TWI616409B - Emulsive composition and method of preparing the same - Google Patents

Abstract

The present invention provides a latex composition comprising a vegetable oil, a biodegradable surfactant, an acid-base buffer, and the balance water. The biodegradable surfactant comprises lecithin and the biodegradable surfactant is from 4.5 to 10.1% by weight of the latex composition. Further, the present invention also provides a method for producing a latex composition which is subjected to an emulsification by ultrasonic waves so that the latex composition has an average emulsified particle diameter of 0.2 to 0.5 μm.

Description

Latex composition and method of producing the same

The present invention relates to a latex composition and a method of producing the same, and more particularly to a latex composition for use in the treatment of chlorine-containing organic matter contamination and a method of producing the same.

The prevention and control of soil and groundwater pollution is an extremely important part in the sustainable development and utilization of environmental resources. When the environment is polluted and continues to expand, it will endanger the environment in which we live and even destroy the natural ecology. In recent years, due to the rapid development of industry, chlorinated aliphatic hydrocarbons (CAHs) have high solubility, low flammability, low boiling point and high vapor pressure. Therefore, they are widely used in industrial metals. And the cleaning, degreasing, surface adhesion and dry cleaning of electronic parts, and because of its higher specific gravity than water, the solubility is also low, also known as dense non-aqueous phase liquid (DNAPL), of which three Trichloroethylene (TCE) and terachloroethylene (PCE) are the most common, causing serious pollution of soil water and difficulty in remediation. This is the goal of continuous research in many studies in recent years.

Under the principle of green remediation, the investigation and remediation planning of polluted sites must have different thinking from the traditional. It is very common for domestic and foreign scholars to use anaerobic bioremediation to treat contaminated sites. As a priority for remediation, rejuvenation is also the goal of green remediation and environmental friendliness. Although the overall response rate of the biological rehabilitative program is low, in the long run, bioremediation is less destructive to the site and more in line with the need for "re-education." In the field application, due to the low overall reaction rate of natural attenuation, enhanced bioremediation technology has received much attention. Enhanced bioremediation is to improve and strengthen bioremediation technology, and its reaction rate is more integrated with engineering. Demand. Therefore, in order to accelerate the rate of biodegradation under appropriate conditions, most of the nutrients are added to the groundwater body to make the groundwater produce sufficient hydrogen and low molecular weight fatty acids, thereby providing carbon sources and improving the ability of anaerobic biolysis. Treatment of contaminated soil and groundwater, such nutrient sources are soluble, low viscosity, solid and diverse experimental properties.

At present, the common methods of enhancing biodegradation can be roughly divided into: (1) adding biodegradable nutrient salts or electron acceptors to the contaminated site, and activating the existing microbial population within the site; (2) directly in the contaminated site Add special strains that have the ability to decompose pollutants, or use genetic engineering techniques to develop genetically modified microorganisms with specific pollutant decomposition capabilities; (3) use biological treatment to transport pollutants to specific biological reactions after aeration or soil washing The device is either a biological filter bed or a biological washing tower to remove pollutants, or is subjected to ground cultivation or composting.

When reductive dechlorination occurs at different stages, the energy generated by the reaction may be utilized by the microorganisms and promote the efficiency of microbial growth to effectively degrade the contaminants. A number of microorganisms have been demonstrated to dechlorinate in the case of electrons, such as Dehalococcoides ethenogenes using H ₂ as an electron provider, Dehalococcoides ethenogenes and a Dehalobacter restrictus Energy can be obtained by dechlorination respiration; other methanogenic producing microorganisms, acetogenic producing microorganisms, and sulfate-reducing microorganisms can also degrade TCE by co-metabolism.

However, even if many microorganisms can dechlorinate under anaerobic conditions, the process of converting vinyl chloride (VC) into ethylene via co-metabolism during biotransformation is quite slow, and the effect is usually incomplete. Therefore, it is easy to cause accumulation of VC, and VC is a known carcinogen. For example, Dehalococcoides sp. strain FL2 in Dehalococcoides species converts dechlorination metabolism TCE into VC; in addition, strain CBDB1 (Ernest et al., 2013), strain BAV1 (Löffler et al., 2013) and strain GT (Chambonet al., 2013) All strains have been confirmed by literature to dechlorinate PCE and TCE to form VC. However, only strains belonging to Dehalococcoides ethenogenes , strain 195 , BAV1 and GT can completely dechlorinate VC to ethylene as a harmless product.

