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CN-117929547-B - Method for predicting maximum adsorption capacity of humic acid to weak acid organic pollutants and application

CN117929547BCN 117929547 BCN117929547 BCN 117929547BCN-117929547-B

Abstract

The invention discloses a method for predicting the maximum adsorption capacity of humic acid to weak acid organic pollutants and application thereof. The method comprises the steps of adding weak acid organic pollutants into humic acid solution, fully stirring and mixing to complete adsorption of the humic acid on the weak acid organic pollutants, obtaining maximum adsorption capacity by changing the concentration and the type of the weak acid organic pollutants, establishing a linear relation between the maximum adsorption capacity and |delta pK a | to obtain an equation, calculating |delta pK a |betweenthe weak acid organic pollutants to be detected and the humic acid through pK a of the weak acid organic pollutants to be detected, and predicting the maximum adsorption capacity of the weak acid organic pollutants to be detected according to the equation. The method has the advantages of simple prediction process and high accuracy.

Inventors

  • ZHANG SIYU
  • LOU WENHAO
  • ZHAO QING
  • ZHANG XUEJIAO

Assignees

  • 广东省科学院生态环境与土壤研究所

Dates

Publication Date
20260512
Application Date
20221017

Claims (6)

  1. 1. The method for predicting the maximum adsorption capacity of humic acid to weak acid organic pollutants is characterized by comprising the following steps: (1) By changing the concentration and the type of the weak acid organic pollutants, the maximum adsorption capacity is obtained, and a linear relation y= -31.83x+196.44 between the maximum adsorption capacity and |delta pK a | is established, so that an equation is obtained, wherein x is|delta pK a |, and y is the predicted maximum adsorption capacity; (2) Calculating |delta pK a |betweenthe weak acid organic pollutant to be detected and humic acid through pK a of the weak acid organic pollutant to be detected, and predicting and obtaining the maximum adsorption capacity of the weak acid organic pollutant to be detected according to the equation obtained in the step (1); The humic acid solution in the step (1) is prepared by adding humic acid particles into a solution containing 0.1 mol/L NaCl and 0.01mol/L NaOH, stirring to fully dissolve the humic acid particles, and regulating the pH value to be 6-7 by using 1mol/L HCl solution to obtain the humic acid solution; the weak acid organic pollutants in the step (1) comprise mandelic acid, 2-naphthoic acid, benzoic acid, p-nitrophenol, 2, 3-dichlorophenol, p-hydroxyacetophenone and phenol; The step of obtaining the maximum adsorption capacity in the step (1) is that the solution which completes the adsorption of humic acid to weak acid organic pollutants is passed through a water system film with the thickness of 0.22 mu m, the precipitated humic acid is removed, and then the content of weak acid organic pollutants in the filtrate is measured by high performance liquid chromatography to obtain the adsorption capacity, and the maximum adsorption capacity is further obtained.
  2. 2. The method for predicting the maximum adsorption capacity of humic acid to weak acid organic pollutants according to claim 1, wherein the method is characterized in that: The concentration of the humic acid solution is 40-60 mg/L; the pH was 6.5.
  3. 3. The method for predicting the maximum adsorption capacity of humic acid to weak acid organic pollutants according to claim 1, wherein the method is characterized in that: The fully stirred and mixed condition in the step (1) is that the reaction is carried out for 60-80 hours under the dark condition of 100-150 rpm and 24-26 ℃.
  4. 4. The method for predicting the maximum adsorption capacity of humic acid to weak acid organic pollutants according to claim 1, wherein the method is characterized in that: the concentration is 0.003-0.24 mmol/L.
  5. 5. The method for predicting the maximum adsorption capacity of humic acid to weak acid organic pollutants according to claim 4, wherein the method comprises the following steps: The concentration is 0.003, 0.009, 0.015, 0.021, 0.027, 0.033, 0.039, 0.045, 0.051, 0.06, 0.07, 0.09, 0.12, 0.16, 0.2 and 0.24mmol/L.
  6. 6. The method for predicting the maximum adsorption capacity of humic acid on weak acid organic pollutants according to any one of claims 1 to 5, wherein the method is used for providing an adsorbent for adsorption treatment of wastewater containing weak acid organic pollutants or predicting migration and degradation of weak acid organic pollutants in soil and rivers.

