And the liquid level H ≥ If so, the drain valve will be opened to prioritize the discharge and lower the liquid level;

[0025] like And the liquid level H ≥ If the discharge valve remains closed, the flow rate of the return pump will be increased, and an alarm signal will be issued to replace the heavy metal trapping packing module.

[0026] Optionally, in step 3, the controller determines the concentration... With limit The difference ΔC adjusts the number of cascade stages: when ΔC is positive and continues for more than the set time. When ΔC ≤ ΔC, the rotary distributor valve core adds one stage of series connection; when ΔC ≤ ΔC, the rotary distributor valve core reduces one stage of series connection to lower flow resistance.

[0027] Optionally, in step 4, the reflux pump is a variable frequency pump, and the controller adjusts the pump based on the concentration. Adjust the flow rate of the return pump; when And the liquid level H ≥ When this occurs, the controller controls the return pump to operate at maximum flow, closes the discharge valve, and issues an alarm signal to replace the heavy metal trapping packing module.

[0028] In summary, the present invention has at least one of the following beneficial technical effects:

[0029] This invention provides a kit and method for intercepting heavy metals in runoff from open microalgae cultivation ponds. It adopts an annular packing chamber and a coaxial annular gap packing module structure, combined with a distribution valve core and a rotary drive motor. The series, parallel or bypass relationship of each packing module can be adjusted in real time according to the heavy metal concentration in the effluent, so as to achieve dynamic matching between residence time and treatment load. Under high load, the number of series stages is increased to ensure the removal effect, and under low load, the number of stages is reduced to reduce flow resistance and operating energy consumption.

[0030] The vortex distributor adopts a tangential inlet structure, which allows the incoming water to enter tangentially along the annular packing cavity and form a vortex, enhancing the contact between the water flow and the heavy metal capture packing module, eliminating short-circuit flow and dead zones, and improving the effective utilization rate of the packing and the efficiency of heavy metal removal.

[0031] The heavy metal capture packing module adopts a modular mesh box and lifting lug structure, and with the removable top cover on the shell, it can be lifted and replaced module by module without emptying the treatment unit, which is convenient for maintenance and ensures continuous operation of the system.

[0032] The discharge unit integrates online heavy metal monitoring sensors and liquid level sensors. The controller controls the discharge valve and return pump based on the concentration and liquid level of the effluent. When the concentration exceeds the standard, the effluent is automatically circulated back to the inlet or open pool. When the concentration meets the standard and the liquid level is safe, the effluent is discharged. When the liquid level exceeds the limit and continues to exceed the standard, an alarm is triggered to prompt the replacement of the packing material, thus forming a closed-loop control of water quality and eliminating the risk of excessive discharge. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the structure of the microalgae culture open pond runoff heavy metal interception kit of the present invention;

[0034] Figure 2 This is a schematic diagram of the heavy metal interception and treatment unit structure of the microalgae culture open pond runoff heavy metal interception kit of the present invention;

[0035] Figure 3 This is a schematic diagram of the heavy metal trapping packing module of the microalgae culture open pond runoff heavy metal interception kit of the present invention;

[0036] Figure 4 This is a schematic diagram of the electrical component connection principle of the microalgae culture open pond runoff heavy metal interception kit of the present invention.

[0037] Explanation of reference numerals in the attached drawings: 1. Shell; 2. Impurity filter; 21. Filter screen; 22. Filter screen support; 31. Outer cylinder of the treatment unit; 32. Central water collection pipe; 33. Annular packing chamber; 34. Heavy metal capturing packing module; 35. Swirl distributor; 37. Distribution valve core; 38. Rotary drive motor; 41. Modular mesh box; 43. Modified biochar-iron-manganese oxide composite packing; 414. Effluent monitoring chamber; 424. Discharge valve; 434. Return pipe; 454. Heavy metal online monitoring sensor; 464. Liquid level sensor; 5. Controller. Detailed Implementation

[0038] The following is in conjunction with the accompanying drawings. Figures 1-4 The present invention will be described in further detail below.

[0039] This invention discloses a kit and method for intercepting heavy metals in runoff from open microalgae culture ponds.

