Solar Photocatalytic Treatment of Sewage using Titanium Dioxide (original) (raw)
Related papers
International Journal of Hydrology Science and Technology, 2018
The use of TiO 2 as a solar photocatalytic oxidant to treat real wastewater effluent from a decentralised unit was investigated. Potassium hydrogen phthalate (KHP) is used here as a standard for both chemical oxygen demand (COD) and total organic carbon (TOC). The catalyst load, initial KHP concentration and pH are the variables studied in this research. The optimum flow rate is 2.5 L/min in the tubular reactor. The removal efficiency of the organic compounds reduces as the initial concentration of KHP increases. The photocatalytic oxidation is dependent on pH and, it increases with the increasing of pH, the results show that a complete oxidation of KHP occurs at pH 9. Treatment of secondary treated wastewater results in about 50% for COD reduction which could attribute to the removal of organic matter and 100% inactivation of E. coli with no regrowth after 24 h storage in dark was obtained.
2017
The solar photocatalytic oxidation of potassium hydrogen phthalate (KHP) was examined in a batch reactor as a model. Catalyst load, initial KHP concentration and pH are variables studied in this research. The kinetics model for the reaction was investigated in this study. The nano particle of TiO2 (P25) used as catalyst for this reaction. The results revealed that the optimum catalyst load in the batch reactor is 1g/L of TiO2 The removal efficiency of the organic compounds reduces as the initial concentration increases, with a first order reaction rate at high concentration and zero order reaction rate at low concentrations were noticed in the study. The zero order at low concentrations reaction has a rate constant of 23.53 mg L -1 h -1 , while high concentrations the first order has a rate constant of 0.6225 h 1. The photocatalytic oxidation is dependent on pH and, it increases with the increasing of pH. Treatment of secondary treated wastewater results in about 50% removal of orga...
Solar Energy, 2006
Photocatalysis by titanium dioxide (TiO 2), operational in the UV-A domain with a potential use of solar radiation, could be an alternative to conventional water detoxification and disinfection technologies. However, employing the photocatalyst as a suspension or slurry makes the scaling-up of the process difficult, as the TiO 2 has to be removed from the decontaminated water to be reused several times. In this work the photocatalytic activity of different types of TiO 2 catalyst (Degussa P-25, Millennium PC-100 and PC-500, Tayca AMT-100 and AMT-600) in suspension or coated on fibrous web were studied in both decontamination and disinfection experiments at laboratory scale. Gallic acid was chosen as the model pollutant for detoxification experiments and Escherichia coli as the model microorganism for disinfection experiments. The influence of the surface area and other characteristics of TiO 2 are discussed concerning the photocatalytic properties of TiO 2. The role of adsorption is suggested, indicating that the reaction occurs at the TiO 2 surface and not in the solution. Gallic acid degradation kinetics were found to be of the same extent for both TiO 2 suspended and fixed, whereas for the bacterial inactivation efficiency was significantly less important with coated than with suspended TiO 2 .
KnE engineering, 2024
The Indonesian region of Sumatra has many rivers, and several of them are currently polluted by household and industrial wastes. Due to this, the river water looks cloudy and not clear. An easy method is needed to reduce the impact of this organic waste pollution. Photocatalysts are known for their ability to destroy organic pollutants which are environmentally friendly, cheap, and have the potential to be widely developed on a large scale. The principal mechanism of photocatalyst are generating the hydroxyl radicals (OH), which act as strong oxidants to mineralize organic contaminants. These principal photocatalyst mechanism includes the generation of hydroxyl radicals (OH), which act as strong oxidants to mineralize organic contaminants. A handy sprayimmobilization method of TiO 2 powders on the solid plastic buffer has been utilized in a destroying effluent system. The photocatalytic activity of the TiO 2-immobilized transparent plastic were evaluated by the degradation of organic contaminant under sunlight irradiation. The titania catalyst have the most potential destroying impact of about 98% after 10 days of sun irradiation. This investigation proved the potential of titanium oxide in handling organic waste in rivers.
Decreasing pH, COD and TSS of Domestic Liquid Waste Using Photocatalysis TiO2 (Titanium Dioxide)
International Journal Of Research In Vocational Studies, 2023
Domestic waste comes from households that must be treated. Based on the Minister of Environment and Forestry Regulation Number P.68/Minister Environment and Forestry Secretary General/2016 concerning Domestic Wastewater Quality Standards, the government has set a maximum limit for waste water that can be disposed of to the environment or receiving water bodies. includes pH, TSS and COD parameters. This is useful for overcoming the problem of environmental pollution caused by wastewater. Waste water that is not managed properly will have an impact on human health. environmental pollution is harmful to humans. Domestic sewage treatment using a titanium dioxide photocatalyst shows the results of testing the pH value on domestic waste as shown below, showing that overall the concentration of parameters has increased the pH decrease 22,8% from acidic to normal best pH value with a value of 6.57 at a contact time of 210 minutes of mass catalyst 2.5 grams.
Applied Sciences
Water resources are depleting, and the availability and supply of clean, potable water are a global concern. Advanced oxidation processes (AOPs) possess immense prospects in water and wastewater treatment settings. This study investigated and optimized the photocatalytic treatment of wastewater using titanium dioxide (TiO2) as the photocatalyst. The one-factor-at-a-time (OFAT) technique was employed to evaluate the effects of reaction time (20–100 min), mixing speed (20–100 rpm), and catalyst load (0.3–1.5 g/L) on pH, colour, turbidity, and chemical oxygen demand (COD) removal from actual municipal wastewater. Reaction time and catalyst load were then identified as the two key factors selected to be modeled and were optimized for turbidity and COD removal using the Central Composite Design (CCD) of response surface methodology (RSM). These statistical models were developed and used to optimize the operating conditions. The results obtained showed a desirability efficiency of 74.7% a...
