CN105251470A - Adsorbing agent for removing phosphorus and heavy metal ions and preparation method thereof - Google Patents

Abstract

The invention belongs to the field of adsorbing materials for sewage treatment, and provides an adsorbing agent for removing phosphorus and heavy metal ions and a preparation method thereof. The method comprises the following steps that 1, water-soluble ferric salt is prepared into a ferric salt solution with the Fe<3+> concentration of 0.2-1.5 mol/L with water; 2, lithium silica powder processed through drying is added into the ferric salt solution according to the solid-liquid ratio of 1 kg: (2-10) L, stirring is performed at the temperature of 25 DEG C-80 DEG C to enable the lithium silica powder to be evenly dispersed in the ferric salt solution to form mixed liquid, then alkali liquid is dropwise added into the mixed liquid under stirring to regulate the pH value of the mixed liquid to 8-11, standing is performed at the temperature of 25 DEG C-80 DEG C for 48-72 h, solid and liquid separation is performed, the obtained solid phase is washed with water until washed liquid is neutral and dried, and then the adsorbing agent is obtained. According to the method, not only are the adsorbing agent varieties enriched, but also the production cost of the adsorbing agent is reduced, and meanwhile resource utilization of the industrial waste lithium silica powder is achieved.

Description

Adsorbent for removing phosphorus and heavy metal ions and preparation method thereof

technical field

The invention belongs to the field of adsorption materials for sewage treatment, and relates to an adsorbent for removing phosphorus and heavy metal ions and a preparation method thereof.

Background technique

With the rapid development of industry, the unreasonable discharge of industrial wastewater containing heavy metal ions has caused the content of heavy metal ions such as lead ions and copper ions in water and soil to exceed the normal range. Since heavy metal ions cannot be degraded by themselves and are prone to bioaccumulation, heavy metal ions in the environment will enter the human body through various channels, causing great harm to human health. At the same time, with the increasingly frequent development and utilization of environmental resources by humans, a large amount of domestic wastewater containing nitrogen and phosphorus nutrients has been produced. This type of wastewater entering the natural water body will cause eutrophication of the water body and cause a large number of algae to multiply, which will seriously damage the water body. The ecological environment poses a serious threat to the survival of aquatic organisms and human health. Phosphorus is a controlling factor for the eutrophication of inland water bodies. Therefore, how to effectively control the content of heavy metal ions and phosphorus in water has become a very urgent task in the field of sewage treatment.

The methods for removing phosphorus and heavy metal ions from wastewater mainly include chemical methods, biological methods and adsorption methods. Among them, the adsorption method has the characteristics of simple process, reliable operation, and the ability to remove and recover phosphorus and heavy metal ions. It is an important wastewater treatment method. Methods for removing phosphorus and heavy metal ions. At present, the commercial adsorbents used to remove phosphorus and heavy metal ions from wastewater are mainly coal-based activated carbon. Due to the high price of this type of adsorbent and the high cost of regeneration after adsorption saturation, this type of adsorbent and its adsorption capacity are limited. The large-scale application of the method in the field of water treatment.

Lithium silicon powder is industrial waste residue produced in the production process of lithium salts. It has a large amount of discharge and belongs to industrial waste. Its main components are SiO ₂ and Al ₂ O ₃ . However, it has not been put into actual large-scale application, so a large amount of lithium silicon powder residue still cannot be used reasonably and effectively. The surface of lithium silicon powder has a porous structure, which has the potential to be used as an adsorbent. Lin Weilan put lithium silicon powder into cerium nitrate or lanthanum nitrate solution, dried after immersion for 24 hours, then washed, dried, and roasted at 150-800°C for 0.5-3 hours to obtain cerium nitrate or lanthanum nitrate modified lithium silicon powder (Lin Weilan , Research on the adsorption and removal of phosphorus by lithium silicon powder and the modification performance of rare earth [D], Xihua University, 2014), the modified lithium silicon powder can absorb phosphorus in wastewater. Since this method uses expensive lanthanide rare earth elements to modify lithium silicon powder, there is a disadvantage that the modification cost is too high, and during use, the dissolution of lanthanide rare earth metals may cause secondary pollution to water bodies. Therefore, if an inexpensive, non-secondary pollution-free adsorbent that can simultaneously remove phosphorus and heavy metal ions in wastewater can be developed based on industrial waste lithium silicon powder, the treatment of wastewater containing phosphorus and heavy metal ions and the recovery of valuable heavy metal resources And the resource utilization of industrial waste slag lithium silicon powder is of great significance.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the prior art, to provide an adsorbent for removing phosphorus and heavy metal ions and its preparation method, to enrich the types of adsorbent and reduce the production cost of the adsorbent, and at the same time resource utilization of industrial waste Lithium silicon powder.