[0040] Example 1

[0041] A microalgae cultivation open pond runoff heavy metal interception kit includes a shell 1, an impurity filter 2, a heavy metal interception and treatment unit, an emission unit, and a controller 5;

[0042] The housing 1 is sequentially equipped with an impurity filter 2, a heavy metal interception and treatment unit, and an emission unit.

[0043] The heavy metal interception and treatment unit includes an outer cylinder 31, a central water collection pipe 32, an annular packing cavity 33, and several independent coaxial annular packing modules. The annular packing cavity 33 is divided into coaxial annular packing modules by radial partitions and annular partitions. Each coaxial annular packing module is detachably equipped with a heavy metal trapping packing module 34. A vortex distributor 35 is located at the water inlet of the heavy metal interception and treatment unit. A distribution valve core 37 is installed in the central water collection pipe 32 and is driven by a rotary drive motor 38 to change the series, parallel, or bypass relationship between the coaxial annular packing modules.

[0044] The discharge unit is used to receive the water effluent from the central water collection pipe 32 and monitor the water quality and level of the effluent; the outlet of the central water collection pipe 32 is connected to the discharge unit; one path of the discharge unit is connected to the qualified water outlet, and the other path is connected to the upstream of the impurity filter 2 or the external microalgae cultivation open pool.

[0045] The controller 5 is connected to the actuator and the rotary drive motor 38 in the discharge unit. The controller 5 controls the rotary drive motor 38 to rotate the distribution valve core 37 according to the concentration of heavy metals in the effluent to change the number of series stages of the coaxial annular packing module. When the concentration of heavy metals in the effluent exceeds the limit, the controller controls the discharge unit to perform closed-loop circulation. When the concentration is lower than the limit and the liquid level is lower than the warning level, the controller controls the discharge unit to discharge.

[0046] By adopting the above technical solution, the impurity filter 2 is installed inside the housing 1 at the water inlet end to intercept large particulate suspended solids and impurities that enter with the runoff. The heavy metal interception and treatment unit includes an outer cylinder 31, a central water collection pipe 32, an annular packing cavity 33, and several independent coaxial annular packing modules. The outer cylinder 31 and the central water collection pipe 32 are coaxially arranged, and the annular space between them constitutes the annular packing cavity 33. The annular packing cavity 33 is divided by radial baffles and annular spacers to form multiple independent coaxial annular packing modules. Each coaxial annular packing module is detachably equipped with a heavy metal trapping packing module 34. The radial baffles are arranged radially along the central water collection pipe; the annular spacers are concentric annular plates, arranged in layers along the axial direction of the cylinder, and the two are cross-divided to obtain multiple layers and multiple rows of coaxial annular packing modules.

[0047] A vortex distributor 35 is located at the inlet of the heavy metal interception and treatment unit, used to distribute the inlet water treated by the impurity filter 2 into the annular packing chamber 33 in a vortex manner. A distribution valve core 37 is installed inside the central water collection pipe 32 and is driven to rotate by a rotary drive motor 38. Changing the rotation position of the distribution valve core 37 alters the series, parallel, or bypass relationships between the coaxial annular packing modules. The distribution valve core 37 has inlet and outlet holes corresponding to each stage of the coaxial annular packing module. When the valve core rotates to the series position, water flows sequentially from the outlet of the previous packing module through the internal flow channel of the valve core to the inlet of the next packing module. When rotated to the parallel position, the total inlet water is simultaneously distributed to the inlets of all packing modules, and the outlet water from each module is collected in the central water collection pipe. In the bypass position, the inlet and outlet of the corresponding module are physically sealed by the valve core, and the module is disconnected from the main water flow path, allowing for offline maintenance. The outlet of the central water collection pipe 32 is connected to the discharge unit. The discharge unit receives the effluent from the central water collection pipe 32, monitors the effluent quality and level, and selects whether to discharge the effluent to a qualified outlet or return it upstream of the impurity filter 2 or to an external microalgae cultivation open tank according to the instructions of the controller 5. The controller 5 is connected to the actuator and the rotary drive motor 38 in the discharge unit. The controller 5 controls the rotary drive motor 38 to rotate the distribution valve core 37 to change the series number of the coaxial annular packing module based on the effluent heavy metal concentration fed back by the discharge unit. When the effluent heavy metal concentration exceeds the discharge limit, the controller 5 controls the discharge unit to perform closed-loop circulation, returning the effluent for further treatment. When the effluent heavy metal concentration is lower than the discharge limit and the level is lower than the warning level, the controller 5 controls the discharge unit to discharge.

