Carbon-cryogel hierarchical composites as effective and scalable filters for removal of trace organic pollutants from water
Research output: Contribution to journal › Article › peer-review
Effective technologies are required to remove organic micropollutants from large ﬂuid volumes to overcome present and future challenges in water and efﬂuent treatment. A novel hierarchical composite ﬁlter material for rapid and effective removal of polar organic contaminants from water was developed. The composite is fabricated from phenolic resin-derived carbon microbeads with controllable porous structure and speciﬁc surface area embedded in a monolithic, ﬂow permeable, poly(vinyl alcohol) cry- ogel. The bead-embedded monolithic composite ﬁlter retains the bulk of the high adsorptive capacity of the carbon microbeads while improving pore diffusion rates of organic pollutants. Water spiked with organic contaminants, both at environmentally relevant concentrations and at high levels of contami- nation, was used to determine the puriﬁcation limits of the ﬁlter. Flow through tests using water spiked with the pesticides atrazine (32 mg/L) and malathion (16 mg/L) indicated maximum adsorptive capac- ities of 641 and 591 mg pollutant/g carbon, respectively. Over 400 bed volumes of water contaminated with 32 mg atrazine/L, and over 27,400 bed volumes of water contaminated with 2 mg atrazine/L, were treated before pesticide guideline values of 0.1 mg/L were exceeded. High adsorptive capacity was maintained when using water with high total organic carbon (TOC) levels and high salinity. The toxicity of water ﬁltrates was tested in vitro with human epithelial cells with no evidence of cytotoxicity afterinitial washing.