TW202302818A - Metal removal agent and soil treatment method - Google Patents

Abstract

A metal removal agent and a soil treatment method are described. The metal removal agent includes 30 to 45 parts by weight of magnesium oxide, wherein the magnesium oxide has a porous structure; 8 to 12 parts by weight of emulsifier; 8 to 12 parts by weight of alkyl glycoside; 8 to 12 parts by weight of fatty alcohol polyoxyethylene; and 35 to 45 parts by weight of water.

Description

Metal removal agent and soil remediation method

The invention relates to a removing agent and a soil conditioning method, in particular to a metal removing agent and a soil conditioning method.

In the era of industrialization, a lot of industrial pollution is often discharged into nature, for example, the soil may be polluted by various metal wastes.

In order to solve the above pollution problems, there are currently many overcoming solutions, such as on-site stabilization technology, adding specific additives to the polluted medium to reduce the toxicity and dissolution mobility of harmful components in chemical or physical ways. The most commonly used method is to reduce the impact on the environment due to percolation by reducing the solubility of harmful substances.

However, existing additives are still insufficient to address metal-contaminated sites. Therefore, it is necessary to provide a remediation method for applying a metal removing agent to soil and groundwater.

One object of the present invention is to provide a metal removal agent applied to the soil and groundwater remediation method, which achieves rapid spreading between the sand particles and pores around the drug injection well by using a specific composition, and also through the plant type Interface agent (such as fatty alcohol polyoxyethylene ether (AEO)), emulsifier (such as Span 20 (span 20), Span 40 (span 40), Span 60 (span 60), Span 80 (span 80) , Tween 20 (tween 20), Tween 40 (tween 40), Tween 60 (tween 60) and Tween 80 (tween 80) at least one) and alkyl glycoside (APG) series to have good diffusion and biodegradable properties. Therefore, it can effectively disperse the mineral powder to the pollution remediation area, and use it to adsorb heavy metals such as fluoride salt, arsenic, lead, etc. in the groundwater polluted site, and remove the heavy metal in the water through the (nano) mineral powder, which is beneficial to the application of the agent in the soil groundwater China Transmission has the advantage of reducing labor management costs.

To achieve the above object, the present invention provides a metal removal agent, comprising: 30 to 45 parts by weight of magnesium oxide, wherein magnesium oxide has a porous structure; 8 to 12 parts by weight of an emulsifier; 8 to 12 parts by weight of an alkyl glycoside; 8 to 12 parts by weight of fatty alcohol polyoxyethylene; and 35 to 45 parts by weight of water.

In an embodiment of the present invention, the metal removing agent further includes 0.5 to 1.0 parts by weight of trace elements.

In one embodiment of the present invention, the trace elements include vitamin B group.

In an embodiment of the present invention, the emulsifier includes at least one of Span 20 , Span 40 , Span 60 , Span 80 , Tween 20 , Tween 40 , Tween 60 and Tween 80 .

In an embodiment of the present invention, the metal removing agent further includes 0.01 to 0.015 parts by weight of lecithin.

In an embodiment of the present invention, the metal removing agent further includes 0.005 to 0.01 parts by weight of carboxymethyl cellulose.

To achieve the above object, the present invention provides a method of soil remediation, comprising the steps of: providing the metal-removing agent of any one of the above-mentioned embodiments; and injecting the metal-removing agent into a soil to be remediated.

In one embodiment of the present invention, the step of providing the metal removing agent comprises: mixing 30 to 45 parts by weight of magnesium oxide, 8 to 12 parts by weight of emulsifier, 8 to 12 parts by weight of alkyl glycoside, 8 to 12 parts by weight Parts by weight of fatty alcohol polyoxyethylene and 35 to 45 parts by weight of water to form a first mixed solution; and uniformly mixing the first mixed solution at a speed of 1500 to 2800 RPM by a homogenizing device to obtain a first mixed solution homogeneous liquid.

