Final Report Summary - CHILTURPOL2 (Innovative materials and methods for water treatment)
In the communication of European Commission related to the European Innovation Partnership on Water (EIPWater) one can read ‘Floods, water scarcity and droughts have enormous environmental, social and economic impacts. Insufficient water quality levels pose threats for public health and bio-diversity and the supply of safe drinking water and sanitation still poses problems, both within Europe and outside. To sustainable manage the increasing pressures on water resources, new and innovative approaches are needed’. Thee Strategic Implementation Plan of EIPWater, published in Dec 2012, informed that ‘…half of Europe freshwaters do not achieve good ecological status […] with adverse effects on biodiversity and public health…’. What is more, the authors of the Implementation Plan predict that ‘Significant investments are needed to build, operate, maintain and adapt water infrastructures in order to face these challenges [water scarcity] inside Europe and in other developed countries.…’ They noted also that ‘….by 2050, 2.3 billion more people than today are projected to live in river basins experiencing severe water stress’ and ‘…exacerbate competition between water users, putting irrigated agriculture, ecosystems, cities, industries and, in general, economic development at risks in several regions of the world’.
The CHILTURPOL2 ‘Innovative materials and methods for water treatment’ stays in line with the problems shown in above documents and is related to water scarcity and searching for more efficient methods to make safer the available water resources. The origin of the project is illustrated in the map of Europe that shows distribution of arsenic in the topsoil. It is clearly shown that Europe cannot be consider as the arsenic-free place The situation on other continents is even worse (like in South America or South-West Asia). Hence, a search for new methods for removal of arsenic from surface water seems to be of the highest priority. The treats from other water contaminant looks similar but they have various origins: chromium comes from human activities (metallurgy, leather industry, chemistry) mostly, boron comes from the use of fungicides, ceramics or results from irrigation with desalinated seawater, manganese is originated from various sectors of chemical and electronic industries.
Figure 1
There are many methods used for decreasing contents of toxic species in potable/agricultural waters but still some innovative methods are being developed and introduced to the industrial practice. The main objectives of the project were: i) to bring together some experts in water purification and create the conditions when they can develop new strategies for water decontaminations, ii) to launch new research on preparation of more versatile materials and methods for removal of toxic species, and iii) to promote collaboration with Chilean institutions and to transfer their knowledge to Europe.
At the beginning of the project two compounds were selected as targets: arsenic and chromium oxyanions. Both of them appear in Chilean and in European surface aquifers. To solve the problem with removal of arsenic and chromium components three participating teams has offered their experiences. University of Concepcion experts in the use of polymer enhanced filtration process that applied water soluble polymers with chelation properties. The dangerous species are adsorbed onto soluble polymers and as large complexes they were easily stopped by porous membrane. The pluses of this approach are: the use of small amounts of chelation polymer, running the process in homogeneous (what means easy to control) conditions, and easiness to scale-up the system. The minuses were related mostly to the use of water soluble polymers. Synthesis of polymers with large enough molecular weight that are not allowed to pass through porous membrane in rather difficult and not so cost effective. The fractionation of synthesized polymers raises the cost of separation process while membrane fouling phenomenon makes polymer enhanced filtration difficult to run. Ege University, the second partner, experts in the use of solvent impregnated resins. Filling of porous polymer matrix with hydrophobic organic liquid that can extract toxic compounds offer versatile separation method – depending of the need, polymer matrix can be impregnated with suitable liquid and use as selective sorbent. The minus of that method is weak operational stability of solvent impregnated resins. Organic solvent can dissolve in aqueous phase and contaminate it. In the same time, properties of impregnated resins change due to decrease of extractant and sorbent loses its capacity. Wroclaw University of Technology, the third partner of the project, experts in synthesis of porous polymer resins that carry selective ligands bound to their surface. Such structures can be used in various configurations: in fixed bed systems, in mixed bed systems, in fluidal systems and in hybrid systems. The sorbents can be regenerated and used in the cyclic mode. Difficult routes of their synthesis and weak versatility are their main disadvantages.