Description

Method for predicting maximum adsorption capacity of humic acid to weak acid organic pollutants and application Technical Field The invention belongs to the technical field of environmental chemistry and environmental pollution control, and particularly relates to a method for predicting the maximum adsorption capacity of humic acid to weak acid organic pollutants and application thereof. Background With the rapid development of industry and agriculture, the environmental input of industrial waste, pesticides, fertilizers and medicines is continuously increased, and weak acid organic pollutants which have high toxicity, high accumulation and difficult degradation and can migrate in a long distance are increasingly introduced into the natural environment, so that potential negative effects are caused on ecology and human health. Humic acid is a main component of soil, contains complex structures such as benzene ring, hydroxyl, carboxyl and the like, can perform adsorption interaction with weak acid organic pollutants to change migration, conversion and trend, and further influences bioaccumulation and biotoxicity of the weak acid organic pollutants. However, the maximum adsorption capacity of humic acid to weak acid organic pollutants needs to be determined through isothermal adsorption experiments, and the process is complex. Disclosure of Invention The primary aim of the invention is to overcome the defects and shortcomings of the prior art and provide a method for predicting the maximum adsorption capacity of humic acid to weak acid organic pollutants. It is still another object of the present invention to provide the use of the above method for predicting the maximum adsorption capacity of humic acid to weak acid organic pollutants. The aim of the invention is achieved by the following technical scheme: A method for predicting the maximum adsorption capacity of humic acid to weak acid organic pollutants comprises the following steps: (1) By changing the type and concentration of the weak acid organic pollutants, obtaining the maximum adsorption capacity, and establishing a linear relation between the maximum adsorption capacity and |delta pK a | to obtain an equation, wherein x is |delta pK a |, and y is the predicted maximum adsorption capacity; (2) Calculating |delta pK a | between the weak acid organic pollutant to be detected and humic acid through pK a of the weak acid organic pollutant to be detected, and predicting and obtaining the maximum adsorption capacity of the weak acid organic pollutant to be detected according to the equation obtained in the step (1). The humic acid solution in the step (1) is preferably prepared by adding humic acid particles into a solution containing 0.1mol/L NaCl and 0.01mol/L NaOH, stirring to fully dissolve the humic acid particles, and regulating the pH value to 6-7 by using 1mol/L HCl solution. Humic acid contains a large amount of weak acid groups, is not easily dissolved in neutral or acidic solution, so that alkaline solution is used for accelerating dissolution, the pH value is regulated to be the pH value under natural conditions by using dilute hydrochloric acid solution, and NaCl is added to simulate the ionic strength under the natural conditions. The concentration of the humic acid solution is 40-60 mg/L, and more preferably 50mg/L. The pH is preferably 6.5. The condition of sufficiently stirring and mixing in the step (1) is preferably that the reaction is carried out under the dark condition of 100-150 rpm and 24-26 ℃ for 60-80 hours, more preferably that the reaction is carried out under the dark condition of 120rpm and 25 ℃ for 72 hours. The weak acid organic contaminants in step (1) include, but are not limited to, mandelic acid, 2-naphthoic acid, benzoic acid, p-nitrophenol, 2, 3-dichlorophenol, p-hydroxyacetophenone, and phenol. The concentration in the step (1) is preferably 0.003-0.24 mmol/L, more preferably 0.003, 0.009, 0.015, 0.021, 0.027, 0.033, 0.039, 0.045, 0.051, 0.06, 0.07, 0.09, 0.12, 0.16, 0.2 and 0.24mmol/L. The step of obtaining the maximum adsorption capacity in the step (1) is that the solution with the adsorption of humic acid to weak acid organic pollutants is passed through a water system film of 0.22 mu m, the precipitated humic acid is removed, then the content of weak acid organic pollutants in the filtrate is measured by high performance liquid chromatography, the adsorption capacity is calculated, and the maximum adsorption capacity is further obtained. The method for predicting the maximum adsorption capacity of humic acid on weak acid organic pollutants can provide an adsorbent for adsorption treatment of wastewater containing weak acid organic pollutants, and theoretical support is provided for predicting migration of weak acid organic pollutants in soil and rivers and degradation process. The principle is that the humic acid molecule contains a large amount of oxygen-containing functional groups such as carboxyl, hydroxy