[0048] Example 2

[0049] The impurity filter 2 includes a filter screen 21 and a filter screen support 22; the filter screen 21 is a multi-layer stainless steel filter screen with a pore size of 0.5mm to 5mm; the filter screen support 22 is detachably installed in the water inlet end of the housing 1.

[0050] By adopting the above technical solution, the filter screen 21 is a multi-layer stainless steel filter screen with a filter pore size of 0.5 mm to 5 mm. The filter screen support 22 is detachably installed in the water inlet end of the housing 1 to fix the filter screen 21. When the impurities trapped by the filter screen 21 accumulate to a certain extent, the filter screen support 22 together with the filter screen 21 can be removed from the housing 1 for cleaning or replacement without disassembling the entire assembly.

[0051] Example 3

[0052] The heavy metal trapping packing module 34 includes a modular mesh box 41, lifting lugs, and modified biochar-iron-manganese oxide composite packing 43. The modular mesh box 41 is a corrosion-resistant mesh box, and the interior is filled with modified biochar-iron-manganese oxide composite packing 43. The lifting lugs are fixed to the top of the modular mesh box 41. The top of the shell 1 is provided with a detachable top cover, which is aligned with the lifting path of the modular mesh box 41.

[0053] By adopting the above technical solution, the heavy metal trapping packing module 34 includes a modular mesh box 41, lifting lugs, and modified biochar-iron-manganese oxide composite packing 43. The modular mesh box 41 is a corrosion-resistant mesh box, filled internally with modified biochar-iron-manganese oxide composite packing 43. The lifting lugs are fixed to the top of the modular mesh box 41, facilitating the lifting of the entire modular mesh box 41 from the corresponding coaxial annular packing module. A detachable top cover is correspondingly provided on the top of the shell 1, and the detachable top cover is aligned with the lifting path of the modular mesh box 41. When the packing needs to be replaced, the detachable top cover is opened, the modular mesh box 41 is lifted out as a whole using the lifting lugs, and then the new heavy metal trapping packing module 34 is placed in the corresponding position.

[0054] Example 4

[0055] The vortex distributor 35 has a tangential inlet structure and is located on the upper part of the outer cylinder 31 of the treatment unit. It allows the water to enter tangentially along the annular packing cavity 33 and form a vortex, thereby enhancing the contact with the heavy metal capture packing module 34.

[0056] By adopting the above technical solution, the cyclone distributor 35 has a tangential inlet structure and is installed on the upper part of the outer cylinder 31 of the treatment unit. The influent water enters tangentially through the cyclone distributor 35 along the annular packing cavity 33, forming a vortex within the annular packing cavity 33. This extends the flow path of the water in the heavy metal capture packing module 34, enhances the contact efficiency between the water and the modified biochar-iron-manganese oxide composite packing 43, and improves the adsorption and interception effect of heavy metals.

[0057] Example 5

[0058] The distribution valve core 37 is a rotary valve core with multiple opening groups. Each opening group is connected to the inlet and outlet of the corresponding coaxial annular packing module. The rotary drive motor 38 changes the series, parallel or bypass relationship between the coaxial annular packing modules by rotating the distribution valve core 37.

[0059] By adopting the above technical solution, the distribution valve core 37 is a rotary valve core with multiple opening groups. Each opening group is connected to the inlet and outlet of the corresponding coaxial annular packing module. The rotary drive motor 38 drives the distribution valve core 37 to rotate, changing the correspondence between each opening group and the coaxial annular packing module, thereby changing the series, parallel, or bypass relationship between the coaxial annular packing modules. When the distribution valve core 37 rotates to the series position, the water flows through multiple coaxial annular packing modules sequentially, extending the treatment time; when it rotates to the parallel position, the water flows into multiple coaxial annular packing modules simultaneously, increasing the treatment throughput; when it rotates to the bypass position, some coaxial annular packing modules are isolated, facilitating replacement or maintenance.

