• Journal of Korean Society of Water and Wastewater
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• v.20 no.3
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• pp.329-338
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• 2006

The research aims to provide the basic data for practical applications by correlating the bio-kinetic coefficients with the load of recalcitrant organic matter in box-mill wastewater. The activated sludge process was employed to a Wastewater disposal plant in an industrial setting, increase of consequently leading to the organic load. The parameter values derived by Monod-kinetic analysis were as follows:specific substrate removal rate $K_{max}=0.17day^{-1}$, half saturation constants $K_s=60.37mg/l$, decay coefficient $K_d=0.142day^{-1}$, microbial yield coefficient y = 0.388mg/mg, and max specific growth rate ${\mu}_{max}=0.006day^{-1}$. In view of biodegradability, the $TCOD_{Mn}/TBOD_5$ ratios of inflow and outflow were 1.07 and 1.41, and the $SCOD_{Mn}/SBOD_5$ ratios of inflow and outflow were 1.10 and 1.50, respectively. The higher $TCOD_{Mn}/TBOD_5$ ratio of outflow indicated that metabolites of a microorganism have accumulated in the cells.

• Journal of Korean Society of Water and Wastewater
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• v.27 no.1
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• pp.83-89
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• 2013

Microbiological treatment, chlorination, and ozonation are usually used for water treatment. However, there is weakness that these methods can't decompose and eliminate recalcitrant organic pollutants perfectly. It is possible to eliminate recalcitrant organic pollutants when photocatalysis of $TiO_2$ is used. In this study, the removal efficiencies of organic pollutants by using photocatalyst of $TiO_2$ in the slightly polluted golf club water hazard and a river were investigated. The amount of $TiO_2$ was divided into three categories of 1 g/L, 2 g/L and 4 g/L in order to investigate the adequate amount of $TiO_2$ and the removal efficiency. UV light was used as a light source for the reaction of photocatalyst. As a conclusion in this study, the efficiency of turbidity removal was increased in proportion to the amount of $TiO_2$ until 4 hours. After then the turbidity was gradually decreased. Finally, the optimum concentration of $TiO_2$ was 4 g/L. The efficiency of COD removal was increased in proportion to the amount of $TiO_2$ regardless of time.

• Journal of Korean Society of Water and Wastewater
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• v.34 no.6
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• pp.445-462
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• 2020

Industrial wastewater often contains a number of recalcitrant organic contaminants. These contaminants are hardly degradable by biological wastewater treatment processes, which requires a more powerful treatment method based on chemical oxidation. Advanced oxidation technology (AOT) has been extensively studied for the treatment of nonbiodegradable organics in water and wastewater. Among different AOTs developed up to date, ozonation and the Fenton process are the representative technologies that widely used in the field. Based on the traditional ozonation and the Fenton process, several modified processes have been also developed to accelerate the production of reactive radicals. This article reviews the chemistry of ozonation and the Fenton process as well as the cases of application of these two AOTs to industrial wastewater treatment. In addition, research needs to improve the cost efficiency of ozonation and the Fenton process were discussed.

• Journal of Korean Society of Water and Wastewater
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• v.18 no.6
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• pp.778-784
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• 2004

Dyeing wastewater contains recalcitrant organics which can not be easily treated by conventional biological treatment. Therefore it has to be treated by other advanced oxidation process in order to remove COD and Color more efficiently. Fenton oxidation process is one of the most commonly applied processes in removal of COD and color for the dyeing wastewater. However it increase the treatment cost and the production of sludge by the use of the excessive chemical reagent. Ozonation is not suitable in Single treatment process because it is not effective in organics removal compared with Color removal. The purpose of this research in order to evaluate the comparable removal efficiency of COD and color by the combination of advanced oxidation processes for the dyeing wastewater. The sequential treatment processes of Fenton process and ozonation was more effective to remove organics and color than ozonation and Fenton process. The result of Fenton process for the pretreatment presented as the 81% removal of organics whereas ozonation process for the pretreatent presented as the 22.1% removal of organics. The removal of colour was higher as 81.3% for the ozonation as the pretreatment than 77.7% for the Fenton process as the pretreatment.

• Journal of Radiation Industry
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• v.2 no.1
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• pp.9-14
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• 2008

Livestock wastewater containing high concentrations of organic matters and ammonia-nitrogen has been known as one of the recalcitrant wastewater. It is difficult to treat by conventional wastewater treatment techniques. This study was carried out to evaluate the feasibility of zeolite ion exchange and gamma-ray irradiation treatment of livestock wastewater. The removal efficiencies of $SCOD_{Cr}$ and $NH_3-N$ were significantly enhanced by gamma-ray irradiation after zeolite ion exchange as a pre-treatment. However, the effects of zeolite particle size on the $SCOD_{Cr}$ and $NH_3-N$ removal efficiencies were insignificant. These results indicate that the combined process of zeolite ion exchange and gamma-ray irradiation has potential for the treatment of livestock wastewater.

