Nanocomposite ultrafiltration membrane incorporating zinc/iron oxide photocatalyst for decolourisation of treated palm oil mill effluent

Palm oil mill effluent (POME) is brownish, high organic loading effluent produced by palm oil industry. Conventionally used biological treatment has successfully reduced the biochemical oxygen demand of POME below 25 ppm, which is considered as clean effluent. However, chemical oxygen demand (COD) a...

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Main Author:	Tan, Yi Hong
Format:	Thesis
Language:	English
Published:	2020
Subjects:	TP Chemical technology
Online Access:	http://eprints.utm.my/id/eprint/92506/1/TanYiHongPSChE2020.pdf.pdf
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spelling	my-utm-ep.925062021-09-30T15:11:16Z Nanocomposite ultrafiltration membrane incorporating zinc/iron oxide photocatalyst for decolourisation of treated palm oil mill effluent 2020 Tan, Yi Hong TP Chemical technology Palm oil mill effluent (POME) is brownish, high organic loading effluent produced by palm oil industry. Conventionally used biological treatment has successfully reduced the biochemical oxygen demand of POME below 25 ppm, which is considered as clean effluent. However, chemical oxygen demand (COD) and colour of the aerobically treated palm oil mill effluent (AT-POME) are still high. Therefore, tertiary treatment such as membrane processes are used to further polish AT-POME in order to reduce its COD and colour to meet discharge standard. However, fouling becomes severe issue in restricting the membrane lifespan and usage in this application. This work aimed to develop hybrid photocatalytic membranes with self-cleaning properties to mitigate the membrane fouling and also photodegrades the chemical compounds in AT-POME. First, coupled zinc-iron oxide (ZIO) was synthesized from its precursor, i.e. zinc nitrate and iron (III) nitrate through solution combustion by varying the molar ratio between zinc and iron (ranging from 1:1 to 1:4 with respect to zinc to iron ratio). Second, the optimum molar ratio of ZIO was calcined at temperature ranging from 400?C to 800?C. Third, the self-synthesised ZIO was incorporated into polyvinylidene fluoride (PVDF) polymer matrix to produce mixed matrix photocatalytic ultrafiltration membrane (MMMs) for decolourisation of AT-POME. Five membranes were formulated by varying ZIO from 0.0 wt % to 2.0 wt%. The fabricated membranes were subjected to physico-chemical analysis, i.e. field emission scanning electron microscope, energy dispersive X-ray spectroscopy, X-ray diffraction, Brunauer-Emmett-Teller, ultraviolet-visible-near infrared, absorption test, filtration process, photodegradation test to identify the self-cleaning properties, separation performance and fouling mitigation properties. Based on the experimental results, ZIO with 1:4 zinc to iron ratio was the optimum ZIO which provided large surface area (30.9130 m2/g), lowest band gap energy (2.07 eV), high photocatalytic activity (achieved 35% of mineralisation in 6.5 hours and 100% degradation in 3.5 hours). On the other hand, as calcination temperature increased, the particle size of ZIO increased gradually. This phenomenon led to the decrease of surface area of ZIO that reduced its performance in absorption and photodegradation of organic compounds. The results demonstrated that calcination temperature of 500?C was the optimum temperature to provide the highest photodegradation. For the MMMs, as the ZIO loading increased, the porosity decreased, and surface negativity increased. However, when higher loading of ZIO was used, the mechanical strength of the membrane structure deteriorated and cannot withstand long-term operation. Therefore, the optimum loading was identified as 0.5 wt% ZIO in which the membrane achieved 75% colour removal efficiency with flux of 20 – 25 LMH (L.m-2.hr-1). Furthermore, the self-fabricated MMMs photocatalytic ultrafiltration (UF) membrane possess the high flux recovery after ultraviolet and visible light cleaning, i.e. 92.3% and 90.3%, respectively. The addition of ZIO in polymeric matrix enabled the photodegradation of colour pigments in AT-POME. After 16 hours of operation, the colour of AT-POME reduced by 8%. In a nutshell, PVDF/ZIO photocatalytic UF membrane had successfully decolourised AT-POME and reduced its COD. 2020 Thesis http://eprints.utm.my/id/eprint/92506/ http://eprints.utm.my/id/eprint/92506/1/TanYiHongPSChE2020.pdf.pdf application/pdf en public http://dms.library.utm.my:8080/vital/access/manager/Repository/vital:139294 phd doctoral Universiti Teknologi Malaysia Faculty of Engineering - School of Chemical & Energy Engineering
institution	Universiti Teknologi Malaysia
collection	UTM Institutional Repository
language	English
topic	TP Chemical technology
spellingShingle	TP Chemical technology Tan, Yi Hong Nanocomposite ultrafiltration membrane incorporating zinc/iron oxide photocatalyst for decolourisation of treated palm oil mill effluent
