Patrick Drogui

To our knowledge, this is the first comprehensive study to investigate how the lifespan and performance of ion‐exchange membranes are affected during electrodialysis of run‐off water laden with road de‐icing salts. This study focuses on optimizing electrocoagulation (EC) and sand filtration as pretreatment methods to reduce membrane clogging in electrodialysis desalination of road run‐off water from de‐icing salts (RRWs). The goal was to minimize membrane fouling. Using factorial and central composite designs, 26 experiments were conducted to identify optimal EC conditions for turbidity and suspended solids (SS) removal. Results showed that electrolysis time was the most significant factor, achieving 78% SS and 86% turbidity removal. The optimal conditions—1.8 A for 3.8 min using an aluminium electrode—achieved over 98% removal. Sand filtration, by comparison, achieved 73.8% SS removal and 66% turbidity removal. Electrodialysis of clarified RRWs revealed that sand filtration led to a 10% decrease in chloride‐ion separation and a 7% increase in energy consumption compared to EC pretreatment.

Geopolymers have recently emerged as a promising class of inorganic aluminosilicate polymer materials. They present a viable alternative to Portland cement, which is well known for its significant contribution to greenhouse gas emissions. To support the reduction of these emissions, this study aims to develop geopolymer cements by investigating the impact of rice husk ash on the geopolymerization of local kaolinite clay using an alkaline solution. Rice husk ash (with a SiO₂ content of 91.6%), obtained by calcining rice husks at 600°C, serves as a source of amorphous silica. The GP₀ geopolymer material, derived from clay calcined at 750°C and activated with a 12N sodium hydroxide solution, exhibits a compressive strength of 9.9 MPa. This mechanical strength was enhanced by incorporating rice husk ash, which produces sodium silicate solutions as activators. The addition of 10% rice husk ash increased the compressive strength from 9.9 MPa to 15.9 MPa. The sodium silicate solution derived from the ash proved to be an effective alkaline activator in the geopolymer synthesis. Consequently, rice husk ash can potentially replace commercial sodium silicate solutions, contributing to the formulation of more eco-friendly materials. However, further research is needed to optimize the mechanical properties of these geopolymers.