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

Abstract

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.

Characteristics of membrane fouling by consecutive chemical cleaning in pressurized ultrafiltration as pre-treatment of seawater desalination

“…The virgin membrane recorded an initial flux of 140 LMH. The flux of the fouled membrane was observed to decrease obtaining only 35 LMH [9,16,41]. The schematic diagram of the lab-scale MF/UF system is shown in Fig.…”

Effect of chemical cleaning conditions on the flux recovery of MF membrane as pretreatment of seawater desalination

“…The initial flux using the virgin membrane was recorded with an average value of 130 LMH. The flux of the fouled membrane was observed to decrease significantly obtaining about 27 LMH [7,15,18,27].…”

“…Advantages of PVDF membrane include high mechanical strength, high thermal stability, low cost, and high chemical resistance [25,26]. The fouled membrane was made from a laboratory treating artificial seawater [27]. Artificial seawater [27] with humic acid and sodium alginate at 10 ppm was used as feed.…”

“…The fouled membrane was made from a laboratory treating artificial seawater [27]. Artificial seawater [27] with humic acid and sodium alginate at 10 ppm was used as feed. Specification of the hollow fiber membrane is summarized in Table 1.…”