description	Palm oil mill effluent (POME) is brownish, high organic loading effluent produced by palm oil industry. Conventionally used biological treatment has successfully reduced the biochemical oxygen demand of POME below 25 ppm, which is considered as clean effluent. However, chemical oxygen demand (COD) and colour of the aerobically treated palm oil mill effluent (AT-POME) are still high. Therefore, tertiary treatment such as membrane processes are used to further polish AT-POME in order to reduce its COD and colour to meet discharge standard. However, fouling becomes severe issue in restricting the membrane lifespan and usage in this application. This work aimed to develop hybrid photocatalytic membranes with self-cleaning properties to mitigate the membrane fouling and also photodegrades the chemical compounds in AT-POME. First, coupled zinc-iron oxide (ZIO) was synthesized from its precursor, i.e. zinc nitrate and iron (III) nitrate through solution combustion by varying the molar ratio between zinc and iron (ranging from 1:1 to 1:4 with respect to zinc to iron ratio). Second, the optimum molar ratio of ZIO was calcined at temperature ranging from 400?C to 800?C. Third, the self-synthesised ZIO was incorporated into polyvinylidene fluoride (PVDF) polymer matrix to produce mixed matrix photocatalytic ultrafiltration membrane (MMMs) for decolourisation of AT-POME. Five membranes were formulated by varying ZIO from 0.0 wt % to 2.0 wt%. The fabricated membranes were subjected to physico-chemical analysis, i.e. field emission scanning electron microscope, energy dispersive X-ray spectroscopy, X-ray diffraction, Brunauer-Emmett-Teller, ultraviolet-visible-near infrared, absorption test, filtration process, photodegradation test to identify the self-cleaning properties, separation performance and fouling mitigation properties. Based on the experimental results, ZIO with 1:4 zinc to iron ratio was the optimum ZIO which provided large surface area (30.9130 m2/g), lowest band gap energy (2.07 eV), high photocatalytic activity (achieved 35% of mineralisation in 6.5 hours and 100% degradation in 3.5 hours). On the other hand, as calcination temperature increased, the particle size of ZIO increased gradually. This phenomenon led to the decrease of surface area of ZIO that reduced its performance in absorption and photodegradation of organic compounds. The results demonstrated that calcination temperature of 500?C was the optimum temperature to provide the highest photodegradation. For the MMMs, as the ZIO loading increased, the porosity decreased, and surface negativity increased. However, when higher loading of ZIO was used, the mechanical strength of the membrane structure deteriorated and cannot withstand long-term operation. Therefore, the optimum loading was identified as 0.5 wt% ZIO in which the membrane achieved 75% colour removal efficiency with flux of 20 – 25 LMH (L.m-2.hr-1). Furthermore, the self-fabricated MMMs photocatalytic ultrafiltration (UF) membrane possess the high flux recovery after ultraviolet and visible light cleaning, i.e. 92.3% and 90.3%, respectively. The addition of ZIO in polymeric matrix enabled the photodegradation of colour pigments in AT-POME. After 16 hours of operation, the colour of AT-POME reduced by 8%. In a nutshell, PVDF/ZIO photocatalytic UF membrane had successfully decolourised AT-POME and reduced its COD.
format	Thesis
qualification_name	Doctor of Philosophy (PhD.)
qualification_level	Doctorate
author	Tan, Yi Hong
author_facet	Tan, Yi Hong
author_sort	Tan, Yi Hong
title	Nanocomposite ultrafiltration membrane incorporating zinc/iron oxide photocatalyst for decolourisation of treated palm oil mill effluent
title_short	Nanocomposite ultrafiltration membrane incorporating zinc/iron oxide photocatalyst for decolourisation of treated palm oil mill effluent
title_full	Nanocomposite ultrafiltration membrane incorporating zinc/iron oxide photocatalyst for decolourisation of treated palm oil mill effluent
title_fullStr	Nanocomposite ultrafiltration membrane incorporating zinc/iron oxide photocatalyst for decolourisation of treated palm oil mill effluent
title_full_unstemmed	Nanocomposite ultrafiltration membrane incorporating zinc/iron oxide photocatalyst for decolourisation of treated palm oil mill effluent
title_sort	nanocomposite ultrafiltration membrane incorporating zinc/iron oxide photocatalyst for decolourisation of treated palm oil mill effluent
granting_institution	Universiti Teknologi Malaysia
granting_department	Faculty of Engineering - School of Chemical & Energy Engineering
publishDate	2020
url	http://eprints.utm.my/id/eprint/92506/1/TanYiHongPSChE2020.pdf.pdf
_version_	1747818598567510016

Nanocomposite ultrafiltration membrane incorporating zinc/iron oxide photocatalyst for decolourisation of treated palm oil mill effluent

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