In one embodiment of the present invention, the step of providing the metal removing agent further comprises: mixing 0.01 to 0.015 parts by weight of lecithin, 0.005 to 0.01 parts by weight of carboxymethyl cellulose, and 0.45 to 0.55 parts by weight of water, to forming a second mixed liquid; uniformly mixing the second mixed liquid with a rotation speed of 11000 to 13000 RPM by the homogenizing device to form a second homogeneous liquid; and mixing the second homogeneous liquid with the first homogeneous liquid to obtain the Metal remover.

In an embodiment of the present invention, the porous structure of magnesium oxide is formed by reacting sodium carbonate solution and magnesium oxide solution to produce magnesium oxide precursor, and calcining the magnesium oxide precursor at 450-500°C.

In order to make the above and other objects, features, and advantages of the present invention more comprehensible, preferred embodiments of the present invention will be exemplified below in detail together with the attached drawings. Furthermore, the directional terms mentioned in the present invention are, for example, up, down, top, bottom, front, back, left, right, inside, outside, side, surrounding, central, horizontal, transverse, vertical, longitudinal, axial, The radial direction, the uppermost layer or the lowermost layer, etc. are only directions referring to the attached drawings. Therefore, the directional terms used are used to illustrate and understand the present invention, but not to limit the present invention.

A metal removing agent according to an embodiment of the present invention comprises: 30 to 45 parts by weight of magnesium oxide, wherein the magnesium oxide has a porous structure; 8 to 12 parts by weight of an emulsifier; 8 to 12 parts by weight of an alkyl glycoside; 8 to 12 parts by weight Fatty alcohol polyoxyethylene in parts by weight; and 35 to 45 parts by weight of water. In one embodiment, the magnesium oxide may be nano-structured (for example, the average particle diameter is between 35 nm and 150 nm). The magnesium oxide, as a nano-mineral powder, can be used to remove heavy metals in water, facilitates the transport of pharmaceuticals in soil and groundwater, and has the advantage of reducing labor management costs. In one embodiment, magnesium oxide may be 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43 or 44 parts by weight.

In one embodiment, the emulsifier comprises Span 20 (span 20), Span 40 (span 40), Span 60 (span 60), Span 80 (span 80), Tween 20 (tween 20), At least one of Tween 40 (tween 40), Tween 60 (tween 60) and Tween 80 (tween 80). In a specific example, the emulsifier has good diffusion and biodegradation properties, can effectively disperse mineral powder to the pollution remediation area, and is used to adsorb heavy metals (such as fluoride salts, arsenic, lead, etc.) in groundwater pollution sites. In one embodiment, the emulsifier may be, for example, 8.5, 9, 9.5, 10, 10.5, 11 or 11.5 parts by weight.

In another embodiment, fatty alcohol polyoxyethylene ether (AEO) is a plant-based interface agent, which has good diffusion and biodegradation characteristics, can effectively disperse mineral powder to the pollution remediation area, and is used to adsorb the groundwater pollution site Heavy metals (such as fluoride salts, arsenic, lead, etc.). In one embodiment, the fatty alcohol polyoxyethylene ether can be, for example, 8.5, 9, 9.5, 10, 10.5, 11 or 11.5 parts by weight.

In yet another embodiment, the alkyl glycoside (APG) has good diffusion and biodegradation characteristics, can effectively disperse the mineral powder to the pollution remediation area, and is used to adsorb heavy metals (such as fluoride salts, arsenic, lead, etc.) etc). In one embodiment, the amount of alkyl glycoside may be 8.5, 9, 9.5, 10, 10.5, 11 or 11.5 parts by weight.

In one embodiment, water acts primarily as a solvent for the metal-removing agent. In another embodiment, water may be, for example, 36, 37, 38, 39, 40, 41, 42, 43 or 44 parts by weight.

It can be seen from the above that the present invention at least utilizes emulsifiers, alkyl glycosides and/or fatty alcohol polyoxyethylene to effectively disperse the mineral powder to the pollution remediation area, and to adsorb heavy metals in groundwater pollution sites, and through the porous structure Magnesium oxide to deal with heavy metals.

In one embodiment, the metal removing agent according to the embodiment of the present invention may further contain 0.5 to 1.0 parts by weight of trace elements, which may be used as micronutrients to provide microorganisms in the soil to be treated. In a specific example, the trace elements include vitamin B group.

