CN111948346A - Response curved surface optimization method for biochar preparation for removing cadmium in solution - Google Patents
Response curved surface optimization method for biochar preparation for removing cadmium in solution Download PDFInfo
- Publication number
- CN111948346A CN111948346A CN202010805211.8A CN202010805211A CN111948346A CN 111948346 A CN111948346 A CN 111948346A CN 202010805211 A CN202010805211 A CN 202010805211A CN 111948346 A CN111948346 A CN 111948346A
- Authority
- CN
- China
- Prior art keywords
- biochar
- cadmium
- prepared
- response curve
- following
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 230000004044 response Effects 0.000 title claims abstract description 53
- BDOSMKKIYDKNTQ-UHFFFAOYSA-N cadmium atom Chemical compound [Cd] BDOSMKKIYDKNTQ-UHFFFAOYSA-N 0.000 title claims abstract description 52
- 229910052793 cadmium Inorganic materials 0.000 title claims abstract description 49
- 238000000034 method Methods 0.000 title claims abstract description 46
- 238000002360 preparation method Methods 0.000 title claims abstract description 15
- 238000005457 optimization Methods 0.000 title claims abstract description 12
- 239000002028 Biomass Substances 0.000 claims abstract description 42
- 238000000197 pyrolysis Methods 0.000 claims abstract description 41
- 239000002994 raw material Substances 0.000 claims abstract description 24
- 238000005470 impregnation Methods 0.000 claims abstract description 22
- 238000013461 design Methods 0.000 claims abstract description 15
- 238000012360 testing method Methods 0.000 claims abstract description 13
- 239000002245 particle Substances 0.000 claims abstract description 12
- 238000004458 analytical method Methods 0.000 claims abstract description 6
- 238000013401 experimental design Methods 0.000 claims abstract description 6
- 239000012299 nitrogen atmosphere Substances 0.000 claims abstract description 5
- 238000010586 diagram Methods 0.000 claims abstract description 3
- 238000002474 experimental method Methods 0.000 claims description 12
- 238000001179 sorption measurement Methods 0.000 claims description 10
- 238000001035 drying Methods 0.000 claims description 9
- 241000124033 Salix Species 0.000 claims description 7
- 230000003213 activating effect Effects 0.000 claims description 7
- 239000003795 chemical substances by application Substances 0.000 claims description 7
- 239000011592 zinc chloride Substances 0.000 claims description 5
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 4
- 229910052799 carbon Inorganic materials 0.000 claims description 4
- 238000001914 filtration Methods 0.000 claims description 4
- 239000010902 straw Substances 0.000 claims description 4
- 238000003306 harvesting Methods 0.000 claims description 3
- 238000007873 sieving Methods 0.000 claims description 3
- 238000005406 washing Methods 0.000 claims description 3
- 238000010521 absorption reaction Methods 0.000 claims description 2
- 239000000706 filtrate Substances 0.000 claims description 2
- 239000007789 gas Substances 0.000 claims description 2
- 238000010438 heat treatment Methods 0.000 claims description 2
- 239000007788 liquid Substances 0.000 claims description 2
- 238000012216 screening Methods 0.000 claims description 2
- 238000002791 soaking Methods 0.000 claims description 2
- 239000012190 activator Substances 0.000 claims 1
- 238000007598 dipping method Methods 0.000 claims 1
- 230000009977 dual effect Effects 0.000 abstract 1
- 230000004913 activation Effects 0.000 description 4
- 230000003993 interaction Effects 0.000 description 4
- 239000003463 adsorbent Substances 0.000 description 3
- 229910001385 heavy metal Inorganic materials 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 238000011160 research Methods 0.000 description 3
- 230000009471 action Effects 0.000 description 2
- 238000000540 analysis of variance Methods 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000007246 mechanism Effects 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 206010005003 Bladder cancer Diseases 0.000 description 1
- 206010058467 Lung neoplasm malignant Diseases 0.000 description 1
- 208000000453 Skin Neoplasms Diseases 0.000 description 1
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 description 1
- 208000007097 Urinary Bladder Neoplasms Diseases 0.000 description 1
- 238000002679 ablation Methods 0.000 description 1
- 238000012271 agricultural production Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000010668 complexation reaction Methods 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 239000008367 deionised water Substances 0.000 description 1
- 229910021641 deionized water Inorganic materials 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 239000003344 environmental pollutant Substances 0.000 description 1
- 210000003608 fece Anatomy 0.000 description 1
- 125000000524 functional group Chemical group 0.000 description 1
- 238000000227 grinding Methods 0.000 description 1
- 231100000086 high toxicity Toxicity 0.000 description 1
- 238000009776 industrial production Methods 0.000 description 1
- 239000002440 industrial waste Substances 0.000 description 1
