REMOVAL AND RECOVERY OF BORON FROM PRODUCED WATER BY ELECTROCOAGULATION AND HYDROTHERMAL MINERALIZATION

Produced water is the largest wastestream of oil and gas exploration and a major
supplement to the increased limited freshwater supply. It is therefore necessary to
ensure that the quality of produced water meets the appropriate standard for use as
potable water. This study investigated the removal and recovery of boron from
produced water by electrocoagulation and hydrothermal mineralization. The
efficiency of the study was investigated in both the batch and continuous mode using
aluminum and iron electrodes. Preliminary studies were conducted with synthetic
wastewater and the obtained optimum conditions applied to produced water. Different
operating parameters were investigated. They include pH, current density, initial
concentration, electrolysis time, inter-electrode spacing, flow rate, retention time. pH
played a significant role in removal efficiency with the best removal efficiency around
pH 7 for both electrodes. Increase in current density also increased removal
efficiency. When the initial concentration was increased, removal efficiency
decreased. Increase in electrolysis time increased removal efficiency. However, when
the spacing between electrodes was increased, removal efficiency decreased. The
removal efficiency decreased when the flowrate was increased. Increase in retention
time also resulted in increase in removal efficiency. A removal efficiency of 98% and
88% were observed for the batch and continuous mode study respectively using
aluminum electrode while a removal efficiency of 97% and 78% were observed for
the batch and continuous mode study, respectively using iron electrode.