The preparation method of the adsorbent used for removing phosphorus and heavy metal ions provided by the invention, the steps are as follows:

(1) Water-soluble iron salt is mixed with water to make Fe ³⁺ concentration be 0.2～1.5mol/L iron salt solution;

(2) Add the dried lithium silicon powder into the iron salt solution prepared in step (1) according to the solid-to-liquid ratio of 1kg:(2-10)L, and stir at 25-80°C to make the lithium-silicon The powder is uniformly dispersed in the iron salt solution to form a mixed solution, and then lye is added dropwise to the mixed solution under stirring to adjust the pH value of the mixed solution to 8-11, and then stand at 25-80°C for 48-72 hours , solid-liquid separation, and the obtained solid phase is washed with water until the eluate is neutral and dried to obtain the adsorbent.

In the above method, the rotation speed of the stirring is 50-150 r/min.

In the above method, the lithium silicon powder is a powder passed through a 100-300 mesh sieve.

In the above method, the concentration of the lye is 0.5-1 mol/L, and the lye is preferably sodium carbonate solution or sodium hydroxide solution.

In the above method, the water-soluble iron salt is ferric chloride, ferric nitrate or ferric sulfate.

In the above method, the drying treatment of the lithium silicon powder is to dry the lithium silicon powder at 105-110° C. for 3-5 hours.

The principle of the method described in the present invention: lithium silicon powder has a well-developed pore structure, which can provide enough active adsorption sites. During the stirring process after lithium silicon powder is added to the water-soluble iron salt solution, Fe ³⁺ will be adsorbed on lithium Silicon powder, and then in the process of adding lye dropwise to adjust the pH value of the mixed solution to 8-11, as the pH value of the mixed solution gradually increases, Fe ³⁺ will be transformed into Fe ₄ HO ₈ .4H ₂ O intermediate, with the further increase of pH value, Fe ₄ HO ₈ .4H ₂ O will convert to α-hydroxy iron (α-FeOOH), and when the mixture contains Cl ^- , NO ^3- , SO ₄ ^{2 -time} , it is beneficial to the formation of β-hydroxyl iron (β-FeOOH), and then, the mixed solution after adjusting the pH value is left at 25-80°C for 48-72h. This standing process is conducive to stabilizing the lithium silicon powder on the surface. The resulting α-FeOOH and β-FeOOH ore phases make the crystallinity of the formed hydroxyl iron higher. Hydroxyl iron—α-FeOOH and β-FeOOH have large specific surface area and strong reactivity, have strong adsorption capacity for heavy metal ions, and can also combine with phosphorus to form Fe(PO ₃ ) ₃ to realize the purification of waste water. Phosphorus removal.

The present invention also provides an adsorbent for removing phosphorus and heavy metal ions prepared by the above method.

The adsorbent provided by the present invention is used for phosphorus removal. When the dosage of adsorption is 1.5g/L, it has a high removal rate of total phosphorus in phosphorus-containing wastewater with a total phosphorus concentration of 10mg/L and a pH value of 3-8. at 90%.

The adsorbent provided by the invention is used to remove Cu ²⁺ . When the dosage of the adsorbent is 3g/L, the removal rate of Cu ²⁺ in copper-containing wastewater with a Cu ²⁺ concentration of 25 mg/L is higher than 98%.

The adsorbent provided by the invention is used to remove Pb ²⁺ . When the dosage of the adsorbent is 4g/L, the removal rate of Pb ²⁺ in lead-containing wastewater with a Pb ²⁺ concentration of 25mg/L is higher than 99%.

