CATALYTIC OZONATION TECHNOLOGY FOR PHENOL REMOVAL IN WASTEWATER USING ZSM-5 NANO ZEOLITES AS CATALYSTS
Phenol (C6H5OH) is aromatic compound that can be found in several industrial wastewaters, such as the petroleum industry, coal processing, coke making, petrochemical, paper industry, etc. Phenol can act as a pollutant even at low concentrations in water and cause serious health problems for human...
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Format: | Theses |
Language: | Indonesia |
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Online Access: | https://digilib.itb.ac.id/gdl/view/64252 |
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Institution: | Institut Teknologi Bandung |
Language: | Indonesia |
Summary: | Phenol (C6H5OH) is aromatic compound that can be found in several industrial
wastewaters, such as the petroleum industry, coal processing, coke making,
petrochemical, paper industry, etc. Phenol can act as a pollutant even at low
concentrations in water and cause serious health problems for humans, animals,
and aquatic life. Therefore, it is necessary to treat wastewater containing phenol
before being discharged into the environment. In Indonesia, the limit of phenol
content in wastewater that is allowed to be directly discharged into the environment
is 7 mg/L.
Ozonation is one of the technologies used for phenol treatment in wastewater.
Ozone has been widely used to remove organic pollutants such as phenol, sulfide,
and nitrate because of its high oxidizing ability. However, the single ozonation
process has several disadvantages, including the slow oxidation process, producing
toxic intermediates, and the low solubility of ozone in water resulting in a high dose
of ozone required. The addition of a catalyst in the ozonation reactor can increase
selectivity, reduce ozone consumption, and increase the reaction rate with
contaminants, this process is known as catalytic ozonation. Zeolite with high silica
content has been used as a catalyst in the catalytic ozonation process to degrade
various organic and inorganic compounds including phenol. ZSM-5 zeolite,
modernite, USY, beta, and de-aluminated Y are several types of zeolites that have
been used as a catalyst in the catalytic ozonation process to remove phenolic
contaminants in water. In the use of zeolite, hydrophilicity/hydrophobicity, ratio of
silica to alumina (SiO2/Al2O3), surface area, and pore size of zeolite need to be
considered.
The general objective of this study is to determine the optimum efficiency of phenol
degradation from wastewater using catalytic ozonation technology with a zeolitebased
catalyst. Zeolite ZSM-5 was selected as the catalyst used in this study. The
specific objectives of this study are (i) Synthesis of ZSM-5 nano zeolite using a
tubular reactor in an oil bath with a batch system. The characterization of the
physical and chemical properties of clinoptilolite natural zeolite, H-Y zeolite,
commercial H-ZSM-5 zeolite and synthetic ZSM-5 nano zeolite using XRD, XRF,
and SEM. ZSM-5 nano zeolite catalyst activity test was compared with natural zeolite and commercial zeolite using catalytic ozonation technology to degrade
phenol from wastewater.
The synthesis method using a tubular reactor in an oil bath with a batch system has
been proven producible to synthesis ZSM-5 nano zeolite and the products have 86-
96nm in size range. The particle size and crystallite size of zeolite increased with
increasing synthesis time and temperature. The SiO2/Al2O3 ratio of the synthesized
zeolite is about 50% compared to the precursors. The optimum phenol degradation
rate constant of 0.111 min-1 was achieved by using catalytic ozonation technology
with ASP-5-210 (ZSM-5 nano zeolite catalyst was synthesized for 5 hours at 210°C
The percentage of phenol degradation of 95.63% can be achieved during 30
minutes at atmospheric pressure (P), temperature (T) = 30ºC, pH = 9, phenol
concentration 200 mg/L, oxygen flow rate 1 L/min, and 0.5 g catalyst. The phenol
degradation efficiency is influenced by: (i) the crystal structure of the zeolite,
especially the pore openings that match the size of the phenol, (ii) the crystallite
size and small particle size also increases the surface area of the zeolite to adsorb
ozone and phenol, (iii) the high ratio of SiO2 /Al2O3 so that the hydrophilic nature
of the zeolite is greatly reduced and become more selective for phenols. Phenol
degradation increases with increasing SiO2/Al2O3 ratio, clinoptilolite zeolite
exclude. Since it has the low SiO2/Al2O3 ratio, however its degradation ability is
high, this is influenced by Lewis acid strength and small crystallite size.
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