Removal of Crotamiton from Reverse Osmosis Concentrate by a TiO2/Zeolite Composite Sheet

Abstract

Abstract:Reverse osmosis (RO) concentrate from wastewater reuse facilities contains concentrated emerging pollutants, such as pharmaceuticals. In this research, a paper-like composite sheet consisting of titanium dioxide (TiO 2 ) and zeolite was synthesized, and removal of the antipruritic agent crotamiton from RO concentrate was studied using the TiO 2 /zeolite composite sheet. The RO concentrate was obtained from a pilot-scale municipal secondary effluent reclamation plant. Effective immobilization of the two powders in the sheet made it easy to handle and to separate the photocatalyst and adsorbent from purified water. The TiO 2 /zeolite composite sheet showed excellent performance for crotamiton adsorption without obvious inhibition by other components in the RO concentrate. With ultraviolet irradiation, crotamiton was simultaneously removed through adsorption and photocatalysis. The photocatalytic decomposition of crotamiton in the RO concentrate was significantly inhibited by the water matrix at high initial crotamiton concentrations, whereas rapid decomposition was achieved at low initial crotamiton concentrations. The major degradation intermediates were also adsorbed by the composite sheet. This result provides a promising method of mitigating secondary pollution caused by the harmful intermediates produced during advanced oxidation processes. The cyclic use of the HSZ-385/P25 composite sheet indicated the feasibility of continuously removing crotamiton from RO concentrate.

Removing crotamiton from reverse osmosis concentrate by using coagulation and a rotating advanced oxidation contactor

“…Similar adsorption of crotamiton by the RAOC in the RO concentrate base tests compared with the ultrapure water base tests demonstrated that the coexisting matter in the RO concentrate (Exhibit 1) had no effect under the experimental condition. Similar results on the treatment of crotamiton using just the HSZ‐385/P25 composite sheet were obtained in another study (Xiang et al., 2017b).…”

“…As shown in Exhibit 7, of the three types of treatment, the lowest amount of degradation intermediates resulted from the treatment of crotamiton using the RAOC. In another report, it was confirmed that the degradation intermediates can be captured on the composite sheet through adsorption (Xiang et al., 2017b). The RAOC could similarly mitigate the negative effect of harmful degradation intermediates produced by advanced oxidation processes.…”

“…TiO 2 ‐HSZ‐385 composite sheets were prepared using organic polyethylene terephthalate (PET) fibers and a dual polymer retention system. Detailed information about the preparation of the composite sheet can be found elsewhere (Fukahori & Fujiwara, 2019; Xiang et al., 2017b).…”

“…During papermaking, Fukahori, Ichiura, Kitaoka, and Tanaka (2003) immobilized powdered TiO 2 photocatalyst and zeolite adsorbent to prepare a novel composite sheet. Such TiO 2 –zeolite composite sheets were also used in a study on treating crotamiton in the RO concentrate (Xiang, Fukahori, Yamashita, Tanaka, & Fujiwara, 2017b). A novel rotating advanced oxidation contactor (RAOC) equipped with composite TiO 2 –zeolite sheets was developed as well.…”

Special Issue on Wastewater Treatment and Reuse Technologies

“…Reverse osmosis (RO) concentrate from wastewater reuse facilities contains concentrated emerging pollutants, such as pharmaceuticals [16]. In an article entitled "Removal of Crotamiton from Reverse Osmosis Concentrate by a TiO 2 /Zeolite Composite Sheet", Xiang et al [17] assessed the removal of the antipruritic agent crotamiton from RO concentrate using a TiO 2 /zeolite composite sheet. The TiO 2 /zeolite composite sheet showed excellent performance for crotamiton adsorption without obvious inhibition by other components in the RO concentrate.…”