CN106977007A - The system and method for bi-membrane method advanced treating brown alga chemical industry waste Ca water - Google Patents

Abstract

The invention discloses a system and method for advanced treatment of waste calcium water from brown algae chemical industry by double-membrane method. The system is: a system for advanced treatment of waste calcium water from brown algae chemical industry by double-membrane method. The treatment tank 1, the ceramic membrane module 2, the activated carbon tank 3 and the reverse osmosis membrane module 4 are connected, and the reverse osmosis membrane module 4 is connected with the production water pipe 9; the ceramic membrane module 2 is connected with the settling tank 6 through the pipeline, and the settling tank 6 is sequentially passed through the pipeline It is connected with the oxidation reactor 7 and the coagulation-air flotation treatment tank 1. The present invention uses ceramic membrane modules as pretreatment for treating waste calcium water, simplifies process steps, occupies less floor space, and has high efficiency in treating actual sewage. After pretreatment with the ceramic ultrafiltration membrane system, the pollution of the reverse osmosis membrane can be significantly reduced, the cost of the pretreatment process is reduced, and the process is easy to scale up.

Description

System and method for advanced treatment of brown algae chemical waste calcium water by double-membrane method

technical field

The invention relates to the field of sewage treatment of seaweed industrial production, in particular to the treatment of waste calcium water produced in the production process of sodium alginate products.

Background technique

Seaweed processing products mainly include red algae gelatinous products and brown algae chemical products. my country's annual production capacity of alginate products is about 35,000 tons, accounting for 60% of the world's total production capacity. It is a pillar product in my country's seaweed processing industry and has been widely used in printing and dyeing, medicine, food, daily necessities and other fields. The production of 1 ton of alginate will consume 1,000 tons of fresh water, and the waste calcium water produced will account for more than 70% of all wastewater. The reuse of the above-mentioned sewage after treatment will effectively reduce the production cost of enterprises, save fresh water resources, and generate huge economic, social and environmental benefits.

Calcium wastewater contains a large amount of Ca ²⁺ , K ⁺ , ClO ^- , SO4 ^2- , Cl ^- and organic pollutants such as alginate, polysaccharide, protein and kelp starch. Due to the large amount of wastewater and complex components, traditional water treatment technologies (such as air flotation) can only reduce the COD content of wastewater to a certain extent to achieve discharge standards. With the increasingly tense water resources and my country's increasingly stringent environmental protection requirements, it is imperative to realize the advanced treatment and reuse of waste calcium water. CN101074140A Chinese invention patent "treatment of alginate production wastewater and recycling zero-emission process", which illustrates that the present invention oxidizes the waste calcium water produced by alginate production, decalcifies treatment, biological filtration oxidation treatment, and air flotation treatment , flocculation and sedimentation treatment; the comprehensive water after the mixture of the two is treated by ozone cycle oxidation treatment, and then filtered and biologically oxidized, and finally advanced treatment by reverse osmosis device. Based on multi-step pretreatment plus reverse osmosis advanced treatment technology, zero discharge treatment of waste calcium water is realized. However, the pretreatment steps of the invention are complicated, the equipment cost and floor area are too large, and the addition of various chemical reagents not only increases the treatment cost but also affects the subsequent treatment process. The Chinese invention patent CN102745841A published in 2012, "A New Recycling Process for Brown Algae Chemical Waste Calcium Water", describes a combined process of chemical precipitation, electrodialysis and ion exchange to treat waste calcium water; the electrodialysis process in this invention can The consumption is too high, the cost of regeneration is high, and a large amount of regeneration waste liquid is produced, the cost of treating actual sewage is too high, and it has no practical value.

Summarizing the above process inventions, it can be seen that most of the disclosed inventions still focus on the purpose of recycling calcium waste water through chemical treatment. However, the above-mentioned technology still needs to use a large amount of chemical agents, and at the same time, the waste calcium water will still produce a large amount of high-salt wastewater after treatment and reuse, and the later wastewater treatment is more difficult.

At present, there is no report on the method of using ceramic membrane modules to treat brown algae chemical waste calcium water.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the prior art and provide a system for the advanced treatment of brown algae chemical waste calcium water by double-membrane method.

The second object of the present invention is to provide a double-membrane method for advanced treatment of brown algae chemical waste calcium water.

Technical scheme of the present invention is summarized as follows:

A system for the advanced treatment of brown algae chemical waste calcium water by double membrane method. Brown algae chemical waste calcium water pipeline 8 is sequentially connected with coagulation-air flotation treatment tank 1, ceramic membrane module 2, activated carbon tank 3 and reverse osmosis membrane module 4. The reverse osmosis membrane The module 4 is connected with a production water pipe 9; the ceramic membrane module 2 is connected with the settling tank 6 through the pipeline, and the settling tank 6 is connected with the oxidation reactor 7 and the coagulation-air flotation treatment tank 1 in turn through the pipeline.

