Load type composite material, preparation method, application and ecological water regulating agent thereof

Abstract

The application discloses a kind of supported composite material and its preparation method, application and ecological water regulating agent, the composite material includes PAC and FeOCl and PAM loaded on the PAC, wherein, the mass of PAM is 0.8~1% of total weight, and the mass ratio of PAC, FeOCl is between 20:1~25:1.The method specifically includes: step one, FeOCl is synthesized by hydrothermal method;Step two, FeOCl is assembled by simple solvent with PAM and PAC according to the above composite material ratio;Step three, the supernatant is removed by centrifugation in the suspension liquid in step two, and the initial product is obtained, and the composite material is obtained after washing and vacuum drying the initial product.The composite material prepared by the preparation method of the application can remove SS, total P and COD synergistically, is non-toxic, harmless and ecological safety, and can be used for natural water surface water quality improvement.The cost of II surface water quality is not more than 0.09 yuan / ton, and the operation is convenient and simple to use.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of water treatment composite materials, and relates to a supported composite material, a preparation method, application and ecological water conditioner thereof. BACKGROUND

[0002] Water suspended solids (SS) and total P and COD are the most critical factors causing water turbidity and water ecological degradation, severely restricting the light absorption and photosynthesis of submerged plants, and further affecting the soundness of water ecology and long-term ecological balance, and even leading to water blackening and stench. At present, there are few studies on the improvement of natural water transparency, and although many studies focus on the reduction of total P and COD, the water atmospheric reoxygenation and solar energy are not fully utilized, and more unfortunately, SS and COD cannot be removed simultaneously. In the existing coagulation technology for removing SS, the coagulant is mainly used for sewage plant process, and the ecological safety cannot be guaranteed. Therefore, it is necessary to develop a material capable of simultaneously and efficiently removing SS, total N, P and COD in water. SUMMARY

[0003] Therefore, the present application provides a supported composite material, a preparation method, application and ecological water conditioner thereof, which can simultaneously and efficiently remove SS, total P and COD in water. The PAC composite material loaded with FeOCl and PAM has the advantages of large specific surface area, good chemical stability, high ecological safety, large adsorption and net trapping capacity, and easy separation from solution. The coagulation effect and net trapping effect of PAM and PAC are utilized to remove the suspended characteristics of SS and total P in water, and convert them from thermodynamic metastable state to thermodynamic unstable state, so as to be settled. At the same time, the adsorption and activation of water dissolved oxygen by the metal Fe ion center are utilized, and under the trigger of natural light, the oxygen is converted from ground state to excited state to derive superoxide free radical active oxygen species, so as to realize the oxidation of total N and the mineralization of organic pollutants. Finally, the water quality is improved and the transparency is increased, the landscape sense is improved, and the light path is increased, so as to be beneficial to the growth of submerged plants and the repair of water ecology.

[0004] To solve the above technical problems, the technical scheme adopted by the present application is as follows:

[0005] A PAC composite material loaded with PAM and FeOCl, wherein the mass of PAM is about 0.8-1% of the total weight, and the mass ratio of PAC to FeOCl is 20:1-25:1. The preparation method of the composite material comprises the following steps:

[0006] (1) synthesizing FeOCl by a hydrothermal method;

[0007] (2) loading FeOCl and PAM on PAC:

[0008] Specifically, a required amount of Fe(NO3)3*5H2O is dissolved in a sufficient amount of water to obtain an initial solution, the pH of the initial solution is adjusted to 2-3, and the initial solution is fully stabilized at room temperature in an air environment; a required amount of cetyltrimethylammonium chloride (CTAC) is measured and added to the initial solution to obtain a mixed solution, and the mixed solution is continuously stirred in an air atmosphere for a certain time and then transferred to a reactor for hydrothermal reaction; a required amount of PAM and PAC is weighed and dissolved in water, and then introduced into the reactor together with the prepared FeOCl for solvothermal reaction in ethylene glycol as a medium solvent.

[0009] (3) The supernatant is removed from the suspension in step (2) by centrifugation to obtain an initial product, and the initial product is washed and then vacuum dried to obtain a PAM-FeOCl@PAC composite material.

[0010] In step (1), the hydrothermal synthesis of TNTs is as follows: 0.9g of Fe(NO3)3*5H2O is added to 60mL of a 1.0mol / L HCl solution, and CTAC is added and mixed uniformly before hydrothermal reaction, the white solid generated after the reaction is first washed, then dispersed with anhydrous ethanol, and finally dried to obtain FeOCl.

[0011] The temperature of the hydrothermal reaction is 120℃, and the time of the hydrothermal reaction is 7.2h.

