• Journal of Korean Society of Environmental Engineers
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• v.36 no.9
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• pp.609-613
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• 2014

The aim of this study was effect of N/P ratio on the nutrient removal in the wastewater using microalgae. For this experiment, 1 to 70 various N/P ratio was prepared and used microalgae as Botryococcus braunii in the wastewater. The results of this study were that 1 to 30 of N/P ratio was need for biomass productivity in the wastewater. TN removal was measured 82% for 1 to 30 N/P ratio and 73-78% for 31 to 70 N/P ratio. TP removal in 1 to 20 N/P ratio was determined up to 80%, but over 21 N/P ratio was decreased significantly and was not changed around 22% of TP removal in the 50 to 70 N/P ratio. Therefore, the optimum N/P ratio in the wastewater was 1 to 30 for biomass productivity, TN and TP removal. The correlation ($R^2$) of TP removal and biomass productivity was 0.9126. However, the relationship between TN removal and biomass productivity was not found. The P content in the wastewater was influenced more than that of TN content.

• Journal of Korean Society on Water Environment
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• v.20 no.2
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• pp.104-109
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• 2004

Removal of nutrients from domestic sewage or industrial wastewater is needed to protect surface waters from eutrophication. This research was carried out to remove the nitrogen (N) and phosphorus (P) from the wastewater using the iron oxide obtained from the steel industry and the natural zeolite, respectively. This research was conducted in both batch and continuous systems. The removal efficiency of the nutrients was evaluated in the batch system using the varying concentrations of zeolite and iron oxide added. The removal efficiency of N was 60% at the 8g of zeolite added. In the same condition, the removal efficiencies of N were 76% and 82% at 12g and 16g of zeolite added, respectively. Removal efficiency of P was 80% as 8g of iron oxide was added. The removal efficiency of P was correspondingly increased as the concentration of iron oxide was increased. Continuous column system was also used to evaluate the removal efficiency of N and P by the addition of zeolite and ferric oxide, respectively. Removal efficiencies of N were compared in the mixed packing, two stage, and four stage columns, respectively. The removal efficiencies (80%) of N in the separate packed columns (two and four stages) were higher than the mixed packing column (400%) after 90 hr. Whereas, the removal efficiencies of P were similar to each other in the three columns.

• Journal of Environmental Science International
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• v.9 no.5
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• pp.415-422
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• 2000

In this study the removal possibility of nutrients of T-P, NH3-N, NO3-N and T-N is examined through a positive experimental study using submerged biofilter of media packing channel method. From the analysis of nutrients removal efficiency for each run of the collected sample following results are obtained. Firstly the result of N/P surveying for inflow shows serious value that excess the limit value of 20 as the values are in the range of 12.0~42.7 and the average is 25.73. Secondly the highest concentration of the incoming NH3-N reaches double of the standard since the concentrations of NH3-N and NO3-N for inflow shows 0.06mg/$\ell$ and 2.5~3.8mg/$\ell$ respectively and the average removal rate which passed the submerged biofilter adopted in this study is a satisfactory level. Next the average removal rate of T-P of 51.5% shows the possiblity of entrophication removal since the removal rate of T-P of 66.8~68.8% in relative low temperature period of RUN 1~2 appeared higher than in RUN 3~6 and T-N shows relatively poor result with the average removal rate of 34.1% And it is known that the bigger BOD/P and BOD/N are the more removal rate increases from the examination result of the relation between BOD/P and BOD/N and the treatment water T-P and T-N to decide the relation with the concentration of organic matters and though that the appropriate proportion is necessary for effective removal of nitrogen and phsophorus.

