Activity Reduction of ²³²Th and ⁴⁰K from Simulated Underground Water Using a Clay-Based Membrane

¹ Department of Mechanical Engineering, Bayero University Kano, PMB 3011 Nigeria
² Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, Johor Bahru, Malaysia

^* Corresponding author: amuazu.mec@buk.edu.ng

Abstract

In this research, the activities of ²³²Th and ⁴⁰K in simulated underground water were reduced using inexpensive clay-based membrane. Starch (10 and 15 wt%) was added to the clay, compacted and fired up to 1300°C to produce the porous membranes. The characterization of the raw clay and the produced membranes was conducted using XRF, XRD, TGA/DTA, BET and FESEM. The activities of ²³²Th and ⁴⁰K in the waste and permeated water were counted using gamma spectroscopy. The produced membranes were having pore sizes in the range 39.68-46.10nm; from the BET isotherm, it shows the membranes produced are mesoporous. Also, the steady flux of the filtered water was found to be in the range 3.83×10^-7-1.77×s10^-6 m³m^-2s^-1. Activities of thorium and potassium in the permeated water were found to be 4.57-5.61 Bq/l and 15.49-25.19 Bq/l respectively. This shows that inexpensive clay can be used to reduce the activities of thorium and potassium in underground water from mining, fracking and produced water from oil and gas.