The adsorbent provided by the invention can be eluted with acid solution after absorbing heavy metal ions, so as to recover valuable heavy metal ions, and can be eluted with alkali solution after absorbing phosphorus. According to actual application conditions, after the phosphorus and heavy metal ions adsorbed on the adsorbent are eluted, the adsorbent of the present invention can be used repeatedly.

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

1. The present invention provides a novel adsorbent for removing phosphorus and heavy metal ions. The adsorbent uses industrial waste lithium silicon powder as a raw material and is prepared by modifying iron salts under alkaline conditions. Because lithium silicon powder has The well-developed pore structure can provide enough active adsorption sites. Therefore, in the water-soluble iron salt solution, Fe ³⁺ can be adsorbed on the pores and surfaces of lithium silicon powder, and the Fe ³⁺ adsorbed on lithium silicon powder is gradually adjusted. When the pH value of the mixed solution reaches 8-11, it can be converted into ferric hydroxy, and the ferric hydroxy will become more stable during the standing process after the pH value is adjusted. Hydroxyl iron has a large specific surface area and strong reactivity, has a strong adsorption capacity for heavy metal ions, and can combine with phosphorus to form Fe(PO ₃ ) ₃ , thereby realizing the removal of phosphorus in wastewater.

2. The adsorbent of the present invention is prepared by using lithium silicon powder as raw material and modified under alkaline conditions by using water-soluble iron salt solution. Since lithium silicon powder is industrial waste, it is cheap and has abundant sources, and water-soluble iron The price of salt is also very low, because the cost of the adsorbent of the present invention is low, using the adsorbent to treat wastewater can effectively reduce the cost of wastewater treatment, and at the same time, the present invention also provides a new idea for the resource utilization of industrial waste , Realized the treatment of waste with waste.

3. Experiments show that when the adsorbent of the present invention is used for phosphorus removal, when the dosage of adsorption is 1.5g/L, it will be effective in phosphorus-containing wastewater with a total phosphorus concentration of 10mg/L and a pH value of 3 to 8. The total phosphorus removal rate is higher than 90%, not only the phosphorus removal effect is good, but also the pH value is wide; the adsorbent is used to remove Cu ²⁺ , when the dosage of the adsorbent is 3g/L, the Cu ²⁺ The removal rate of Cu ²⁺ in copper-containing wastewater with a concentration of 25mg/L is higher than 98%; the adsorbent is used to remove Pb ²⁺ , when the dosage of the adsorbent is 4g/L, the concentration of Pb ²⁺ The removal rate of Pb ²⁺ in the lead-containing wastewater of L was higher than 99%.

4. Experiments show that when the dosage of the adsorbent in the copper-containing wastewater is 1-4g/L, the oscillation reaction is 3h, and the concentration of iron ions in the wastewater is lower than 0.03mg/L, indicating that the adsorption of the present invention Among them, iron hydroxy has high stability on lithium silicon powder, and it is not easy to dissolve or fall off during use, and will not cause secondary pollution.

5. the present invention also provides a kind of method for preparing above-mentioned adsorbent, because this method is reasonable to the control of conditions and parameters such as raw material solid-liquid ratio, iron salt concentration, reaction temperature and time, pH value and stirring, thus Fe ³⁺ It can be efficiently adsorbed on lithium silicon powder and converted into hydroxyl iron that exists stably on lithium silicon powder and has a large specific surface area and high reactivity, thereby obtaining an adsorbent with good adsorption performance for phosphorus and heavy metal ions.

6. The process of the method of the present invention is simple, the production cost is low, and is conducive to popularization and application.

Description of drawings

Fig. 1 is the adsorbent prepared in embodiment 1 and the removal effect curve of lithium silicon powder to copper ion;

Fig. 2 is the adsorbent prepared in embodiment 4 and the removal effect curve of lithium silicon powder to total phosphorus;

Fig. 3 is the removal effect curve of the adsorbent prepared in Example 7 on total phosphorus under different pH conditions.

detailed description

The adsorbent for removing phosphorus and heavy metal ions of the present invention, its preparation method, and the removal effect of the adsorbent on phosphorus and heavy metal ions will be further described through examples below.

In each of the following examples, the lithium silicon powder is industrial lithium silicon powder waste residue.