Numerous nutrient substrates have been widely used in on-site anaerobic biodegradation technologies, such as sugars (molasses), organic acids (lactate, formate, butyrate, propionate and benzoate), alcohols. (Methanol and ethanol) and yeast extracts can improve degradation efficiency. However, these nutrient matrices must have high solubility and high biodegradability, and often need to be supplemented to promote the growth of microorganisms. In addition, the nutrient matrix injected may cause problems such as groundwater blockage and acidification, and the problem of sulphate smelting caused by sulfate reduction also causes poor transmission effect of the nutrient substrate, poor groundwater quality and increased operation and maintenance costs. problem.

Therefore, it is necessary to provide a latex composition which can be used for remediation of chlorinated organic pollutants and a method for producing the same to solve the problems in the prior art.

The main object of the present invention is to provide a latex composition which can be used for the remediation of chlorinated organic contaminants such as trichloroethylene, tetrachloroethylene and the like. The latex composition has sustained release The characteristic hydrogen-releasing latex matrix can form a passive bioreactor wall with nanometer average emulsified particle size and excellent homogeneity, which can effectively and continuously degrade chlorinated organic matter in anaerobic environment and prevent remediation. The acidification of water or soil during the process makes the overall environment beneficial to biodegradation treatment and achieves the purpose of green remediation, which is very suitable for local remediation.

A secondary object of the present invention is to provide a method for producing a latex composition which can produce a latex composition having a nanometer average emulsified particle size and excellent homogeneity, has an emulsification degree of 100%, and can be prepared in a short time. .

To achieve the above object, an embodiment of the present invention provides a latex composition for rectifying a chlorine-containing organic contaminant, the latex composition comprising a vegetable oil, a biodegradable surfactant, an acid-base buffer, and the rest Is water, wherein the biodegradable surfactant comprises lecithin, and the biodegradable surfactant is 4.5 to 10.1% by weight of the latex composition.

In one embodiment of the invention, the weight ratio of the vegetable oil to the biodegradable surfactant is 1.5:1.

In one embodiment of the invention, the vegetable oil is from 9 to 18.2% by weight of the latex composition.

In one embodiment of the invention, the lecithin is from 4.5 to 9.1% by weight of the latex composition.

In one embodiment of the invention, the biodegradable surfactant further comprises a butyl cellosolve, and the butyl cellosolve is from 0 to 1% by weight of the latex composition.

In one embodiment of the invention, the acid-base buffer is from 8 to 9.5% by weight of the latex composition.

In one embodiment of the invention, the acid-base buffer is selected from the group consisting of citric acid, disodium hydrogen phosphate, or mixtures thereof.

In one embodiment of the invention, the acid-base buffer comprises citric acid and disodium hydrogen phosphate, and the weight ratio of the citric acid to the disodium hydrogen phosphate is 1:9.

In one embodiment of the invention, the acid-base buffer has a concentration of from 0.1 M to 0.2 M.

In one embodiment of the invention, the latex composition has an emulsified average particle size of from 0.2 to 0.5 microns.

Furthermore, another embodiment of the present invention provides a method of producing a latex composition comprising the steps of: mixing a vegetable oil, a biodegradable surfactant, an acid-base buffer, and water to form a mixture; The mixture is applied with ultrasonic waves to effect an emulsification to form a latex composition as described above, wherein the biodegradable surfactant comprises lecithin, and the biodegradable surfactant is 4.5 to 10.1 by weight of the mixture. %.

In an embodiment of the invention, the ultrasonic power is 10 to 60%.

In one embodiment of the invention, the ultrasound system is applied for 15 minutes.

In one embodiment of the invention, the weight ratio of the vegetable oil to the biodegradable surfactant is 1.5:1.

In one embodiment of the invention, the vegetable oil is from 9 to 18.2% by weight of the mixture.

In one embodiment of the invention, the lecithin is from 4.5 to 9.1% by weight of the mixture.

In an embodiment of the invention, the biodegradable surfactant further comprises Monobutyl cellosolve, and the butyl cellosolve is 0 to 1% by weight of the mixture.

In one embodiment of the invention, the acid-base buffer is from 8 to 9.5% by weight of the latex composition.

In one embodiment of the invention, the acid-base buffer is selected from the group consisting of citric acid, disodium hydrogen phosphate, or mixtures thereof.

In one embodiment of the invention, the acid-base buffer comprises citric acid and disodium hydrogen phosphate, and the weight ratio of the citric acid to the disodium hydrogen phosphate is 1:9.

In one embodiment of the invention, the acid-base buffer has a concentration of from 0.1 M to 0.2 M.