[0060] Example 6

[0061] The discharge unit includes an effluent monitoring chamber 414, a discharge valve 424, a return pipe 434, a return pump, a heavy metal online monitoring sensor 454, and a liquid level sensor 464; the outlet of the central water collection pipe 32 is connected to the effluent monitoring chamber 414; one path of the effluent monitoring chamber 414 is connected to the compliant effluent outlet via the discharge valve 424, and the other path is connected to the inlet upstream of the impurity filter 2 or the return outlet of the external microalgae cultivation open pool via the return pipe 434 and the return pump; the heavy metal online monitoring sensor 454 and the liquid level sensor 464 are installed inside the effluent monitoring chamber 414; the discharge valve 424 is an electric valve; and the return pump is a variable frequency pump.

[0062] By adopting the above technical solution, the discharge unit includes an effluent monitoring chamber 414, a discharge valve 424, a return pipe 434, a return pump, a heavy metal online monitoring sensor 454, and a liquid level sensor 464. The outlet of the central water collection pipe 32 is connected to the effluent monitoring chamber 414. One path of the effluent monitoring chamber 414 is connected to the compliant effluent outlet via the discharge valve 424, and the other path is connected to the inlet upstream of the impurity filter 2 or the return outlet of the external microalgae cultivation open tank via the return pipe 434 and the return pump. The heavy metal online monitoring sensor 454 and the liquid level sensor 464 are installed inside the effluent monitoring chamber 414. The discharge valve 424 is an electric valve, and the return pump is a variable frequency pump. The controller 5 obtains effluent water quality and liquid level information through the heavy metal online monitoring sensor 454 and the liquid level sensor 464, and controls the discharge valve 424 and the return pump to achieve discharge or return.

[0063] Example 7

[0064] The controller 5 includes a signal acquisition module, a threshold comparison module, a path switching module, and an actuator drive module; the signal acquisition module is connected to the heavy metal online monitoring sensor 454 and the liquid level sensor 464 in the emission unit; the actuator drive module is connected to the rotary drive motor 38 and the emission valve 424 and the return pump in the emission unit.

[0065] By adopting the above technical solution, the controller 5 includes a signal acquisition module, a threshold comparison module, a path switching module, and an actuator drive module. The signal acquisition module connects to the heavy metal online monitoring sensor 454 and the level sensor 464 in the discharge unit, and is used to acquire the effluent heavy metal concentration and level signals in real time. The threshold comparison module compares the acquired concentration with the discharge limit and the level with the warning level. The path switching module generates control commands for the rotary drive motor 38 based on the comparison results. The actuator drive module connects to the rotary drive motor 38, the discharge valve 424 in the discharge unit, and the return pump, and is used to perform path switching and discharge or return actions.

[0066] Example 8

[0067] A method for controlling a heavy metal interception kit for runoff in an open microalgae culture pond, characterized by comprising the following steps:

[0068] Step 1: Controller 5 collects the concentration of heavy metals in the emission unit from the online monitoring sensor 454 in real time. And the liquid level H of the liquid level sensor 464;

[0069] Step 2, controller 5 simultaneously determines With emission limits The relationship between size, liquid level H and warning liquid level Size relationship;

[0070] Step 3, if And the liquid level H < The controller 5 controls the rotary drive motor 38 to rotate the distribution valve core 37, increasing the number of series stages of the coaxial annular packing module and extending the residence time;

[0071] Step 4, re-collect data ,like Still greater than If the discharge valve 424 in the control discharge unit is closed, the return pump is started, and the effluent is returned to the upstream of the impurity filter 2 or the external microalgae cultivation open tank through the return pipe 434 for closed-loop circulation.

[0072] Step 5, if ≤ And the liquid level H < Then, the discharge valve 424 will be opened to discharge the pollutant;

[0073] like ≤ And the liquid level H ≥ If so, the drain valve 424 will be opened to prioritize the discharge and lower the liquid level;

[0074] like And the liquid level H ≥ If the discharge valve 424 is closed, the flow rate of the return pump will be increased, and an alarm signal will be issued to replace the heavy metal trapping packing module 34.