Example 1

In the present embodiment, the preparation method of the adsorbent for removing phosphorus and heavy metal ions is as follows:

(1) Pass the lithium silicon powder through a 100-mesh sieve, place it at 105°C and dry it for 3 hours; prepare ferric chloride with deionized water to make an aqueous ferric chloride solution with a Fe ³⁺ concentration of 0.2mol/L;

(2) Add the dried lithium silicon powder into the ferric chloride aqueous solution prepared in step (1) according to the ratio of solid-to-liquid ratio of 1kg:10L, stir on a magnetic stirrer at a speed of 150r/min at 25°C, Make the lithium silicon powder uniformly disperse in the ferric chloride aqueous solution to form a mixed solution, then add 0.2 mol/L sodium hydroxide aqueous solution dropwise to the mixed solution under the aforementioned stirring conditions to adjust the pH value of the mixed solution to 9, and stop stirring , and then stand at 25°C for 48h, filter, wash the obtained solid phase with water until the eluate is neutral and dry at 105°C to obtain the adsorbent.

The removal ability of the adsorbent and lithium silicon powder prepared in this example to Cu ²⁺ will be investigated below.

Take 5 parts of Cu ²⁺ solution with a concentration of 25mg/L as simulated wastewater, and add this For the adsorbent prepared in the examples, at the same time, take 5 parts of the above-mentioned simulated wastewater, add lithium silicon powder through a 100-mesh sieve to the simulated wastewater according to the above-mentioned dosage, and shake and react at room temperature at a speed of 150r/min for 3h. Filter with a filter membrane with a pore size of 0.45 μm, and then use an atomic absorption spectrophotometer to measure the Cu ²⁺ concentration in the filtered simulated wastewater, and compare the removal capabilities of the two for copper ions. The results are shown in Figure 1. As can be seen from Figure 1, the adsorbent prepared in this example has a much higher removal capacity for copper ^ions than lithium silicon powder. The removal rate has reached more than 98%.

Example 2

In the present embodiment, the preparation method of the adsorbent material for removing phosphorus and heavy metal ions is as follows:

(1) Pass the lithium silicon powder through a 150-mesh sieve, place it at 105°C and dry it for 4 hours; prepare ferric nitrate with deionized water to make an aqueous ferric nitrate solution with a Fe ³⁺ concentration of 0.3mol/L;

(2) Add the dried lithium silicon powder into the ferric nitrate aqueous solution prepared in step (1) according to the solid-to-liquid ratio of 1kg:8L, and place it on a magnetic stirrer at a speed of 80r/min in a water bath at 40°C Stir to make the lithium silicon powder uniformly disperse in the ferric nitrate aqueous solution to form a mixed solution, then add 0.8 mol/L sodium hydroxide solution dropwise to the mixed solution under the aforementioned stirring conditions to adjust the pH value of the mixed solution to 10, stop Stir, then stand still in a water bath at 40°C for 48h, filter, wash the obtained solid phase with water until the eluate is neutral, and dry at 105°C to obtain the adsorbent.

The removal ability of the adsorbent prepared in this example to Pb ²⁺ is investigated below.

The Pb ²⁺ solution with a concentration of 25mg/L was used as the simulated wastewater, and the adsorbent prepared in this example was added to the simulated wastewater according to the dosage of 4g/L, and the reaction was oscillated at room temperature at a speed of 150r/min for 3h , filter with a filter membrane with a pore size of 0.45 μm, and then use an atomic absorption spectrophotometer to measure the Pb ²⁺ concentration in the simulated wastewater after filtration. The results show that the adsorbent prepared in this example can remove Pb ²⁺ in the simulated wastewater The rate reached more than 99%.

Example 3

In the present embodiment, the preparation method of the adsorbent material for removing phosphorus and heavy metal ions is as follows:

(1) Pass the lithium silicon powder through a 180-mesh sieve, and dry it at 110°C for 3.5 hours; prepare ferric nitrate with deionized water to make an aqueous solution of ferric nitrate with a Fe ³⁺ concentration of 0.4mol/L;

(2) Add the dried lithium silicon powder into the ferric nitrate aqueous solution prepared in step (1) according to the solid-to-liquid ratio of 1kg:5L, and place it on a magnetic stirrer in a water bath at 50°C at a speed of 60r/min Stir to make the lithium silicon powder uniformly disperse in the ferric nitrate aqueous solution to form a mixed solution, then add 0.8 mol/L aqueous sodium hydroxide solution dropwise to the mixed solution under the aforementioned stirring conditions to adjust the pH value of the mixed solution to 11, stop Stir, then stand still in a water bath at 50°C for 48 hours, filter, wash the obtained solid phase with water until the eluate is neutral, and dry at 110°C to obtain the adsorbent.