In one embodiment, the metal removing agent according to the embodiment of the present invention may further comprise 0.01 to 0.015 parts by weight of lecithin, which may be used as a surfactant.

In one embodiment, the metal removing agent according to the embodiment of the present invention may further comprise 0.005 to 0.01 parts by weight of carboxymethyl cellulose. The presence of carboxymethyl cellulose can make the metal removing agent of the embodiment of the present invention have latex-like high polymerization characteristics, and effectively diffuse the drug to the pollution remediation area.

On the other hand, the metal removing agent of the present invention basically consists of specific weight parts of magnesium oxide, emulsifiers, alkyl glycosides, fatty alcohol polyoxyethylene and water (optionally, can also include specific weight parts of trace elements and /or lecithin and/or carboxymethylcellulose).

It should be mentioned that the metal removing agent of the embodiment of the present invention is at least based on nano-magnesium with a porous structure to treat heavy metals in soil, and also achieves diffusion and biodegradation effects through other components.

In addition, it should be mentioned that the metal removal agent of the embodiment of the present invention can simultaneously treat multiple types of heavy metals by including at least specific weight parts of magnesium oxide, emulsifier, alkyl glycoside, fatty alcohol polyoxyethylene and water. Contaminated soil (such as fluoride salts, arsenic, lead, etc.).

Please refer to Fig. 1, the soil remediation method 10 of an embodiment of the present invention, mainly comprises following steps 11 to 12: provide the metal removal agent of any embodiment of the present invention (step 11); And inject this metal removal agent to In the soil to be treated (step 12).

In one embodiment, the step of providing the metal removing agent comprises: mixing 30 to 45 parts by weight of magnesium oxide, 8 to 12 parts by weight of emulsifier, 8 to 12 parts by weight of alkyl glycoside, 8 to 12 parts by weight Fatty alcohol polyoxyethylene and 35 to 45 parts by weight of water to form a first mixed solution; and uniformly mix the first mixed solution at a speed of 1500 to 2800 RPM by a homogenizing device (such as a commercially available homogenizer) , to obtain a first homogeneous solution. In one example, the first homogeneous liquid may be a metal-removing agent.

In another embodiment, the step of providing the metal removing agent further comprises: mixing 0.01 to 0.015 parts by weight of lecithin, 0.005 to 0.01 parts by weight of carboxymethyl cellulose, and 0.45 to 0.55 parts by weight of water to form A second mixed liquid; uniformly mix the second mixed liquid with a rotation speed of 11000 to 13000 RPM by the homogenizing device to form a second homogeneous liquid; and mix the second homogeneous liquid with the first homogeneous liquid to obtain the metal Remover. In other words, the step of providing the metal-removing agent may be provided by mixing the first homogeneous liquid with the second homogeneous liquid. However, it should be mentioned that, in some cases, lecithin and carboxymethyl cellulose can also be directly added to the first mixed solution and then uniformly mixed with a homogenizing device.

In one embodiment, the porous structure of magnesium oxide is formed by reacting sodium carbonate solution and magnesium oxide solution to produce magnesium oxide precursor, and calcining the magnesium oxide precursor at 450-500°C. Specifically, magnesium oxide (MgO) with a porous structure is prepared by a chemical precipitation method. In a specific example, the overall reaction can be carried out at room temperature (e.g., 25-30°C), and about 100 mL of 1 M sodium carbonate solution is slowly added to about 80 mL of 1 M MgO to produce a white precipitate (i.e. MgO precursor), and then through high temperature calcination at 450~500℃ to synthesize porous structure MgO. In one example, the MgO material is rich in porous structure material (about 65-75%) and powder with nanometer particle size (about 25-35%).

An example is given below to illustrate that the metal removing agent of the embodiment of the present invention can indeed treat heavy metals in soil.