[0075] By adopting the above technical solution, in step 1, the controller 5 collects the concentration of heavy metals in the emission unit from the online monitoring sensor 454 in real time. And the liquid level H of the liquid level sensor 464. Step 2, the controller 5 determines... Does it exceed the emission limit? Step 3, if Greater than Controller 5 controls the rotary drive motor 38 to rotate the distribution valve core 37, increasing the number of series stages of the coaxial annular packing module and extending the residence time of runoff in the heavy metal interception and treatment unit. Step 4, if Still greater than If the controller 5 closes the discharge valve 424 in the discharge unit and starts the return pump, the effluent will be returned to the upstream of the impurity filter 2 or the external microalgae cultivation open tank via the return pipe 434 for closed-loop circulation. Step 5, if Not greater than And the liquid level H is less than Then, the discharge valve 424 will be opened to discharge the pollutant. Greater than And the liquid level H is not less than If the discharge valve 424 remains closed, the flow rate of the return pump is increased, and an alarm signal is issued to replace the heavy metal trapping packing module 34.

[0076] Example 9

[0077] In step 3, controller 5 determines the concentration based on... With limit The difference ΔC adjusts the number of cascade stages: when ΔC is positive and continues for more than the set time. When ΔC ≤ 0, the rotary distributor valve core 37 adds one stage of series connection; when ΔC ≤ 0, the rotary distributor valve core 37 reduces one stage of series connection to lower flow resistance.

[0078] By adopting the above technical solution, in step 3, the controller 5 adjusts the concentration... With limit The difference ΔC adjusts the number of series stages. When ΔC is positive and remains positive for more than a set time... When ΔC is not greater than 0, the rotary distributor valve 37 adds one stage of series connection to enhance processing capacity. When ΔC is not greater than 0, the rotary distributor valve 37 reduces one stage of series connection to reduce flow resistance and energy consumption.

[0079] Example 10

[0080] In step 4, the reflux pump is a variable frequency pump, and the controller 5 adjusts the flow rate according to the concentration. Adjust the flow rate of the return pump; when And the liquid level H ≥ At this time, controller 5 controls the return pump to operate at maximum flow, closes the discharge valve 424, and issues an alarm signal to replace the heavy metal trapping packing module 34.

[0081] By adopting the above technical solution, the reflux pump in step 4 is a variable frequency pump, and the controller 5 adjusts the flow rate according to the concentration. Adjust the flow rate of the return pump. When Greater than And the liquid level H is not less than At this time, controller 5 controls the return pump to operate at maximum flow, closes the discharge valve 424, and issues an alarm signal to replace the heavy metal trapping packing module 34, prompting the operator to replace the saturated packing module in a timely manner.

[0082] The following specific embodiments illustrate the implementation principle of the present invention:

[0083] A coastal microalgae cultivation base has constructed open microalgae culture ponds with an area of ​​2000 m². 2 A runoff collection ditch is installed around the pool, and the outlet of the runoff collection ditch is connected to the inlet of the runoff heavy metal interception kit for this microalgae cultivation open pool. This kit is used to intercept heavy metals such as copper, zinc, and cadmium carried in rainwater runoff.

[0084] The kit includes a housing 1, an impurity filter 2, a heavy metal interception and treatment unit 3, a discharge unit, and a controller 5. The housing 1 is a rectangular box with a length of 3000mm, a width of 2000mm, and a height of 2500mm. Inside, the impurity filter 2, the heavy metal interception and treatment unit 3, and the discharge unit are arranged sequentially along the water flow direction.

[0085] The impurity filter 2 is installed inside the housing 1 at the water inlet end and includes a filter screen 21 and a filter screen support 22. The filter screen 21 is a 3-layer stainless steel filter screen with a filter pore size of 2mm. The filter screen support 22 is detachably installed inside the housing 1 at the water inlet end to fix the filter screen 21. At the initial stage of rainfall, the runoff is at a rate of 6... The flow rate enters the housing 1 and is filtered by the impurity filter 2 to intercept suspended particles and debris with a diameter greater than 2 mm.

