A device for recycling salt and alkali and organic matters in seaweed wastewater

Abstract

The utility model relates to the seaweed wastewater treatment field relates to a device of recycling salt alkali and organic matter in seaweed wastewater, the utility model device, include: pretreatment unit, filter adsorption unit, membrane separation unit and collection unit, pretreatment unit includes cyclone desander and multistage sedimentation tank, filter adsorption unit includes multistage sand filter jar and disc filter, membrane separation unit includes alkali -resistant nanofiltration ware and reverse osmosis membrane group, collection unit includes thick water collection jar no.

Description

Technical Field

[0001] This utility model relates to the field of seaweed wastewater treatment, and specifically to a device for recovering salt, alkali and organic matter from seaweed wastewater. Background Technology

[0002] The production of polysaccharides such as carrageenan and agar using seaweeds such as Euphorbia milii, Gracilaria dichotoma, Gracilaria dichotoma, and Gracilaria dichotoma involves a large amount of mud and salt in the seaweed itself. During the production process, high concentrations of alkali and salt are used in the pretreatment, followed by washing with a large amount of water, which generates a large amount of wastewater containing alkali, salt, and high organic matter.

[0003] In the existing technology, the treatment of seaweed wastewater is mainly carried out by traditional anaerobic and aerobic biological processes. Although this method can decompose organic matter and meet the COD emission standards, it cannot achieve the recovery of organic matter, and the salt in the wastewater is also discharged in the end, resulting in waste of resources and environmental pollution. Utility Model Content

[0004] This invention addresses the problems of existing technologies by providing a device for recovering salt, alkali, and organic matter from seaweed wastewater.

[0005] The objective of this utility model can be achieved through the following technical solution: A device for recovering salt, alkali, and organic matter from seaweed wastewater includes: a pretreatment unit, a filtration and adsorption unit, a membrane separation unit, and a collection unit. The pretreatment unit includes a hydrocyclone sand separator and a multi-stage sedimentation tank. The filtration and adsorption unit includes a multi-stage sand filter and a disc filter. The membrane separation unit includes an alkali-resistant nanofiltration unit and a reverse osmosis membrane module. The collection unit includes a concentrate collection tank and a concentrate collection tank. After the seaweed wastewater passes through the hydrocyclone sand separator to remove large particulate impurities, it passes through the multi-stage sedimentation tank to separate suspended solids and some organic matter. Then, it passes through the multi-stage sand filter to adsorb residual organic matter and micron-sized particles, and then through the disc filter to filter small particles. Finally, it passes through the alkali-resistant nanofiltration unit to retain large molecular organic matter and sends the organic matter to the concentrate collection tank for collection. The remaining products enter the reverse osmosis membrane module for deep desalination. The purified water is sent back to the use workshop, and the salt-containing concentrate enters the concentrate collection tank for collection.

[0006] Further improvements include: the multi-stage sedimentation tank comprising a primary sedimentation tank, a secondary sedimentation tank, and a tertiary sedimentation tank arranged sequentially; the multi-stage sand filter comprising a primary sand filter, a secondary sand filter, and an activated carbon adsorption tank arranged sequentially; the outlet of the tertiary sedimentation tank being connected to the inlet of the primary sand filter via a pipeline; two sets of disc filters arranged in parallel, with the outlet of the activated carbon adsorption tank connected in parallel to the two sets of disc filters; two sets of alkaline nanofiltration filters arranged in parallel, with the outlets of the two sets of disc filters connected in parallel to the inlets of the two sets of alkaline nanofiltration filters; and two sets of reverse osmosis membrane modules arranged in parallel.

[0007] In a further improvement, the bottom of the primary sedimentation tank, the secondary sedimentation tank, and the tertiary sedimentation tank are connected to a chamber plate and frame filter press via pipes. The lower end of the chamber plate and frame filter press is connected to a filtrate tank. The filtrate tank is connected to the connecting pipeline between the tertiary sedimentation tank and the primary sand filter tank via branch pipes. The rear end of the chamber plate and frame filter press is connected to a pneumatic sludge hopper.

