Boron removal by activated carbon and microfiltration for pre-treatment of seawater desalination

摘要

This study aimed to enhance boron removal through powdered activated carbon adsorption (PAC) and application of a micro-filtration (MF) process as a pretreatment of a seawater reverse osmosis (SWRO) process. Batch and continuous experiments were conducted to investigate the effect of membrane filtration as well as PAC addition on boron removal in reconstituted seawater. In batch test, two kinds of polyvinylidene fluoride (PVDF) hollow fiber membrane, Module A and Module B, were used to assess the influence of pH and PAC on boron removal, whereas in continuous mode, two MF systems with submerged PVDF flat-sheet membrane were run in parallel. Modules A and B obtained the highest percentage boron removal at pH 9 in the batch experiment with an average value of 47.33%, and their concentration of boron was further reduced after addition of PAC increasing the removal to 51.33 and 69.33%, respectively. For the continuous operation, PAC addition decreased the boron concentration by 20-30 and 40% in the reactor and effluent, respectively. On the other hand, only 5% reduction was obtained inside the reactor and 30-40% in the effluent for the system without PAC. Thus, operating the system at high pH with PAC addition could enhance the performance of the adsorption-MF system, which can be used as a pretreatment for the SWRO process.