FIGURE 10 - uploaded by Barry L. Loeb
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Potential ozone applications at municipal wastewater plants (Oneby et al., 2010) (color figure available online).
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One question often raised when ozone professionals gather is “How much ozone capacity is installed?” Although the use of ozone for industrial purposes is growing, the largest use for ozone resides in the use of treatment of municipal drinking and wastewater. It is very difficult to summarize ozone capacity for industrial applications as much data a...
Citations
... Recently, techniques concerning ozone production created by dielectric barrier discharge (DBD) are more and more used in industry. [1][2][3][4][5][6] The ozone (O 3 ) represents a strong oxidizing and bleaching agents and it used in many ozone applications such as water disinfectant treatments, odor elimination, and effluent disinfection; [7][8][9][10][11][12] and also in plasma medicine applications such as infection control, wound healing, dermatological therapy, dental care, and cancer treatment. 13 In addition, ozone generated by plasma discharge, in particular by dielectrics barriers discharge (DBDs) is commonly used in large installations; 14 and it provides an important efficiency in ozone production. ...
In this work, a dielectrics barriers discharge (DBD) in an Ar/O<sub>2</sub> gas mixture excited with sinusoidal applied voltage for ozone generation has been investigated in order to draw attention to the important role of the kinetic scheme of this gas mixture in the plasma discharge. The adopted model was based on argon-oxygen plasma chemistry, the external circuit, and the Boltzmann equations. This approach predicts the optimal operating conditions and can also describes the chemical and electrical aspects of the DBD reactor. The kinetic scheme of an Ar/O<sub>2</sub> gas mixture takes into account 15 species regrouped in 123 reactions. The time evolutions of kinetic and electric characteristics of plasma discharges, and the effect of the main discharge parameters on DBD behavior and ozone efficiency are analyzed and discussed.
... Ozonation is widely applied in drinking water treatment for the purpose of disinfection and oxidative removal of chemical contaminants [13,14]. Ozonation is also a viable pre-treatment option for conventional membrane filtration to improve membrane flux and permeate quality [15]. ...
Gravity-driven membrane (GDM) filtration has been proposed as an alternative to sand filtration for drinking water treatment, but its low membrane flux and poor permeate quality hinder its widespread application. This study investigated the effect of pre-ozonation (with various dosages and application timings) on membrane flux, fouling layer characteristics, and permeate quality during GDM filtration of river water. Pre-ozonation with 3 mg/L ozone increased the mean membrane flux by 9–54%, resulting in approximately 30% increased water production and reduced dissolved organic carbon (DOC) and extracellular polymeric substance (EPS) production by 12–35% and 9–18%, respectively. The timing of pre-ozonation significantly affected the time-dependent flux behavior and morphological characteristics of the fouling layers. Pre-ozonation from the beginning of GDM filtration enhanced the initial flux because of organic fouling control but showed a gradual flux decline with time due to EPS accumulation and biologically inactive fouling layers. Pre-ozonation from the middle of GDM filtration period created heterogeneous and porous membrane fouling layers with high biological activity, showing increased membrane fluxes and improved permeate quality by removing DOC and assimilable organic carbon (AOC) via the combined action of ozone oxidation and biodegradation/sorption in the fouling layer. Overall, our results demonstrate pre-ozonation as a potential option to overcome the limitations of GDM filtration.
... In various countries, wastewater utilities have installed or are in the process of installing ozone generators to treat secondary effluents [36,37]. Potable water utilities are doing the same to remove a variety of contaminants in potable water, surface water, and groundwater [1,19]. ...
Effective treatments improving both the chemical and microbiological quality of reclaimed wastewater are urgently needed. Ozone is a clean, economic, and environmentally friendly method to sanitize solutions and surfaces and to degrade organic pollutants. A simple, continuous-flow water-ozoniser system was tested to evaluate its effectiveness in batch treating various kinds of wastewater, including the effluent from small municipal plants. The degradation effects on a mixture of urban and industrial standard pollutants were investigated by HPLC-UV-MS analysis and biotoxicological assays. The results revealed that the concentration of most organic pollutants was reduced to 20–0% of the initial one within one hour. One resultant compound was recalcitrant (40% reduction only). The bioassays indicated the definitive reduction in toxic effects after treatment. Similar results were obtained when secondary, post sedimentation, wastewater treatment plant effluents were treated. Heterotrophic plate counts confirmed the strong biocidal activity of ozone. The developed prototype can successfully treat locally produced wastewater, secondary effluents from small–medium plants, and non-potable water resources.
... Preoksidasi termasuk metode tambahan yang efektif dan diterapkan pada pengolahan air di Negara Jepang, Jerman, serta Amerika Serikat (Loeb et al., 2012). Preoksidasi dilakukan sebelum proses pengolahan utama karena hasil yang baik, operasional relatif mudah, biaya yang cenderung lebih rendah, serta mengurangi beban dan memperpanjang masa pakai unit pengolahan utama. ...
