| Water is the basic material of all life,and the protection and management of water resources is the basic guarantee for people’s healthy life.However,due to the rapid development of modern industry,the pollution of heavy metals in water bodies has become more and more serious,posing a serious threat to the living environment of mankind.Especially mercury,a heavy metal with strong toxicity and hard-to-degradability.With the full launch of the 2017 Minamata Convention,mercury ion pollution in wastewater has become an important issue related to human life and health.For this reason,people urgently need to develop an effective method to remove Hg(Ⅱ)ions in wastewater.At present,the adsorption method has become one of the most widely used and most effective methods for removing heavy metal ions in water by virtue of its advantages of low material cost,wide sources and simple operation process.However,most mercury ion adsorbents currently have many shortcomings,such as low adsorption capacity,high cost,and difficulty in regeneration.Based on this,this work designed two cheap,efficient and fast adsorption materials to remove mercury ions in the solution.Firstly,the aminated mesoporous material is used as the carrier,and the poly-o-phenylene diamine modified mesoporous composite material(MPP)is obtained by loading poly-o-phenylene diamine.Secondly,in order to save cost and increase the adsorption capacity,it contains a large amount of The aquatic plants of cellulose and lignin were doped,and a mesoporous composite material(MPP-AC)modified by aquatic plants/poly-o-phenylenediamine was prepared.Subsequently,FI-IR,XRD,SEM,TEM,TGA and other methods were used to characterize and analyze the composition,structure,and morphology of the prepared material.In order to explore the best adsorption effect of the material,the pH value of the Hg(Ⅱ)solution,adsorption time,initial Hg(Ⅱ)concentration,adsorption temperature,and interference of coexisting ions in the solution were investigated respectively,and the regeneration performance of the adsorbent was carried out.Investigate.Finally,the adsorption kinetics,adsorption isotherm adsorption model and adsorption thermodynamics of the adsorbent are studied,which provides a theoretical basis and technical support for the industrial application of the adsorbent.The main research contents of this paper are as follows:In the second chapter of the paper,the mesoporous material MCM-41 was prepared by hydrothermal method using cheap diatomaceous earth as the silicon source and CTAB as the template.Then,the aminated mesoporous material was obtained by reacting with KH550.Material(MCM-41-NH2),and then,using MCM-41-NH2 as a carrier and supporting poly-o-phenylenediamine to obtain a composite adsorbent(MPP).The study found that when the pH,temperature,initial Hg(Ⅱ)concentration,and adsorption time of the MPP adsorbent were 4,298.15 K,100 mg/L,and 240 min,the maximum saturated adsorption capacity reached 225 mg/g.When there are common interfering ions in the solution,the adsorption of Hg(Ⅱ)by MPP still has good selectivity.The adsorption of Hg(Ⅱ)by MPP follows the quasi-second-order kinetics and Langmuir adsorption isotherm model,indicating that the adsorption process is a chemical adsorption process.At the same time,it is found through thermodynamic research that the adsorption process is a spontaneous endothermic process.Interfering ion experiments show that the adsorption of Hg(Ⅱ)by MPP is almost unaffected by other competing ions,and the adsorption of Hg(Ⅱ)in industrial wastewater by MPP has a high removal rate.After 5 cycles of adsorbent regeneration experiments,the adsorption capacity of MPP can reach 191.67 mg/g,and its value does not decrease significantly,indicating that the adsorbent has good regeneration performance and has potential application value.In the third chapter of the thesis,a composite adsorbent(MPP-AC)was prepared by using MCM-41-NH2 as the inorganic carrier,aquatic cellulose as the dopant,and supporting poly-o-phenylenediamine.The study found that when the solution pH is 4,the temperature is 25℃,the adsorption time is 240 min,and the initial Hg(Ⅱ)concentration is 100 mg/L,the maximum saturated adsorption capacity reaches 231.25 mg/g.Data fitting analysis found that the adsorption of Hg(Ⅱ)by MPP-AC conforms to the quasi-second-order kinetic model,and the process is an endothermic process,and follows the Langmuir adsorption isotherm model.Interfering ion experiments show that coexisting cations have almost no competitive effect on the removal of Hg(Ⅱ),indicating that the adsorbent has good selectivity for Hg(Ⅱ)adsorption,and MPP-AC can adsorb Hg(Ⅱ)in industrial wastewater.Has a high removal rate.After 5 cycles of adsorbent regeneration experiments,the adsorption capacity of MPP-AC can reach 200 mg/g,indicating that the adsorbent has good regeneration performance.Therefore,the composite material can be used as an effective and economical potential adsorbent for the adsorption of mercury ions. |
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