- 238000005342 ion exchange Methods 0.000 description 1
- 239000010871 livestock manure Substances 0.000 description 1
- 201000005202 lung cancer Diseases 0.000 description 1
- 208000020816 lung neoplasm Diseases 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 239000010908 plant waste Substances 0.000 description 1
- 231100000719 pollutant Toxicity 0.000 description 1
- 244000144977 poultry Species 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 238000005067 remediation Methods 0.000 description 1
- 238000001223 reverse osmosis Methods 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 201000000849 skin cancer Diseases 0.000 description 1
- 239000010802 sludge Substances 0.000 description 1
- 239000002689 soil Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000007619 statistical method Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000005211 surface analysis Methods 0.000 description 1
- 235000013619 trace mineral Nutrition 0.000 description 1
- 239000011573 trace mineral Substances 0.000 description 1
- 201000005112 urinary bladder cancer Diseases 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
- 239000002351 wastewater Substances 0.000 description 1
- 239000002916 wood waste Substances 0.000 description 1
- JIAARYAFYJHUJI-UHFFFAOYSA-L zinc dichloride Chemical compound [Cl-].[Cl-].[Zn+2] JIAARYAFYJHUJI-UHFFFAOYSA-L 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/0098—Plants or trees
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N1/00—Sampling; Preparing specimens for investigation
- G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
- G01N1/286—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q involving mechanical work, e.g. chopping, disintegrating, compacting, homogenising
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N1/00—Sampling; Preparing specimens for investigation
- G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
- G01N1/30—Staining; Impregnating ; Fixation; Dehydration; Multistep processes for preparing samples of tissue, cell or nucleic acid material and the like for analysis
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N1/00—Sampling; Preparing specimens for investigation
- G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
- G01N1/44—Sample treatment involving radiation, e.g. heat
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F17/00—Digital computing or data processing equipment or methods, specially adapted for specific functions
- G06F17/10—Complex mathematical operations
- G06F17/18—Complex mathematical operations for evaluating statistical data, e.g. average values, frequency distributions, probability functions, regression analysis
Abstract
The invention discloses a response curved surface optimization method prepared from biochar for removing cadmium in a solution, which comprises the following steps: (1) preparing biomass; (2) single factor test: the biomass particle size, the impregnation ratio, the pyrolysis temperature and the pyrolysis time are taken as main variables, the biomass raw material is placed in a tubular furnace under nitrogen atmosphere for high-temperature pyrolysis to obtain biochar, the single-factor test is carried out, and the yield of the biochar is calculated; (3) the response surface optimization method comprises the following steps: according to the single-factor test result, the Design expert8.0 software is used for carrying out experimental Design according to the Box-Behnken Design principle, and a quadratic multiple regression model equation is established: (4) and performing drawing analysis on the relationship between the independent variable and the response value by using Design expert8.0 software according to a quadratic multiple regression model equation to obtain a response surface diagram of the regression equation, and determining the optimal preparation process of the biochar. The preparation method is simple and strong in operability, optimizes the preparation process of the biochar by utilizing a response surface method, can ensure that the aim of efficiently removing cadmium in the solution is fulfilled under the condition of high biochar yield, and realizes the dual aims of economy and high efficiency.
Description
Technical Field
The invention relates to the technical field of environmental protection, in particular to a response curved surface optimization method prepared from biochar for removing cadmium in a solution.
Background
Cadmium is a trace element harmful to humans and has been shown by modern studies to be associated with various types of skin, bladder and lung cancer. Naturally occurring and man-made sources of cadmium pollution in the environment include geothermal zones, cadmium bearing sulfide deposits, poultry bedding and industrial waste, among others. Cadmium has extremely high toxicity and non-biodegradability, and therefore, the cadmium poses a serious threat to the safety of the whole agricultural production. Therefore, the development of cost-effective and reliable remediation techniques to remediate cadmium contamination in the environment has been elusive.