The phosphorus removal ability of the adsorbent prepared in this example will be investigated below.

A solution with a total phosphorus concentration of 1mg/L and a pH value of 7 was used as the simulated wastewater, and the adsorbent prepared in this example was added to the simulated wastewater according to the dosage of 0.5g/L. Lower the shaking reaction for 3 hours, filter with a filter membrane with a pore size of 0.45 μm, and then measure the total phosphorus concentration of the filtrate by molybdenum antimony antispectrophotometry. The results show that the adsorbent prepared in this example has a removal rate of total phosphorus in the simulated wastewater 90%.

Example 4

In the present embodiment, the preparation method of the adsorbent material for removing phosphorus and heavy metal ions is as follows:

(1) Pass the lithium silicon powder through a 200-mesh sieve, and dry it at 110°C for 3.5 hours; prepare ferric nitrate with deionized water to make an aqueous solution of ferric nitrate with a Fe ³⁺ concentration of 0.5mol/L;

(2) Add the dried lithium silicon powder into the ferric nitrate aqueous solution prepared in step (1) according to the solid-to-liquid ratio of 1kg:5L, and place it on a magnetic stirrer in a water bath at 65°C at a speed of 55r/min. Stir to make the lithium silicon powder uniformly disperse in the ferric nitrate aqueous solution to form a mixed solution, then add dropwise 0.5 mol/L sodium carbonate aqueous solution to the mixed solution under the aforementioned stirring conditions to adjust the pH value of the mixed solution to 8, and stop stirring , and then stood in a water bath at 65°C for 48h, filtered, washed the obtained solid phase with water until the eluate was neutral and dried at 110°C to obtain the adsorbent.

The ability of the adsorbent powder prepared in this example to remove Cu ²⁺ and total phosphorus, and the stability of the adsorbent prepared in this example during use will be investigated below.

Take 5 parts of Cu ²⁺ solution with a concentration of 10mg/L as simulated wastewater, and add this The adsorbent prepared in the examples was shaken and reacted at room temperature for 3 hours at a speed of 150 r/min, and filtered with a filter membrane with a pore size of 0.45 μm, and then the Cu ²⁺ in the filtered simulated wastewater was measured by an atomic absorption spectrophotometer. Concentration, the results show that when the dosage is 2g/L, the adsorbent prepared in this example has a removal rate of more than 95% for Cu ²⁺ in simulated wastewater. Utilize the atomic absorption spectrophotometer to measure the concentration of the iron ion dissolved from the adsorbent in the simulated waste water, the result iron ion concentration is all lower than 0.03mg/L, this shows that the adsorbent prepared in this embodiment not only has superior copper ion adsorption ability, and high stability during use, will not produce secondary pollution.

Take 6 parts of solutions with a total phosphorus concentration of 10mg/L and a pH value of 7 as simulated wastewater. Dosing of the adsorbent prepared in this example into the simulated wastewater, and at the same time, take 6 parts of the above-mentioned simulated wastewater, and add lithium silicon powder through a 250 mesh sieve to the simulated wastewater according to the above dosage, and place it at room temperature at 150r Oscillating and reacting for 3 hours at a rotating speed of 1/min, filtering with a filter membrane with a pore size of 0.45 μm, and then measuring the total phosphorus concentration of the filtrate by molybdenum antimony anti-spectrophotometry, comparing the two for phosphorus removal ability, the results are shown in Figure 2 . It can be seen from Figure 2 that when the dosage is 2g/L, the removal rate of the total phosphorus in the simulated wastewater by the adsorbent prepared in this example reaches more than 98%, while when the dosage of lithium silicon powder is 7/L , the removal rate of the total phosphorus in the simulated wastewater was only about 20%, and the phosphorus removal ability of the adsorbent prepared in this example was significantly higher than that of lithium silicon powder.