The above and other objects, features, and advantages of the present invention will become more apparent from The singular forms "a", "the", and "the" For example, the term "a compound" or "at least one compound" may include a plurality of compounds, including mixtures thereof; "%" as referred to in the present specification means "percent by weight (wt%)" unless otherwise specified; For example, 10%~11% of A) include upper and lower limits (ie 10% ≦A≦11%) unless otherwise specified; if the value range does not define a lower limit (such as B below 0.2%, or 0.2) B) below B) means that the lower limit may be 0 (ie 0% ≦ B ≦ 0.2%); the proportional relationship of the "weight percentage" of each component may also be replaced by the proportional relationship of "parts by weight". The above terms are used to illustrate and understand the present invention and are not intended to limit the invention.

The present invention provides a latex composition for treating chlorine-containing organic pollutants, the latex composition mainly comprising a vegetable oil, a biodegradable surfactant, an acid-base The buffering agent and the balance being water, wherein the biodegradable surfactant comprises lecithin, the lecithin being 4.5 to 9.1% by weight of the latex composition, which may be, for example, 5, 8 or 9%, preferably 8 ~9.1%. The biodegradable surfactant is 4.5 to 10.1% by weight of the latex composition, and may be, for example, 6.5, 9.1 or 10.1%, but is not limited thereto. The latex composition has an emulsified average particle diameter of 0.2 to 0.5 μm and may be, for example, 0.28, 0.35 or 0.46 μm, but is not limited thereto. Preferably, the weight ratio of the vegetable oil to the biodegradable surfactant is 1.5:1. For example, when the vegetable oil is 15% by weight of the latex composition, the biodegradable surfactant is 10% of the latex composition is not limited thereto.

In an embodiment of the invention, the vegetable oil can be, for example, soybean oil. Taking rectification of trichloroethylene (TCE) as an example, soybean oil has strong adsorption capacity for TCE, so that high concentration of TCE can be concentrated in the oil droplets of the latex composition, so there is no anaerobic production in the initial environment of remediation. When the hydrogen reaction occurs, the soybean oil can effectively block the TCE from being dissolved in the water. After the growth of the existing microorganisms, the hindrance of the soybean oil and the microbial anaerobic hydrogen production dechlorination reaction occur simultaneously, thereby enhancing the treatment efficiency of the TCE. Preferably, the vegetable oil is from 9 to 18.2% by weight of the latex composition, and may be, for example, 10.5, 13.6 or 15.8%, but is not limited thereto. Preferably, the vegetable oil is from 13 to 15% by weight of the latex composition.

Furthermore, in addition to lecithin, the biodegradable surfactant may further comprise a hydrophilic surfactant such as 2-Butoxyethanol. Since lecithin is a lipophilic surfactant, it can produce a high-coating protective film after emulsification with the hydrophilic butyl cellosolve, so that the oil droplet form in the latex composition is not easily broken and causes coagulation. By increasing the emulsified particle size, the stability of the latex composition can be maintained. The lecithin may be from 4.5 to 9.1%, preferably from 8 to 9.1% by weight of the latex composition, and may be, for example, 8.2, 8.7 or 9.1. %, but not limited to this. The butyl cellosolve may be 0 to 1% by weight of the latex composition, and may be, for example, 0, 0.5 or 0.9%, but is not limited thereto, but when the butyl cellosolve exceeds 1%, the emulsification effect and stability are no help. For example, when the biodegradable surfactant contains 8.2% by weight of the lecithin, the butyl cellosolve may be 0.9% by weight of the latex composition, the sum of the two being 9.1%; or, the lecithin alone is 9.1% of the latex composition, but is not limited thereto.

The acid-base buffer is from 8 to 9.5% by weight of the latex composition. Since the anaerobic reduction dechlorination reaction of the microorganism is an acidogenic reaction, the soil or the groundwater is acidified to inhibit the growth of the existing microorganisms, so the acid-base buffer of the latex composition of the present invention can be hydrolyzed to form an ionic state. A yoke base pair (OH ^- ) to buffer changes in pH and maintain a neutral environment conducive to microbial growth. The acid-base buffer is selected from the group consisting of citric acid, disodium hydrogen phosphate or a mixture of the two, and has a concentration of 0.1 M to 0.2 M (volume concentration), which may be, for example, 0.1 M, 0.15 M or 0.2 M, but not Limited to this. Preferably, the acid-base buffer comprises both citric acid and disodium hydrogen phosphate, and the weight ratio of the citric acid to the disodium hydrogen phosphate is 1:9. The acid-base buffer can maintain the pH of the latex composition at about 7 to 7.5, such as 7.2, 7.25 or 7.5, but is not limited thereto.