Common cadmium pollution treatment technologies include chemical oxidation, precipitation, adsorption exchange, reverse osmosis, membrane separation, and the like. Of these methods, adsorption of cadmium onto a particular adsorbent is one of the most effective strategies, and a wide variety of adsorbents can be used. Among these adsorbents, biochar is a carbon-rich solid, prepared by pyrolysis of crop residues, sludge, wood waste, manure and biogas residues at high temperature and under nitrogen atmosphere, and has excellent thermal stability and good physicochemical properties.
In recent years, biochar has shown great potential for adsorption of pollutants in soil and water, especially in the removal of heavy metal cadmium from wastewater bodies. The action mechanism of the biochar on the heavy metal comprises physical adsorption, ion exchange, functional group complexation and the like, and the action mechanism is closely related to factors such as raw materials of the biochar, pyrolysis temperature and the like. Therefore, the important research on a plurality of variables in the preparation process of the biochar is beneficial to improving the adsorption performance of the biochar on heavy metals. Since the preparation process of biochar is interfered by various factors and can not be independently split, a feasible method is necessary to be introduced to consider the influence capability of different factors. The response surface method is considered as an effective tool for researching the interaction between two or more factors, and is a statistical method for establishing a model and analyzing the interaction of independent factors. Compared with the traditional orthogonal design method, the response surface method is a more economical method with less time consumption, and is a comprehensive research method. Meanwhile, the difference significance of different influence factors can be comprehensively analyzed from the angle of model and graphic analysis, so that the optimal experimental parameters can be obtained.
At present, the research on the preparation process of the biochar is one-sided, and the mutual influence of various factors cannot be comprehensively analyzed. Therefore, the method has important significance in determining the optimal preparation process of the biochar by introducing a response surface method to consider the interaction among multiple factors so as to realize the efficient removal of cadmium in the solution.
Disclosure of Invention
The invention aims to overcome the defects of a single-factor experiment and provide a method for optimizing the removal efficiency of the biochar on cadmium in a solution by utilizing a response surface method and researching parameters which have important influence on the physicochemical properties of the biochar, wherein the parameters comprise biomass particle size, impregnation ratio, pyrolysis temperature and pyrolysis time.
The invention solves the technical problems by the following technical scheme:
(1) preparing biochar:
harvesting crop straws, washing, drying, crushing and screening to obtain a biomass raw material, soaking the biomass raw material by an activating agent, and then filtering and drying; putting the biomass raw material into a tubular furnace under nitrogen atmosphere for high-temperature pyrolysis to obtain biochar;
(2) single factor test:
performing single-factor test on cadmium in the prepared biochar absorption solution by taking the biomass particle size, the impregnation ratio, the pyrolysis temperature and the pyrolysis time as main variables, and calculating the yield of the biochar;
(3) the response surface optimization method comprises the following steps:
according to the single-factor test result, Design expert8.0 software is utilized to carry out experimental Design according to the Box-Behnken Design principle, and the biomass particle size X is used1Impregnation ratio X2Pyrolysis temperature X3And pyrolysis time X4As independent variable, in terms of biochar yield (Y)1) And removal rate (Y) of cadmium2) Establishing a quadratic multiple regression model equation for the response value:
Y1＝+40.02-0.81*X1+0.021*X2-1.31*X3-0.65*X4-0.12*X1*X2-0.31*X1*X3+0.25*X1*X4+1.00*X2*X3-0.56*X2*X4
Y2＝+52.49+1.66*X1+0.49*X2-0.78*X3+1.00*X4-3.53*X1*X2-0.53*X1*X3+1.22*X1*X4+4.18*X2*X3+0.38*X2*X4+0.050*X3*X4-4.92*X1 2-0.13*X2 2-2.38*X3 2-2.40*X4 2
(4) and performing drawing analysis on the relationship between the independent variable and the response value by using Design expert8.0 software according to a quadratic multiple regression model equation to obtain a response surface diagram of the regression equation, and determining the optimal preparation process of the biochar.
Further, the preparation of the biochar comprises the following steps: the biomass raw material in the method is willow.
Further, the drying temperature of the biomass raw material is 60-90 ℃, and the sieving particle size is 20-100 meshes.
