CN115301201A - Volcanic ash soil-based adsorbent for enriching phosphorus in water body and preparation method and application thereof - Google Patents

Abstract

The invention discloses an adsorbent for enriching phosphorus in a water body based on volcanic ash soil, and a preparation method and application thereof, and belongs to the field of sewage treatment. The method comprises the steps of mixing volcanic ash soil, biochar, quartz powder and other materials according to a certain proportion and then processing to obtain the phosphorus adsorbent. The phosphorus-enriched sewage is put into domestic sewage to absorb phosphorus in the sewage, so that the aim of enriching the phosphorus is fulfilled. The content of phosphorus in the volcanic ash soil is further improved, so that the fertility of the volcanic ash soil is improved, the volcanic ash soil is more suitable for improving soil, and the addition amount is greatly reduced. The phosphorus adsorbent prepared by the invention has the advantages of wide raw material source, low cost, simple preparation method and obvious energy-saving effect; the phosphorus adsorbent prepared by the invention is used for removing phosphorus in domestic sewage or treating natural water eutrophication. The phosphorus removal efficiency of the invention can reach 94.4%, the produced sludge can be recycled, the treatment cost is low, the production benefit is high, and no secondary pollution is generated.

Description

A kind of adsorbent based on volcanic ash soil enriching phosphorus in water body and its preparation method and application

technical field

The invention belongs to the field of sewage treatment, and in particular relates to an adsorbent for enriching phosphorus in water bodies based on volcanic ash soil and its preparation method and application.

Background technique

Volcanic ash soil is a variety of soils formed from volcanic ash parent material in the Quaternary volcanic activity area. Distributed in areas with frequent modern volcanic activities around the world, the distribution area in China is very small. Some sections of volcanic ash soil with deeper development degree are obviously differentiated and have higher fertility. This soil is characterized by a coarse texture, high porosity, high risk of erosion and high mineral content of volcanic origin.

Those with a younger soil-forming age and a low degree of development still retain the original characteristics of volcanic ash, and the section differentiation is weak; those with a deeper development degree have obvious section differentiation, and the organic matter content in the surface layer can reach more than 15%, and the soil color is dark gray. quite high. This kind of soil has high porosity, coarse texture, and is easy to be eroded. It contains a large amount of minerals of volcanic origin (such as volcanic glass, volcanic debris, etc.), the amount of which exceeds 70%; the clay minerals are mainly plumberite, and phosphorus Has a fixed effect. However, in the volcanic ash soil, there is a higher phosphorus sorption capacity and a good correlation with the pH (NaF) value, but when the pH (NaF) value is > 9.4, the phosphate sorption capacity is > 85%, which is Due to the high phosphorus adsorption properties of allophane-like and aluminum-humic complexes in volcanic soils.

With the advent of the new era, with the continuous improvement of social economy and people's living standards, urban domestic water consumption has increased sharply, and the amount of domestic sewage that sewage treatment plants need to process is also increasing. Due to the increase of sewage volume, the content of organic matter in sewage treatment plants has decreased, and the content of phosphorus has gradually increased. The research on phosphorus removal in urban domestic sewage has become the bottleneck of sewage treatment. From the perspective of the source of phosphorus in urban domestic sewage, it mainly comes from domestic sewage containing excreta, food residues, pesticides, and chemical fertilizers. If the phosphorus in it is not handled properly, it will inevitably cause eutrophication of the water body. Therefore, in the process of treating urban domestic sewage at this stage, it is necessary to study phosphorus removal technology to improve the efficiency and level of domestic sewage treatment while improving the efficiency of phosphorus removal.

Phosphorus removal from urban domestic sewage refers to the conversion of phosphate in sewage into solid particles in various ways, so as to remove phosphorus from sewage. Judging from these solid particles, they belong to insoluble phosphate precipitates, or microbial solids in activated sludge, or plant components in constructed wetlands. From the perspective of urban domestic sewage phosphorus removal technology, there are many types of sewage phosphorus removal technologies at this stage, but the best phosphorus removal effect and wide application range are mainly biological methods, chemical precipitation methods and adsorption methods. The key to phosphorus removal by adsorption is the choice of adsorbent. The phosphorus removal adsorbent should have the characteristics of low production cost, large adsorption capacity, and wide source of raw materials. At present, the commonly used adsorbents are mainly natural materials and waste residues, activated alumina and its modified products, and artificially synthesized adsorbents. The application of natural materials and activated alumina is limited due to their small adsorption capacity, high cost, and easy to produce secondary pollution. Now artificially synthesized phosphorus removal adsorbents are getting more and more attention.