Another embodiment of the present invention provides a method for producing a latex composition, which mainly comprises the steps of: (S01), mixing a vegetable oil, a biodegradable surfactant, an acid-base buffer, and water to form a mixture; And (S02), applying ultrasonic waves to the mixture for a predetermined period of time to perform an emulsification to form the latex composition described above. The details of the implementation of the above-described steps of the preferred embodiment and the principles thereof will be described in detail below. Further, since the emulsification is a change in the physical state, the ratio of the various components in the step (S01) will theoretically correspond roughly to the weight ratio of each component in the latex composition, which will be described first.

The method for producing a latex composition according to an embodiment of the present invention is first: (S01), mixing a vegetable oil, a biodegradable surfactant, an acid-base buffer, and water to form a mixture. In this step, the biodegradable surfactant comprises lecithin, and the biodegradable surfactant is 4.5 to 10.1% by weight of the mixture. The weight ratio of the vegetable oil to the biodegradable surfactant is 1.5:1. For example, when the vegetable oil is 15% by weight of the latex composition, the biodegradable surfactant is 10% of the mixture. However, it is not limited to this. The vegetable oil is from 9 to 18.2%, preferably from 13 to 15% by weight of the latex composition. The lecithin is 4.5 to 9.1% by weight, preferably 8 to 9.1% by weight of the mixture, and may be, for example, 8, 8.5 or 9.1%, but is not limited thereto. The biodegradable surfactant may further comprise monobutyl cellosolve, and the butyl cellosolve is 0 to 1% by weight of the mixture, and may be, for example, 0, 0.5 or 0.9%, but is not limited thereto. For example, when the biodegradable surfactant contains 8.2% by weight of the lecithin, the butyl cellosolve may be 0.9% by weight of the mixture, and the sum of the two is 9.1%; or The lecithin alone is 9.1% of the mixture, but is not limited thereto.

Further, in this step, the acid-base buffer is from 8 to 9.5% by weight of the mixture. The acid-base buffer may be citric acid, disodium hydrogen phosphate or a mixture thereof, and the concentration of the acid-base buffer may be 0.1M to 0.2M, and may be, for example, 0.1M, 0.15M or 0.2M, but is not limited thereto. . Preferably, the acid-base buffer comprises both citric acid and disodium hydrogen phosphate, and the weight ratio of the citric acid to the disodium hydrogen phosphate is 1:9. The acid-base buffer can maintain the pH of the latex composition at about 7 to 7.5, such as 7.2, 7.25 or 7.5, but is not limited thereto.

A method for producing a latex composition according to an embodiment of the present invention is followed by: (S02), applying ultrasonic waves to the mixture to perform an emulsification to form the above-described latex composition. In this step, the ultrasonic wave can be, for example, an analog cell pulverizer (Branson Model 250/450), which uses the mechanical and cavitation effects of ultrasonic waves to cause intense particle collision and high temperature during the emulsification process. Fine oil droplets with high pressure and high fluidity. The ultrasonic power may be 10 to 60%, preferably 40 to 60%, and the time for applying the ultrasonic wave lasts for about 1 to 15 minutes, preferably 10 to 15 minutes, but is not limited thereto. The latex composition has an average emulsified particle diameter of 0.2 to 0.5 μm, for example, 0.28 μm, but is not limited thereto. Moreover, the Zeda Potential of the latex composition has a negative value, which is favorable for transport between soil pores.

In order to understand whether the latex composition can effectively control the acidification of groundwater, the present invention simulates the reaction with a micro-ecological system. The groundwater used in the experiment was an unspoiled area in the field and was sampled at 4 °C in accordance with the Environmental Protection Agency's announcement (NIEA W103.54B). Its batch experimental design simulates the local environment with a microcosm system.

First, a 500 ml fine-mouthed serum bottle is maintained at a high temperature and high pressure (121 ° C, 15 lb / in ² ) for 30 minutes sterilization time to ensure that the reaction bottle is sterile, and the latex composition is added, and then the dispenser is added. The underground groundwater is divided into 500 ml. The experimental results are briefly described below.

During the reaction, the initial pH value was 7.7, and the pH value decreased to 6.8 after the fifth day of the reaction. The pH value was maintained at neutral environmental conditions (pH 6.8-7.0) at the late stage of the reaction. It is speculated that the latex composition was initially subjected to anaerobic fermentation. After the large amount of H ₂ and low molecular organic acids produced, the pH value is lowered, and the water quality environment is acidified. However, since the latex composition contains an acid-base buffer and hydrolyzed to form an ionic conjugate base pair (OH ^- ), the concentration of H ⁺ and OH ^- ions in the buffer water can be effectively changed. In terms of dissolved oxygen, the initial concentration is 1.99 mg/L, and the reaction can be reduced to about 0.82 mg/L on the fifth day, and the dissolved oxygen is maintained at 0.6 mg/L during the reaction. The initial value of the oxidation-reduction potential (ORP) was 163 mV, and the reaction decreased to -163 mV on the fifth day, after which the reaction was maintained between -200 and -300 mV, indicating that the latex composition can effectively consume dissolved oxygen in the water. The environment is anaerobic and enhances the effect of reductive dechlorination. It is known from the above water quality trends that the latex composition can stimulate microbial reactions in a limited amount of dissolved oxygen and create an environment for anaerobic reductive dechlorination.