[0012] The solvothermal temperature is 105℃, and the drying time is 4.5h.

[0013] The above composite material is applied to in-situ removal of SS, total P and COD in natural surface water bodies.

[0014] An ecological water regulating agent comprises the supported composite material as described above.

[0015] The composite material prepared by the method of the application is used under conventional atmospheric environmental conditions, and the composite material (PAM-FeOCl@PAC) is suitable for a concentration of 5-10mg / L in the aqueous phase for removal of suspended particulate matter, total P and dissolved organic matter in water bodies, and the removal reaction time is 240min.

[0016] Through the above specific reaction conditions, the composite material with low crystallinity is prepared, and the loading of FeOCl and PAM realizes the strengthening of synergistic effect. 3+ , Fe-O -The groups, -NH2 groups and the like promote the adsorption of the composite material to water pollutants through van der Waals force, Lewis acid-base interaction, electrostatic interaction and hydrogen bonding, and then the pollutants are quickly settled by coagulation using PAC and the auxiliary effect of PAM.

[0017] In addition, there is a strong synergistic effect between the heterogeneous metal nodes in the composite material: the introduction of FeOCl induces the composite material to have an expanded specific surface area, excellent optical and electrical properties under the condition of low crystallinity, and the ability to generate active oxygen species such as hydroxyl radicals, superoxide radicals and photo-generated holes using water-sorbed dissolved oxygen as energy. The derived active oxygen species have extremely strong oxidizing properties, and can directly oxidize and mineralize part of the dissolved organic pollutants in the water into H2O and CO2, thereby improving water transparency and achieving water purification. Moreover, FeOCl has magnetism, which is helpful for recycling the composite material after use.

[0018] Finally, zebrafish embryo development experiments, zebrafish larva movement behavior experiments and natural water purification experiments were carried out, and the results showed that the use of the material does not affect the physiological activities of animals and plants in the water, and it is confirmed that the present application is an ecologically safe water conditioner.

[0019] In summary, compared with the prior art, the present application has the following significant effects:

[0020] The method of the present application is simple, the preparation cost is low, and the prepared composite material has the advantages of large specific surface area, good chemical stability, high ecological safety, strong adsorption performance and easy separation from solution.

[0021] Firstly, PAC can remove suspended solids and organic pollutants in water through adsorption. FeOCl, as a highly efficient oxidant, can oxidize organic matter and color that is difficult to be treated by coagulants and flocculants. When PAC is combined with FeOCl, FeOCl can oxidize some organic pollutants that are difficult to be adsorbed by PAC through oxidation reaction, thereby improving the adsorption effect and achieving better pollutant removal effect.

[0022] Secondly, PAC is a commonly used coagulant that can aggregate suspended solids and colloidal particles by forming precipitates, thereby achieving solid-liquid separation. PAM, as a high molecular flocculant, can aggregate small suspended particles in water into large flocculation bodies, thereby improving the effect of coagulants. When PAC and PAM are combined with FeOCl, PAC and PAM can aggregate suspended particles and colloidal particles in water into larger flocculation bodies, and FeOCl can oxidize organic matter and color that is difficult to be treated by coagulants and flocculants, thereby improving the effect of coagulation and flocculation and achieving better suspended solids removal effect.

[0023] Finally, both PAC and PAM have adsorption effect, which can adsorb pollutants in water on the surface or internal pores of the material. At the same time, PAM can adsorb small particles of flocculation together to form larger particles. When PAC and PAM are compounded with FeOCl, FeOCl can oxidize organic pollutants that are difficult to be treated by PAC and PAM, improve the effect of adsorption and flocculation, and thus achieve better pollutant removal effect.

[0024] In summary, the use of FeOCl, polyaluminum chloride and polyacrylamide in combination can achieve synergistic effect, improve water treatment effect, and thus achieve better water quality purification effect.

[0025] It can effectively adsorb pollutants in water, capture SS and P-containing substances by means of coagulation and net capture effect of PAC, and realize rapid production of alum flowers by using the auxiliary effect of PAM, so as to quickly settle to the bottom of water body. At the same time, the composite material can produce free radical substances with strong oxidizing property, which can completely degrade part of the adsorbed soluble organic matter into H2O and CO2. The composite material can effectively remove SS, P-containing substances and organic pollutants in water, achieve the goal of improving water transparency while purifying water quality. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 Zebrafish embryo development observation results under stress of the composite material PAM-FeOCl@PAC prepared by the present application;

[0027] Figure 2 Zebrafish larva movement behavior observation results under stress of the composite material PAM-FeOCl@PAC of the present application;

[0028] Figure 3 Turbidity comparison effect diagram before and after treatment of the composite material PAM-FeOCl@PAC of the present application on polluted water body;

[0029] Figure 4 Submerged plant growth comparison diagram before and after treatment of the composite material PAM-FeOCl@PAC of the present application on water body. DETAILED DESCRIPTION

[0030] The technical solutions of the present application are further described below in combination with the drawings, but the scope of protection claimed by the present application is not limited thereto.