Further, the activating agent adopted by the biomass raw material impregnation is ZnCl2。
Further, the biomass raw material is soaked in the activating agent for 48 hours, and the drying temperature is 60-90 ℃.
Further, the ratio of the activating agent to the biomass in the biomass raw material impregnation is 0.5-2.5: 1 (w/w).
Furthermore, the pyrolysis temperature in the single-factor experiment is 450-750 ℃, and the pyrolysis time is 0.5-2 h.
Furthermore, the heating rate in the single-factor experiment is 15 ℃/min, and the pyrolysis gas speed is 0.5L/min.
Further, the yield of biochar in the single-factor experiment is calculated by adopting the following method:
Y1＝(m/M)×100％
wherein, Y1M is the mass (g) of the biochar, and M is the mass (g) of the biomass feedstock.
In addition, the invention also provides a method for removing cadmium in the solution by using the biochar optimally prepared by the response surface method, which comprises the following steps:
(1) adding biochar into a solution containing 40mg/L of cadmium, keeping the solid-to-liquid ratio at 2g/L, oscillating at the speed of 180r/min for 12h at room temperature, filtering, and determining the cadmium content in the filtrate;
(2) the removal efficiency of the biochar to cadmium in the solution is calculated by adopting the following method:
wherein, Y2C0 is the original concentration (mg/L) of cadmium in the solution, and Ce is the concentration (mg/L) of cadmium in the solution at the equilibrium of adsorption.
Compared with the prior art, the invention has the following advantages:
(1) the biomass raw material adopted by the invention is willow, and can be popularized to other crop straws, so that the resource utilization of wastes can be realized.
(2) Compared with an orthogonal method, the response surface optimization method overcomes the defects of multiple times of single-factor experiments, long period, large workload and the like, simultaneously considers the interaction influence among multiple factors, and can obtain an optimization result under fewer times of experiments; the method realizes the high-efficiency removal of cadmium in the solution under the condition of ensuring higher biochar yield, and has practical significance for industrial production.
(3) The preparation method is simple, has strong operability, and can realize double targets of economy and high efficiency.
Drawings
FIG. 1 is a graph of the response curve of the effect of impregnation ratio and pyrolysis temperature on biochar yield according to the present invention;
FIG. 2 is a graph of the response curve of the effect of pyrolysis temperature and pyrolysis time on cadmium removal rate in accordance with the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention are clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In this example, willow is selected as a biomass raw material, and experimental Design is performed according to Box-Behnken Design principle by using Design expert8.0 software, and biomass particle size X is used1Impregnation ratio X2Pyrolysis temperature X3And pyrolysis time X4The method is used as an independent variable to carry out adsorption (removal) test of cadmium in the solution to obtain a response surface graph of a regression equation and determine the optimal preparation process of the biochar, and comprises the following steps:
(1) pretreatment: harvesting willow straws, washing with deionized water, drying at 60 ℃, grinding, crushing, and sieving with 20-mesh, 60-mesh and 100-mesh sieves respectively to obtain a biomass raw material for later use;
(2) biomass impregnation: the biomass raw material obtained in the step (1) is put through ZnCl2By impregnation treatment, ZnCl2The impregnation ratio of the biomass to the biomass is 0.5-2.5: 1, and then the biomass is filtered and dried at 60 ℃;
(3) single factor test: the biomass raw material is placed in a tubular furnace under nitrogen atmosphere for high-temperature pyrolysis to obtain biochar for single-factor test by taking the biomass particle size (20-100 meshes), the impregnation ratio (0.5-2.5: 1), the pyrolysis temperature (450-;