[0008] In a further improvement, the lower ends of the two sets of alkaline nanofiltration filters are connected to a concentrate collection tank, and the upper ends of the two sets of alkaline nanofiltration filters are connected to an NF permeate tank. The NF permeate tank is connected in parallel to the inlet of the two sets of reverse osmosis membranes. The lower ends of the two sets of reverse osmosis membranes are connected to a concentrate collection tank, and the upper ends of the two sets of reverse osmosis membranes are connected to an RO permeate tank. The RO permeate tank is pumped back to the workshop.

[0009] Compared with existing technologies, the beneficial effects of this utility model's device for recovering salt, alkali, and organic matter from seaweed wastewater are as follows:

[0010] Through the synergistic effect of multiple units such as pretreatment, filtration and adsorption, and membrane separation, the effective separation and recovery of salt and alkali and organic matter in seaweed wastewater are achieved. Salt and alkali can be reused in production, reducing the consumption of raw materials and saving production costs; organic matter can be used to develop seaweed fertilizer, creating new economic value and greatly improving the utilization rate of resources.

[0011] The multi-stage treatment unit purifies the wastewater layer by layer, first removing large particulate impurities and suspended solids, then adsorbing residual organic matter and particles, and finally performing deep desalination, which greatly reduces the pollution level of wastewater and reduces the load on subsequent wastewater treatment.

[0012] After treatment, the clean water can be returned to the workshop for reuse, reducing the consumption of fresh water resources; the concentrated water containing salt, alkali and organic matter is collected and treated, avoiding direct discharge and pollution to the environment, meeting environmental protection requirements, and realizing the resource utilization and reduction of wastewater. Attached Figure Description

[0013] Figure 1 This is a structural schematic diagram of process one of the present invention.

[0014] Figure 2 This is a structural schematic diagram of process two of this utility model.

[0015] In the diagram, 11-cyclone sand separator, 12-multi-stage sedimentation tank, 121-primary sedimentation tank, 122-secondary sedimentation tank, 123-tertiary sedimentation tank, 21-multi-stage sand filter, 211-primary sand filter, 212-secondary sand filter, 213-activated carbon adsorption tank, 22-disc filter, 31-alkali-resistant nanofiltration unit, 32-reverse osmosis membrane module, 41-concentrate collection tank one, 42-concentrate collection tank, 5-plate and frame filter press, 51-filtrate tank, 52-branch pipe, 52-pneumatic sludge hopper, 61-NF permeate tank one, 62-RO permeate tank. Detailed Implementation

[0016] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model; unless otherwise expressly specified and limited, the terms "installed," "connected," and "joined" should be interpreted broadly, for example, they can refer to fixed connections or detachable connections, etc. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0017] The following is a description of the embodiments and appendices. Figures 1-2 The technical solution of this utility model will be further described below.

[0018] An apparatus for recovering salt, alkali and organic matter from seaweed wastewater includes: a pretreatment unit, a filtration and adsorption unit, a membrane separation unit and a collection unit. The pretreatment unit includes a hydrocyclone sand separator 11 and a multi-stage sedimentation tank 12. The filtration and adsorption unit includes a multi-stage sand filter tank 21 and a disc filter 22. The membrane separation unit includes an alkali-resistant nanofiltration unit 31 and a reverse osmosis membrane module 32. The collection unit includes a concentrate collection tank 41 and a concentrate collection tank 42.

[0019] Seaweed wastewater is treated by a hydrocyclone separator 11 to remove large particulate impurities such as mud, sand and shells (particle size > 200 μm), reducing the load on subsequent treatment.

[0020] Then, the suspended solids and some organic matter are separated by the multi-stage sedimentation tank 12;

[0021] The residual organic matter and micron-sized particles are then adsorbed by the multi-stage sand filter tank 21.

[0022] Then, the disc filter 22 intercepts particles larger than 50μm, protecting the alkali-resistant nanofiltration membrane;

[0023] The alkali-resistant nanofiltration device 31 then traps large molecular organic matter (seaweed polysaccharides, proteins, etc.) and sends the organic matter to the concentrate collection tank 41 for collection and use in the production of alkaline seaweed fertilizer.