Semakin menurunnya kualitas air sungai sebagai air baku air minum membawa tantangan tersendiri bagi PDAM agar instalasi pengolahan air (IPA) yang ada tetap bisa mengolah air dengan baik. Salah satu yang dapat dilakukan adalah dengan melakukan pretreatment sebelum air diolah di IPA. Salah satu teknologi pretreatment yang dapat diterapkan adalah preoksidasi dengan menggunakan ozon yang disebut dengan preozonasi. Penelitian ini bertujuan untuk menganalisis pengaruh penambahan preozonasi, sebagai bentuk pretreatment air baku, terhadap perubahan parameter pH, warna, kekeruhan, TSS, COD, dan amonia. Metedologi dalam penelitian ini adalah dengan menginjeksi ozon ke dalam sampel air (effluent bak prasedimentasi IPAM Ngagel I) dengan variasi laju alir (1, 2, dan 3 L/min) serta variasi waktu kontak (10, 20, dan 30 menit). Berdasarkan penelitian yang dilakukan, didapatkan bahwa preozonasi mampu menyisihkan kekeruhan (3%), warna (4%), TSS (0%), COD (26%), dan amonia (35%) serta pH yang sedikit meningkat (mendekati kondisi netral). Penyisihan tersebut didapatkan dengan cukup menggunakan variasi laju alir sebesar 2,6 L/min dan waktu kontak selama 30 menit. Preozonasi signifikan dalam menyisihkan parameter kimia (COD dan amonia) dan tidak terlalu berpengaruh terhadap parameter fisik (kekeruhan, warna, dan TSS). Dengan penambahan preozonasi ini diharapkan dapat meringankan beban pengolahan selanjutnya yaitu unit koagulasi dan flokulasi sehingga dapat mengurangi konsumsi koagulan
... These radicals can oxidize or mineralize refractory organic compounds into tiny molecules [58], making AOPs a research hotspot. AOPs, such as the Fenton process [59], UV/chlorine AOPs [58], ozone-based technologies [60], etc., can achieve rapid reduction of odorous substances. However, most AOPs are only applied in WWTPs. ...
... AOPs a research hotspot. AOPs, such as the Fenton process [59], UV/chlorine AOPs [58], ozone-based technologies [60], etc., can achieve rapid reduction of odorous substances. However, most AOPs are only applied in WWTPs. ...
The existence of odors in drainage pipelines is one of the most prominent environmental problems that urban residents complain about nowadays. Odorous substances in sewage can cause corrosion and erosion in drainage pipelines, and even lead to great harm to the human body and environments. Ideas for in situ odor control can be divided into two main categories: the elimination of odorous substances and the inhibition of the production of odorous substances. However, there is a lack of comprehensive summary of in situ overall deodorization techniques, which has limited the wide application of these methods. We conducted a systematic review to summarize recent advances in in situ overall deodorization. Firstly, the main odorous substances in drainage pipelines and their basic characteristics are concluded. Special attention has been paid to volatile sulfur compounds (VSCs) and nitrogen-containing compounds, as the main odorous substances. Subsequently, typical sources of these odorous substances are summarized based on their formation mechanisms. Then, in situ deodorization techniques (including pipeline condition optimization techniques, odor source control techniques, chemical control techniques, and biological control techniques) are introduced. Finally, upcoming research efforts on deodorization mechanism improvement, research gap supplementation, and economic efficiency enhancement to meet practical conditions are proposed.
... In this study, dissolved ozone was only detected in high saline water (35 ppt sea salt, 35 ppt NaCl, or natural seawater) and increased with treatment time, reaching its highest level of 0.16 mg/L at 120 min in one of our tanks with natural seawater (Fig. 5). Although this level of ozone is low for the typical water disinfection threshold (i.e., >1.5 mg/L)) (Ding et al., 2019;Loeb et al., 2012), it could have a deleterious effect on bacteria if exposure time was sufficient. ...
... Ozone is particularly powerful against bacteria due to its significant oxidizing potential, even at a concentration of 0.01 ppm [4]. Furthermore, ozone has the ability to eliminate color, odor, and taste [5]. Due to their high oxidizing characteristics, chemical interactions between water and ozone increase the generation of reactive oxygen species (ROS) such as radicals (O 2 • -, •OH -) [6], which cause oxidative stress in bacteria. ...
Disinfection process in commercial drinking water production has an important role to fulfill the quality standards. The ozonation process requires fidelity of duration, in order the production efficiency at Teaching Factory can be achieved. During this time, the ozone generator with a capacity of 5 grams / hour, for 20 minutes application still did not fill the standard. SNI 3554 2015 test results showed that out of 31 parameters, there are 2 parameters that haven't reached the requirements, namely the microbiological aspects. The target of this research is to get the exact ozonization time, until the total number of the bacteria become zero. The duration time used in the ozonation process are 50, 60, 70, 80, 90, 100, 120 minutes, before refined with ultra violet process. The result showed that the ozonation process have able to inactivated all bacteria up to 100%, except 83% Escherichia coli . Further processes need to be added to inactivated bacteria up to 100% for a larger scale commercial drinking water, so that all SNI requirements were fulfilled. The ozonation process is superior as an alternative to a safe desinfection process. The accuracy of duration time has an impact on the entire series of processes in order to provide efficiency for Teaching Factory.
