• Journal of the Korean GEO-environmental Society
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• v.8 no.3
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• pp.5-10
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• 2007

The paper presents results of qualitative analysis of non-regulated organic pollutants in municipal wastewater and treated municipal wastewater with flocculation, ozone and UV process using GC-MS. The majority of the pollutants in the influent of the municipal wastewater treatment facility were either food related or due to the diffuse discharge from products used both in households and in industry. In the case of biological treatment process removed some organic pollutants effectively. But some organic pollutants were not removed with biological treatment. Thus, additional steps to improve the quality of effluent municipal wastewater will require a more rigorous control of consumer products used in household and municipal wastewater process using advanced treatment processs. The obtained data contributed to the evaluation of pollutants discharges to the ecosystem as well as to the characterization of pollution sources in the basin.

• Journal of Environmental Science International
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• v.31 no.4
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• pp.319-328
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• 2022

This study investigated the treatment of acetaminophen in municipal wastewater by conventional ozonation, ozone-based advanced oxidation, ozone/UV, and the electro-peroxone process. The ozone/UV process and electro-peroxone process of electric power consumption increased 1.25 and 2.04 times, respectively, compared to the ozone process. The pseudo-steady OH radical concentration was the greatest in the electro-peroxone process and lowest in the ozone process. The specific energy consumption for TOC decomposition of the ozone/UV process and electro-peroxone process were 22.8% and 15.5% of the ozone process, respectively. Results suggest that it is advantageous in terms of degradation performance and energy consumption to use a combination of processes in municipal wastewater treatment, rather than an ozone process alone. In combination with the ozone process, the electrolysis process was found to be more advantageous than the UV process.

• 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 on Water Environment
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• v.24 no.5
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• pp.618-625
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• 2008

Advanced Phase Isolation Ditch (APID) process was studied to develop economic retrofitting technology, for the plants where retrofitting of common activated sludge process is required. In this study, to evaluate the effluent BOD, SS, T-N, and T-P concentrations as process capable and stable parameters for treating municipal wastewater, a demonstration plant was installed and operated in the existing sewage treatment plant of P city. During this study, the average effluent BOD, SS, T-N, and T-P concentrations were 4.56, 5.20, 9.30, and 1.75 mg/L at the conventional mode and 3.95, 3.17, 7.65, and 1.18 mg/L at the modified mode. The modified mode (BOD: 3.69, SS: 3.19, T-N: 1.27, and T-P: 0.69) increased the process capability more than the conventional mode (BOD: 1.80, SS: 1.05, T-N: 2.17, and T-P: 0.15) in this study. If process capability over 1.0, this process is capable and stable to treat wastewater. Therefore, newly developed APID process with modified intermittent aeration mode can be one of the useful processes for stable organic matter and nutrients removal.

• Journal of Korean Society on Water Environment
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• v.20 no.2
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• pp.190-195
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• 2004

A new technology for advanced wastewater treatment was developed using a modified Rotating Biological Contactor (RBC) process, named as Rotating Activated Bacillus Contactor (RABC) process that utilizes Bacillus sp., the facultatively anaerobic or activated microaerophilic bacteria on multiple-stage reticular rotating carriers, as a predominant species. The RABC process for a municipal wastewater with relatively low concentrations of organics, nitrogen, and phosphorus showed stable and high removal efficiencies, less than $BOD_5$ 10 mg/L, T-N 15 mg/L, and T-P 1.5 mg/L in final effluent. The performance load of RABC process was shown to be $1.23kg{\cdot}BOD/m^2{\cdot}day$ for the first stage (average $0.31kg{\cdot}BOD/m^2{\cdot}day$ for the total stages) based on both removed BOD and converted disc area corresponding to the reticular one. The sludge produced in the RABC process is characterized by low generation rate (about $0.18kg{\cdot}MLSS/kg{\cdot}BOD$) and excellent settleability. The number ratio of Bacillus ($2.4{\times}10^6CFU/ml$) to heterotrophic bacteria ($3.6{\times}10^7CFU/ml$) inhabiting in the biofilms of the RABC process was 6.7 %, indicating that Bacillus sp. was a predominant species in the biofilms. The RABC process with reticular rotating carriers showed its excellent performance for the advanced wastewater treatment without any offensive odor problem due to organic overloading.

• Journal of Korean Society on Water Environment
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• v.20 no.6
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• pp.563-570
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• 2004

Phased isolation intrachannel clarifier ditch process developed in this study is an enhanced biological nutrient removal process employing two ditches with intrachannel clarifiers. Bench-scale phased isolation ditch process was used to evaluate the system performance on municipal wastewater and detailed assessment of internal behavior in a ditch and each reactions. When the system was operated at the HRTs of 6~12hours, SRTs of 9~31 days, and cycle times of 4hours, the system showed removals of BOD, TN, and TP as high as 88~97%, 73~78%, and 65~90%, respectively. The internal behavior were well matched on each reactions such as nitrification, denitrification, and phosphorus release and uptake. As the SRT became longer, TN removal increased gradually, whereas TP removal decreased contrarily. However, the system was capable of producing an effluent TP concentration 1mg/L or less even at longer SRTs except the case of solids discharge by malfunction of intra-clarifier occurred by its geometrical limit. The system performance slightly decreased by hydraulic shock loading(increasing of influent flowrate and decreasing of system HRT). However, the higher system performance could be achieved again after four cycles. Thus, the system reliability could be successfully achieved short-term hydraulic shock loading that occurred in medium- and small-sized wastewater treatment plants suffering fluctuation of influent quality and flowrate during wet season.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.4
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• pp.333-340
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• 2010