The ceramic membrane module 2 is a ceramic membrane module with a hydrophilic surface. The ceramic membrane module 2 is a flat ceramic membrane module or a tubular ceramic membrane module. The average pore diameter of the ceramic membrane is 10nm-200nm.

The reverse osmosis membrane module 4 is a hollow reverse osmosis membrane module, a tube-type reverse osmosis membrane module, a flat-plate reverse osmosis membrane module, a roll-type reverse osmosis membrane module or a disk-type reverse osmosis membrane module.

The method for advanced treatment of brown algae chemical waste calcium water by double-membrane method comprises the following steps:

(1) use the double-membrane method advanced treatment system of brown algae chemical waste calcium water of claim 1;

(2) Put the brown algae chemical waste calcium water into the coagulation-air flotation treatment tank 1 through the brown algae chemical waste calcium water pipeline 8 to remove the alginate and then into the ceramic membrane module 2, and separate it under the condition of operating pressure of 0.1-0.4MPa Obtain filtrate 1 and concentrated water, filtrate 1 is passed into activated carbon tank 3 for filtration and then passed into reverse osmosis membrane module 4, filtered under the condition of operating pressure of 0.6-1.5MPa, and then output production water through production water pipe 9; After the water is input into the settling tank 6 through the pipeline for sedimentation, the supernatant is input into the oxidation reactor 7, oxidized with sodium hypochlorite, and returned to the coagulation-air flotation treatment tank 1 after the oxidation reaction. Reverse osmosis concentrated water can be concentrated by thermal method to achieve zero discharge treatment.

Advantages of the present invention:

The present invention uses ceramic membrane modules as pretreatment for treating waste calcium water, simplifies process steps, occupies less floor space, and has high efficiency in treating actual sewage. After pretreatment with the ceramic ultrafiltration membrane system, the pollution of the reverse osmosis membrane can be significantly reduced, the pretreatment process is simplified, the cost of the pretreatment process is reduced, and the process is easy to scale up.

Description of drawings

Figure 1 is a schematic diagram of a system for advanced treatment of brown algae chemical waste calcium water by double-membrane method.

detailed description

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

The system for the advanced treatment of brown algae chemical waste calcium water by double-membrane method is shown in Figure 1. The brown algae chemical waste calcium water pipeline 8 is sequentially connected with the coagulation-air flotation treatment tank 1, ceramic membrane module 2, activated carbon tank 3 and reverse osmosis membrane module 4, The reverse osmosis membrane module 4 is connected to the production water pipe 9; the ceramic membrane module 2 is connected to the settling tank 6 through the pipeline, and the settling tank 6 is connected to the oxidation reactor 7 and the coagulation-air flotation treatment tank 1 in turn through the pipeline.

A high-pressure reverse osmosis membrane module can also be connected between the reverse osmosis membrane module 4 and the production water pipe 9 .

The ceramic membrane module 2 is a ceramic membrane module with a hydrophilic surface. The ceramic membrane module 2 is a flat ceramic membrane module or a tubular ceramic membrane module. The average pore diameter of the ceramic membrane is 10nm-200nm.

The reverse osmosis membrane module 4 is a hollow reverse osmosis membrane module, a tubular reverse osmosis membrane module, a flat reverse osmosis membrane module, a roll type reverse osmosis membrane module or a disc tube type reverse osmosis membrane module.

Example 1

The method for advanced treatment of brown algae chemical waste calcium water by double-membrane method comprises the following steps:

(1) A system for advanced treatment of brown algae chemical waste calcium water using a double-membrane method; the ceramic membrane module 2 is a flat ceramic membrane module with a hydrophilic surface, and the average pore size of the ceramic membrane is 100nm; the reverse osmosis membrane module 4 is a hollow reverse osmosis membrane module. Permeable membrane components;

(2) The brown algae chemical waste calcium water is input into the coagulation-air flotation treatment tank 1 through the brown algae chemical waste calcium water pipeline 8 to remove alginate, and then input into the ceramic membrane module 2, and the filtrate is obtained by separating under the condition of operating pressure of 0.2 MPa 1 and concentrated water, the filtrate 1 is passed into the activated carbon tank 3 for filtration and then passed into the reverse osmosis membrane module 4, filtered under the condition of operating pressure of 1.0MPa, and then output the production water through the production water pipe 9; the concentrated water is input through the pipeline After settling in the settling tank 6, the supernatant is input into the oxidation reactor 7, oxidized with sodium hypochlorite, and returned to the coagulation-air flotation treatment tank 1 after the oxidation reaction. See Table 1.