... However, ozone is unstable, reducing to oxygen gas at a half-life rate ranging from seconds to a day, depending on the mass flow rate, humidity, and temperature [8]. For this reason it is manufactured at water treatment facilities by plasma discharge, which has become a more prevalent method of water treatment [9]. Chlorine treatment is generally accepted as being more economical than ozone treatment [10], although this position has been disputed by the ozone water treatment community [11]. ...
Water contaminants such as endocrine inhibitors, pharmaceuticals, and chlorine treatment by-products are only recently being identified as significant hazards to human health. Since current chlorine treatment does not address many of these compounds and conventional ozone processing is not seen as an economic alternative, water adjacent plasma treatment has been investigated as a more efficient and effective decontamination method. This work investigates the use of a surface dielectric barrier discharge electrode as a reduced discharge voltage portable plasma water treatment method. The gas passes through holes in the electrodes, normal to the discharge surface, so that the entire cross-sectional area of the feed gas is exposed to plasma, prior to passing through a hydrophobic filter and bubbling into the water. The decontamination effectiveness is quantified by measuring the degradation of methylene blue with absorption spectroscopy. Studies of the different processing parameters (treatment time, solution volume, initial concentration, electrode-filter distance, and gas flow rate) clarify the potential range of performance for this plasma treatment configuration. The setup has a yield energy of 0.45 g/kW h at 25 ml of 1 mg / 100 ml methylene blue treated over 5 minutes for a 92% degradation. The degradation rate is dependent upon the volume ratio of air to methylene blue solution, suggesting a first order chemical reaction process. The reaction rate is increased by increasing the quantity of either reactant. There is no change in the degradation between when the plasma is 1mm or 1cm from the water surface.
... Since in many industrial and commercial indoor environments the ozone concentration could be higher than the permissible limits, the use of ozone removal technologies is essential. These technologies are commonly required to eliminate the ozone that may get accidently released from ozone-handling facilities or are routinely discharged from ozone generators in water treatment units, pulp and paper plants, and hospitals; and, to clean the air intake of aircraft cabins in aviation systems [11][12][13][14][15][16][17][18]. ...
Ozone is one of the critical air pollutants having direct and indirect adverse health effects. The occupational safety and health administration (OSHA) set 100 ppb as the ozone's permissible exposure limit, highlighting the need for an ozone removal mechanism in many indoor settings. Activated carbon (AC) and metal oxide catalyst based ozone removal are two widely-used technologies for ozone mitigation; however, currently, little insight exists for choosing the best technology based on the application requirements. AC tests were typically limited to low ozone concentration (e.g., ppb level) making it difficult to obtain a broad picture of the link between their performance and properties. Additionally, the ozone removal by ACs and catalysts lacked a complete assessment of performance degradation over time. To fill this gap, this study involves a systematic evaluation of the ozone removal by various granular ACs and granular manganese oxide-cuprous oxide catalysts. The testing methodology was initially based on ASHRAE 145.1 standard; however, test conditions were later made more challenging to better capture the performance decline. It was surprisingly found that, among ACs, the coconut shell-based one have a substantial capacity to remove ozone at moderate and mild concentration levels (<200 ppm), even higher than catalyst, although all ACs get considerably deactivated at high concentration (>99% efficiency at 1 ppm down to <40% efficiency at 900 ppm). By contrast, catalysts feature a slow steady decrease of active sites over time (99% efficiency at 1 ppm down to >70% efficiency at 900 ppm). Subsequent analysis of the material properties demonstrated a strong link between material's type and its physical and chemical characteristics with its ozone removal capacity. The knowledge is envisioned to be of significant utility for numerous applications where ozone contamination is a challenging problem.
... Wastewater matrices containing DOC, suspended solids, residual nitrite, or particulate matter from activated sludge treatment can deplete ozone, reducing disinfection effectiveness. Increasing ozone doses to improve disinfection is often associated with the formation of carcinogenic bromate (Loeb et al. 2012, Rekhate et al. 2020). ...
Advanced wastewater treatment technologies are effective methods and currently attract growing attention, especially in arid and semi-arid areas, for reusing water, reducing water pollution, and explicitly declining, inactivating, or removing SARS-CoV-2. Overall, removing organic matter and micropollutants prior to wastewater reuse is critical, considering that water reclamation can help provide a crop irrigation system and domestic purified water. Advanced wastewater treatment processes are highly recommended for contaminants such as monovalent ions from an abiotic source and SARS-CoV-2 from an abiotic source. This work introduces the fundamental knowledge of various methods in advanced water treatment, including membranes, filtration, Ultraviolet (UV) irradiation, ozonation, chlorination, advanced oxidation processes, activated carbon (AC), and algae. Following that, an analysis of each process for organic matter removal and mitigation or prevention of SARS-CoV-2 contamination is discussed. Next, a comprehensive overview of recent advances and breakthroughs is provided for each technology. Finally, the advantages and disadvantages of each method are discussed.