(4) the response surface optimization method comprises the following steps: selecting four factors which have obvious influence on the biomass particle size, the impregnation ratio, the pyrolysis temperature and the pyrolysis time according to a single-factor test result, carrying out experimental Design by using Design expert8.0 software according to the Box-Behnken Design principle, and using the biomass particle size X1Impregnation ratio X2Pyrolysis temperature X3And pyrolysis time X4As independent variable, in terms of biochar yield (Y)1) And removal rate (Y) of cadmium2) Establishing a quadratic multiple regression model equation for the response value:
Y1＝+40.02-0.81*X1+0.021*X2-1.31*X3-0.65*X4-0.12*X1*X2-0.31*X1*X3+0.25*X1*X4+1.00*X2*X3-0.56*X2*X4
Y2＝+52.49+1.66*X1+0.49*X2-0.78*X3+1.00*X4-3.53*X1*X2-0.53*X1*X3+1.22*X1*X4+4.18*X2*X3+0.38*X2*X4+0.050*X3*X4-4.92*X1 2-0.13*X2 2-2.38*X3 2-2.40*X4 2
TABLE 1 Experimental factors and level settings
TABLE 2 Box-Behnken Experimental design and results
TABLE 3 analysis of variance of response surface quadratic model for biochar yield
| Origin of origin | Sum of squares | Degree of freedom | Sum of mean square | F value | Prob>F |
| Regression model | 44.16 | 14 | 3.15 | 1.53 | 0.0178 |
| X1 | 7.92 | 1 | 7.92 | 3.84 | 0.0701 |
| X2 | 5.21E-03 | 1 | 5.21E-03 | 2.53E-03 | 0.0306 |
| X3 | 20.67 | 1 | 20.67 | 10.03 | 0.0068 |
| X4 | 5.01 | 1 | 5.01 | 2.43 | 0.1414 |
| X1X2 | 0.062 | 1 | 0.062 | 0.03 | 0.8642 |
| X1X3 | 0.39 | 1 | 0.39 | 0.19 | 0.6699 |
| X1X4 | 0.25 | 1 | 0.25 | 0.12 | 0.7328 |
| X2X3 | 4 | 1 | 4 | 1.94 | 0.1852 |
| X2X4 | 1.27 | 1 | 1.27 | 0.61 | 0.4462 |
| X3X4 | 0.56 | 1 | 0.56 | 0.27 | 0.6095 |
| X1 2 | 0.026 | 1 | 0.026 | 0.012 | 0.9127 |
| X2 2 | 2.54 | 1 | 2.54 | 1.23 | 0.2858 |
| X3 2 | 2.06 | 1 | 2.06 | 1 | 0.3348 |
| X4 2 | 0.41 | 1 | 0.41 | 0.2 | 0.6636 |
| Residual error | 28.84 | 14 | 2.06 | ||
| Misestimate value | 26.29 | 10 | 2.63 | 4.12 | 0.0024 |
When the difference of the analysis result Prob > F is less than 0.05, the model is meaningful, and conversely, when the difference is more than 0.1, the model is meaningless. From table 3, it can be seen that F is 1.53 and Prob > F is 0.0178, and it is clear that the model is meaningful to build, and it can be shown that the experiment is only 1.78% probable to be an error. Therefore, the regression model established by the yield of the biochar is meaningful. Meanwhile, it can be found that the significant level of the biochar yield influence is sequentially activation temperature > impregnation ratio > mesh number > activation time.
TABLE 4 analysis of variance of response surface quadratic model for cadmium removal rate
| Origin of origin | Sum of squares | Degree of freedom | Sum of mean square | F value | Prob>F |
| Regression model | 374.42 | 14 | 26.74 | 2.06 | 0.0039 |
| X1 | 33.07 | 1 | 33.07 | 2.55 | 0.1325 |
| X2 | 2.84 | 1 | 2.84 | 0.22 | 0.0468 |
| X3 | 7.36 | 1 | 7.36 | 0.57 | 0.0635 |
| X4 | 11.96 | 1 | 11.96 | 0.92 | 0.3531 |
| X1X2 | 49.77 | 1 | 49.77 | 3.84 | 0.0703 |
| X1X3 | 1.14 | 1 | 1.14 | 0.088 | 0.7707 |
| X1X4 | 5.98 | 1 | 5.98 | 0.46 | 0.5081 |
| X2X3 | 70.06 | 1 | 70.06 | 5.41 | 0.0356 |
| X2X4 | 0.57 | 1 | 0.57 | 0.044 | 0.8369 |
| X3X4 | 0.01 | 1 | 0.01 | 7.72E-04 | 0.9782 |
| X1 2 | 156.87 | 1 | 156.87 | 12.1 | 0.0037 |
| X2 2 | 0.11 | 1 | 0.11 | 8.17E-03 | 0.9293 |
| X3 2 | 36.67 | 1 | 36.67 | 2.83 | 0.1147 |
| X4 2 | 37.21 | 1 | 37.21 | 2.87 | 0.1123 |
| Residual error | 181.46 | 14 | 12.96 | ||
| Misestimate value | 181.18 | 10 | 18.12 | 260.06 | ＜0.0001 |
From table 4, it can be seen that the model F has a value of 2.06 and the Prob > F difference is 0.0039, and it is clear that the model is meaningful to establish, and it also indicates that experiment F has a probability of error of only 1.78%. Meanwhile, the significance level of the cadmium removal rate influence is sequentially that the impregnation ratio is greater than the activation temperature and the mesh number is greater than the activation time.
