An international conference on multiphase flow was held at the campus of the Federal University of Rio de Janeiro (UFRJ) in Brazil on May 7-9, 2025. Formally called "Challenges and Opportunities in Porous Media Multiphase Flow and Contaminant Transport", the conference was organized by the LASME section within the Department of Nuclear Engineering of COPPE/UFRJ at the occasion of the 80th birthday of Martinus Th. (“Rien”) van Genuchten (pictured to the far left alongside Menggui Jin).

In 2018, Dr. van Genuchten received the groundwater award of the Prince Sultan Bin Abdulaziz International Prize for Water (PSIPW) for his long-time work on water flow and contaminant transport in variably saturated porous media. In 2023, for similar reasons, he won the Wolf Prize in agriculture.

Dr. van Genuchten is a collaborating professor of UFRJ’s Department of Nuclear Engineering.

About 150 participants from all over the world, including many who worked with Dr. van Genuchten over the years or benefitted from his work, attended the conference.

Participants represented a mixed group of soil, hydrogeology, agricultural and environmental groups, with several also representing the oil and gas industry and mining/milling operations in Brazil and elsewhere. Many are or were previous coauthors, colleagues or past students of Dr. van Genuchten.

PSIPW supported the plenary speaker, Menggui Jin, Professor of Hydrogeology at China University of Geosciences, who spoke on "Nitrogen dynamics in hyporheic zones: Interactions among porous media flow, reactive nutrient transport, and biofilm growth".

Professor Jin is a distinguished hydrogeologist specializing in variably saturated flow, groundwater systems, surface–groundwater interactions, and soil-water dynamics. He has led numerous National Natural Science Foundation of China (NSFC) projects, focusing on topics such as groundwater recharge patterns, soil salinity regulation, and the transport of contaminants like chromium and cadmium in agricultural settings. His research also addresses water-saving irrigation strategies and the remediation of polluted water and soil.

Professor Jin's work frequently incorporates the van Genuchten model, a widely used framework for describing soil-water retention and hydraulic conductivity in unsaturated soils. For instance, he has applied this model to study the distribution of soil-water characteristic curves across China's Loess Plateau, employing trend surface analysis and regression methods to predict unsaturated permeability coefficients. Dr. van Genuchten developed the model in the 1980s, and it has since become a fundamental tool in soil science and hydrology. The widespread adoption of his model by prestigious researchers like Professor Jin highlights its enduring impact on the field.