Membranes for electrodyalysis
Ion Exchange Nanostructural Membranes for Processes of Electrodyalysis
Tech Area / Field
- CHE-POL/Polymer Chemistry/Chemistry
- ENV-WPC/Water Pollution and Control/Environment
3 Approved without Funding
Institute of Chemical Sciences, Kazakstan, Almaty
- The Republican Government Enterprise on the basic of economic control rights “Research Institute for Biological Safety Problems” , Kazakstan, Gvardeiski\nMembrane technologies Limited Liability Company, Kazakstan, Almaty
- Stevens Institute of Technology, USA, NJ, Hoboken\nAwareness Center, Denmark, Roskilde
Project summaryGoal of the Project – development of methods of obtaining of reactive monomers and oligomers, as well as synthesis of highly selective nanosize ion-exchange membranes of different type on their basis. Study of physical-mechanical, electrochemical and transportation properties of membranes and development of electro-membrane technologies of desalination of natural mineralized waters and purification of industrial waste waters.
Actuality. The tasks, put forward by the modern production, can be solved on the basis of promising multifunctional synthetic materials and principally new wasteless technologies. Among them a special place is occupied by the membrane technology, which has found a wide application practically in all spheres of human activity. In a number of large-tonnage industries it manifests its technical-economical advantage and high efficiency. With the help of the membrane technology, about one third of the world desalinated water is produced. An application of electrodialysis with ion-selective membranes in water treatment in modern power engineering allows one to economize acids, alkali and a big number of ion-exchangers.
The most important features of ion-exchange membranes with nanosize pores are their selectivity upon ions transportation in the process of electrodialysis, and a value of specific electroconductivity, determining their technological value.
Desalination of mineralized waters with the help of electrodialysis with the minimal expense of electric power is more economically profitable in comparison with the known methods (distillation, freezing, etc.) even with the considerable salt concentrations. The development of rational and economical constructions of multi-chamber electrodialyzers of large capacity both in Kazakhstan and abroad has created necessary prerequisites for a wide application of this method of demineralization.
For the further development of membrane technology it is necessary to carry out an intensive elaboration of new methods of obtaining of nanostructural ion-exchange membranes on the basis of polymer films with different functional groups, stable in aggressive media and at high temperatures.
Prospects of the creation of new types of nanoporous ion-exchange membranes of different types (homogenous, heterogeneous, interpolymer, bipolar ones) are connected with the improvement of their transportation properties, and, respectively, selectivity upon the separation of ions of organic and inorganic origin in comparison with the known analogous methods. Their use in the processes of electrodialysis will make it possible to create ecologically pure wasteless membrane technologies, which, in its turn, will create a favorable situation for the provision of arid regions of Kazakhstan with pure drinking water.
Expected results and their application. As a result of the conducted studies there will be synthesized new ion-exchangers on the basis of oligomers and copolymers of diphenyl ether (DPhO) and formaldehyde, epichlorhydrine (ECH), allylamine (AA) and its oligomers, mono- and diglycidyl ethers of dioxybenzenes and di- and polyamines, revealed the main regularities and peculiarities of their formation. There will be developed methods of synthesis and will be investigated mechanism and kinetics of formation and physical-chemical properties of polyfunctional ionites.
On their basis - developed the methods of obtaining and forming of ion-exchange membranes of different types (heterogeneous, interpolymer, homogeneous and bipolar) and studied their physical-mechanical, electrochemical and transportation properties.
On the basis of the synthesized ion-exchange membranes there will be studied a possibility of their application in the modern sorption and membrane technologies of purification of industrial waste waters and desalination of mineralized waters by the method of electrodialysis. There will be developed new constructions of apparatuses – electrodializers, carried out experimental-industrial trials of the principle sample of the apparatuses.
The volume of activity. With the support of ISTC we plan to synthesize new ion-exchange polymers, containing different functional groups, on the basis of which there will be obtained membranes of anion-, cation and amphoteric types, widely applied in electrodialysis processes fit for application in sorption processes, electrodialysis. The research program, proposed by us, consists of 3 stages, the fulfillment of each of the stages possesses a definite scientific and practical importance.
