• Journal of Industrial and Engineering Chemistry
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• v.67
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• pp.219-230
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• 2018

The present study examined a moving bed biofilm reactor (MBBR) bioreactor on a laboratory scale for simultaneous removal of atrazine, organic carbon, and nutrients from wastewater. The maximum removal efficiency of atrazine, chemical oxygen demand (COD), total phosphorus (TP) and total nitrogen (TN) were 83.57%, 90.36%, 90.74% and 87.93 respectively. Increasing salinity up to 40 g/L NaCl in influent flow could inhibit atrazine biodegradation process strongly in the MBBR reactor.Results showed that MBBR is so suitable process for efficiently biodegrading of atrazine and nitrogen removal process was based on the simultaneous nitrification-denitrification (SND) process.

• Membrane and Water Treatment
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• v.3 no.2
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• pp.133-140
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• 2012

The overall performance of BNR-MBR, so-called Anoxic-Anaerobic-Aerobic Membrane Bioreactor ($A^3$-MBR), developed for nutrient removal was studied to determine the efficiencies and mechanisms under different solid retention time (SRT). The reactor was fed by synthetic high-rise building wastewater with a COD:N:P ratio of 100:10:2.5. The results showed that TKN, TN and phosphorus removal by the system was higher than 95%, 93% and 80%, respectively. Nitrogen removal in the system was related to the simultaneous nitrification-denitrification (SND) reaction which removed all nitrogen forms in aerobic condition. SND reaction in the system occurred because of the large floc size formation. Phosphorus removal in the system related to the high phosphorus content in bacterial cells and the little effects of nitrate nitrogen on phosphorus release in the anaerobic condition. Therefore, high quality of treated effluent could be achieved with the $A^3$-MBR system for various water reuse purposes.

• Journal of Korean Society of Water and Wastewater
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• v.12 no.2
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• pp.106-114
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• 1998

In this research, single-, two- and four-stage intermittently aerated activated sludge system were investigated for simultaneous removal of nitrogen and phosphorus with swine wastewater. For the comparison of removal efficiency, conventional activated sludge system was operated. Operational conditions of intermittently aerated activated sludge system were SRT 20day, HRT 24hr and aeration/nonaeration time 1hr/1hr, respectively. Nitrogen and phosphorus removal efficiency in Intermittently aerated activated sludge system was upgraded compare with conventional activated sludge system. In single-stage intermittently aerated activated sludge system, release-uptake of $PO_4^{3-}-P$ was observed very well but, phosphosrus removal in effluent was not effective. In single-stage intermittently aerated activated sludge system, release-uptake of $PO_4^{3-}-P$ in first reactor, was observed very well but, in following reactor, $PO_4^{3-}-P$ concentation showed almost no change. T-N removal efficiency in conventional activated sludge system, single-, two-, and four-stage intermittently aerated activated sludge system were 48, 87, 90.9 and 95.5%, respectively, and phosphorus removal efficiency were 48, 75, 97 and 95%, respectively. Intermittently aerated activated sludge system as a alternative processes of conventional system leads to meet satisfactory effleunt with only on/off aeration regulation and save energy for aeration.

• Journal of environmental and Sanitary engineering
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• v.14 no.4
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• pp.21-28
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• 1999

This study was carried out the simultaneous removal or organics and Cr(VI) in aqueous suspensions of phtocatalyst under circular type reactor and UV light illumination. In this experiment, comparison on the removal of Cr(VI) by photoreduction using UV light, photocatalyst adsorption using TiO2, ZnO, and FeCl3 as photocatalyst, and phtocatalysis using UV light with photocatalysts as well as the effect of experimental parameters such as phtocatalyst dosage, a kinds of organics and their concentration was examined. The major results of this study were as follows; 1. It was found that photocatalyst adsorption and phtocatalysis were applicable to the removal of Cr(VI), and Cr(VI) was more effectively eliminated by TiO2 than ZnO, and FeCl3. 2. phtocatalytic removal efficiency of Cr (VI) increased with increasing phtocatalyst dosage. However, over 1.0g/l of phtocatalyst dosage, the efficiency reached a plateau. 3. phtocatalytic removal of Cr(VI) was enhanced by addition of organics such as salicylic acid, mandelic acid, EDTA, and citric acid, and phtocatalytic oxidation of organics were also observed. 4. It was found that the simultaneous removal of organics and Cr(VI) using phtocatalysis was possible.

• Journal of Environmental Science International
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• v.17 no.1
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• pp.7-17
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• 2008

Simultaneous removal of $NH_3,\;H_2S$ and toluene in a contaminated air stream was investigated over 185 days in a biofilter packed with Zeocarbon granule as microbial support. In this study, multi-microorganisms including Nitrosomonas and Nitrobacter for nitrogen removal, Thiobacillus thioparus (ATCC 23645) for $H_2S$ removal, and Pseudomonas aeruginosa (ATCC 15692), Pseudomonas putida (ATCC 17484) and Pseudomonas putida (ATCC 23973) for toluene removal were used simultaneously. The empty bed residence time (EBRT) was 40-120 seconds and the feed (inlet) concentrations of $NH_3,\;H_2S$ and toluene were 0.02-0.11, 0.05-0.23 and 0.15-0.21 ppmv, respectively. The observed removal efficiency was 85%-99% for $NH_3$, 100% for $H_2S$, and 20-90% for toluene, respectively. The maximum elimination capacities were 9.3, 20.6 and $17g/m^3/hr\;for\;NH_3,\;H_2S$ and toluene, respectively. The results of kinetic model analysis showed that there were no particular evidences of interactions or inhibitions among the microorganisms, and that the three bio degradation reactions took place independently within a finite area of biofilm developed on the surface of the Zeocarbon carrier.