Wastewater treatment using algal communities and biodiesel production from wastewater-cultivated algal biomass is a promising green growth technology. In literature, there are many studies providing information on algal species producing high content of lipid. However, very little is known about adaptability and wastewater treatability of such high-lipid algal species. In this study, we attempted to characterize algal biomass production and wastewater treatability of high-lipid algal species under municipal wastewater condition. For this, four known high-lipid algal strains including Chlorella vulgaris AG 10032, Ankistrodesmus gracilis SAG 278-2, Scenedesmus quadricauda, and Botryococcus braunii UTEX 572 were individually inoculated into municipal wastewater where its indigenuous algal populations were removed prior to the inoculation, and the algae-inoculated wastewater was incubated in the presence of light source (80${\mu}E$) for 9 days in laboratory batch reactors. During the incubations, algal biomass production (dry weight) and the removals of dissolved organics (COD), nitrogen and phosphorous were measured in laboratory batch reactors. According to algal growth results, C. vulgaris, A. gracilis and S. quadricauda exhibited faster growth than indigenuous wastewater algal populations while B. braunii did not. The wastewater-growing strains exhibited efficient removals of total-N, ${NH_4}^+$-N, Total-P and ${PO_4}^{3-}$-P which satisfy the Korea water quality standards for effluent from municipal wastewater treatment plants. A. gracilis and S. quadricauda exhibited efficient and stable treatability of COD but C. vulgaris showed unstable treatability. Taken together with the results, A. gracilis and S. quadricauda were found to be suitable species for biomass production and wastewater treatment under municipal wastewater condition.

• Journal of the Korean Society of Marine Environment & Safety
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• v.4 no.1
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• pp.49-56
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• 1998

The Microfiltration and Ultrafiltration were used to treat effluent of secondary municipal wastewater treatment system(Sequencing Batch Reactor). The cross-flow hollow fiber, UF 500,000(NMWC) and MF 0.65$\mu$ membrane were selected as suitable membrane. Short term and long term fouling effect were measured as a factor of flux decrease and the fouling removal effect of mixing air bubble in the penetrant was studied. The removal of anionic sulfactants before and after formation of micelle with several kinds of oil were checked. The test results show that removal of TOC was 70~80%, TN 28% and TP 16%. The decrease of flux due to fouling were 85%(UF) and 90%(MF) after running of 100hrs. The removal of anionic sulfactants were 60~70% notwithstanding micelle or not.

• Journal of Environmental Science International
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• v.12 no.10
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• pp.1085-1093
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• 2003

This study was conducted to investigate anoxic-RBC (rotating biological contactor) and its application in advanced municipal wastewater treatment process to remove biologically organics and ammonia nitrogen. Effluent COD and nitrogen concentration increased as the increase of volumetric loading rate. But, the concentration changes of NO$_2$$\^$-/ -N and NO$_3$$\^$-/ -N were little, as compared to COD and NH$_4$$\^$+/ -N. When the volumetric loading rate increased, COD removal efficiency and nitrification appeared very high as 96.7∼98.8% and 92.5∼98.8%, respectively. However, denitrification rate decreased to 76.2∼88.0%. These results showed that the change of volumetric loading rate affected to the denitrification rate more than COD removal efficiency or nitrification rate. The surface loading rates applied to RBC were 0.13～6.0lg COD/㎡-day and 0.312∼1.677g NH$_4$$\^$+/-N㎡-day and they were increased as the increase of volumetric loading rate. However, the nitrification rate showed higher than 90%. The thickness of the biofilm in RBC was 0.130 ∼0.141mm and the density of biofilm was 79.62∼83.78mg/㎤. They were increased as surface loading rate increased. From batch kinetic tests, the k$\_$maxH/ and k$\_$maxN/ were obtained as 1.586 g C/g VSS-day, and 0.276 g N/g VSS-day, respectively. Kinetic constants of denitrifer in anoxic reactor, Y, k$\_$e/, K$\_$s/, and k were 0.678 mg VSS/mg N, 0.0032 day$\^$-1/, 29.0 mg N/l , and 0.108 day$\^$-l/, respectively. P and K$\_$s/, values of nitrification and organics removal in RBC were 0.556 g N/㎡-day and 18.71 g COD/㎡-day, respectively.

• Membrane Journal
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• v.1 no.1
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• pp.78-95
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• 1991

Water factory 21(WF 2) in Orange County California, is a advanced wastewater treatment(AWT) plant designed to reclaim biologically treated munidpal wastewater for injection into a seawater barrier system. Processes included are lime treatment air stripping, filtration, activated carbon adsorption, reverse osmosis(RO), and chlorination. The effectiveness of each treatment process is presented including pretreatment, RO dimineralization. The data collected show that the processes, including RO, used at WF-21 are capable of producing a very high quality water on a reliable basis. Treatment reduced all contaminants, to levels below national primary drinldng water regulation maximum contaminant levels. It was found that lime clarified secondary effluent can be used as feedwater to a RO dimineralizer. Experiments with new low pressure membrane(250psi) show great potential for reducing RO cost.