• Journal of Korean Society on Water Environment
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• v.22 no.5
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• pp.846-850
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• 2006

The biological nutrient removal from domestic wastewater with low C/N ratio is difficult. Therefore, this study was performed to increase influent C/N ratio by ammonia stripping without required carbon source and for improving treatment efficiencies of sewerage by the combination process of ammonia stripping and BNR (StripBNR). The results of this study were summarized as follows. BOD removal efficiencies of BNR and StripBNR were 95.3% and 93.2%, respectively. T-N and T-P removal efficiencies of BNR were 53.3% and 40.8%, respectively. T-N and T-P removal efficiencies of StripBNR were 72.8% and 62.9%, respectively. Concentrations of $NH_3-N$, $NO_2-N$ and $NO_3-N$ at BNR effluent were 0.03 mg/L, 0.08 mg/L and 9.12 mg/L, respectively. On the other hands, concentrations of $NH_3-N$, $NO_2-N$ and $NO_3-N$ at StripBNR effluent were 5.79 mg/L, 0.01 mg/L and 0.14 mg/L, respectively. Consequently, influent C/N ratio of BNR process was increased by ammonia stripping. Removal efficiency of T-N and T-P was improved about 20% by the process of StripBNR.

• Journal of Environmental Health Sciences
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• v.43 no.6
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• pp.525-531
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• 2017

Objectives: The purpose of this experiment is to better understand the nitrogen and phosphorus removal ratio according to operating conditions in an iron electrolysis system consisting of an anoxic basin, aerobic basin, and iron precipitation apparatus. Methods: Iron electrolysis consists of an iron precipitation reactor composed of iron plates in oxic and anoxic basins. We studied the interrelation coefficient between T-N and T-P removal rates and F/M ratio, and the C/N ratio and BOD removal rate. Results: The F/M ratio and the T-N and T-P removal rate per unit area have interrelation coefficients of 0.362 and 0.603, respectively. The removal rate per MLVSS and the T-N and T-P removal rate per unit area have respective interrelation coefficients of 0.49 and 0.59. Conclusions: The removal rate of T-N and T-P increased with the increasing F/M ratio in the influent, and they also linearly increased in proportion to the C/N ratio of influent and BOD removal rate of the reactor.

• Journal of Environmental Health Sciences
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• v.23 no.1
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• pp.50-54
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• 1997

The removal efficiency of nutrient was investicated by using Glycine max Meer seedling. After budding, Glycine max Merr was raised at darkness for 4 days. During cultivation, the removal efficiency of $NO_2-N+NO_3-N$ was up to 90% with initial concentration of 20-100 ppm. The removal efficiency of PO$_4$-P was up to 80% with initial concentration at 30 ppm, but it was down to 22% and 27% at 40 ppm and 50 ppm. When the removal efficiency of nutrient was compared with alternating 12 hours' light and darkness, the removal efficiency of NO$_2$-N + NO$_3$-N was up to 90% at below 60 ppm. It was not different from each other. But it was particularly low about 62% and 34% at 80 ppm and 100 ppm in alternating 12 hours' light. The removal efficiency of PO$_4$-P was low at alternating 12 hours' light between 10-50 ppm on the whole range. The neutralizing capacity of pH was shown in acidity and alkalinity except strong acidity(below pH 3). The initial pH was neutralized at 6.0-7.7 of pH after 4 days. Particularly, Glycine max Meer seedling that was difference from other water plants, was shown the neutralizing capacity in strong alkalinity.

• Journal of Korean Society on Water Environment
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• v.26 no.4
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• pp.664-672
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• 2010

This study was performed to evaluate the feasibility of industrial by-products such as converter slag, olivine, red mud and fly ash as a seed crystal of struvite crystallization for the removal of highly concentrated $NH_4-N$ and $PO_4-P$. In the kinetic experiments, more than 90% of $NH_4-N$ and $PO_4-P$ was eliminated by struvite crystallization within 30 minutes of reaction time. The pH range in meta-stable region of struvite crystallization was found to be pH 7.0~9.0 under the Mg:N:P=1:1:1 equi-molar condition with 100 mg/L of $NH_4-N$. Total removal efficiencies of $NH_4-N$ and $PO_4-P$ by both struvite precipitation and crystallization were increased with the increase of pH. Removal efficiencies of $NH_4-N$ and $PO_4-P$ were significantly enhanced by struvite crystallization using industrial by-products as a seed crystal compared with those by struvite precipitation without seed crystal. Red mud, converter slag, olivine and fly ash enhanced the removal efficiencies of $NH_4-N$ by 40.9%, 37.7%, 28.4% and 16.4%, respectively. Removal efficiencies of $PO_4-P$ for converter slag, red mud, fly ash, olivine were increased by 3.7 times, 2.6 times, 72.4% and 68.0%, respectively. Converter slag and red mud showed higher feasibility as a seed crystal than others for the removal of highly concentrated $NH_4-N$ and $PO_4-P$. In particular, converter slag might have a high capacity of phosphorus removal.