[0024] The remaining products then enter the reverse osmosis membrane module 32 for deep desalination. The purified water is sent back to the use workshop, while the concentrated water containing salt and alkali is collected in the concentrated water collection tank 42 for use in the pretreatment of seaweed.

[0025] As a further preferred embodiment, the multi-stage sedimentation tank 12 includes a primary sedimentation tank 121, a secondary sedimentation tank 122, and a tertiary sedimentation tank 123 arranged sequentially; the multi-stage sand filter tank 21 includes a primary sand filter tank 211, a secondary sand filter tank 212, and an activated carbon adsorption tank 213 arranged sequentially; the outlet of the tertiary sedimentation tank 123 is connected to the inlet of the primary sand filter tank 211 via a pipe; two sets of disc filters 22 are arranged in parallel, and the outlet of the activated carbon adsorption tank 213 is connected in parallel to the two sets of disc filters 22; two sets of alkaline nanofiltration units 31 are arranged in parallel, and the outlets of the two sets of disc filters 22 are connected in parallel to the inlets of the two sets of alkaline nanofiltration units 31; two sets of reverse osmosis membrane modules 32 are arranged in parallel. The three-stage sedimentation tank progressively reduces the suspended solids concentration, avoiding excessive load on a single stage of sedimentation; the three-stage sand filter tank progressively filters through coarse sand, fine sand, and activated carbon, with adsorption efficiency increasing step by step. The parallel arrangement of disc filters, nanofiltration units, and reverse osmosis membrane modules enhances the overall performance.

[0026] In a further preferred embodiment, the bottoms of the primary sedimentation tank 121, secondary sedimentation tank 122, and tertiary sedimentation tank 123 are connected to a plate and frame filter press 5 via pipes. The lower end of the plate and frame filter press 5 is connected to a filtrate tank 51, which is connected to the tertiary sedimentation tank 123 and the primary sand filter tank 211 via branch pipes 52. A pneumatic sludge hopper 52 is connected to the rear end of the plate and frame filter press 5. The sludge at the bottom of the sedimentation tanks is dewatered by the filter press, and the filtrate is returned to the treatment system to avoid secondary pollution. The pneumatic sludge hopper automatically discharges dry sludge, which can be used as fuel or fertilizer.

[0027] As a further preferred embodiment, the lower ends of the two sets of alkaline nanofiltration units 31 are connected to a concentrate collection tank 41, and the upper ends of the two sets of alkaline nanofiltration units 31 are connected to an NF permeate tank 61. The NF permeate tank 61 is connected in parallel to the inlet of two sets of reverse osmosis membrane modules 321. The lower ends of the two sets of reverse osmosis membrane modules 321 are connected to a concentrate collection tank 42, and the upper ends of the two sets of reverse osmosis membrane modules 321 are connected to an RO permeate tank 62. The RO permeate tank 62 sends water back to the processing workshop via a transfer pump. The two sets of nanofiltration units and reverse osmosis membrane modules operate in parallel, and the NF permeate tank and RO permeate tank stabilize the water pressure, avoiding the impact of flow fluctuations on membrane performance.

[0028] The specific steps for recovering salt, alkali, and organic matter from seaweed wastewater using process parameter one are as follows:

[0029] (1) Wastewater from the production of carrageenan from Euphorbia milii;

[0030] (2) Cyclone sand separator, feed pressure ≥ 0.3 MPa, sand discharge cycle 4h / time, to prevent large particles from entering the subsequent process;

[0031] (3) Vertical flow sedimentation tank, surface load 0.8 m³ / (m².h), sludge return 15%, sludge discharge once every 4 hours to prevent sludge caking;

[0032] (4) Sand filter tank, flow rate 10m / h, backwash intensity 15L / (s.m²), activated carbon to be replaced every 6 months;

[0033] (5) Disc filter, intercepts particles larger than 50μm, and protects the alkali-resistant nanofiltration membrane;

[0034] (6) Alkali-resistant nanofiltration, special material, operating pressure 1.8MPa, recovery rate 90%.

[0035] (7) SWRO, operating pressure 5.5MPa, recovery rate 90%.

