AP19577049 Synthesis, characterization and physicochemical study of sorbents of biomass origin for purification of industrial waters from radionuclides
The goals of the project: (1) to synthesize activated carbons by chemical activation, doping with nitrogen using the hydrothermal method, (2) to characterize the material and (3) to test their use for industrial samples of the National Atomic Center (Kurchatov).
Relevance:
The problem this project addresses is Kazakhstan's growing need to clean up radioactive runoff from existing uranium mines (129 in total) that leach radioisotopes into fresh water (eg, on the Shu River, South Kazakhstan) (1); modern biomedical treatments using radioisotopes (eg 124I and 131I) (2) in hospitals; future introduction of nuclear energy in the country (3) and support the decontamination of the site where nuclear weapons were tested (Semipalatinsk Test Site (SIP) and which is a source of radionuclides (137Cs) into the environment.
Our approach to this will be to prepare a device for capturing radionuclides from contaminated wastewater. The device will be made by converting lignocellulose-rich agricultural waste biomass (walnut husks, rice husks, buckwheat husks) into carbon-containing material. These carbon materials will be modified (with sulfur, nitrogen, silver and ferrocyanide) to introduce active sites capable of trapping the above radionuclides. The device will be produced using hydrothermal synthesis, pyrolysis and pyrolysis followed by activation. To achieve this, modifications before and after heat treatment will be tested. the sorbent will be included in a carbon monolith (made of powdered carbon and resin). Carbon materials are known to shield radiation, which makes them safer to use. This study will also examine the recovery of the resulting sorbent from radioisotope sand during reuse. The device is expected to have a surface area of >200 m2 and include meso (2-50 nm) and macro porosity (>50 nm), reduce radionuclide concentrations by 50% each cycle, operate in a recirculation mode, and be capable of treating water over a wide range pH appropriate for the application. These results will be published in Q1 journals (3), presented at local and international conferences (3) and regularly posted on social media. This research will help train budding researchers (4) and will contribute to the improvement of the country's universities in collaboration with them. The team has proof of concept for the core of the device (preparing sorbent from a biomass type only) at technology readiness level (TRL3) and experience scaling up to pilot production from previously produced carbon-based materials that are now commercially available. We aim to achieve TRL 6, which will bring the device closer to commercialization and impact jobs in Kazakhstan, as well as have a greater impact on environmental health, especially as the device is scaled up. The scientific organizations involved include KazNRTU named after. K.I. Satpayev with experience in the field of materials science, in particular carbon materials, the National Nuclear Center (Kurchatov), which will be the end user of the technology and will test the separation of radionuclides using the device, as well as international cooperation, including Kingston University (UK) with experience in analytical characterization of materials, nanotechnology, wastewater treatment and has connections with the nuclear, military and water industries. All organizations previously collaborated in separate consortia. This project will find the best approach to prepare an effective radionuclide decontamination device, validate it in the laboratory and in two relevant scenarios (cleaning up contaminated fresh water and nuclear waste).
As part of this project, a tool will be developed that will make Kazakhstani sites that are contaminated with radionuclides and have fresh water flows (mines and former nuclear test sites) safer. These are pressing issues that need to be addressed. It will also allow Kazakhstan to recycle radioactive waste from hospitals. Finally, it will support Kazakhstan in preparing for the introduction of a nuclear industry, helping to improve nuclear waste management and protect waste streams from the radiation pollution that will be generated. The outcome of this study will be of international significance as the issues addressed are of global importance.
Scientific supervisor: PhD, Kudaibergenov K.K.
Quantitative and qualitative composition of project performers: 7 performers, consisting of: 3 PhD doctors, 2 masters, 2 bachelors.
Results:
A technology for producing sorbents has been developed. The kinetics and isotherm of radionuclide sorption were studied using the example of the non-toxic stable isotope 127I on a series of activated carbons obtained from waste buckwheat (457 mg/g), rice husk (462 mg/g) and walnut shells (459 mg/g).
project start – 2023
Implementation period: 2023-2025.