Example 5

In the present embodiment, the preparation method of the adsorbent material for removing phosphorus and heavy metal ions is as follows:

(1) Pass the lithium silicon powder through a 250-mesh sieve, and dry it at 105°C for 5 hours; prepare the iron sulfate with deionized water to make an aqueous solution of iron sulfate with a Fe3 ⁺ concentration of 1mol/L;

(2) Add the dried lithium silicon powder into the ferric sulfate aqueous solution prepared in step (1) according to the solid-to-liquid ratio of 1kg:3L, and place it in a water bath at 70°C on a magnetic stirrer at a speed of 70r/min Stir to make the lithium silicon powder uniformly disperse in the ferric sulfate aqueous solution to form a mixed solution, then add 0.2 mol/L sodium carbonate aqueous solution dropwise to the mixed solution under the aforementioned stirring conditions to adjust the pH value of the mixed solution to 8, and stop stirring , put it in a water bath at 70°C for 60h, filter, wash the obtained solid phase with water until the eluate is neutral and dry at 105°C to obtain the adsorbent.

The removal ability of the adsorbent prepared in this example to Pb ²⁺ is investigated below.

The Pb ²⁺ solution with a concentration of 10mg/L was used as the simulated wastewater, and the adsorbent prepared in this example was added to the simulated wastewater according to the dosage of 2g/L, and the reaction was oscillated at room temperature at a speed of 150r/min for 3h , filter with a filter membrane with a pore size of 0.45 μm, and then use an atomic absorption spectrophotometer to measure the Pb ²⁺ concentration in the simulated wastewater after filtration. The results show that the adsorbent prepared in this example can remove Pb ²⁺ in the simulated wastewater The rate reached more than 99%.

Example 6

In the present embodiment, the preparation method of the adsorbent material for removing phosphorus and heavy metal ions is as follows:

(1) Pass the lithium silicon powder through a 300-mesh sieve, place it at 105° C. and dry it for 4 hours; prepare ferric nitrate with deionized water to make an aqueous solution of ferric nitrate with a Fe ³⁺ concentration of 1.5 mol/L;

(2) Add the dried lithium silicon powder into the ferric nitrate aqueous solution prepared in step (1) according to the solid-to-liquid ratio of 1kg:2L, and place it on a magnetic stirrer in a water bath at 80°C at a speed of 50r/min Stir to make the lithium silicon powder uniformly disperse in the ferric nitrate aqueous solution to form a mixed solution, then add 0.2 mol/L aqueous sodium hydroxide solution dropwise to the mixed solution under the aforementioned stirring conditions to adjust the pH value of the mixed solution to 9, stop Stir, stand in a water bath at 80°C for 72 hours, filter, wash the obtained solid phase with water until the eluate is neutral, and dry at 110°C to obtain the adsorbent.

The phosphorus removal ability of the adsorbent prepared in this example and the industrial lithium silicon powder will be investigated below.

Take 6 parts of solutions with a total phosphorus concentration of 10mg/L and a pH value of 7 as simulated wastewater. Dosing of the adsorbent prepared in this example into the simulated waste water, and at the same time, take 6 parts of the above-mentioned simulated waste water, and add lithium silicon powder through a 300 mesh sieve to the simulated waste water according to the above dosage, and place it at room temperature at 150r Oscillating and reacting for 3 hours at a rotational speed of 1/min, filtering with a filter membrane with a pore size of 0.45 μm, and then measuring the total phosphorus concentration of the filtrate by molybdenum antimony anti-spectrophotometry, and comparing the phosphorus removal ability of the two, the results show that: When it is 5g/L, the adsorbent prepared in this example has a removal rate of more than 95% to the total phosphorus in the simulated wastewater, and when the dosage of lithium silicon powder is 7g/L, its removal rate to the total phosphorus in the simulated wastewater The removal rate is only about 20%, and the phosphorus removal ability of the adsorbent prepared in this example is significantly higher than that of lithium silicon powder.

