Photodegradation of Molasses Wastewater Using TiO2–ZnO Nanohybrid Photocatalyst Supported on Activated Carbon

Benton Otieno, Seth Apollo, Bobby E. Naidoo, Aoyi Ochieng

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

Molasses wastewater (MWW) is characterized by high organic loading and a recalcitrant dark brown color. A study was carried out to determine the photocatalytic efficiency of TiO2–ZnO nanohybrid supported onto activated carbon (AC) for the remediation of MWW. Immobilization of ZnO onto TiO2 formed TiO2–ZnO, which was then supported onto AC forming TiO2–ZnO–AC composite. X-ray diffraction (XRD), scanning electron (SEM), energy-dispersive X-ray (EDX) and Fourier transform infrared (FTIR) spectroscopies, and transmission electron (TEM) microscopy revealed the successful hybridization of TiO2 and ZnO, and the subsequent support of the hybrid onto AC. Photoluminescence (PL) spectroscopy further revealed a restrained electron-hole pair recombination resulting from both the successful formation of a heterojunction, and the introduction of electron accepting AC support. Photodegradation process was monitored by color and total organic carbon (TOC) reductions. It was observed that TiO2–ZnO (ratio 3:1) supported onto AC (30% loading) had a higher adsorptive capacity and catalytic activity than bare TiO2–ZnO resulting in a 14% increment in overall color reduction. UV-photodegradation was found to be very effective for color as compared to TOC reduction, with 96% and 9% reductions, respectively, after 1 hour of irradiation. A pH of 5 was found to be optimum for photodegradation.

Original languageEnglish
Pages (from-to)1443-1454
JournalChemical Engineering Communications
Volume203
Issue number11
DOIs
Publication statusPublished - 2016

Fingerprint

Molasses
Photodegradation
Photocatalysts
Activated carbon
Wastewater
Color
Electrons
Organic carbon
Infrared transmission
Photoluminescence spectroscopy
Remediation
Fourier transform infrared spectroscopy
Heterojunctions
Catalyst activity
Microscopic examination
Irradiation
Transmission electron microscopy
Scanning
X ray diffraction
X rays

Cite this

@article{ba1e3ceda3e84e8abe3d7509ba7cd834,
title = "Photodegradation of Molasses Wastewater Using TiO2–ZnO Nanohybrid Photocatalyst Supported on Activated Carbon",
abstract = "Molasses wastewater (MWW) is characterized by high organic loading and a recalcitrant dark brown color. A study was carried out to determine the photocatalytic efficiency of TiO2–ZnO nanohybrid supported onto activated carbon (AC) for the remediation of MWW. Immobilization of ZnO onto TiO2 formed TiO2–ZnO, which was then supported onto AC forming TiO2–ZnO–AC composite. X-ray diffraction (XRD), scanning electron (SEM), energy-dispersive X-ray (EDX) and Fourier transform infrared (FTIR) spectroscopies, and transmission electron (TEM) microscopy revealed the successful hybridization of TiO2 and ZnO, and the subsequent support of the hybrid onto AC. Photoluminescence (PL) spectroscopy further revealed a restrained electron-hole pair recombination resulting from both the successful formation of a heterojunction, and the introduction of electron accepting AC support. Photodegradation process was monitored by color and total organic carbon (TOC) reductions. It was observed that TiO2–ZnO (ratio 3:1) supported onto AC (30{\%} loading) had a higher adsorptive capacity and catalytic activity than bare TiO2–ZnO resulting in a 14{\%} increment in overall color reduction. UV-photodegradation was found to be very effective for color as compared to TOC reduction, with 96{\%} and 9{\%} reductions, respectively, after 1 hour of irradiation. A pH of 5 was found to be optimum for photodegradation.",
author = "Benton Otieno and Seth Apollo and Naidoo, {Bobby E.} and Aoyi Ochieng",
year = "2016",
doi = "10.1080/00986445.2016.1201659",
language = "English",
volume = "203",
pages = "1443--1454",
journal = "Chemical Engineering Communications",
issn = "0098-6445",
publisher = "Taylor and Francis Ltd.",
number = "11",

}

Photodegradation of Molasses Wastewater Using TiO2–ZnO Nanohybrid Photocatalyst Supported on Activated Carbon. / Otieno, Benton; Apollo, Seth; Naidoo, Bobby E.; Ochieng, Aoyi.