(5) Carrying out drawing analysis on the relationship between independent variables and response values by using Design expert8.0 software according to a quadratic multivariate regression model equation to obtain a response surface graph of a regression equation, wherein the response surface graph is shown in fig. 1 and 2; the optimal process for producing biochar was determined according to fig. 1 and 2, as shown in table 5.
Fig. 1 and 2 show the relationship between the factors in the response surface. As can be seen from fig. 1, the biochar yield increases with increasing impregnation ratio and decreases with increasing pyrolysis temperature. As can be seen from fig. 2, the cadmium removal rate starts to increase as the pyrolysis temperature and the pyrolysis time increase, and then gradually decreases as the pyrolysis temperature and the pyrolysis time further increase. When the temperature reaches more than 750 ℃, the adsorption capacity of the carbon pore channel structure is reduced possibly along with ablation of the carbon pore channel structure.
TABLE 5 model optimization Process
Table 5 shows the optimal process conditions for biochar preparation obtained by response surface analysis, and the predicted values and experimental values of biochar yield and cadmium removal rate obtained under the conditions. The optimized conditions are that the biomass particle size is 60 meshes, the impregnation ratio is 1.5, the pyrolysis temperature is 600 ℃, and the pyrolysis time is 70 min. The yield of the willow biochar prepared under the optimal condition and the cadmium removal rate are 40.5 percent and 52.78 percent and are close to the predicted values.
The above detailed description is specific to one possible embodiment of the present invention, and the embodiment is not intended to limit the scope of the present invention, and all equivalent implementations or modifications without departing from the scope of the present invention should be included in the technical scope of the present invention.
Claims (10)
1. A response curved surface optimization method prepared by biochar for removing cadmium in a solution is characterized by comprising the following steps:
(1) preparing biochar:
harvesting crop straws, washing, drying, crushing and screening to obtain a biomass raw material, soaking the biomass raw material by an activating agent, and then filtering and drying; putting the biomass raw material into a tubular furnace under nitrogen atmosphere for high-temperature pyrolysis to obtain biochar;
(2) single factor test:
performing single-factor test on cadmium in the prepared biochar absorption solution by taking the biomass particle size, the impregnation ratio, the pyrolysis temperature and the pyrolysis time as main variables, and calculating the yield of the biochar;
(3) the response surface optimization method comprises the following steps:
according to the single-factor test result, Design expert8.0 software is utilized to carry out experimental Design according to the Box-Behnken Design principle, and the biomass particle size X is used1Impregnation ratio X2Pyrolysis temperature X3And pyrolysis time X4As independent variable, in terms of biochar yield (Y)1) And removal rate (Y) of cadmium2) Establishing a quadratic multiple regression model equation for the response value:
Y1＝+40.02-0.81*X1+0.021*X2-1.31*X3-0.65*X4-0.12*X1*X2-0.31*X1*X3+0.25*X1*X4+1.00*X2*X3-0.56*X2*X4
Y2＝+52.49+1.66*X1+0.49*X2-0.78*X3+1.00*X4-3.53*X1*X2-0.53*X1*X3+1.22*X1*X4+4.18*X2*X3+0.38*X2*X4+0.050*X3*X4-4.92*X1 2-0.13*X2 2-2.38*X3 2-2.40*X4 2
(4) and performing drawing analysis on the relationship between the independent variable and the response value by using Design expert8.0 software according to a quadratic multiple regression model equation to obtain a response surface diagram of the regression equation, and determining the optimal preparation process of the biochar.
2. The method for optimizing the response curve prepared from the biochar for removing the cadmium in the solution according to claim 1, wherein the response curve is prepared by the following steps: the biomass raw material selected for preparing the biochar in the step (1) is willow.
3. The method for optimizing the response curve prepared by the biochar for removing the cadmium in the solution according to claim 2, wherein the response curve is prepared by the following steps: the drying temperature of willow for preparing biomass raw materials is 60-90 ℃, and the sieving grain size is 20-100 meshes.
