Research On Key Technologies Of Separating Heavy Metal Ions In Water Based On Nanofluidic

Heavy metal water pollution has always been an important part of the environmental protection field.Heavy metal water pollution will bring huge safety hazards,which will cause damage to the ecological environment and human health.On the other hand,a large amount of heavy metal ions is not recycled,resulting in a waste of metallic element.Therefore,research on the detection and treatment of heavy metal water pollution has become a major issue related to ecological environment health and human health.As an important aspect of heavy metal water pollution detection,electrochemical sensors have good stability,high selectivity,high sensitivity,simple structure,simple operation and low cost.The selection and preparation of electrode modification materials is a key challenge in the development of electrochemical sensing technology.It has a decisive influence on the performance of electrochemical sensors.On the other hand,dealing with heavy metal ions in polluted water has become an important issue in the field of environmental protection for heavy metal polluted water.Therefore,it is urgent to develop a low-cost,high-selectivity and high-efficiency water-weight metal ion separation technology.To this end,it has become an inevitable trend to explore a rapid detection technology for heavy metal water pollution and a sequential separation technique for heavy metal ions to meet people’s growing awareness of environmental protection.Based on the above analysis,this paper aims to develop a kind of multiple heavy metal ions sensors with rapid detection function and a rapid separation platform for heavy metal ions.Based on the design idea of “detection-separation treatment-recycling” for heavy metal ions polluted water,a thiacalix[4]arene(TCA)with good recognition and selective complexation for heavy metal ions was selected based on experimental requirements.Then,the design and manufacturing of experimental platform for detection and treatment of heavy metal ions in polluted water is completed.Firstly,Electrochemical sensor was made by direct modification.The electrochemical sensors were characterized by electrochemical workstation,optical microscopy and scanning electron microscope.The effects of the manufacturing process of modified electrode,the detection environment and the setting of the detection parameters on the detection results of the sensor were further explored for making certain theoretical and experimental guidance.The qualitative and quantitative detection mechanism of electrochemical sensors was analyzed and summarized based on the certain experimental data,providing theoretical support for the modifying electrode detection principle of heavy metal ions.Secondly,based on the selective complexation of TCA to heavy metal ions,the sulfonation of TCA is completed to obtain sulfonated thiacalix[4]arene-p-tetrasulfonate(TCAS).Fourier transform infrared spectroscopy,UV-visible spectroscopy,etc.Characterization techniques were used to complete the characterization of the prepared products.Based on the properties of the prepared products,a kind of nano-U-type device with multi-field coupling function was designed.The fabrication and construction of separation platform was completed.In the mixed solution containing multiple heavy metal ions,the selective complexation of TCAS to specific heavy metal ions was finally realized through experiments.On the basis of this,the sequential separation of heavy metal ions in water was realized by the U-type device.In order to improve the practical application value of the proposed scheme,this paper explores the selective complexation mechanism of TCAS to heavy metal ions and the sequential separation mechanism of multiple heavy metal ions.Based on the obtained experimental data and results,the dynamics of heavy metal ions in nanochannels based on nanofluids was analyzed.Finally,TCAS extraction and recycling were realized through experiments in order to improve the cycle utilization rate of TCAS.The effects of different dissociation of complexation reagents on dissociation of complexation from TCAS were mainly studied,including nitric acid,sulfuric acid and hydrochloric acid.Nitric acid was used as the best dissociation of complexation reagent.Further experiments were conducted to determine the optimal concentration for dissociation of complexation from TCAS.TCAS was successfully extracted and subjected to secondary adsorption experiments by certain chemical means.The electrochemical sensor prepared in this paper has good selectivity and sensitivity for water-weight metal ions.The measurement error is within 5% compared with conventional detection instruments.Through the multi-field coupling separation platform,the gradual separation of four heavy metal ions of copper,cadmium,lead and barium was completed.The separation efficiency reached more than 90%.