[0086] The heavy metal interception and treatment unit 3 is located downstream of the impurity filter 2 and includes an outer cylinder 31, a central water collection pipe 32, an annular packing chamber 33, a heavy metal trapping packing module 34, a vortex distributor 35, a removable top cover, a distribution valve core 37, a rotary drive motor 38, radial baffles, and annular spacers. The outer cylinder 31 and the central water collection pipe 32 are coaxially arranged. The inner diameter of the outer cylinder 31 is 1200 mm, and the outer diameter of the central water collection pipe 32 is 300 mm. The annular space between them forms the annular packing chamber 33, which has a radial width of 450 mm and a height of 1800 mm. The annular packing chamber 33 is radially divided into 4 independent chambers by 3 radial baffles and axially divided into 3 stages by 2 annular spacers, thus forming 12 independent coaxial annular packing modules. Each coaxial annular packing module contains one removable heavy metal trapping packing module 34.

[0087] The heavy metal trapping packing module 34 includes a modular grate cage 41, lifting lugs, and modified biochar-iron-manganese oxide composite packing 43. The modular grate cage 41 is a corrosion-resistant stainless steel grate cage, 400mm long, 300mm wide, and 500mm high, filled internally with modified biochar-iron-manganese oxide composite packing 43, with a packing mass of 30kg. The lifting lugs are fixed to the top of the modular grate cage 41. A removable top cover is correspondingly provided on the top of the shell 1, and the removable top cover is aligned with the lifting path of the modular grate cage 41.

[0088] The vortex distributor 35 has a tangential inlet structure and is located on the upper part of the outer cylinder 31 of the treatment unit. Water enters tangentially along the annular packing cavity 33, forming a vortex. The distribution valve core 37 is installed inside the central water collection pipe 32 and is a rotary valve core with 12 sets of openings. Each opening set is connected to the inlet and outlet of the corresponding coaxial annular packing module. The rotary drive motor 38 is connected to the distribution valve core 37 and has a power of 120W. It can drive the distribution valve core 37 to rotate within the range of 0 degrees to 360 degrees, changing the series, parallel, or bypass relationships between the coaxial annular packing modules.

[0089] The discharge unit includes an effluent monitoring chamber 414, a discharge valve 424, a return pipe 434, a return pump, an online heavy metal monitoring sensor 454, and a level sensor 464. The outlet of the central water collection pipe 32 is connected to the effluent monitoring chamber 414. The effluent monitoring chamber 414 has a volume of 200L and houses the online heavy metal monitoring sensor 454 and the level sensor 464. The discharge valve 424 is an electric valve with a nominal diameter of DN80. The return pump is a variable frequency pump with a flow range of 0 to 10 L. The head is 15m. One path from the effluent monitoring chamber 414 connects to the compliant effluent outlet via discharge valve 424, and the other path connects to the inlet upstream of the impurity filter 2 via return pipe 434 and return pump. The heavy metal online monitoring sensor 454 has a measurement range of 0 to 1 mg / L and a measurement accuracy of 0.001 mg / L. The level sensor 464 has a range of 0 to 2m and a measurement accuracy of 0.01m.

[0090] Controller 5 employs a programmable logic controller (PLC), comprising a signal acquisition module, a threshold comparison module, a path switching module, and an actuator drive module. The signal acquisition module connects to the heavy metal online monitoring sensor 454 and the liquid level sensor 464. The actuator drive module connects to the rotary drive motor 38, the discharge valve 424, and the reflux pump.

[0091] In one rainfall event, the rainfall intensity was 8 mm / h and the runoff flow was 6. Initial runoff enters the kit. Controller 5 collects the concentration of heavy metals in the emission unit from the online monitoring sensor 454 in real time. The liquid level H is measured by liquid level sensor 464. Controller 5 sets the emission limit. The concentration is 0.05 mg / L, warning level. It is 1.2m.

[0092] Ten minutes before rainfall, the heavy metal online monitoring sensor 454 detected the concentration in the effluent monitoring chamber 414. It is 0.32 mg / L, which is greater than Controller 5 controls the rotary drive motor 38 to rotate the distribution valve core 37, switching the 12 coaxial annular packing modules from parallel operation to 3-stage series operation. This increases the number of series stages, extending the residence time of runoff in the heavy metal interception and treatment unit 3 from 15 minutes to 50 minutes. After series treatment, the effluent concentration... It decreased to 0.04 mg / L, below And the liquid level H is 0.6m, which is lower than... Controller 5 opens discharge valve 424, with 4 The discharge flow rate meets the standards for effluent.

