Conidi Carmela, Macedonio Francesca, Ali Aamer, Cassano Alfredo, Criscuoli Alessandra, Argurio Pietro, Drioli Enrico
Institute on Membrane Technology, ITM-CNR, c/o University of Calabria, via P. Bucci, 17/C, I-87036 Rende (CS), Italy.
Department of Environmental and Chemical Engineering, University of Calabria, Via P. Bucci, 44/A, I-87036 Rende (CS), Italy.
Membranes (Basel). 2018 Nov 26;8(4):117. doi: 10.3390/membranes8040117.
An integrated membrane process for the treatment of wastewaters from a flue gas desulfurization (FGD) plant was implemented on a laboratory scale to reduce their salt content and to produce a water stream to be recycled in the power industry. The process is based on a preliminary pretreatment of FGD wastewaters, which includes chemical softening and ultrafiltration (UF) to remove Ca and Mg ions as well as organic compounds. The pretreated wastewaters were submitted to a reverse osmosis (RO) step to separate salts from water. The RO retentate was finally submitted to a membrane distillation (MD) step to extract more water, thus increasing the total water recovery factor while producing a high-purity permeate stream. The performance of RO and MD membranes was evaluated by calculating salts rejection, permeate flux, fouling index, and water recovery. The investigated integrated system allowed a total recovery factor of about 94% to be reached, with a consequent reduction of the volume of FGD wastewater to be disposed, and an MD permeate stream with an electrical conductivity of 80 μS/cm, able to be reused in the power plant, with a saving in fresh water demand.
在实验室规模上实施了一种用于处理烟气脱硫（FGD）工厂废水的集成膜工艺，以降低其盐分含量，并产生可在电力行业中循环利用的水流。该工艺基于FGD废水的初步预处理，包括化学软化和超滤（UF），以去除钙和镁离子以及有机化合物。预处理后的废水进入反渗透（RO）步骤以实现水盐分离。RO截留液最终进入膜蒸馏（MD）步骤以提取更多水分，从而提高总水回收率，同时产生高纯度渗透物流。通过计算盐分截留率、渗透通量、污染指数和水回收率来评估RO和MD膜的性能。所研究的集成系统实现了约94%的总回收率，从而减少了需处置的FGD废水量，并且MD渗透物流的电导率为80 μS/cm，可在发电厂中重复使用，节省了新鲜水需求量。