Contents of the invention

The first purpose of the present invention is to provide an adsorbent for enriching phosphorus in water based on volcanic ash soil; the second purpose is to provide a preparation method of the adsorbent; the third purpose is to provide the application of the adsorbent.

The first object of the present invention is achieved in that the volcanic ash soil-based adsorbent for enriching phosphorus in water includes the following raw materials: volcanic ash soil, biochar, quartz powder and dilute nitric acid.

Further, the mass percent of the raw material is:

Volcanic ash soil 70%~90%;

Quartz powder 10%~30%;

Biochar 5%~20%;

Add 40~50mL of dilute nitric acid to every 100g of mixed powder of volcanic ash soil, biochar, and quartz powder.

Further, the dilute nitric acid is dilute nitric acid with a mass percentage not greater than 1%. Because of the instability of nitric acid, the thicker it is, the easier it is to decompose.

The second object of the present invention is achieved in that the preparation method of the sorbent based on pozzolanic soil enrichment of phosphorus in the water body comprises the following steps:

(1) Mix volcanic ash soil, biochar, and quartz powder evenly in proportion to obtain mixed powder;

(2) Add dilute nitric acid with a mass percentage not greater than 1% to the mixed powder obtained in step (1), and stir to form a muddy mixture;

(3) Extrude the muddy mixture obtained in step (2) into blocks, air-dry naturally, and then heat at 600-800°C for 2-3 hours to finally obtain the phosphorus adsorbent.

Further, the block length in step (3) is 30-50 mm, the width is 20-30 mm, and the height is 5-10 mm.

The third object of the present invention is achieved by using the adsorbent in the removal of phosphorus in domestic sewage or in the treatment and repair of eutrophication in water bodies.

Further, the application method of the described adsorbent based on volcanic ash soil enrichment of phosphorus in water is:

Put the prepared adsorbent into the phosphorus-containing sewage, fully contact the sewage with the adsorbent, and make the phosphorus in the wastewater react with the adsorbent for 6-10 hours. The adsorption capacity of the volcanic ash soil will absorb and enrich the phosphorus in the sewage. Phosphorus, so as to achieve a significant effect of phosphorus removal, which can ensure the discharge of sewage up to standard. After adsorption, the phosphorus-removing adsorbent attaches a large amount of phosphorus and suspended matter to form phosphorus-containing sludge. The volcanic ash soil in the sludge absorbs and enriches phosphorus in the sewage, and further increases the phosphorus content in the volcanic ash soil, thereby improving the fertility of the volcanic ash soil and making it It is more suitable for improving soil, and the amount added will be greatly reduced, without causing secondary pollution, and realizing a virtuous circle of environment and economy.

Compared with the prior art, the present invention has the following technical effects:

1. The volcanic ash soil used in the method of the present invention is generally porous, has good water permeability, extremely high humus content in the surface layer, obvious humification effect, small soil bulk density, and has a fixing effect on phosphorus. Volcanic ash soil has a higher phosphorus uptake capacity. Compared with other materials, the phosphorus removal efficiency is greatly improved.

2. The adsorbent prepared by the method of the present invention has large surface area, large contact surface and high phosphorus removal efficiency.

3. The sludge enriched with phosphorus in sewage obtained by the method of the present invention is more suitable for improving soil, and the added amount will be greatly reduced.

4. The phosphorus removal adsorbent obtained by the method of the present invention, under a certain ratio, the more pozzolanic soil is added, the better the phosphorus removal effect, and the phosphorus removal efficiency can reach 95%.

5. The phosphorus removal adsorbent obtained by the method of the present invention has good phosphorus removal effect and simple and convenient operation.

Detailed ways

The present invention will be further described below, but the present invention is not limited in any way. Any transformation or replacement based on the teaching of the present invention belongs to the protection scope of the present invention.

The present invention will be further described in conjunction with embodiment 1～4.

Example 1

A method for absorbing phosphorus in domestic sewage by using volcanic ash soil, comprising the following steps:

S1. The raw materials of phosphorus removal adsorbent include volcanic ash soil, biochar, quartz powder and dilute nitric acid.

S2, mix it by mass:

70g of volcanic ash soil;

Quartz powder 20g;

Biochar 10g;

Mix pozzolanic soil, biochar and quartz powder into powder, and add 40mL of dilute nitric acid with a mass percentage not greater than 1%. Stir it into mud, extrude it into a block, and dry it naturally to make a length of 30mm, a width of 20mm, and a height of 5mm. Spread the obtained massive particles on the bottom of the crucible, put them into an intermediate frequency furnace and heat them at 600° C. for 2 hours, and finally take them out to obtain the phosphorus removal adsorbent.