[0093] After 30 minutes of continuous rainfall, the concentration in water monitoring room 414 was... The concentration increased to 0.11 mg / L, but was still greater than [a certain value]. Controller 5 rotates the distribution valve core 37 again to confirm that the coaxial annular packing module is in the maximum series configuration of 3 stages. Because... Still greater than Controller 5 closes discharge valve 424 and starts the return pump, at 5 The flow rate will return the effluent through return pipe 434 to the inlet upstream of impurity filter 2 for closed-loop circulation. After 15 minutes of recirculation, the concentration... When the concentration drops to 0.02 mg / L and the liquid level H is 0.9 m, controller 5 opens discharge valve 424 to restore normal discharge.

[0094] Before the rainfall ended, the concentration in water monitoring room 414 was... The concentration was raised again to 0.12 mg / L, and the liquid level H reached 1.2 m. Controller 5 controls the return pump at a maximum flow rate of 10. The system operates with the discharge valve 424 closed and issues an alarm signal to replace the heavy metal trapping packing module 34. Upon receiving the alarm, the operator closes the inlet water supply to the kit, opens the removable top cover of the housing 1, and uses the lifting lugs to lift the saturated modular mesh box 41 entirely from the corresponding coaxial annular packing module, replacing it with a new heavy metal trapping packing module 34. After replacement, the controller 5 resumes normal operation, and the effluent concentration... When the concentration drops to 0.03 mg / L, discharge valve 424 opens, and the treated runoff is discharged into the park's rainwater pipe network in compliance with standards.

[0095] The above are all preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A heavy metal interception kit for runoff from open microalgae cultivation ponds, characterized in that: It includes a housing (1), an impurity filter (2), a heavy metal interception and treatment unit, an emission unit, and a controller (5). The housing (1) is provided with an impurity filter (2), a heavy metal interception and treatment unit and a discharge unit in sequence; the heavy metal interception and treatment unit includes an outer cylinder (31), a central water collection pipe (32), an annular packing cavity (33) and multiple coaxial annular packing modules; the annular packing cavity (33) is separated by radial partitions and annular partitions to form the coaxial annular packing modules; each coaxial annular packing module is detachably provided with a heavy metal trapping packing module (34); a vortex distributor (35) is provided at the water inlet of the heavy metal interception and treatment unit; the distribution valve core (37) is installed in the central water collection pipe (32) and driven by a rotary drive motor (38) to change the series, parallel or bypass relationship between each coaxial annular packing module; The discharge unit is used to receive the effluent from the central water collection pipe (32) and monitor the effluent quality and level; the outlet of the central water collection pipe (32) is connected to the discharge unit; one path of the discharge unit is connected to the qualified effluent outlet, and the other path is connected to the upstream of the impurity filter (2) or the external microalgae cultivation open pool; The controller (5) is connected to the actuator and the rotary drive motor (38) in the discharge unit. The controller (5) controls the rotary drive motor (38) to rotate the distribution valve core (37) according to the concentration of heavy metals in the effluent to change the number of series stages of the coaxial annular packing module. When the concentration of heavy metals in the effluent exceeds the limit, the discharge unit is controlled to perform closed-loop circulation. When the concentration is lower than the limit and the liquid level is lower than the warning liquid level, the discharge unit is controlled to discharge.

2. The microalgae culture open pond runoff heavy metal interception kit according to claim 1, characterized in that: The impurity filter (2) includes a filter screen (21) and a filter screen support (22); the filter screen (21) is a multi-layer stainless steel filter screen with a pore size of 0.5mm to 5mm; the filter screen support (22) is detachably installed in the water inlet end of the housing (1).

3. The microalgae culture open pond runoff heavy metal interception kit according to claim 2, characterized in that: The heavy metal trapping packing module (34) includes a modular mesh box (41), lifting lugs and modified biochar-iron-manganese oxide composite packing (43); the modular mesh box (41) is a corrosion-resistant mesh box, and the interior is filled with modified biochar-iron-manganese oxide composite packing (43); the lifting lugs are fixed to the top of the modular mesh box (41); the top of the shell (1) is provided with a detachable top cover, and the detachable top cover is aligned with the lifting path of the modular mesh box (41).