Synthesis of water soluble polymers and their use in separation of arsenates and chromates, and later borates or vanadates by the polymer enhanced techniques gave the background for the further studies. Preparation of solvent impregnated resins that did not lose their properties with time was the second step of the project. That materials were prepared for extraction of chromates and arsenates mostly. The last step was related to synthesis of fine porous polymer particles and grafted with polymer chains that bound chromates and arsenates. Additionally, that particles were filled with organic extractant and tested in sorption-membrane filtration system. It was found that the best properties in the process showed polymer particles grafted with polymeric chains. Solvent impregnated resins bled some amounts of organic liquid that fouled filtration membrane or passed through it contaminating water.
The CHILTURPOL2 ‘Innovative materials and methods for water treatment’ stays in line with the problems shown in above documents and is related to water scarcity and searching for more efficient methods to make safer the available water resources. The origin of the project is illustrated in the map of Europe that shows distribution of arsenic in the topsoil. It is clearly shown that Europe cannot be consider as the arsenic-free place The situation on other continents is even worse (like in South America or South-West Asia). Hence, a search for new methods for removal of arsenic from surface water seems to be of the highest priority. The treats from other water contaminant looks similar but they have various origins: chromium comes from human activities (metallurgy, leather industry, chemistry) mostly, boron comes from the use of fungicides, ceramics or results from irrigation with desalinated seawater, manganese is originated from various sectors of chemical and electronic industries.
Figure 1
There are many methods used for decreasing contents of toxic species in potable/agricultural waters but still some innovative methods are being developed and introduced to the industrial practice. The main objectives of the project were: i) to bring together some experts in water purification and create the conditions when they can develop new strategies for water decontaminations, ii) to launch new research on preparation of more versatile materials and methods for removal of toxic species, and iii) to promote collaboration with Chilean institutions and to transfer their knowledge to Europe.
At the beginning of the project two compounds were selected as targets: arsenic and chromium oxyanions. Both of them appear in Chilean and in European surface aquifers. To solve the problem with removal of arsenic and chromium components three participating teams has offered their experiences. University of Concepcion experts in the use of polymer enhanced filtration process that applied water soluble polymers with chelation properties. The dangerous species are adsorbed onto soluble polymers and as large complexes they were easily stopped by porous membrane. The pluses of this approach are: the use of small amounts of chelation polymer, running the process in homogeneous (what means easy to control) conditions, and easiness to scale-up the system. The minuses were related mostly to the use of water soluble polymers. Synthesis of polymers with large enough molecular weight that are not allowed to pass through porous membrane in rather difficult and not so cost effective. The fractionation of synthesized polymers raises the cost of separation process while membrane fouling phenomenon makes polymer enhanced filtration difficult to run. Ege University, the second partner, experts in the use of solvent impregnated resins. Filling of porous polymer matrix with hydrophobic organic liquid that can extract toxic compounds offer versatile separation method – depending of the need, polymer matrix can be impregnated with suitable liquid and use as selective sorbent. The minus of that method is weak operational stability of solvent impregnated resins. Organic solvent can dissolve in aqueous phase and contaminate it. In the same time, properties of impregnated resins change due to decrease of extractant and sorbent loses its capacity. Wroclaw University of Technology, the third partner of the project, experts in synthesis of porous polymer resins that carry selective ligands bound to their surface. Such structures can be used in various configurations: in fixed bed systems, in mixed bed systems, in fluidal systems and in hybrid systems. The sorbents can be regenerated and used in the cyclic mode. Difficult routes of their synthesis and weak versatility are their main disadvantages.
Synthesis of water soluble polymers and their use in separation of arsenates and chromates, and later borates or vanadates by the polymer enhanced techniques gave the background for the further studies. Preparation of solvent impregnated resins that did not lose their properties with time was the second step of the project. That materials were prepared for extraction of chromates and arsenates mostly. The last step was related to synthesis of fine porous polymer particles and grafted with polymer chains that bound chromates and arsenates. Additionally, that particles were filled with organic extractant and tested in sorption-membrane filtration system. It was found that the best properties in the process showed polymer particles grafted with polymeric chains. Solvent impregnated resins bled some amounts of organic liquid that fouled filtration membrane or passed through it contaminating water.