Photocatalytic Oxidation in Drinking Water Treatment Using Hypochlorite and Titanium Dioxide
2013
The main focus of this thesis is to study the advanced oxidation processes (AOPs) of water pollutants via UV/hypochlorite (homogeneous AOPs), and UV solar light/TiO2 (heterogeneous AOPs) in which the highly oxidative hydroxyl radicals (OH) are produced. These radicals are capable of destructing the emerging organic pollutants in water. The combined action of both OH and Cl that are produced during the NaOCl/UV processes increased the chlorination potential of humic acids (HA). In addition, at a high free-radical dose, such as in swimming pool water recirculation systems, the equal levels of adsorbable organic halogens (AOX) and CHCl3 are formed with both low pressure (LP) and medium pressure (MP), respectively. CHCl3, once formed, is not degraded with either LP or MP. Moreover, the photo-degradation of HA in LPUV/NaOCl process is higher than that for the MPUV/NaOCl process, which results in a higher initial rate of AOX and CHCl3 formation. This raised the attention to the risk of...
Distillery Waste Water Treatment using Photo-catalytic UV-TiO2 System
International Journal of Advances in Scientific Research and Engineering (ijasre), 2019
In this study, removal of chemical oxygen demand COD, total suspended solids TSS, total dissolved solids TDS and colour of distillery wastewater using photo-catalytic process with TiO2 was carried out. Wastewater treatment from anaerobic sedimentation tank, COD: 4476 mg/L, TSS: 640 mg/L, total dissolved solids TDS: 720 mg/L was used for the photocatalytic process. The effectiveness of heterogeneous photocatalytic degradation on distillery wastewater using the UV-TiO2 process was investigated in a laboratory scale. For the photocatalytic process, the effect of the catalyst was studied using various amounts of TiO2 (0.1 to 0.5 g/L). Also, the effect of contact time (30 to 180 min) with the different UV power (10 to 30 W) was studied. For 0.1 g/L TiO2 dosage, COD removal 94% with minimum contact time 110 min in 20 W UV power. For 0.2 g/L TiO2 dosage, COD removal 94% with minimum contact time 110 min in 20 W UV power. For 0.3 g/L TiO2 dosage, COD removal 95% with minimum contact time 100 min in 30 W UV power. For 0.4 g/L TiO2 dosage, COD removal 95% with minimum contact time 80 min in 20 W UV power. For 0.5 g/L TiO2 dosage, COD removal 95%L with minimum contact time 80 min in 30 W UV power. By the usage of TiO2 dosage (0.1 to 0.5) g/L, the COD values of treated water effluents were reduced to standard emission guideline 250 mg/L. In the use of the energy usage, the condition with UV power 20 W with TiO2 dosage at the contact time of 110 min was the optimum. In the use of processing time, the condition with UV power 30 W with the 0.4 g/L of TiO2 dosage at the contact time of 80 min was the optimum.
Photocatalytic Water Treatment by Titanium Dioxide: Recent Updates
Photocatalytic water treatment using nanocrystalline titanium dioxide (NTO) is a well-known advanced oxidation process (AOP) for environmental remediation. With the in situ generation of electron-hole pairs upon irradiation with light, NTO can mineralize a wide range of organic compounds into harmless end products such as carbon dioxide, water, and inorganic ions. Photocatalytic degradation kinetics of pollutants by NTO is a topic of debate and the mostly reporting Langmuir-Hinshelwood kinetics must accompanied with proper experimental evidences. Different NTO morphologies or surface treatments on NTO can increase the photocatalytic efficiency in degradation reactions. Wisely designed photocatalytic reactors can decrease energy consumption or can avoid post-separation stages in photocatalytic water treatment processes. Doping NTO with metals or non-metals can reduce the band gap of the doped catalyst, enabling light absorption in the visible region. Coupling NTO photocatalysis with other water-treatment technologies can be more beneficial, especially in large-scale treatments. This review describes recent developments in the field of photocatalytic water treatment using NTO.
Chemical Engineering Journal, 2011
Photocatalytic processes in the presence of titanium dioxide provide an interesting route to destroy hazardous organic contaminants, being operational in the UV-A domain with a potential use of solar radiation. The solar photocatalytic degradation of paper mill wastewater has been studied over synthesized nano TiO 2. The catalyst was characterized by techniques like X-ray diffraction (XRD), gravimetric-differential thermal analysis (TG-DTA) and IR. The enhanced photocatalytic activity of the synthesized catalyst is attributed to the crystallinity, nano-size, large amount of surface hydroxyl species and reduced band-gap. The results show that prepared TiO 2 in the presence of solar light can be employed as an effective photocatalyst for the removal of chemical oxygen demand (COD) from the wastewater but in optimized conditions. The effects of catalyst loading and pH have been investigated. The degradation was strongly enhanced in the presence of electron acceptor such as H 2 O 2. It was found that the photocatalytic degradation of the paper mill wastewater obeys the pseudo-first order kinetic reaction in the presence of the photocatalyst. At optimum dose of 0.75 g/L TiO 2 and pH value of 6.5, 75% COD removal of the wastewater was achieved within 180 min solar irradiation time. A reduction of 80% of total suspended solids (TSS) from the wastewater was also obtained at the same operating conditions. The experimental results have also shown that the non-biodegradable substances can be very effectively degraded by the solar photocatalytic treatment. The biodegradability of the wastewater treated photocatalytically was measured in terms of BOD 5 /COD. A substantial improvement in BOD 5 /COD (0.35) could be achieved, but it required the removal of at least 70.5% of the total organic carbon originally in the water.