Example 1

First, the metal removal agent of the embodiment of the present invention is provided, for example, mixing 30 to 45 parts by weight of magnesium oxide, 8 to 12 parts by weight of emulsifier, 8 to 12 parts by weight of alkyl glycoside, and 8 to 12 parts by weight of fat Alcohol polyoxyethylene and 35 to 45 parts by weight of water to form a first mixed solution (optionally add 0.5 to 1.0 parts by weight of trace elements (such as including vitamin B group). It should be mentioned that magnesium oxide has a porous Structure, the porous structure of magnesium oxide is formed, for example, by reacting sodium carbonate solution and magnesium oxide solution to produce a magnesium oxide precursor, and calcining the magnesium oxide precursor at about 450°C.

Afterwards, the first mixed liquid is uniformly mixed by a homogenizing device at a rotational speed of 1500 to 2800 RPM to obtain a first homogeneous liquid. Next, mix 0.01 to 0.015 parts by weight of lecithin, 0.005 to 0.01 parts by weight of carboxymethyl cellulose and 0.45 to 0.55 parts by weight of water to form a second mixed liquid; Mix the second mixed liquid uniformly at a rotating speed to form a second homogeneous liquid; and mix the second homogeneous liquid with the first homogeneous liquid to obtain the metal removing agent of Example 1.

Example 2

The preparation method of Example 2 is substantially the same as that of Example 1, except that the porous structure of the magnesium oxide is formed by calcining the magnesium oxide precursor at about 500°C.

Afterwards, the metal-removing agents of Examples 1 and 2 were respectively injected into a soil to be treated, and the concentration changes of each metal were measured by commercially available instruments. The analysis results are as follows:

First of all, no matter it is embodiment 1 or 2, under the situation that the dosage is 0.2g/L to 1.0g/L, all can reduce the concentration of arsenic from 0.8 mg/L to <0.01mg/L (the first control standard 0.05 mg/L).

On the other hand, no matter it is Example 1 or 2, it has a good fluoride salt removal effect (between 80-99%) in different acid-base water (pH 2-10), and the removal effect is not easily affected by the coexistence of anions in water. According to the results of the field model field, Example 1 or 2 has the characteristics of high transmission, and the removal effect can be achieved through the diffusion of water into the pores of the soil and the reaction of pollutants in a short period of time. According to the results of dosing at sites affected by fluoride salts (the concentration of fluoride salts is between 7.0 and 10.0 mg/L), it is known that the concentration of fluoride salts in water can be controlled within the monitoring standard (4.0 mg/L L) or less, and the efficacy can be maintained for more than 1 to 2 months after infusion. Therefore, using Example 1 or 2 to remediate groundwater fluoride salt pollution will not cause secondary pollution and is applicable to most environmental conditions. The remediation process can also achieve the purpose of pollution control through the slow release and immediate effect of the material. , does have market application potential.

On the other hand, the groundwater contaminated by lead was actually tested in the polluted site, and Example 1 or 2 (about 1% (w/w)) was added for benefit verification. The initial concentration of lead pollution in groundwater was 0.824 mg/L (about 8 to 10 times higher than the control standard value), and the pH value was 3.3 to 3.5. After one month of reaction, the lead concentration dropped rapidly to 0.007 to 0.008 (pH 8.0), obviously Lower than the groundwater monitoring standard value (0.05mg/L). Since the removal of metals in water by Example 1 or 2 has strong affinity and adsorption, there is no sign of re-release of lead pollution in groundwater.

On the other hand, comparing Example 1 and Example 2 in detail with the removal of lead ions in water, Example 2 has a higher efficiency than Example 1. For example, when the lead water taken on site is reacted, the reaction time is 15 minutes, the oscillation frequency is 100rpm, the dosage is 0.5g/L, and the water sample volume is 50mL, the concentration of lead ion in the water is originally 0.446mg/L. Example 1 and measured after 15 minutes can obtain lead ion concentration to drop to 0.091 mg/L (about 79.5%), add embodiment 2 and can obtain lead ion concentration to drop to 0.043 mg/L (about 79.5%) after 15 minutes. removed 90.3%). In addition, if the waiting time is lengthened, add Example 1 and measure after 12 hours to obtain lead ion concentration down to 0.055 mg/L (approximately remove 87.6%), add Example 2 and measure after 12 hours to obtain lead The ion concentration dropped to 0.039 mg/L (about 91.2% removed).