Furthermore, the latex composition is a biodegradable sustained release hydrogen release matrix having an initial organic carbon (TOC) concentration of 253 mg/L and a reduction of 221 mg/L on the 10th day of the reaction by monitoring changes in TOC concentration. The trend is to understand the situation in which the latex composition can be effectively utilized by microorganisms. The total number of bacteria was analyzed. The initial total bacterial count was 5.72×10 ² CFU/mL, and the total number of bacteria on the 10th day of the reaction was 2.24×10 ⁵ CFU/mL, indicating that the latex composition can provide a source of microbial growth for a long time.

Compared with the prior art, the latex composition provided by the present invention and the method for producing the same can provide a latex composition having a finely emulsified particle diameter, and the average emulsified particle diameter can be 0.2 to 0.5 μm (that is, having a nanometer level). Average emulsified particle size), and has the following advantages: (1) using emulsified oil droplets to block pollutants, can limit the range of pollutants; (2) can improve the pH buffer capacity of existing soil aquifers or groundwater, and maintain microbial growth Neutral environment; and (3) can quickly create an anaerobic environment and increase the richness of existing strains.

The present invention has been disclosed in its preferred embodiments, and is not intended to limit the invention, and the present invention may be modified and modified without departing from the spirit and scope of the invention. The scope of protection is subject to the definition of the scope of the patent application.

Claims (14)

A latex composition for treating a chlorine-containing organic contaminant, the latex composition comprising a vegetable oil, a biodegradable surfactant, an acid-base buffer, and the balance being water, wherein the biodegradable surfactant comprises an egg a phospholipid, and the biodegradable surfactant is 4.5 to 10.1% by weight of the latex composition; the vegetable oil is 9 to 18.2% by weight of the latex composition; the acid-base buffer is by weight 8 to 9.5% of the latex composition; the acid-base buffer comprises both citric acid and disodium hydrogen phosphate; and the latex composition has an emulsified average particle diameter of 0.2 to 0.5 μm. The latex composition of claim 1, wherein the weight ratio of the vegetable oil to the biodegradable surfactant is 1.5:1. The latex composition of claim 1, wherein the lecithin is from 4.5 to 9.1% by weight of the latex composition. The latex composition of claim 1, wherein the biodegradable surfactant further comprises monobutyl cellosolve, and the butyl cellosolve is from 0 to 1% by weight of the latex composition. The latex composition of claim 1, wherein the weight ratio of the citric acid to the disodium hydrogen phosphate is 1:9. The latex composition of claim 1, wherein the acid-base buffer has a concentration of 0.1 M to 0.2 M. A method for producing a latex composition, comprising the steps of: mixing a vegetable oil, a biodegradable surfactant, an acid-base buffer, and water to form a mixture; and applying ultrasonic waves to the mixture to perform an emulsification, The latex composition according to claim 1, wherein the biodegradable surfactant comprises lecithin, and the biodegradable surfactant is 4.5 to 10.1% by weight of the mixture; the vegetable oil 9 to 18.2% by weight of the mixture; the acid-base buffer is 8 to 9.5% by weight of the mixture; the acid-base buffer contains both citric acid and disodium hydrogen phosphate. The method for producing a latex composition according to claim 7, wherein the ultrasonic wave has a power of 10 to 60%. The method for producing a latex composition according to claim 7, wherein the ultrasonic system is applied for 15 minutes. The method for producing a latex composition according to claim 7, wherein the weight ratio of the vegetable oil to the biodegradable surfactant is 1.5:1. The method for producing a latex composition according to claim 7, wherein the lecithin is 4.5 to 9.1% by weight of the mixture. The method for producing a latex composition according to claim 7, wherein the biodegradable surfactant further comprises monobutyl cellosolve, and the butyl cellosolve is from 0 to 1% by weight of the mixture. The method for producing a latex composition according to claim 7, wherein the weight ratio of the citric acid to the disodium hydrogen phosphate is 1:9. The method for producing a latex composition according to claim 7, wherein the acid-base buffer has a concentration of 0.1 M to 0.2 M.