This work deals with
the removal of Cr (III) and Cr (VI) from synthetic solutions via a novel
composite adsorbent prepared by precipitating iron (III) hydroxide on paper
mill sludge (PMS). To obtain Fe(OH)3 loaded PMS, -8+16 mesh fraction
of PMS was saponified with NaOH solution, then iron (III) chloride was
impregnated, hydrolyzed in NaOH solution and dried. The influences of pH, time,
initial concentration and temperature on removal of Cr (III) and Cr (VI) were
examined and it was determined that Cr (VI) removal occurs simultaneously with
a reduction reaction. Maximum removal yields for Cr (III) and Cr (VI) occurred
at approximately pH = 5 and the adsorption achieved equilibrium in 90 min. Cr
(VI) adsorption ratio decreases while Cr (III) removal percentage increases
with raising in temperature. Experimental results are consistent with Langmuir
isotherm. Adsorption capacities of Cr (III) and Cr (VI) were calculated as
8.49, 10.14, 12.62 mg/g and 7.64, 5.39 and 4.17 mg/g for 25, 40 and 55 °C,
respectively. Enthalpy changes for Cr (III) and Cr (VI) were calculated as
24.67 kJ/mol and -12.46 kJ/mol, respectively. These results demonstrated that
the adsorption phenomenon of Cr (III) and Cr (VI) are endothermic and
exothermic.
Birincil Dil | İngilizce |
---|---|
Konular | Kimya Mühendisliği |
Bölüm | Araştırma Makalesi |
Yazarlar | |
Yayımlanma Tarihi | 1 Aralık 2019 |
Gönderilme Tarihi | 11 Ekim 2018 |
Kabul Tarihi | 17 Ocak 2019 |
Yayımlandığı Sayı | Yıl 2019 |
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.