Table 1 Example 1 Treatment of Brown Algae Chemical Waste Calcium Water Water Quality Data: Unit is mg/L

Example 2

The method for advanced treatment of brown algae chemical waste calcium water by double-membrane method comprises the following steps:

(1) A system for advanced treatment of waste calcium water from brown algae chemical industry using a double-membrane method; the ceramic membrane module 2 is a tubular ceramic membrane module with a hydrophilic surface, and the average pore size of the ceramic membrane is 10nm; the reverse osmosis membrane module 4 is a tubular ceramic membrane module. reverse osmosis membrane module;

(2) The brown algae chemical waste calcium water is input into the coagulation-air flotation treatment tank 1 through the brown algae chemical waste calcium water pipeline 8 to remove the alginate, and then input into the ceramic membrane module 2, and the filtrate is obtained by separating under the condition of an operating pressure of 0.1 MPa 1 and concentrated water, the filtrate 1 is passed into the activated carbon tank 3 for filtration and then passed into the reverse osmosis membrane module 4, filtered under the condition of operating pressure of 0.6MPa, and then the production water is output through the production water pipe 9; the concentrated water is input through the pipeline After settling in the settling tank 6, the supernatant is input into the oxidation reactor 7, oxidized with sodium hypochlorite, and returned to the coagulation-air flotation treatment tank 1 after the oxidation reaction.

Example 3

The method for advanced treatment of brown algae chemical waste calcium water by double-membrane method comprises the following steps:

(1) A system for advanced treatment of waste calcium water from brown algae chemical industry using a double-membrane method; the ceramic membrane module 2 is a tubular ceramic membrane module with a hydrophilic surface, and the average pore size of the ceramic membrane is 200nm; the reverse osmosis membrane module 4 is a flat plate reverse osmosis membrane components;

(2) The brown algae chemical waste calcium water is input into the coagulation-air flotation treatment tank 1 through the brown algae chemical waste calcium water pipeline 8 to remove the alginate, and then input into the ceramic membrane module 2, and the filtrate is obtained by separating under the condition of an operating pressure of 0.4MPa 1 and concentrated water, the filtrate 1 is passed into the activated carbon tank 3 for filtration and then passed into the reverse osmosis membrane module 4, filtered under the condition of operating pressure of 1.5MPa, and then the production water is output through the production water pipe 9; the concentrated water is input through the pipeline After settling in the settling tank 6, the supernatant is input into the oxidation reactor 7, oxidized with sodium hypochlorite, and returned to the coagulation-air flotation treatment tank 1 after the oxidation reaction.

The flat reverse osmosis membrane module in this embodiment can also be replaced by a roll type reverse osmosis membrane module or a disc tube type reverse osmosis membrane module as the reverse osmosis membrane module 4, and the other is the same as in this embodiment for the treatment of brown algae chemical waste calcium water.

The present invention uses sodium hypochlorite to oxidize the sewage separated by ceramic membrane modules and then precipitated, without introducing new impurity particles, low in cost, and does not produce a large amount of sludge compared with other oxidizing reagents such as Fenton, and the water quality is clear in color.

Claims (4)

1. the system of bi-membrane method advanced treating brown alga chemical industry waste Ca water, it is characterized in that brown alga chemical industry waste Ca water pipeline (8) successively with Coagulation-air-flotation process pond (1), ceramic film component (2), charcoal canister (3) and reverse osmosis membrane assembly (4) connection, reverse osmosis membrane group Part (4) is connected with industrial water pipe (9)；Ceramic film component (2) is connected by pipeline with subsider (6), and subsider (6) passes through pipe Road is connected with oxidation reactor (7) and the coagulation-air-flotation process pond (1) successively.

2. system according to claim 1, it is characterized in that the ceramic film component (2), which is surface, has hydrophilic ceramics Membrane module, the ceramic film component (2) is flat ceramic membrane module or tubular ceramic membrane module, the average pore size of the ceramic membrane 10nm-200nm。

3. system according to claim 1, it is characterized in that the reverse osmosis membrane assembly (4) be hollow reverse osmosis membrane assembly, Tubular type reverse osmosis membrane assembly, flat plate reverse osmosis membrane module, coiled reverse osmosis membrane component or disc tube reverse osmosis (dt-ro) membrane module.

4. the method for bi-membrane method advanced treating brown alga chemical industry waste Ca water, it is characterized in that comprising the following steps：

(1) system of the bi-membrane method advanced treating brown alga chemical industry waste Ca water of usage right requirement 1；

(2) brown alga chemical industry waste Ca water is inputted in coagulation-air-flotation process pond (1) by brown alga chemical industry waste Ca water pipeline (8) and removed Ceramic film component (2) is inputted after algin, isolated filtrate 1 and concentrated water under conditions of operating pressure is 0.1-0.4MPa, Filtrate 1 is passed through reverse osmosis membrane assembly (4) after being passed through charcoal canister (3) filtering, under conditions of operating pressure is 0.6-1.5MPa Filtering, then export industrial water through industrial water pipe (9)；After the concentrated water is settled by pipeline input subsider (6), on Clear liquid input oxidation reactor (7), is aoxidized with sodium hypochlorite, coagulation-air-flotation process pond is back to after oxidized reaction (1)。