4. The method for optimizing the response curve prepared from the biochar for removing the cadmium in the solution according to claim 1, wherein the response curve is prepared by the following steps: the biomass raw material passes through an activating agent ZnCl2And (4) carrying out impregnation treatment.
5. The method for optimizing the response curve prepared by the biochar for removing the cadmium in the solution according to claim 4, wherein the response curve is prepared by the following steps: the activator ZnCl2The time for dipping the biomass raw material is 48 hours, and the drying temperature is 60-90 ℃.
6. The method for optimizing the response curve prepared by the biochar for removing the cadmium in the solution according to claim 4, wherein the response curve is prepared by the following steps: the ratio of the activating agent to the biomass raw material in the biomass raw material impregnation is 0.5-2.5: 1 (w/w).
7. The method for optimizing the response curve prepared from the biochar for removing the cadmium in the solution according to claim 1, wherein the response curve is prepared by the following steps: the pyrolysis temperature in the single-factor experiment is 450-750 ℃, and the pyrolysis time is 0.5-2 h.
8. The method for optimizing the response curve prepared from the biochar for removing the cadmium in the solution according to claim 1, wherein the response curve is prepared by the following steps: the heating rate in the single-factor experiment is 15 ℃/min, and the pyrolysis gas speed is 0.5L/min.
9. The method for optimizing the response curve prepared from the biochar for removing the cadmium in the solution according to claim 1, wherein the response curve is prepared by the following steps: the yield of the biochar in the single-factor experiment is calculated by adopting the following method:
Y1＝(m/M)×100％
wherein, Y1M is the mass (g) of the biochar, and M is the mass (g) of the biomass feedstock.
10. The method for optimizing the response curve prepared from the biochar for removing the cadmium in the solution according to claim 1, wherein the response curve is prepared by the following steps: the method for removing cadmium in the solution by the adsorption of the biochar prepared in the single-factor experiment comprises the following steps:
(1) adding biochar into a solution containing 40mg/L of cadmium, keeping the solid-to-liquid ratio at 2g/L, oscillating at the speed of 180r/min for 12h at room temperature, filtering, and determining the cadmium content in the filtrate;
(2) the removal efficiency of the biochar to cadmium in the solution is calculated by adopting the following method:
wherein, Y2The removal rate of the biological carbon to cadmium, C0The original concentration (mg/L) of cadmium in the solution, and the concentration (mg/L) of cadmium in the solution at the adsorption equilibrium.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010805211.8A CN111948346A (en) | 2020-08-11 | 2020-08-11 | Response curved surface optimization method for biochar preparation for removing cadmium in solution |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010805211.8A CN111948346A (en) | 2020-08-11 | 2020-08-11 | Response curved surface optimization method for biochar preparation for removing cadmium in solution |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111948346A true CN111948346A (en) | 2020-11-17 |
Family
ID=73333388
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010805211.8A Pending CN111948346A (en) | 2020-08-11 | 2020-08-11 | Response curved surface optimization method for biochar preparation for removing cadmium in solution |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111948346A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113522242A (en) * | 2021-08-09 | 2021-10-22 | 北京科技大学 | Method for preparing dephosphorization modified biochar based on response surface method |
| CN114084955A (en) * | 2021-11-26 | 2022-02-25 | 桂林理工大学 | Response surface method-based method for optimizing denitrification performance of anaerobic ammonia oxidation membrane bioreactor and denitrification method |
| CN115193280A (en) * | 2021-04-14 | 2022-10-18 | 天津大学 | Method for establishing waste tributyl phosphate/kerosene emulsification formula |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103877937A (en) * | 2014-04-15 | 2014-06-25 | 江苏省农业科学院 | Improved charcoal-based phosphorous removal adsorbent and preparation method thereof |
| CN106971080A (en) * | 2017-04-21 | 2017-07-21 | 上海交通大学 | A kind of modification biological charcoal adsorbs the response surface optimization method of Phosphorus From Wastewater |
