School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China.
School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China.
J Environ Sci (China). 2022 Jan;111:292-300. doi: 10.1016/j.jes.2021.03.046. Epub 2021 Apr 21.
The effects of Ca on membrane fouling and trace organic compounds (TrOCs) removal in an electric field-assisted microfiltration system were investigated in the presence of Na alone for comparison. In the electric field, negatively charged bovine serum albumin (BSA) migrated towards the anode far away from the membrane surface, resulting in a 42.9% transmembrane pressure (TMP) reduction in the presence of Na at 1.5 V. In contrast, because of the stronger charge shielding of Ca, the electrophoretic migration of BSA was limited and led to a neglectable effect of the electric field (1.5 V) on membrane fouling. However, under 3 V applied voltage, the synergistic effects of electrochemical oxidation and bridging interaction between Ca and BSA promoted the formation of denser settleable flocs and a thinner porous cake layer, which alleviated membrane fouling with a 64.5% decrease in TMP and nearly 100% BSA removal. The TrOCs elimination increased with voltage and reached 29.4%-80.4% at 3 V. The electric field could prolong the contact between TrOCs and strong oxidants generated on the anode, which enhanced the TrOCs removal. However, a stronger charge shielding ability of Ca weakened the electric field force and thus lowered the TrOCs removal.
在电场辅助微滤系统中，研究了 Ca 对膜污染和痕量有机物 (TrOCs) 去除的影响，并与单独存在 Na 的情况进行了比较。在电场中，带负电荷的牛血清白蛋白 (BSA) 向阳极迁移，远离膜表面，导致在 1.5 V 时存在 Na 的情况下跨膜压力 (TMP) 降低了 42.9%。相比之下，由于 Ca 的电荷屏蔽作用更强，BSA 的电泳迁移受到限制，电场 (1.5 V) 对膜污染的影响可以忽略不计。然而，在施加 3 V 电压下，电化学氧化和 Ca 与 BSA 之间桥接相互作用的协同效应促进了更致密的可沉降絮体和更薄的多孔蛋糕层的形成，从而减轻了膜污染，TMP 降低了 64.5%，BSA 几乎 100%被去除。随着电压的增加，TrOCs 的去除率也增加，在 3 V 时达到 29.4%-80.4%。电场可以延长 TrOCs 与阳极上生成的强氧化剂之间的接触时间，从而增强 TrOCs 的去除。然而，Ca 更强的电荷屏蔽能力削弱了电场力，从而降低了 TrOCs 的去除率。