In: Chemical Engineering Communications, Vol. 203, No. 11, 2016, p. 1443-1454.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Photodegradation of Molasses Wastewater Using TiO2–ZnO Nanohybrid Photocatalyst Supported on Activated Carbon

AU - Otieno, Benton

AU - Apollo, Seth

AU - Naidoo, Bobby E.

AU - Ochieng, Aoyi

PY - 2016

Y1 - 2016

N2 - Molasses wastewater (MWW) is characterized by high organic loading and a recalcitrant dark brown color. A study was carried out to determine the photocatalytic efficiency of TiO2–ZnO nanohybrid supported onto activated carbon (AC) for the remediation of MWW. Immobilization of ZnO onto TiO2 formed TiO2–ZnO, which was then supported onto AC forming TiO2–ZnO–AC composite. X-ray diffraction (XRD), scanning electron (SEM), energy-dispersive X-ray (EDX) and Fourier transform infrared (FTIR) spectroscopies, and transmission electron (TEM) microscopy revealed the successful hybridization of TiO2 and ZnO, and the subsequent support of the hybrid onto AC. Photoluminescence (PL) spectroscopy further revealed a restrained electron-hole pair recombination resulting from both the successful formation of a heterojunction, and the introduction of electron accepting AC support. Photodegradation process was monitored by color and total organic carbon (TOC) reductions. It was observed that TiO2–ZnO (ratio 3:1) supported onto AC (30% loading) had a higher adsorptive capacity and catalytic activity than bare TiO2–ZnO resulting in a 14% increment in overall color reduction. UV-photodegradation was found to be very effective for color as compared to TOC reduction, with 96% and 9% reductions, respectively, after 1 hour of irradiation. A pH of 5 was found to be optimum for photodegradation.

AB - Molasses wastewater (MWW) is characterized by high organic loading and a recalcitrant dark brown color. A study was carried out to determine the photocatalytic efficiency of TiO2–ZnO nanohybrid supported onto activated carbon (AC) for the remediation of MWW. Immobilization of ZnO onto TiO2 formed TiO2–ZnO, which was then supported onto AC forming TiO2–ZnO–AC composite. X-ray diffraction (XRD), scanning electron (SEM), energy-dispersive X-ray (EDX) and Fourier transform infrared (FTIR) spectroscopies, and transmission electron (TEM) microscopy revealed the successful hybridization of TiO2 and ZnO, and the subsequent support of the hybrid onto AC. Photoluminescence (PL) spectroscopy further revealed a restrained electron-hole pair recombination resulting from both the successful formation of a heterojunction, and the introduction of electron accepting AC support. Photodegradation process was monitored by color and total organic carbon (TOC) reductions. It was observed that TiO2–ZnO (ratio 3:1) supported onto AC (30% loading) had a higher adsorptive capacity and catalytic activity than bare TiO2–ZnO resulting in a 14% increment in overall color reduction. UV-photodegradation was found to be very effective for color as compared to TOC reduction, with 96% and 9% reductions, respectively, after 1 hour of irradiation. A pH of 5 was found to be optimum for photodegradation.

U2 - 10.1080/00986445.2016.1201659

DO - 10.1080/00986445.2016.1201659

M3 - Article

VL - 203

SP - 1443

EP - 1454

JO - Chemical Engineering Communications

JF - Chemical Engineering Communications

SN - 0098-6445

IS - 11

ER -