Putting the above-mentioned phosphorus-removing adsorbent in the pre-reaction tank of the sewage treatment plant will consume 2.6 kg of phosphorus-removing adsorbent for every ton of phosphorus-containing sewage. The phosphorus in the wastewater reacts with the phosphorus removal adsorbent in it for 8 hours, the concentration of phosphorus in the final wastewater can be reduced from 5.0mg/L before treatment to 0.5mg/L after treatment, and the phosphorus removal rate can be as high as 90%. It can ensure that the discharge of sewage reaches the standard. After adsorption, the phosphorus-removing adsorbent attaches a large amount of phosphorus and suspended matter to form phosphorus-containing sludge. The volcanic ash soil in the sludge absorbs and enriches phosphorus in the sewage, and further increases the phosphorus content in the volcanic ash soil, thereby improving the fertility of the volcanic ash soil and making it It is more suitable for improving soil, and the amount added will be greatly reduced, without causing secondary pollution, and realizing a virtuous circle of environment and economy. Continuous dosing of the phosphorus removal adsorbent can ensure a stable phosphorus removal rate.

Example 2

A method for absorbing phosphorus in domestic sewage by using volcanic ash soil, comprising the following steps:

S1. The raw materials of phosphorus removal adsorbent include volcanic ash soil, biochar, quartz powder and dilute nitric acid.

S2, mix it by mass:

75g of volcanic ash soil;

Quartz powder 15g;

Biochar 10g;

Mix pozzolanic soil, biochar and quartz powder into powder, and add 40mL of dilute nitric acid with a mass percentage not greater than 1%. Stir it into mud, extrude it into a block, and dry it naturally to make a length of 40mm, a width of 30mm, and a height of 5mm. Spread the obtained massive particles on the bottom of the crucible, put them into an intermediate frequency furnace and heat them at 800°C for 2 hours, and finally take them out to obtain the phosphorus removal adsorbent.

Put the above-mentioned phosphorus removal adsorbent in the pre-reaction tank of the sewage treatment plant, and it will consume 2.4 kg of phosphorus removal adsorbent to treat 1 ton of phosphorus-containing sewage. By reacting the phosphorus in the wastewater with the phosphorus-removing adsorbent for 8 hours, the concentration of phosphorus in the final wastewater can be reduced from 5.0mg/L before treatment to 0.42mg/L after treatment, and the phosphorus removal rate can be as high as 91.6%. It can ensure that the discharge of sewage reaches the standard. After adsorption, the phosphorus-removing adsorbent attaches a large amount of phosphorus and suspended matter to form phosphorus-containing sludge. The volcanic ash soil in the sludge absorbs and enriches phosphorus in the sewage, and further increases the phosphorus content in the volcanic ash soil, thereby improving the fertility of the volcanic ash soil and making it It is more suitable for improving soil, and the amount added will be greatly reduced, without causing secondary pollution, and realizing a virtuous circle of environment and economy. Continuous dosing of the phosphorus removal adsorbent can ensure a stable phosphorus removal rate.

Example 3

A method for absorbing phosphorus in domestic sewage by using volcanic ash soil, comprising the following steps:

S1. The raw materials of phosphorus removal adsorbent include volcanic ash soil, biochar, quartz powder and dilute nitric acid.

S2, mix it by mass:

Volcanic ash soil 80g;

Quartz powder 10g;

Biochar 10g;

Mix pozzolanic soil, biochar and quartz powder into powder, and add 40mL of dilute nitric acid with a mass percentage not greater than 1%. Stir it into mud, extrude it into a block, and dry it naturally to make it into a length of 50mm, a width of 30mm, and a height of 5mm. Spread the obtained massive particles on the bottom of the crucible, put them into an intermediate frequency furnace and heat them at 600-800°C for 2 hours, and finally take them out to obtain the phosphorus removal adsorbent.

Put the above-mentioned phosphorus removal adsorbent in the pre-reaction tank of the sewage treatment plant, and it will consume 2.2 kg of phosphorus removal adsorbent to treat 1 ton of phosphorus-containing sewage. By reacting the phosphorus in the wastewater with the phosphorus-removing adsorbent for 8 hours, the concentration of phosphorus in the final wastewater can be reduced from 5.0mg/L before treatment to 0.38mg/L after treatment, and the phosphorus removal rate can be as high as 92.4%. It can ensure that the discharge of sewage reaches the standard. After adsorption, the phosphorus-removing adsorbent attaches a large amount of phosphorus and suspended matter to form phosphorus-containing sludge. The volcanic ash soil in the sludge absorbs and enriches phosphorus in the sewage, and further increases the phosphorus content in the volcanic ash soil, thereby improving the fertility of the volcanic ash soil and making it It is more suitable for improving soil, and the amount added will be greatly reduced, without causing secondary pollution, and realizing a virtuous circle of environment and economy. Continuous dosing of the phosphorus removal adsorbent can ensure a stable phosphorus removal rate.