[0036] The specific data is shown in the table below:

[0037]

[0038] The specific steps for recovering salt, alkali and organic matter from seaweed wastewater using process parameter two are as follows:

[0039] (1) Wastewater from the production of carrageenan from Euphorbia milii;

[0040] (2) Hydrocyclone sand separator, feed pressure ≥0.3MPa, sand discharge cycle 2h / time, to prevent large particles from entering the subsequent process;

[0041] (3) Vertical flow sedimentation tank, surface load 0.8 m³ / (m².h), sludge return 25%, sludge discharge once every 2 hours to prevent sludge caking;

[0042] (4) Sand filter tank, flow rate 10m / h, backwash intensity 15L / (s.m²), activated carbon to be replaced every 6 months;

[0043] (5) Disc filter, intercepts particles larger than 50μm, and protects the alkali-resistant nanofiltration membrane;

[0044] (6) Alkali-resistant nanofiltration, special material, operating pressure 1.8MPa, recovery rate 90%.

[0045] The specific data is shown in the table below:

[0046]

[0047] The preferred embodiments of this utility model have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of this utility model without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of this utility model through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A device for recovering salt, alkali, and organic matter from seaweed wastewater, characterized in that, include: The system comprises a pretreatment unit, a filtration and adsorption unit, a membrane separation unit, and a collection unit. The pretreatment unit includes a hydrocyclone sand separator and a multi-stage sedimentation tank. The filtration and adsorption unit includes a multi-stage sand filter and a disc filter. The membrane separation unit includes an alkali-resistant nanofiltration unit and a reverse osmosis membrane module. The collection unit includes a concentrate collection tank and a concentrate collection tank. After the seaweed wastewater passes through the hydrocyclone sand separator to remove large particulate impurities, it passes through the multi-stage sedimentation tank to separate suspended solids and some organic matter. Then, it passes through the multi-stage sand filter to adsorb residual organic matter and micron-sized particles, and then through the disc filter to filter small particles. Finally, it passes through the alkali-resistant nanofiltration unit to retain large molecular organic matter and sends the organic matter to the concentrate collection tank for collection. The remaining products enter the reverse osmosis membrane module for deep desalination. The purified water is sent back to the use workshop, and the salt-containing concentrate is collected in the concentrate collection tank.

2. The device for recovering salt, alkali, and organic matter from seaweed wastewater according to claim 1, characterized in that, The multi-stage sedimentation tank includes a primary sedimentation tank, a secondary sedimentation tank, and a tertiary sedimentation tank arranged sequentially; the multi-stage sand filter includes a primary sand filter, a secondary sand filter, and an activated carbon adsorption tank arranged sequentially; the outlet of the tertiary sedimentation tank is connected to the inlet of the primary sand filter via a pipeline; two sets of disc filters are arranged in parallel, and the outlet of the activated carbon adsorption tank is connected in parallel to the two sets of disc filters; two sets of alkaline nanofiltration devices are arranged in parallel, and the outlets of the two sets of disc filters are connected in parallel to the inlets of the two sets of alkaline nanofiltration devices; two sets of reverse osmosis membrane modules are arranged in parallel.

3. The apparatus for recovering salt, alkali, and organic matter from seaweed wastewater according to claim 2, characterized in that, The bottoms of the primary sedimentation tank, secondary sedimentation tank, and tertiary sedimentation tank are connected to a plate and frame filter press via pipes. The lower end of the plate and frame filter press is connected to a filtrate tank. The filtrate tank is connected to the connecting pipes of the tertiary sedimentation tank and the primary sand filter tank via branch pipes. The rear end of the plate and frame filter press is connected to a pneumatic sludge hopper.

4. The apparatus for recovering salt, alkali, and organic matter from seaweed wastewater according to claim 1, characterized in that, The lower ends of the two sets of alkaline nanofiltration membranes are connected to a concentrate collection tank, and the upper ends of the two sets of alkaline nanofiltration membranes are connected to an NF permeate tank. The NF permeate tank is connected in parallel to the inlet of the two sets of reverse osmosis membranes. The lower ends of the two sets of reverse osmosis membranes are connected to a concentrate collection tank, and the upper ends of the two sets of reverse osmosis membranes are connected to an RO permeate tank. The RO permeate tank is pumped back to the workshop.

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