In addition, compared with the 10ppm lead ion solution under the above-mentioned similar conditions, Example 2 also has a higher efficiency than Example 1. For example, the lead ion solution of 10ppm is reacted, the reaction time is 15 minutes, the oscillation frequency is 100rpm, the dosage is 0.5g/L, and the water sample volume is 50mL, the lead ion concentration in the water is 10.308 mg/L. 1 and measure after 15 minutes and can obtain lead ion concentration and drop to 4.418 mg/L (approximately remove 57.1%), add embodiment 2 and measure after 15 minutes and can obtain lead ion concentration and drop to 1.157 mg/L (approximately remove except 88.8%). In addition, if the waiting time is lengthened, add Example 1 and measure after 12 hours to obtain lead ion concentration down to 1.111 mg/L (about 89.2% removed), add Example 2 and measure after 12 hours to obtain lead The ion concentration dropped to 0.414 mg/L (about 96.0% removed).

It can be seen from the above that Examples 1 and 2 of the present invention can effectively disperse the mineral powder to the pollution remediation area, and use it to adsorb heavy metals such as fluoride salt, arsenic, lead, etc. in the groundwater pollution site, and remove them through (nano) mineral powder Heavy metals in water, which are beneficial to the transport of pharmaceuticals in soil and groundwater and have the advantage of reducing labor management costs.

Although the present invention has been disclosed with preferred embodiments, it is not intended to limit the present invention. Anyone skilled in this art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the present invention The scope of protection shall be determined by the scope of the attached patent application.

10: method 11~12: Steps

Fig. 1 is a schematic flow chart of a soil remediation method according to an embodiment of the present invention.

10: method

11~12: Steps

Claims (10)

A metal remover comprising: 30 to 45 parts by weight of magnesium oxide, wherein magnesium oxide has a porous structure; 8 to 12 parts by weight of emulsifier; 8 to 12 parts by weight of alkyl glycosides; 8 to 12 parts by weight of fatty alcohol polyoxyethylene; and 35 to 45 parts by weight of water. The metal removing agent according to claim 1 further comprises 0.5 to 1.0 parts by weight of trace elements. The metal removing agent as described in claim 2, wherein the trace element comprises vitamin B group. The metal removing agent as described in claim 1, wherein the emulsifier comprises Span 20, Span 40, Span 60, Span 80, Tween 20, Tween 40, Tween 60 and Tween 80 at least one. The metal removing agent according to claim 1, further comprising 0.01 to 0.015 parts by weight of lecithin. The metal removing agent according to claim 1, further comprising 0.005 to 0.01 parts by weight of carboxymethyl cellulose. A soil remediation method comprising the steps of: Provide the metal removal agent as described in Claim 1; and Inject the metal remover into a soil to be treated. The soil remediation method as described in claim item 7, wherein the step of providing the metal removal agent comprises: Mix 30 to 45 parts by weight of magnesium oxide, 8 to 12 parts by weight of emulsifier, 8 to 12 parts by weight of alkyl glucoside, 8 to 12 parts by weight of fatty alcohol polyoxyethylene and 35 to 45 parts by weight of water, to forming a first mixture; and The first mixed liquid is uniformly mixed by a homogenizing device at a rotational speed of 1500 to 2800 RPM to obtain a first homogeneous liquid. The soil remediation method as described in claim item 8, wherein the step of providing the metal removal agent also includes: mixing 0.01 to 0.015 parts by weight of lecithin, 0.005 to 0.01 parts by weight of carboxymethyl cellulose and 0.45 to 0.55 parts by weight of water to form a second mixed solution; uniformly mixing the second mixed liquid at a rotational speed of 11000 to 13000 RPM by the homogenizing device to form a second homogeneous liquid; and mixing the second homogeneous liquid and the first homogeneous liquid to obtain the metal-removing agent. The soil remediation method as claimed in item 7, wherein the porous structure of magnesium oxide is formed by reacting sodium carbonate solution and magnesium oxide solution to produce magnesium oxide precursor, and calcining the magnesium oxide precursor at 450 to 500°C.

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