• KSBB Journal
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• v.18 no.3
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• pp.234-238
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• 2003

Biofilm process is preferred to activated sludge process in small domestic wastewater treatment plant because of its simplicity in operation and maintenance. Column reactor filled with waste ceramics and with waste plastics was used to remove pollutants in restaurant wastewater. COD removal at 18 hours of hydraulic retention time (HRT) gave 93.7%, COD removal during the experimental period, where maximum COD removal was observed. Under same condition, average removal of total nitrogen and total phosphorus were 82.3% and 25.9%, respectively Organic and nitrogen were efficiently removed with the HRT of 18 hours or more.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.1
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• pp.62-67
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• 2007

It was investigated to develop the technology for simultaneous removal of $SO_2/NO$ in flue gas using liquid homogeneous catalyst. Test was carried out using a bench scale and a pilot scale experiment. The investigation led to the following results: 1) Removal efficiency of $SO_2$ gas showed good results regardless of operating condition. Removal efficiency of NO gas, however, proportionally increased with higher packing height, lower concentration and larger injection rate of catalyst 2) The optimum design parameters for simultaneous removal of $SO_2/NO$ gas using Fe(II)-EDTA catalyst were as follow: HTU(height of transfer unit) = 0.5 m, liquid gas ratio = 20 $L/m^3$, NTU (number of transfer unit) = 3 stages, cross dimension of scrubber=0.025 $m^2$ 3) The removal efficiencies of $SO_2$ and NO were 95% and 81%, repletely. 4) The high HTU is advantageous on removal of the NO, but the excessive HTU diminishes operating efficiency. Consequently, it is important to decide the HTU of optimum.

• Journal of Environmental Science International
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• v.10 no.1
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• pp.59-64
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• 2001

The effect of major operating parameters in spray drying sorber(=SDS) for automatic control for the simultaneous removal of acidic and organic gaseous pollutants from solid waste incinerator was performed. The field experiment was carried out in pilot scale test for the quantification of major operating parameters of hydrophilic and the hydrophobic pollutants. The removal efficiencies of $SO_2$and HCI in the 5wt% slurry condition were being increased with the increase of the stoichiometric ration which is the molecular ratio of lime to the pollutant concentration, and with the decrease of inflow flue gas temperature in the pilot SDS reactor. The removal efficiency along the height of spray drying sorber was closely related to the temperature profile, and more than 90% of total removal efficiency was achieved in an absorption region. For the removal of acidic gas the optimum operating condition considering the economics and a stable operation is the 5wt% of slurry concentration, 1.2 of stoichiometric ratio and 25$0^{\circ}C$ of inflow flue gas temperature. For the organic gases of benzene and toluene the removal efficiencies were 20-60% which is much lower than that of acidic gas. The best removal efficiency was obtained at 1.5 of stoichiometric ratio and 25$0^{\circ}C$ of inflow flue gas temperature. The organic\`s removal efficiency along the height of spray drying sorber was quite different from that of acidic gas, that is, more than 60% of the total removal efficiency for benzene and 90% of the total removal for toluene were achieved in the dried adsorption region, which was formed at the lower or exit part of the reactor.

• Journal of Soil and Groundwater Environment
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• v.8 no.3
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• pp.30-36
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• 2003

The effect of humic acid on the simultaneous removal of nitrate and phosphate was investigated in a micellar-enhanced ultrafiltration (MEUF). At the low molar ratio of cetylpyridinium chloride (CPC) to contaminants, the removal of nitrate was lower to 50％ by 100 ppm of humic acid due to the competition for binding on micelles. At the molar ratio higher than 3, however, the removal of nitrate was over 80％. Phosphate was removed over 80% at the molar ratio higher than 1. The CPC and humic acid were rejected over 99 ％ by UF membrane. The flux did not decrease by 100 ppm of humic acid but rather slightly increased since the humic acid adsorbed on the membrane made the membrane more hydrophilic. As a result, humic acid did not diminish the performance of MEUF in the simultaneous removal of nitrate and phosphate.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.09a
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• pp.417-421
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• 2003

Three kinds of surfactant systems - cationic surfactant (system 1), combinition of two cationic surfactants (system 2), and combination of two cationic surfactant and non-ionic surfactant (system 3) - for the simultaneous removal of nitrate and phosphate by micellar-enhanced ultrafiltration (MEUF) were investigated. The highest removal efficiencies of nitrate and phosphate were observed in system 2, which were 90 % of nitrate and 72 % of phosphate. The COD of permeate in system 3 was the lowest, because the added non-ionic surfactant made critical micelle concentration (CMC) lower than that of other surfactant systems. In all systems, the flux decline was similar.