Arsenite removal by adsorption onto iron oxide-coated pumice and sepiolite

Abstract

The present study describes the removal of arsenite by iron oxide-coated pumice and iron oxide-coated sepiolite. Pumice and sepiolite were coated with iron oxide and used as adsorbents for the removal of arsenite from aqueous solution in batch experiments. Arsenite concentration decreased exponentially with time, and equilibrium was attained in 84 h. The kinetics of the adsorption process was tested for the pseudo-first-order, pseudo-second-order, and intraparticle diffusion models. The adsorption of arsenite onto iron oxide-coated pumice and iron oxidecoated sepiolite followed the pseudo-second-order model. Freundlich, Dubinin-Radushkevitch, and Temkin isotherm models were applied to the experimental equilibrium data. The adsorption of arsenite fit these isotherm models. The results indicated that the iron oxide-coated pumice and iron oxide sepiolite could be alternative adsorbents for arsenite removal. Among the adsorbents, iron oxide-coated pumice was found to be more effective than iron oxide sepiolite in the removal of arsenite.

Geochemical properties and pollution assessment of heavy metals in the sediments of Daechung Lake, Korea

“…Concentrations of As were highest in the sediments collect at station Dam, where the clay fraction was the highest and the silt fraction was the lowest among study stations (Exhibits and ). It is well‐known that As has a high affinity with Fe oxides (Öztel, Akbal, & Altaş, ). In addition, clays and their minerals (e.g., smectites and kaolinite) also play a role as absorbents for heavy metals, including As (Lin & Puls, ; Uddin, ).…”

“…Concentrations of As were highest in the sediments collect at station Dam, where the clay fraction was the highest and the silt fraction was the lowest among study stations (Exhibits 5 and 6). It is well-known that As has a high affinity with Fe oxides (Öztel, Akbal, & Altaş, 2015).…”

Doğal ve modifiye edilmiş sepiyolit ile sulu çözeltilerden arsenik ve manganın adsorpsiyon ile ayrımı

“…Doğal sepiyolitin As(V) adsorpsiyon kapasitesi, sepiyolitin kaynağına ve çözeltinin başlangıç pH'na bağlı olarak 0.005-10.5 mg g -1 aralığında değişmektedir. Diğer yandan, NaOH, Fe (III) oksihidroksit [24], [52], [53], [55] ve 2-aminometilpridin (AMP) [23] ile modifikasyonlar, sepiyolitin adsorpsiyon kapasitesini önemli miktarda artırabilmektedir. Literatürde rapor edilmiş sonuçlar, sepiyolitin çoğunlukla Fe (III) oksihidroksit ile modifiye edildiğinde ve başlangıç pH'ın değerine bağlı olarak sepiyolitin As(V) adsorpsiyon kapasitesinin 50.0 mg g -1 'a kadar arttığı rapor edilmiştir [24], [52], [55].…”

Modifiye Edilmiş Pomza Kullanılarak Sulu Ortamlardan Adsorpsiyon Prosesi ile Arsenat (V) Giderimi

“…konsantrasyon aralığında, optimum koşullarda sulu çözeltilerden As(V) adsorpsiyonunda elde edilen deneysel verilerinin Langmuir, Freundlich ve D-R izotermlerine uygunluğu incelenmiştir. HIP (kırmızı) ve DOKIP (yeşil)'nın FTIR spektrumu[16,17]. Gözlenmiş olan bu farklılıklar HIP üzerine demir oksit kaplama işleminin gerçekleştiğini göstermektedir.…”

“…konsantrasyon aralığında, optimum koşullarda sulu çözeltilerden As(V) adsorpsiyonunda elde edilen deneysel verilerinin Langmuir, Freundlich ve D-R izotermlerine uygunluğu incelenmiştir [16,17]…”