• Journal of Environmental Health Sciences
• /
• v.34 no.1
• /
• pp.76-85
• /
• 2008

Biological nutrient removal (BNR) sludge was added to a sequencing batch reactor (SBR) in the addition ratios of 0%, 20%, 40%, 50% while observing the variation of nutrient removal characteristics and microorganism groups. When the BNR sludge was added in a ratio over 40%, the characteristics of EBPR (enhanced biological phosphorus removal) was shown at the 27 days. However, a distinct BNR was not shown when the addition ratio of BNR sludge was lower than 40%. The organic removal efficiency were shown as 90% in all SBRs irrespective of the addition ratio of BNR sludge. At the 27 days, the phosphorus removal efficiencies were shown as 40%, 55%, 77% and 69%, respectively, according to the addition ratio of BNR sludge. Overall, efficient nitrification and phosphorus removal was shown when the added BNR sludge ratio was over 40%.

• Journal of Korean Society on Water Environment
• /
• v.22 no.4
• /
• pp.639-647
• /
• 2006

The temperature effect at $20^{\circ}$ and $10^{\circ}$ on the nutrient removal efficiency was evaluated in the combined biological nutrient removal system (CBNR) with anaerobic-intermittent aerobic-oxic reactors. The test was conducted under the conditions of various ratios of intermittent aeration time and distribution of influent raw water to CBNR. The removal efficiencies of organics, nitrogen and phosphorus were a little bit better at $20^{\circ}$ than at $10^{\circ}$. However the large difference of temperature effect on the nutrient removal efficiency between $20^{\circ}$ and $10^{\circ}$ was not appeared because of highly sustained MLSS concentrations in the reactors and controlled intermittent aeration time. In the removal of phosphorus, Mode III (50/70 min in aeration on/off time, 3 times of intermittent aeration) showed more effective compared with short aeration time of Mode IV. In case of N, P removal, the denitrification rate was lower in Mode A with splitted inflow into anaerobic and intermittent aeration basins than in Mode B with sole inflow into anaerobic basin.

• Membrane and Water Treatment
• /
• v.15 no.1
• /
• pp.1-9
• /
• 2024

Biological nutrient removal is gaining increasing attention in wastewater treatment plants; however, it is adversely affected by low temperatures. This study examined temperature effects on nutrient removal and morphological stability of the granular and denitrifying phosphorus accumulating organisms (PAO and DPAO, respectively) using sequencing batch reactors (SBRs) at 5, 10, and 20 ℃. Lab-scale SBRs were continuously operated using anaerobic-anoxic and anaerobic-oxic cycles to develop the PAO and DPAO granules for 230 d. Sludge granulation in the two SBRs was observed after approximately 200 d. The average removal efficiency of soluble chemical oxygen demand (SCOD) and PO₄^3--P remained >90% throughout, even when the temperature dropped to 5 ℃. The average removal efficiency of NO₃^--N remained >80% consistently in DPAO SBR. However, nitrification drastically decreased at 10 ℃. Hence, the removal efficiency of NH₄⁺-N was decreased from 99.1% to 54.5% in PAO SBR. Owing to the increased oxygen penetration depth at low temperatures, the influence on nitrification rates was limited. The granule in DPAO and PAO SBR was observed to be unstable and disintegrated at 10 ℃. In conclusion, morphological characteristics showed that changed conversion rates at low temperatures in aerobic granular sludge altered both nutrient removal efficiencies and granule formation.

• Journal of Environmental Health Sciences
• /
• v.40 no.4
• /
• pp.322-329
• /
• 2014

Objectives: The purpose of this study was to investigate the effect of BIO-CLOD on advanced wastewater treatment for enhanced removal efficiency and meeting the stringent discharge water requirements of wastewater treatment plants. Methods: Two experimental apparatuses consisting of anaerobic, anoxic and aeration tanks were operated. One included a BIO-CLOD cultivation tank. Organic and nutrient parameters and removal efficiency were analyzed by pH, BOD, CODcr, SS, T-N and T-P. Results: The average removal efficiencies of BOD, COD and SS from the apparatus with BIO-CLOD tank installation were 95.5%, 88.6% and 92.9%, respectively, and these were higher than the results from the apparatus without BIO-CLOD. The average TP removal efficiency with BIO-CLOD tank marked 56.0%, higher than the 47.3% from the apparatus without one. BIO-CLOD showed a higher performance for TN removal at 49.6%, compared to the result without BIO-CLOD of 34.3% Conclusion: By reaction with BIO-CLOD, ammonia removal was effective in the aeration tank, as was phosphorus release in the anaerobic tank. Phosphorus luxury uptake and nitrification in aeration tank proceeded smoothly. The application of BIO-CLOD can improve the decrease of odor and settleability of activated sludge in a wastewater treatment plant, as well as increase the removal efficiency of organic and nutrient materials in water.