[0031] Example 1

[0032] The present application provides a preparation method of a composite material (FeOCl-PAM@PAC) of PAC loaded with PAM and FeOCl, which comprises the following steps:

[0033] Step 1, synthesizing FeOCl by mild hydrothermal method;

[0034] Specifically, 0.9 g of Fe(NO3)3·5H2O was added to 60 mL of HCl solution with a concentration of 1.0 mol / L, 4.8 mL of CTAC was measured and added to the mixed solution, and the mixture was stirred at room temperature with a magnetic stirrer for 2 h until it was uniformly mixed; the mixed solution was transferred to a polytetrafluoroethylene-lined stainless steel reaction kettle (the effective volume of the reaction kettle was 100 mL), and hydrothermal reaction was carried out at 120°C for 7.2 h; after the reaction, the generated white solid was washed with deionized water until the supernatant was neutral, then dispersed with anhydrous ethanol, and dried at 80°C for 4 h to obtain FeOCl.

[0035] Step 2, FeOCl and PAM (polyacrylamide) were loaded on PAC (polyaluminum chloride);

[0036] Specifically, 0.02 g of PAM, 0.02 g of FeOCl and 1.96 g of PAC were added to 50 mL of deionized water, dispersed with 10 mL of ethylene glycol, and naturally pH-adjusted, and then magnetically stirred for 2 h or more, and then transferred into a polytetrafluoroethylene-lined stainless steel reaction kettle with an effective volume of 100 mL, and placed in a constant temperature oven set at 105°C for solvothermal reaction for 4.5 h, and then naturally cooled. After cooling, the supernatant was removed by centrifugation to obtain the initial product, which was washed with anhydrous ethanol for 1-2 times, and then vacuum dried to obtain 1-FeOCl-PAM@PAC composite material.

[0037] Example 2

[0038] Different from Example 1, in Step 2, 0.08 g of FeOCl was used, and finally 2-FeOCl-PAM@PAC powder was obtained.

[0039] Example 3

[0040] Different from Example 1, in Step 2, 2.96 g of PAC was used, and finally 3-FeOCl-PAM@PAC powder was obtained.

[0041] Example 4

[0042] Different from Example 2, in Step 2, 0.1 g of PAM, 0.4 g of FeOCl and 9.8 g of PAC were used, and finally 2-FeOCl-PAM@PAC powder was obtained.

[0043] The effects of the composite materials prepared in Examples 1-4 on the synergistic removal of SS, total P and COD in water were compared.

[0044] Take 3 groups of initial turbidity of 93 NTU (measured, WZS186 turbidity detector), total P of 1.35 mg / L (measured, ammonium molybdate spectrophotometry, GB / T 11893-1989), COD initial concentration of 62.5 mg / L (measured, chromium method, G70Pro detector) of 100 mL of water sample, respectively into the conical flask with plug, each group of water sample respectively add equal amount (4 ppm, calculated amount) of composite material (FeOCl-PAM@PAC) prepared by examples 1-4, the three groups of conical flask with plug are placed in constant temperature oscillator at 25℃ for 240 min, then take the supernatant directly to measure the concentration of SS, total P and COD. According to the formula R = (C0-C e ) / C0 to calculate the removal rate; wherein, in the formula: R is the removal rate (%), C0 is the initial concentration of each solution (NTU, mg / L), C e is the concentration of each substance after reaction (NTU, mg / L); the results are shown in tables 1-3;

[0045] Table 1-removal of SS in water

[0046]

[0047] Table 2-removal of total P in water

[0048]

[0049]

[0050] Table 3-removal of SS in water

[0051]

[0052] From tables 1-3, it can be concluded that the 2-FeOCl-PAM@PAC composite material obtained in example 2 has the best removal ability for SS, total P and COD. The material in example 1 has a small amount of FeOCl, so its oxidation effect is weak: the main role of FeOCl is to oxidize and decompose organic matter in wastewater to reduce the content of COD. When the proportion of FeOCl is low, the ability to oxidize and decompose organic matter in wastewater will be weakened, resulting in a decrease in treatment effect. Secondly, when the proportion of FeOCl is low, it may cause excessive flocculation of PAC, increasing the difficulty of subsequent treatment.

