Group members

Our group consists of 6 people from which 4 are PhD students.

Here you can find the contact and personal information of our group.

Risto Koivula

Hi, my name is Risto Koivula and I have worked with ion exchangers since my graduation on radiochemistry in 1996 (M.Sc.). My first project concerned the removal of heavy metals from metal plating industry (Brite Euram EU-project 96-99) where chelating ion exchangers were used mainly as end-of-pipe polishing materials. Since then my focus has been on inorganic ion exchange materials. I got my PhD. (2003) from the selective removal of activated corrosion products from nuclear power plant waste waters utilizing highly selective metal oxides. The following years has been filled with different projects and innovations in the area of selective separations, working mainly with inorganic materials in association with nuclear and mining industry.

Over two decades work in the ion exchange group has deepened my knowledge and interest on the selective separations and educated me from the junior researcher into the group leader (2016) that I now am. This position allows me to seek out new materials and methods for selective separations and boldly use them in applications where they haven’t been used before.

Valtteri Suorsa

Back­ground and edu­ca­tion

I finished my master's thesis and received my M.Sc degree in Chemistry from University of Helsinki in spring term 2017. The subject of my master's thesis was the interaction of radionuclides with clay minerals, especially clay colloids. The work was done partly in University of Helsinki and partly in Institute for Nuclear Waste Disposal (INE) in Karslruhe Institute of Technology (KIT). In Karlsruhe I utilized Laser-Induced Breakdown Detection for particle analysis of montmorillonite colloids. During my studies I have worked as a research assistant in bentonite erosion and radionuclide sorption studies (2013-2015) before working on my Master's thesis. After finishing my M.Sc studies I worked over a year with nanofibres studied for decontamination materials for radioactive wastes.

Cur­rent work

I started my PhD project in 2018 and it deals with the removal of iodine from process and ground waters utilizing inorganic ionexchangers. Compared to the previous subject of my studies, the inorganic ion exchange research have a different approach and view to the same natural processes that are going in the sorption of radionuclides onto natural clay minerals. Of course, the material science is a new subject for me and offers a new branch of expertise to learn.

In­terests and skills

I have knowledge on different analytical methods for Radioactivity detection (LSC, gamma detectors), elemental analysis (ICP-MS, MP-OES), particle analysis (Dynamic Light Scattering, Zeta potential measurements), speciation analysis with HPLC-ICP-MS. In addition, during my PhD studies I have had chance to perform iodine related studies with X-ray absorption spectroscopy both at synchrotrons (Petra III, Alba) as well as laboratory-based instruments at Center for X-ray Spectroscopy at our university.

Group member doctoral researcher Valtteri Suorsa receives an highly distinguished Roy G. Post scholarship

Scholarship winner Valtteri Suorsa presented his research in the scholarship winners poster display session with his poster Zirconium Oxides for Radioactive Iodate Removal.

Roy G. Post awarded the scholarship to graduate and undergraduate students from all around the world who are accomplished and excel both inside and outside of their academic role in the field of nuclear waste management.

The annual Waste Management Symposia is regarded as a leading conference in the field of radioactive waste management and is held in 2022 between 6-10 of March in Phoenix Arizona USA.

Information on the Roy G. Post foundation can be found at the foundation website

Otto-Matti Hiltunen

Background and education

I originally come from the catalysis and green chemistry group of Helsinki university where I finished my Master’s project (2019). In my Masters’s thesis I was exploring the possibilities of carbon dioxide in the NHC-copper(I)-catalyzed synthesis of different carboxylic acids from unsaturated hydrocarbons. Organometallic chemistry, catalysis and CO2 utilization in organic synthesis were the main topics when working in the catalysis group. During my studies I have worked as a research assistant in the catalysis group and participated in two publications. These publications were related to copper(I)-Schiff-base-complexes in order to oxidize alcohols in a more selective and efficient ways and preparation of pharmaceutically relevant cyclic carbamate structures. I also have experience as a teaching assistant from basic inorganic chemistry laboratory courses.

Current work

I started my PhD project in May 2019 in which I develop strategies for group separation of lanthanides and actinides. The focus is on porous inorganics combined to different f-metal selective organic functional groups which create a framework for Ac/Ln selective hybridmaterials.

Interests and skills

I have experience in basic analytical techniques, such as GC-MS, LC and NMR. I am excited to gain expertise in the field of radiochemistry and I am also interested in learning new different techniques, for example XAS and XRD.

Miho Otaki


Education and background

I obtained a BSc degree in chemistry from the University of Tokyo, and an MSc degree in radiochemistry from the University of Helsinki. During the studies, I developed my knowledge in materials science (solid-state physics, transition-metal chemistry, etc.) and radiochemistry (radiochemical analysis, naturally occurring radioactivity, etc.). My background also includes research experience at the High Energy Accelerator Research Organization of Japan, Harvard School of Engineering and Applied Sciences, and the Radiation and Nuclear Safety Authority of Finland (Säteilyturvakeskus). 

Current work

I am currently working on the “USEMA” project funded by the Academy of Finland. The project aims at developing organic-inorganic hybrid materials for selective separation of Group 3 and f-block elements, where I am especially focusing on materials to separate Lu-177 for medical applications. 

Interests and skills

I have been interested in radionuclides since childhood, but the Fukushima nuclear disaster particularly kindled my passion to be a radiochemist. Throughout my research experience, I have learned various techniques of radiochemical analysis (gamma spectrometry, LSC), radiation dosimetry, materials characterization (XRD, AFM, XAS, electric and magnetic characterization), elemental analysis (MP-AES, ICP-MS), and inorganic synthesis.

Toni Penttinen


Education and background

I received my M. Sc. degree from University of Helsinki in 2020 after finishing my master’s thesis. The main focus of my studies was on radiochemistry, which proved to be immensely interesting to me. My previous work experience includes working at the Loviisa NPP (Fortum) and for the Finnish Radiation and Nuclear Safety Authority (STUK).

Current work

I am currently working in a joint project between the University of Helsinki and Fortum wherein I am developing a synthesis route for a strontium-selective ion-exchange material.

Interests and skills

Through my current work I have gotten valuable experience regarding gamma spectrometry, elemental analysis and synthesis work. Regarding radiochemistry, I am especially interested in the nuclear power industry.

Topi Suominen


Education and background

I finished my M.Sc. degree in chemistry and molecular sciences at the University of Helsinki in 2020. In my studies I focused on radiochemistry, and in my master's thesis I studied the current state of two mine waste sites, focusing on possible transport of radionuclides and other harmful elements. The thesis was done in cooperation between the Radiation and Nuclear Safety Authority (STUK) and the University of Helsinki. I've also worked as a university trainee at STUK in 2019 and 2018, where I was tasked with pretreatment of natural samples. I obtained my B.Sc. in chemistry from the University of Helsinki in 2018.

Current work

I am currently working as a PhD student in an Academy of Finland funded project “USEMA”, which aims at developing hybrid materials for ultra-selective separation of Group 3 and f-block elements.

Interests and skills

I have a lot of experience working with natural samples. I am familiar with gamma spectroscopy and elemental analysis with ICP-MS. I also have some experience with XRD and TGA along with some radioanalytical methods. My interests lie in all aspects of radiochemistry, from environmental radiochemistry and ion exchange applications to radiopharmaceutical chemistry.

Lauri Pettilä