CN102897884A - Composite flocculant as well as preparation method and application thereof on processing printing and dyeing wastewater - Google Patents

Abstract

The present invention relates to a composite flocculant and its preparation and application in the treatment of printing and dyeing wastewater. The components of the composite flocculant include: aluminum sulfate, ferric chloride, diatomaceous earth, potassium permanganate, wherein aluminum sulfate, The mass ratio of ferric chloride, diatomaceous earth and potassium permanganate is 15:4:10-12:0.06-0.08; its preparation includes: dissolving aluminum sulfate, ferric chloride, diatomaceous earth and potassium permanganate respectively Prepare a solution in water to obtain an aqueous solution of each component; then mix the above components according to the mass ratio of aluminum sulfate, ferric chloride, diatomaceous earth and potassium permanganate as 15:4:10-12:0.06-0.08 The aqueous solution mixed, that is. The composite flocculant of the invention is suitable for removing suspended matter and impurities in printing and dyeing wastewater, and has excellent treatment effect, no secondary pollution, high ecological safety, simple preparation process and low price.

Description

A kind of composite flocculant and its preparation and application in the treatment of printing and dyeing wastewater

technical field

The invention belongs to the field of water treatment inorganic flocculant and its preparation and application, in particular to a composite flocculant, its preparation and its application in treating printing and dyeing wastewater.

Background technique

Water is the source of human life and the foundation on which all life depends. It plays an indispensable role in the development of social economy. However, with the population growth in modern society, the rapid development of industrial and agricultural production activities and the rapid process of urbanization, the global water environment is deteriorating day by day, which seriously threatens the well-being of human beings. In order to ensure the sustainable use of water resources and solve the problem of water pollution, a lot of research has been carried out at home and abroad, and various water treatment processes have emerged, such as: flocculation sedimentation method, biochemical method, adsorption method, ion exchange method, chemical oxidation method , electrodialysis and sewage ecological treatment technology. Among them, the flocculation-sedimentation method, as one of the important unit operations of water pollution control, is still the most widely used method for dealing with particulate matter and organic matter, and occupies an extremely important position in water treatment. In addition, the flocculation and sedimentation method of treating sewage with flocculants is also the cheapest method. In this method, the core and key role is the selection and use of flocculants.

At present, the world's water treatment chemicals are tending to develop in the direction of high efficiency, low toxicity, pollution-free, multi-functional and compound green industries. Environmental protection, safety and stability, economical applicability and high efficiency will be the key indicators for evaluating the development of the flocculant industry. The development of water treatment flocculants has gone through from traditional inorganic flocculants to inorganic polymer flocculants, and then to organic polymer flocculants; organic polymer flocculants have experienced from simple to complex, and then developed synthetic and natural modified organic flocculants. Polymer flocculants; later, in order to further improve the deficiencies of flocculants, they developed into more promising microbial flocculants and composite flocculants.

Composite flocculant is a new type of flocculant that has only been developed in recent years. It can overcome many shortcomings of using a single flocculant, and has a wide range of applications. It has good water purification for low or high concentration water quality, colored wastewater, and other industrial wastewater. Effect, good sludge removal, wide range of pH, can also improve the removal rate of organic matter in the flocculation process, and can reduce the concentration of residual metal ions and reduce secondary pollution.

Contents of the invention

The technical problem to be solved by the present invention is to provide a composite flocculant and its preparation and application in the treatment of printing and dyeing wastewater. The composite flocculant has fast floc settlement, excellent treatment effect, no secondary pollution, and high ecological safety. The preparation process is simple, easy to operate and low in price.

A kind of composite flocculant of the present invention, its component comprises: aluminum sulfate, ferric chloride, diatomite, potassium permanganate, wherein the mass ratio of aluminum sulfate, ferric chloride, diatomite and potassium permanganate is 15:4:10-12:0.06-0.08.

The mass ratio of the aluminum sulfate, ferric chloride, diatomaceous earth and potassium permanganate is 15:4:11:0.07.

A kind of preparation method of composite flocculant of the present invention comprises:

Dissolve aluminum sulfate, ferric chloride, diatomaceous earth and potassium permanganate in water respectively to prepare a solution to obtain an aqueous solution of each component; then, according to the quality of aluminum sulfate, ferric chloride, diatomite and potassium permanganate The ratio is 15:4:10-12:0.06-0.08. Mix the aqueous solutions of the above components to obtain the composite flocculant.

A composite flocculant of the present invention is applied to treat water quality with a pH value of 7.0-8.5.

A composite flocculant of the invention is applied to the treatment of printing and dyeing wastewater.

The specific operation method for the above-mentioned treatment of printing and dyeing wastewater is as follows: adjust the pH value of the printing and dyeing wastewater to 7.0-8.5, then add a composite flocculant and stir.

The dosage of the composite flocculant is as follows: 600 grams of aluminum sulfate, 160 grams of ferric chloride, 400-480 grams of diatomite and 2.4-3.2 grams of potassium permanganate are added to 1 ton of printing and dyeing wastewater.

The dosage of the composite flocculant is to add the composite flocculant according to the ratio of adding 600 grams of aluminum sulfate, 160 grams of ferric chloride, 440 grams of diatomaceous earth and 2.8 grams of potassium permanganate to 1 ton of printing and dyeing wastewater.