• Journal of Korean Society on Water Environment
• /
• v.28 no.5
• /
• pp.663-668
• /
• 2012

The feasibility of enhancing biological nutrient removal from an industrial wastewater was tested with food waste leachate and sugar liquid waste as external carbon sources. Long term influences of adding external carbon sources were investigated to see how the biological nutrient removal process worked in terms of the removal efficiency. The addition of the external carbons led to a significant improvement in the removal efficiency of nutrients: from 49% to approximately 76% for nitrogen and from 64% to around 80% for phosphorus. Approximately, 20% of the removal nitrogen was synthesized into biomass, while the remaining 80% was denitrified. Though the addition of external carbon sources improved nutrient removal, it also increased the waste sludge production substantially. The optimal observed BOD/TN ratio, based on nitrogen removal and sludge production, was around 4.0 in this study.

• Journal of Korean Society on Water Environment
• /
• v.30 no.4
• /
• pp.386-393
• /
• 2014

The aim of this study was to investigate the nutrient removal and biomass productivity in the wastewater using MMBR (Microalgae Membrane Bioreactor). MMBR process was combined OPPBR (Optical Panel Photobioreactor) and MBR (Membrane bioreactor). The OPPBR and MBR were operated 3 days and 9h HRT (Hydraulic retention time), respectively, using microalgae as Chlorella vulgaris. The obtained result indicated that the biomass productivity of 0.498 g/L/d with light transmittance of 92% at a 305 mm depth in the OPPBR was achieved. The total consumption of BOD (Biochemical Oxygen Demand) and COD (Chemical Oxygen Demand) in the MMBR were found to be 97.56% and 96.06%, respectively. Additionally, the removal of TN, $NO_3-N$, TP and $PO_4-P$ were 94.94%, 91.04%, 99.54% and 93.06% in MMBR, respectively. These results indicated that the MMBR process was highly effective for COD, BOD and nutrient removal when compared to the separate OPPBR or MBR process. The MMBR process was effective for nutrient removal and biomass productivity and can be applied to treat wastewater in sewage treatment plant.

• Membrane and Water Treatment
• /
• v.10 no.3
• /
• pp.191-199
• /
• 2019

In this study, we investigated the cultivation possibility using Hydrodictyon reticulatum in a continuous raceway pond as a tertiary sewage treatment plant. The cultivation possibility was evaluated by varying the light quantity, wavelength, and hydraulic retention time (HRT). Experimental results showed that the growth rates of algae and the removal efficiencies of nutrients increased as the light quantity increased, and the maximum photosynthetic rate was maintained at $100{\mu}mol/m^2{\cdot}s$ or higher. When wavelength was varied, nutrient removal efficiency and growth rate increased in the following order: green light, red light, white light, and blue light. The nutrient removal efficiencies and algae productivity in HRT 4 d were better than in HRT 8 d. We conclude that if Hydrodictyon reticulatum is cultivated in a raceway pond and used as a tertiary treatment facility in a sewage treatment plant, nutrients can be effectively removed, and production costs can be reduced.

• Membrane and Water Treatment
• /
• v.3 no.2
• /
• pp.133-140
• /
• 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 Environmental Health Sciences
• /
• v.28 no.1
• /
• pp.93-97
• /
• 2002

The aim of this study was to evaluate on the removal effect of total nitrogen and phosphorus with municipal wastewater in ultrasonic nutrient removal (UNR) process using ultrasonic sludge carbon source. The removal efficiency for total nitrogen was 44.2% at biological nutrient removal (BNR) process, 50.8% at UNR process. The removal efficiency for total phosphorus was 45.6% at BNR process, 46.2% at UNR process. The removal of nitrogen was effectively influenced by ultrasonic sludge carbon source.

• Korean Journal of Hydrosciences
• /
• v.1
• /
• pp.99-106
• /
• 1990

An extensive biological nutrient removal pilot plant study of anoxic/anaerobic/ aerobic treatment process was conducted to eastblish an optimum operational mode using primary dffluent. Two operational modes, (1) Qr/Q was 3.0 and maintaining EMLSS of 3100 mg/L in which the best operational results were obtained from previous bench scale study using synthetic wastewater (2) Qr/Q was 0.5 and EMLSS of 2200 mg/L which was compatible with the main plant, were Compared and evaluated for removal of nitrogen and/or phosphorous under field conditions. The nitrogen removal increased with increasing recycle ratios, but the phosphorous removal revealed more consistent results with 83percent removal efficiency in the second mode compared with 80 percent in the first mode. Above all, the two modes equally showed good BOD and nitrogen removals by nitrification-denitrification processes. It was also observed that no scum formed in the pilot plant and the sludge exhibited excellent settling characteristic all the time. The modified biological nutrient removal train can be adopted to the main plant without any major changes of their operational modes.