4. The microalgae culture open pond runoff heavy metal interception kit according to claim 3, characterized in that: The vortex distributor (35) has a tangential inlet structure and is located on the upper part of the outer cylinder (31) of the treatment unit. This allows the water to enter tangentially along the annular packing cavity (33) and form a vortex, thereby enhancing the contact with the heavy metal capture packing module (34).

5. The microalgae culture open pond runoff heavy metal interception kit according to claim 4, characterized in that: The distribution valve core (37) is a rotary valve core with multiple opening groups. Each opening group is connected to the inlet and outlet of the corresponding coaxial annular packing module. The rotary drive motor (38) changes the series, parallel or bypass relationship between the coaxial annular packing modules by rotating the distribution valve core (37).

6. The microalgae culture open pond runoff heavy metal interception kit according to claim 5, characterized in that: The discharge unit includes an effluent monitoring chamber (414), a discharge valve (424), a return pipe (434), a return pump, a heavy metal online monitoring sensor (454), and a liquid level sensor (464); the outlet of the central water collection pipe (32) is connected to the effluent monitoring chamber (414); one path of the effluent monitoring chamber (414) is connected to the qualified effluent outlet via the discharge valve (424), and the other path is connected to the inlet upstream of the impurity filter (2) or the return outlet of the external microalgae cultivation open pool via the return pipe (434) and the return pump; the heavy metal online monitoring sensor (454) and the liquid level sensor (464) are installed in the effluent monitoring chamber (414); the discharge valve (424) is an electric valve; the return pump is a variable frequency pump.

7. The microalgae culture open pond runoff heavy metal interception kit according to claim 6, characterized in that: The controller (5) includes a signal acquisition module, a threshold comparison module, a path switching module and an actuator drive module; the signal acquisition module is connected to the heavy metal online monitoring sensor (454) and the liquid level sensor (464) in the emission unit; the actuator drive module is connected to the rotary drive motor (38) and the emission valve (424) and the return pump in the emission unit.

8. A control method for the heavy metal interception kit for runoff in an open microalgae culture pond as described in claim 7, characterized in that, Includes the following steps: Step 1: The controller (5) collects the concentration of heavy metals in the emission unit from the online monitoring sensor (454) in real time. The liquid level H of the liquid level sensor (464); Step 2, the controller (5) simultaneously determines With emission limits The relationship between size, liquid level H and warning liquid level Size relationship; Step 3, if And the liquid level H < The controller (5) controls the rotary drive motor (38) to rotate the distribution valve core (37), increasing the number of series stages of the coaxial annular packing module and extending the residence time; Step 4, re-collect data ,like Still greater than If the discharge valve (424) in the control discharge unit is closed, the return pump is started, and the effluent is returned to the upstream of the impurity filter (2) or the external microalgae culture open pool through the return pipe (434) for closed-loop circulation; Step 5, if ≤ And the liquid level H < Then the discharge valve (424) will be opened to discharge; like ≤ And the liquid level H ≥ If so, the drain valve (424) will be opened to prioritize the discharge and lower the liquid level; like And the liquid level H ≥ If the discharge valve (424) is closed, the flow rate of the return pump is increased, and an alarm signal is issued to replace the heavy metal trapping packing module (34).

9. The control method according to claim 8, characterized in that, In step 3, the controller (5) adjusts the concentration... With limit The difference ΔC adjusts the number of cascade stages: when ΔC is positive and continues for more than the set time. When ΔC ≤ 0, the rotary distributor valve core (37) adds one stage of series connection; when ΔC ≤ 0, the rotary distributor valve core (37) reduces one stage of series connection to reduce flow resistance.

10. The control method according to claim 9, characterized in that, In step 4, the reflux pump is a variable frequency pump, and the controller (5) adjusts the flow rate according to the concentration. Adjust the flow rate of the return pump; when And the liquid level H ≥ At that time, the controller (5) controls the return pump to operate at maximum flow, closes the discharge valve (424), and issues an alarm signal to replace the heavy metal trapping packing module (34).

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