The composite flocculant of the present invention is most suitable for treating water quality with a pH range of 7.0-8.5, and has a good treatment effect for alkaline water quality.

The present invention combines four raw materials of aluminum sulfate, ferric chloride, potassium permanganate and diatomaceous earth, seeks the appropriate proportion of the four medicines, and reduces the consumption of aluminum sulfate and ferric chloride as much as possible in practical applications, While combining the advantages of aluminum sulfate and ferric chloride, it makes up for its shortcomings. In addition, the present invention makes full use of the oxidation of potassium permanganate to transform the macromolecular substances in the printing and dyeing wastewater into small molecular particles that are easy to strengthen flocculation, and at the same time combines the coagulation-assisting effect of diatomite to prepare an integrated oxidation and flocculation Multifunctional composite flocculant, especially suitable for removing suspended solids and impurities in printing and dyeing wastewater.

Beneficial effect:

(1) The preparation method of the present invention is simple, easy to operate, low in cost and wide in source of raw materials;

(2) The floc settling speed of the composite flocculant of the present invention is fast, the treatment effect is excellent, the secondary pollution is low, and the ecological safety is high;

(3) The ratio of aluminum sulfate, ferric chloride, diatomaceous earth and potassium permanganate contained in the flocculant of the present invention can be adjusted according to the water quality of different printing and dyeing wastewater, so as to obtain the best flocculant product.

Detailed ways

Below in conjunction with specific embodiment, further illustrate the present invention. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the teachings of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of the present application.

Example 1

(1) Weigh 15 grams of aluminum sulfate, 4 grams of ferric chloride, 11 grams of diatomaceous earth, and 0.7 grams of potassium permanganate and dissolve them in 1 liter of deionized water to obtain an aqueous solution of each component; then take the prepared sulfuric acid 40 milliliters of aluminum aqueous solution, ferric chloride aqueous solution, diatomite aqueous solution and 4 milliliters of potassium permanganate aqueous solution are mixed to obtain a composite flocculant;

(2) Add 10% sodium hydroxide dropwise to 1 liter of printing and dyeing wastewater to adjust the pH to 8.5, then add the composite flocculant obtained in step (1), and stir thoroughly for 10 minutes. The body particles become larger, let it stand for 15 minutes, take the supernatant and measure it, and use the potassium dichromate method to calculate the COD removal rate of 68.4%.

Example 2

(1) Weigh 15 grams of aluminum sulfate, 4 grams of ferric chloride, 11 grams of diatomaceous earth, and 0.7 grams of potassium permanganate and dissolve them in 1 liter of deionized water to obtain an aqueous solution of each component; then take the prepared sulfuric acid 40 milliliters of aluminum aqueous solution, ferric chloride aqueous solution, diatomite aqueous solution and 4 milliliters of potassium permanganate aqueous solution are mixed to obtain a composite flocculant;

(2) Adjust the pH value of 1 liter of printing and dyeing wastewater to 7.0, then add the composite flocculant obtained in step (1), and stir thoroughly for 10 minutes. With stirring, a large number of floc particles will be produced, and the floc particles will become larger. After 15 minutes, the supernatant was taken for measurement and the COD removal rate was calculated to be 60.6% by the potassium dichromate method.

Claims (8)

1. A composite flocculant, its component comprises: aluminum sulfate, ferric chloride, diatomite, potassium permanganate, wherein the mass ratio of aluminum sulfate, ferric chloride, diatomite and potassium permanganate is 15 :4:10-12:0.06-0.08. 2. A composite flocculant according to claim 1, characterized in that the mass ratio of aluminum sulfate, ferric chloride, diatomaceous earth and potassium permanganate is 15:4:11:0.07. 3. A preparation method of a composite flocculant, comprising: Dissolve aluminum sulfate, ferric chloride, diatomaceous earth and potassium permanganate in water respectively to prepare a solution to obtain an aqueous solution of each component; then, according to the quality of aluminum sulfate, ferric chloride, diatomite and potassium permanganate The ratio is 15:4:10-12:0.06-0.08 by mixing the aqueous solutions of the above components. 4. A composite flocculant as claimed in claim 1 is used to treat water with a pH value of 7.0-8.5. 5. A composite flocculant as claimed in claim 1 is applied to the treatment of printing and dyeing wastewater. 6. A kind of composite flocculant according to claim 5 is applied to the treatment of printing and dyeing wastewater, characterized in that: the specific operation method of the treatment of printing and dyeing wastewater is: adjust the pH value of printing and dyeing wastewater to 7.0-8.5, and then add the compound Flocculant, just after stirring. 7. A kind of composite flocculant according to claim 6 is applied to the treatment of printing and dyeing wastewater, it is characterized in that: the consumption of described composite flocculant is to add 600 grams of aluminum sulfate, 160 grams of ferric chloride according to 1 ton of printing and dyeing wastewater , 400-480 grams of diatomaceous earth and 2.4-3.2 grams of potassium permanganate are added to the composite flocculant. 8. A kind of composite flocculant according to claim 7 is applied to the treatment of printing and dyeing wastewater, it is characterized in that: the consumption of described composite flocculant is to add 600 grams of aluminum sulfate, 160 grams of ferric chloride according to 1 ton of printing and dyeing wastewater , 440 grams of diatomaceous earth and 2.8 grams of potassium permanganate were added to the composite flocculant.