• Journal of Environmental Science International
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• v.32 no.7
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• pp.483-492
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• 2023

In this study, the treatment of livestock wastewater using an aerobic granular sludge based sequencing batch reactor was investigated. The reactor operation was carried out by general injection and split injection methods. The average removal efficiency of organic matter after the adaptation period was 71.5 and 87.4%, respectively. Some untreated organic matter was attributed to recalcitrant organic matter. The average removal efficiency of total nitrogen was 65.6 and 88.4%, respectively. These results indicate that the denitrification reaction by split injection was carried out smoothly. As for the solids, the ratio of aerobic granular sludge/mixed liquor suspended solid can be determined as the main factor of the process operation, and the ratio increased gradually and finally reached 86.0%. Correspondingly, the sludge volume index (SVI) was also improved, reaching 54 mL/g at the end of operation, and it is believed that the application of a short settling time contributed to the improvement of settleability.

• Advances in environmental research
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• v.9 no.3
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• pp.191-214
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• 2020

The rise in population and industrialization accounts for the generation of a huge amount of wastewaters. The treatment of this wastewater is obligatory to safeguard the environment and various life forms. Conventional methods for high strength wastewater treatment coming out to be ineffective. Advanced oxidation processes (AOPs) for such wastewater treatment proved to be very effective particularly for the removal of various refractory compounds present in the wastewater. Ozone based AOPs with its high oxidizing power and excellent disinfectant properties is considered to be an attractive choice for the elimination of a large spectrum of refractory compounds. Furthermore, it enhances the biodegradability of wastewaters after treatment which favors subsequent biological treatments. In this review, a detailed overview of the AOPs (like the Fenton process, photocatalysis, Electrochemical oxidation, wet air oxidation, and Supercritical water oxidation process) has been discussed explicitly focusing on ozone-based AOPs (like O₃, O₃/H₂O₂, O₃/UV, Ozone/Activated carbon process, Ozone/Ultrasound process, O₃/UV/H₂O₂ process). This review also comprises the involved mechanisms and applications of various ozone-based AOPs for effective municipal/industrial wastewaters and landfill leachate treatment. Process limitations and rough economical analysis were also introduced. The conclusive remarks with future research directions also underlined. It was found that ozonation in combination with other effective AOPs and biological methods enhances treatment efficacies. This review will serve as a reference document for the researchers working in the AOPs field particularly focusing on ozone-based AOPs for wastewater treatment and management systems.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.11
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• pp.847-854
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• 2011

To deal with issues from global climate changes, renewable bioenergy has become important. Algae have been regarded as a good resource for biorefinery and bioenergy, and also have potential capability to remove nutrient and non-decompositional pollutants for wastewater advanced treatment. Although algal-bacterial ecological interaction would be a crucially important factor in using algae for wastewater advanced treatment and resource recovery from wastewater, very little is known about ecological interaction between algae and bacteria in a real wastewater environment. In this study, under a real municipal wastewater condition, we characterized wastewater pollutant treatability and bacterial communities in response to growth of Ankistrodesmus gracilis SAG278-2, which can grow in wastewater and has a high lipid contents. The growth of algal population using the wastewater was inhibited by increase in wastewater bacteria while bacterial survival and cellular decay rate were not influenced by the algal growth. Removals of recalcitrant organic matters and total nitrogen were improved in the presence of algal growth. According to T-RFLP and statistical analysis, algal growth affected time-course changes in bacterial community structures. The following 16S rRNA gene amplicon, cloning results showed that the algal growth changes in bacterial community structure, and that bacterial populations belonging to Sediminibacterium, Sphingobacterium, Mucilaginibacter genera were identified as cooperative with the algal growth in the wastewater.

• Journal of Electrochemical Science and Technology
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• v.13 no.1
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• pp.1-18
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• 2022

Persistent organic pollutants (POPs) and emerging pollutants (EP) are characterized by their difficulty to be removed through biological oxidation processes (BOPs); they persist in the environment and could have adverse effects on the aquatic ecosystem and human health. The electro-oxidation (EO) process has been successfully used as an alternative technique to oxidize many kinds of the aforementioned pollutants in wastewater. However, the EO process has been criticized for its high energy consumption cost and its potential generation of by-products. In order to decrease these drawbacks, its combination with biological oxidation processes has been reported as a solution to reduce costs and to reach high rates of recalcitrant pollutants removal from wastewaters. Thus, the location of EO in the treatment line is an important decision to make, since this decision affects the formation of by-products and biodegradability enhancement. This paper reviews the advantages and disadvantages of EO as a pre and post-treatment in combination with BOPs. A perspective of the EO scale-up is also presented, where hydrodynamics and the relationship of A/V (area of the electrode/working volume of the electrochemical cell) experiments are examined and discussed.

• KSBB Journal
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• v.27 no.5
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• pp.281-288
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• 2012

Phytoremediation-the use of plants for the in situ treatment of contaminated soil and water-has recently emerged as an inexpensive and user-friendly alternative to traditional methods of environmental clean-up. The present article outlines the characteristics of phytoremediation based on accumulated research evidence, along with discussions on its advantages and disadvantages. It further reviews various mechanisms involved in the phytoremediation processes: phytoextraction, rhizofiltration, phytostabilization, phytovolatilization and phytodegradation. Along the way, the author summarizes examples of its applications to environmental pollution control. These include wastewater treatment, removal of heavy metals, and hydrocarbons, remediation of recalcitrant contaminants, phytoremediation of radionuclides, and application of transgenic plants for enhanced biodegradation and phytoremediation. The remainder of the article briefly concludes with directions for future research.