[0053] For the material of Example 3, firstly, the excess PAC can excessively adsorb organic matter and other pollutants in the sewage, leading to a decline in treatment effect. Because the adsorption capacity of PAC is limited, if PAC is excessive, it will occupy the limited adsorption sites, leading to the failure of other agents to fully play their roles. Secondly, the use amount of PAC directly affects the cost of sewage treatment. When the proportion of PAC is too high, the treatment cost will increase, and excessive use will waste reagent resources and increase the subsequent treatment cost. Finally, the excess PAC can cause some organic matter and other pollutants to be incompletely adsorbed in PAC, resulting in the generation of residual pollutants. These residual pollutants can be re-released in the subsequent treatment process, reducing the effect of sewage treatment.

[0054] Therefore, the best synthesis condition of the composite material in this study is Example 2. The FeOCl-PAM@PAC composite material obtained in Example 2 has a synergistic removal capacity for SS, total P and COD. The turbidity after treatment under natural conditions without any external factors is close to that of tap water, the total P removal can reach about 80%, and the total COD removal can reach about 70%. And the performance of the material synthesized on a larger scale does not decrease but increases, which provides a reliable basis for large-scale industrial production.

[0055] Figure 1 The ecological safety performance evaluation of the composite material using zebrafish embryos (7 days of age) and juvenile fish (2.5 cm) showed that it was ecologically safe and non-toxic. The above composite material was used in situ in natural water bodies and black and odorous water bodies, and the water quality treatment effect comparison showed that the improvement effect was significant. Figures 3-4 As shown, the improvement effect is significant. The comparison of the growth of submerged plants in the improved water body and the in-situ water body shows that the improvement of water quality has a significant promoting effect. Table 4 is the application effect of the loaded composite material in each attribution.

[0056] Table 4-Application effect in natural water body

[0057]

[0058]

[0059] The above description and the description of the embodiments are for the convenience of the ordinary skilled person in the art to understand and apply the present application. Those skilled in the art can easily make various modifications to these contents, and apply the general principles described herein to other embodiments without creative labor. Therefore, the present application is not limited to the above description and the description of the embodiments, and the improvements and modifications made by those skilled in the art within the scope of the present application without departing from the scope of the present application should be within the protection scope of the present application.

Claims

1. A supported composite material, characterized by: The carrier comprises PAC, and the FeOCl and PAM are loaded on the carrier, wherein the mass of the PAM is 0.8-1% of the total weight, and the mass ratio of the PAC to the FeOCl is 20:1-25:

1. The preparation method comprises the following steps: Step (1): synthesizing FeOCl by a hydrothermal method: a required amount of Fe(NO3)3 is added into water to obtain an initial solution, the pH of the initial solution is adjusted to 2-3 and is left for a period of time; a required amount of cetyltrimethylammonium chloride is weighed and added into the initial solution to obtain a mixed solution; the mixed solution is stirred by a magnetic stirrer for a certain period of time, is transferred to a reaction kettle and is left in a blast drying oven, and FeOCl is obtained by controlling the reaction temperature and time; Step (2): loading FeOCl and PAM on PAC by a solvothermal method: the obtained solid FeOCl, PAM and PAC are added into an alcohol solution, are fully stirred by a magnetic stirrer, are transferred to a reaction kettle, and are reacted at a certain temperature to obtain a suspension; the alcohol solution is an ethylene glycol solution, a propylene glycol solution or a polyethylene glycol solution; Step (3): the suspension in step (2) is centrifuged to remove supernatant, and an initial product is obtained; the initial product is washed and is vacuum dried to obtain a composite material.

2. The supported composite material of claim 1, wherein: In step (1), the FeOCl is synthesized by a hydrothermal method, and the specific process is as follows: 0.9 g of Fe(NO3)3 is added into 60 mL of a HCl solution with a concentration of 1.0 mol / L, 4.8 mL of cetyltrimethylammonium chloride is further added, the mixture is shaken and mixed uniformly, and a hydrothermal reaction is performed; the white solid generated after the reaction is washed, is dispersed by using anhydrous ethanol, and is finally dried to obtain FeOCl.

3. The supported composite of claim 1, wherein: The hydrothermal reaction is performed at a constant temperature of 110-130 °C for 6-8 h, and the solvothermal reaction is performed at a constant temperature of 100-130 °C for 4-5 h.

4. The supported composite of claim 1, wherein: In step (3), the drying temperature is 80 °C, and the drying time is 12 h.

5. An application of the supported composite material in claim 1 in removing SS, total P and COD in a water body.

6. An ecological water conditioner characterized by, The supported composite material in claim 1 is contained.

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