Tang Chuyang Y, Fu Q Shiang, Robertson A P, Criddle Craig S, Leckie James O
Environmental Engineering and Science, Department of Civil and Environmental Engineering, Stanford University, Stanford, California 94305-4020, USA.
Environ Sci Technol. 2006 Dec 1;40(23):7343-9. doi: 10.1021/es060831q.
Perfluorooctane sulfonate (PFOS) and related substances are persistent, bioaccumulative, and toxic, and thus of substantial environmental concern. PFOS is an essential photolithographic chemical in the semiconductor industry with no substitutes yet identified. The industry seeks effective treatment technologies. The feasibility of using reverse osmosis (RO) membranes for treating semiconductor wastewater containing PFOS has been investigated. Commercial RO membranes were characterized in terms of permeability, salt rejection, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and membrane surface zeta potential (streaming potential measurements). Filtration tests were performed to determine the membrane flux and PFOS rejection. Over a wide range of feed concentrations (0.5 - 1500 ppm), the RO membranes generally rejected 99% or more of the PFOS. Rejection was better for tighter membranes, but was not affected by membrane zeta potential. Flux decreased with increasing PFOS concentration. While the flux reduction was severe for a loose RO membrane probably due to its higher initial flux, very stable flux was maintained for tighter membranes. At a very high feed concentration (about 500 ppm), all the membranes exhibited an identical stable flux. Isopropyl alcohol, present in some semiconductor wastewaters, had a detrimental effect on membrane flux. Where present it needs to be removed from the wastewater prior to using RO membranes.
全氟辛烷磺酸（PFOS）及相关物质具有持久性、生物累积性和毒性，因此受到了极大的环境关注。PFOS是半导体行业中一种重要的光刻化学品，目前尚未找到替代品。该行业正在寻求有效的处理技术。研究了使用反渗透（RO）膜处理含PFOS半导体废水的可行性。对商用RO膜进行了渗透率、脱盐率、扫描电子显微镜（SEM）、透射电子显微镜（TEM）以及膜表面zeta电位（流动电位测量）等方面的表征。进行过滤测试以确定膜通量和PFOS截留率。在较宽的进料浓度范围（0.5 - 1500 ppm）内，RO膜通常能截留99%或更多的PFOS。截留率对于孔径更小的膜更好，但不受膜zeta电位的影响。通量随着PFOS浓度的增加而降低。虽然对于孔径较大的RO膜通量降低很严重，可能是由于其初始通量较高，但对于孔径更小的膜通量能保持非常稳定。在非常高的进料浓度（约500 ppm）下，所有膜都表现出相同的稳定通量。一些半导体废水中存在的异丙醇对膜通量有不利影响。如果存在，在使用RO膜之前需要从废水中去除。