Example 4

A method for absorbing phosphorus in domestic sewage by using volcanic ash soil, comprising the following steps:

S1. The raw materials of phosphorus removal adsorbent include volcanic ash soil, biochar, quartz powder and dilute nitric acid.

S2, mix it by mass:

Volcanic ash soil 85g;

Quartz powder 10g;

Biochar 5g;

Mix pozzolanic soil, biochar and quartz powder into powder, and add 40mL of dilute nitric acid with a mass percentage not greater than 1%. Stir it into mud, extrude it into a block, and dry it naturally to make it with a length of 50mm, a width of 40mm, and a height of 5mm. Spread the obtained massive particles on the bottom of the crucible, put them into an intermediate frequency furnace and heat them at 600-800°C for 2 hours, and finally take them out to obtain the phosphorus removal adsorbent.

Put the above-mentioned phosphorus removal adsorbent in the pre-reaction tank of the sewage treatment plant, and it will consume 2.0 kg of phosphorus removal adsorbent to treat 1 ton of phosphorus-containing sewage. The phosphorus in the wastewater reacts with the phosphorus removal adsorbent in it for 8 hours, and the concentration of phosphorus in the final wastewater can be reduced from 5.0mg/L before treatment to 0.28mg/L after treatment, and the phosphorus removal rate can be as high as 94.4%. It can ensure that the discharge of sewage reaches the standard. After adsorption, the phosphorus-removing adsorbent attaches a large amount of phosphorus and suspended matter to form phosphorus-containing sludge. The volcanic ash soil in the sludge absorbs and enriches phosphorus in the sewage, and further increases the phosphorus content in the volcanic ash soil, thereby improving the fertility of the volcanic ash soil and making it It is more suitable for improving soil, and the amount added will be greatly reduced, without causing secondary pollution, and realizing a virtuous circle of environment and economy. Continuous dosing of the phosphorus removal adsorbent can ensure a stable phosphorus removal rate.

Claims (7)

1. An adsorbent for enriching phosphorus in water based on volcanic ash soil is characterized by comprising the following raw materials: volcanic ash soil, charcoal, quartz powder and dilute nitric acid.

2. The volcanic ash soil based adsorbent for enriching phosphorus in water body according to claim 1, wherein the raw materials comprise, by mass:

70% -90% of volcanic ash soil;

10% -30% of quartz powder;

5% -20% of charcoal;

adding dilute nitric acid into 100g of mixed powder of volcanic ash soil, biochar and quartz powder for 40-50mL.

3. The volcanic ash soil-based adsorbent for enriching phosphorus in water body according to claim 1, wherein the dilute nitric acid is a dilute nitric acid with a mass percentage of not more than 1%.

4. A method for preparing the volcanic ash soil based adsorbent for enriching phosphorus in water according to any one of claims 1 to 3, which comprises the following steps:

(1) Uniformly mixing volcanic ash soil, biochar and quartz powder according to a proportion to obtain mixed powder;

(2) Adding dilute nitric acid with the mass percent not more than 1% into the mixed powder obtained in the step (1), and stirring to form a muddy mixture;

(3) And (3) extruding the pasty mixture obtained in the step (2) into blocks, naturally drying the blocks, and heating the blocks at the temperature of 600 to 800 ℃ for 2 to 3 hours to finally obtain the phosphorus adsorbent.

5. The preparation method of the volcanic ash soil-based adsorbent for enriching phosphorus in water body according to claim 4, wherein the block length in the step (3) is 30 to 50mm, the width is 20 to 30mm, and the height is 5 to 10mm.

6. The application of the volcanic ash soil-based adsorbent for enriching phosphorus in water according to any one of claims 1 to 3, wherein the adsorbent is applied to phosphorus removal in domestic sewage or water eutrophication treatment and restoration.

7. The application of the volcanic ash soil-based adsorbent for enriching phosphorus in water body according to claim 6, characterized in that the application method comprises the following steps: and putting the prepared adsorbent into a water body to be treated, and reacting phosphorus in the wastewater with the adsorbent for 6-10 hours.