• Journal of Korean Society of Water and Wastewater
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• v.13 no.4
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• pp.54-61
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• 1999

SBR process used to evaluate the removal of organics, nitrogen and phosphorus on the basis of a report of research on a precedence at various operation cycle and condition change. Effluent concentration of COD were 50mg/l, 50mg/l, 90mg/l respectively, The removal rates of COD were nearly over 95% at Run 1, 2 and 4. But at Run 3, Effluent concentration of COD was 255.0mg/l, The removal rate of COD was 87% at Run 3. As Oxic/Anoxic rate was fixed and operating cycle of Oxic/Anoxic was changed, the removal rates of T-N were 74.7%, 46.9%, 28.5%, 63.3% respectively at Run 1~4. The case of Run 1 was best result. The removal rates of T-P was appeared in proportion to T-N removal rates and rest of $NO_2-N$. The removal rates of T-P were 51.2%, 35.5%, 41.5%, 51.9% respectively. The removal rates of COD, T-N, T-P were influenced on the change of SBR operation cycle. As organic loading rate was $1.43kgCOD/m^3day$ and C/N ratio was 3.0, operation cycle of Run 1 was best condition of T-N removal rates and T-P removal.

• Journal of Korean Society of Water and Wastewater
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• v.27 no.1
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• pp.77-82
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• 2013

The growth and removal capacity of nitrogen and phosphorus of Chlorella vulgaris were evaluated in artificial wastewater with different nitrogen and phosphorus concentrations as element growing components for microalgae growth. The nitrogen concentration was varied in 9, 15, 30 and 60 mg-N/L with fixed phosphorus concentration of 3 mg-P/L. The growth and phosphorus removal capacity of C. vulgaris were high at initial nitrogen concentration of 15 and 30 mg-N/L, and the corresponding N/P ratios calculated were 5 and 10. In the case of varying in 1.5, 3, 6 and 10 mg-P/L of phosphorus concentration with fixed nitrogen concentration of 30 mg-N/L, the growth and removal capacity of nitrogen and phosphorus were excellent with phosphorus concentration of 3 and 6 mg-P/L. The corresponding N/P ratios were shown as 10 and 5. Therefore, the appropriate N/P ratio was concluded between 5 and 10 for wastewater treatment using C. vulgaris.

• Applied Chemistry for Engineering
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• v.33 no.6
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• pp.666-674
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• 2022

The removal efficiencies of nutrients (N and P) and heavy metals (Cu and Ni) by Rhodobacter blasticus and R. blasticus attached to polysulfone carriers, alginate carriers, PVA carriers, and PVA + zeolite carriers in synthetic wastewater were compared. In the comparison of the nutrient removal efficiency based on varying concentrations (100, 200, 500, and 1000 mg/L), R. blasticus + polysulfone carrier treatment showed removal efficiencies of 98.9~99.84% for N and 96.92~99.21% for P. The R. blasticus + alginate carrier treatment showed removal efficiencies of 88.04~97.1% for N and 90.33~97.13% for P. The R. blasticus + PVA carrier treatment showed removal efficiencies of 18.53~44.25% for N and 14.93~43.63% for P. The R. blasticus + PVA + zeolite carrier treatment showed removal efficiencies of 26.65~64.33% for N and 23.44~64.05% for P. In addition, at the minimum inhibitory concentration of heavy metals, R. blasticus (dead cells) + polysulfone carrier treatment showed removal efficiencies of 7.77% for Cu and 12.19% for Ni. Rhodobacter blasticus (dead cells) + alginate carrier treatment showed removal efficiencies of 25.83% for Cu and 31.12% for Ni.