| CN110609978A (en) * | 2019-10-11 | 2019-12-24 | 河海大学 | Microalgae flocculation recovery parameter optimization method based on response surface method and implementation scheme |
-
2020
- 2020-08-11 CN CN202010805211.8A patent/CN111948346A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103877937A (en) * | 2014-04-15 | 2014-06-25 | 江苏省农业科学院 | Improved charcoal-based phosphorous removal adsorbent and preparation method thereof |
| CN106971080A (en) * | 2017-04-21 | 2017-07-21 | 上海交通大学 | A kind of modification biological charcoal adsorbs the response surface optimization method of Phosphorus From Wastewater |
| CN110609978A (en) * | 2019-10-11 | 2019-12-24 | 河海大学 | Microalgae flocculation recovery parameter optimization method based on response surface method and implementation scheme |
Non-Patent Citations (1)
| Title |
|---|
| 李飞: "农林废弃物生物炭的制备、改性及在Cd污染治理中的应用", 《中国优秀博硕士学位论文全文数据库(硕士) 工程科技Ⅰ辑》, 15 May 2019 (2019-05-15), pages 2 - 3 * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115193280A (en) * | 2021-04-14 | 2022-10-18 | 天津大学 | Method for establishing waste tributyl phosphate/kerosene emulsification formula |
| CN115193280B (en) * | 2021-04-14 | 2023-12-29 | 天津大学 | Method for establishing waste tributyl phosphate/kerosene emulsion formula |
| CN113522242A (en) * | 2021-08-09 | 2021-10-22 | 北京科技大学 | Method for preparing dephosphorization modified biochar based on response surface method |
| CN114084955A (en) * | 2021-11-26 | 2022-02-25 | 桂林理工大学 | Response surface method-based method for optimizing denitrification performance of anaerobic ammonia oxidation membrane bioreactor and denitrification method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111948346A (en) | Response curved surface optimization method for biochar preparation for removing cadmium in solution | |
| Park et al. | Recycling of rice straw through pyrolysis and its adsorption behaviors for Cu and Zn ions in aqueous solution | |
| CN110237818B (en) | Preparation method and application of nitrogen and sulfur co-doped biochar | |
| CN105170091A (en) | Preparation method of iron-modified reed biological carbon, and application of iron-modified reed biological carbon in treatment of phosphorus wastewater | |
| CN110697707A (en) | Method for preparing high-performance activated carbon organic pollutant adsorbent by using edible fungus residues | |
| CN108311104A (en) | A kind of charcoal preparation method of synchronous pyrolysis load iron | |
| CN105536715A (en) | Method for preparation of adsorption material by using maple leaf | |
| CN111135790A (en) | Dephosphorization composite adsorbent, preparation method thereof and application thereof in sewage treatment | |
| CN113786804B (en) | Preparation method and application of magnetic porous composite material for adsorbing heavy metals | |
| CN103936002A (en) | Preparation method of water hyacinth biochar | |
| Azadi et al. | Experimental investigation and modeling of nickel removal from wastewater using modified rice husk in continuous reactor by response surface methodology | |
| CN104511272A (en) | Preparation and application methods of adsorbent for removing cadmium in wastewater | |
| CN112058227A (en) | Preparation method and application of blue algae modified biochar with high adsorption efficiency | |
| CN111569830A (en) | Modified biochar and preparation method, application method and recycling method thereof | |
| CN103480330B (en) | Biomass-modified adsorbent for adsorbing coking wastewater, and preparation method and application thereof | |
| CN109173999A (en) | A kind of preparation method and applications of biology carbon microspheres | |
| CN111054306A (en) | Modified biochar and preparation method and application method thereof | |
| CN110152608A (en) | A kind of nitrogen-atoms auto-dope chicken feather charcoal adsorbent material and preparation method thereof | |
| CN109928492A (en) | The preparation method of modified activated carbon biologic packing material for biofilter | |
| CN106311148B (en) | A kind of charcoal composite material and preparation method | |
| CN107684898A (en) | A kind of method that trace oxygen atmosphere pyrolysis prepares mao bamboon charcoal | |
| CN111530413A (en) | Biochar for enhancing soil self-repair and preparation method and application thereof | |
| CN114653332B (en) | Method for degrading antibiotics in water body by pyrite modified biochar | |
| CN114053999B (en) | Coffee residue biochar and preparation method and application thereof | |
| CN116440866A (en) | Preparation method and application of three-dimensional spongy porous heavy metal ion adsorbent based on activated eggshells |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20201117 |
|
| RJ01 | Rejection of invention patent application after publication |