The first stage: Synthesis of reactive monomers and oligomers and study of methods their involving in reaction of polymerformation, investigation of the mechanism of their formation and structural peculiarities of macromoleculs and study of physical-chemical, sorption and complex-forming properties of the final products.
As a result of the first stage there will be synthesized reactive monomers, oligomers and polymers and determined optimal conditions of their obtaining and studied the main physical-chemical, sorption and complex-forming characteristics.
The second stage: Synthesis of higly selective ion-exchange membranes on the basis of the obtained ionites of different type, and study on experimental electrodialysis cells their electrochemical, transportation, physical-mecanical properties, as well as the conditions of the formation and armouring of the membranes.
As a result of the second stage there will be established main characteristics of the synthesized ion-exchange membranes and developed recommendations for their efficient use in the processes of electrodialysis for the purification of industrial waste waters and desalination of demineralized waters.
The third stage:
Development of new constructions of deionizing apparatuses, experimental-industrial trials of the principal sample of the apparatuses. Creation of membrane and sorption technologies of desalination of mineralized waters and purification of industrial waste waters.
As a result of the third stage there will be created new constructions of electodialysis apparatuses and carried out their experimental-industrial trials.
Realization of ISTC goals and tasks. A possibility will be given to weapon-scientists for their reorientation to the field of scientific researches, directed to the creation of ecologically pure, wasteless sorption and membrane technologies, and, as a result, demineralization of nature and sterilization and waste waters. It will create prerequisits for the solution of many ecological problems (it primarily concerns the provision of the arid regions of Kazakhstan with drinking water and purification of industrial discharges).
The role of foreign Collaborators.
In accordance with the volume of activity in the framework of the proposed Project with a foreign collaborator there will be ensured:
- fulfillment of the main requirements at all the stages, up to its finishing;
- exchange of information in the course of Project realization.
Technical approach and methodology. For the fulfillment of the project there will be applied widely known methods of organic synthesis, chemistry of high-molecular compounds, ion-exchange, analytical, physical chemistry. The significant attention will be given to physical-chemical methods of investigation as initial monomers, as forming oligomers, polyelectrolytes and membranes.
The chaise of initial reagents for creatin of ion-exchange membranes – epoxy and allyl compounds will assist the successful carrying out of the project. The last are known to provide polymer materials on their base with high firm, thermal, chemical and radiation characteristics and that is why they are widely used in practice. The high reactive ability of initial monomers and oligomers will ensure the creation of higly efficient, mini-stages methods of synthesis of polyelectrolytes and ion-exchange membranes with high mechanic strength, exchange capacity and selectivity. The application of the given initial compounds, containing several functional groups, gives a big positive effect in the development of new sorption and membrane technologies.
Synthesis and test of the obtained highly permeable polymers and membranes for sorption and demineralization of the underground salt industrial waste waters will be carried out by the scientists of the laboratory of ion-exchange resins and Membranes of JSC ICS, RIBSP and MT LLC.
As a result of the conducted studies there will be obtained experimental data on the creation of new synthetic ion-exchange polymers and membranes with high kinetic characteristics and selectivity. Besides, they can be used in hydrometallurgy for separation and isolation from the productive solutions of lump leaching and industrial discharges of ions of non-ferrous, rare and dissipated metals, in food and pharmaceutical industries, in biotechnology, medicine and many other branches of science and technique. The most perspective will be use of synthesized membranes in conditions of electrodialys’s for purification and concentration of mineralized solutions and for obtaining fresh water.
The proposed Project will be fulfilled by high-qualified specialists of JSC ICS, RIBSP and MT LLC. It will be provided with the patent services in accordance with the Patent Law of the RK. All participants of the Project are largely experienced in the development, creation, research of polyfunctional polymer materials; they perfectly know the modern physical-chemical methods of investigation of high-molecular compounds, construction and creation of desalination apparatuses of different capacity.