Example 7

In the present embodiment, the preparation method of the adsorbent material for removing phosphorus and heavy metal ions is as follows:

(1) Pass the lithium silicon powder through a 200-mesh sieve, place it at 105°C and dry it for 3 hours; prepare the ferric chloride with deionized water to make an aqueous ferric chloride solution with a Fe ³⁺ concentration of 0.5mol/L;

(2) Add the dried lithium silicon powder into the ferric chloride aqueous solution prepared in step (1) according to the ratio of solid-to-liquid ratio of 1kg:5L. Stir at a rotating speed, so that the lithium silicon powder is uniformly dispersed in the ferric chloride aqueous solution to form a mixed solution, and then add 0.5 mol/L sodium carbonate aqueous solution dropwise to the mixed solution under the aforementioned stirring conditions to adjust the pH value of the mixed solution to 8, Stop stirring, then let stand in a water bath at 65°C for 48 hours, filter, wash the obtained solid phase with water until the eluate is neutral and dry at 110°C to obtain the adsorbent.

The phosphorus removal ability of the adsorbent prepared in this example under different pH conditions will be investigated below.

Take 7 solutions with a total phosphorus concentration of 10mg/L, adjust the pH values of each solution to 1, 3, 5, 7, 8, 10, and 12 to form simulated wastewater, and add 1.5g/L to the simulated wastewater Add the adsorbent prepared in this example, shake and react at room temperature for 3 hours at a speed of 150 r/min, filter with a filter membrane with a pore size of 0.45 μm, and then measure the total phosphorus concentration of the filtrate by molybdenum antimony anti-spectrophotometry , calculate the total phosphorus removal rate, the results are shown in Figure 3, as can be seen from Figure 3, when the pH value of the simulated wastewater is 3 to 8, the adsorbent prepared in this example has a total phosphorus removal rate of 90% for the simulated wastewater The above shows that the adsorbent provided by the present invention is suitable for a wide range of pH values when removing phosphorus, and is suitable for both acidic and alkaline conditions.

Claims (10)

1., for the preparation method of the adsorbent of dephosphorization and heavy metal ion, it is characterized in that step is as follows:

(1) water-soluble molysite water is mixed with Fe ³⁺concentration is 0.2 ~ 1.5mol/L iron salt solutions;

(2) being 1kg:(2 ~ 10 according to solid-to-liquid ratio) the lithium silica flour of drying process adds in the iron salt solutions that step (1) prepares by the ratio of L, stir under 25 ~ 80 DEG C of conditions, make lithium silica flour dispersed formation mixed liquor in iron salt solutions, then under agitation in described mixed liquor, pH value to 8 ~ 11 that alkali lye regulates described mixed liquor are dripped, 48 ~ 72h is left standstill again at 25 ~ 80 DEG C, Separation of Solid and Liquid, gained solid phase is washed to eluate in neutral and dry, obtains adsorbent.

2., according to claim 1 for the preparation method of the adsorbent of dephosphorization and heavy metal ion, it is characterized in that the rotating speed of described stirring is 50 ~ 150r/min.

3. according to claim 1 or 2 for the preparation method of the adsorbent of dephosphorization and heavy metal ion, it is characterized in that described lithium silica flour was the powder of 100 ~ 300 mesh sieves.

4. according to claim 1 or 2 for the preparation method of the adsorbent of dephosphorization and heavy metal ion, it is characterized in that the concentration of alkali lye is 0.5 ~ 1mol/L.

5., according to claim 4 for the preparation method of the adsorbent of dephosphorization and heavy metal ion, it is characterized in that described alkali lye is sodium carbonate liquor or sodium hydroxide solution.

6. according to claim 1 or 2 for the preparation method of the adsorbent of dephosphorization and heavy metal ion, it is characterized in that described water-soluble molysite is iron chloride, ferric nitrate or ferric sulfate.

7., according to claim 3 for the preparation method of the adsorbent of dephosphorization and heavy metal ion, it is characterized in that described water-soluble molysite is iron chloride, ferric nitrate or ferric sulfate.

8., according to claim 4 for the preparation method of the adsorbent of dephosphorization and heavy metal ion, it is characterized in that described water-soluble molysite is iron chloride, ferric nitrate or ferric sulfate.

9. according to claim 1 or 2 for the preparation method of the adsorbent of dephosphorization and heavy metal ion, it is characterized in that the drying process of described lithium silica flour is at 105 ~ 110 DEG C of drying 3 ~ 5h by lithium silica flour.

10. the adsorbent for dephosphorization and heavy metal ion that in claim 1 to 9 prepared by method described in arbitrary claim.