• Membrane Journal
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• v.20 no.3
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• pp.241-248
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• 2010

The effect of organic material loadings on nutrient removal characteristics were investigated in sequencing batch reactor, in which a flat sheet type microfiltration membrane with a pore size of $0.4\;{\mu}m$ was submerged. Three organic concentrations of 200 mg/L (Run-1), 400 mg/L (Run-2) and 800 mg/L (Run-3) were carried out continuously to identify their effect on the filtration performance and nutrient removal. The removal efficiencies of T-N and T-P were increased with the increase of COD/N and COD/P. The T-N removal efficiencies of Run-1, Run-2 and Run-3 were 28.1, 32.6 and 90.4%, the average concentrations of T-N in permeate were 32.0, 30.0, and 4.3 mg/L, respectively. The T-P removal efficiencies of Run-1, Run-2 and Run-3 were 13.6, 35.3 and 93.1%, the average concentrations of T-P in permeate were 3.11, 2.33, and 0.25 mg/L, respectively.

• Korean Journal of Agricultural and Forest Meteorology
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• v.7 no.3
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• pp.192-200
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• 2005

This study was conducted to investigate inorganic nutrient contents in spur leaf and shoot leaf of 'Niitaka' pear during the growing season and leaf inorganic nutrient contents as influenced by meteorological elements. The contents of N, P, K, and Mg were decreased in spur leaf during their vegetative growth, while Ca and Mn increased. The contents of N, P, K, Mg, and Fe showed no differences between spur leaf and shoot leaf. However Ca, Mn, Zn, and Cu contents were higher in spur leaf than those in shoot leaf, but B content was lower in spur leaf than those in shoot leaf. The content of N in shoot leaf was positively correlated with mean temperature, whereas negatively correlated with maximum temperature. The content of P in spur leaf was negatively correlated with maximum temperature. The content of Ca in spur leaf was negatively correlated with mean temperature, whereas positively correlated with maximum and minimum temperature. The contents of Mg and B in shoot and spur leaf were positively correlated with mean temperature, whereas negatively correlated with maximum and minimum temperature. The contents of Ca and Mn showed significant differences between spur leaf and shoot leaf at mid-July to early August. These results suggest that sampling is important to distinguish between spur leaf and shoot leaf for diagnosis of nutrient conditions in pear trees.

• Journal of Environmental Science International
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• v.11 no.7
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• pp.705-711
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• 2002

In order to determine the factors causing Microcystis spp. bloom in the lower Nakdong River (Mulgum), we prepared wide ranges of pH, nutrient(N, P) concentration and the light through an enclosure experiment far 10days (pH gradient. 6.5, 7.5, 8.5, 9.5; gradient of N, P: ${\frac{1}{2}}DW+{\frac{1}{2}}River$ Water (RW), RW only; four different levels of nutrient addition/day; light: 100, 85, 60, 30, 15% of full sun light). From three days, the difference of Microcystis density in each enclosures was observed. The high density of Microcystis was maintained in the treatments over pH 9.5 and 85% of full sun light. However, in all nutrient treatments, relatively lower cell density than that of pH and light treatments was observed. These results suggested that pH and light input may play more important roles than nutrients in the early development of Microcystis bloom in the eutrophic lower Nakdong River.

• Korean Journal of Environmental Agriculture
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• v.33 no.1
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• pp.44-51
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• 2014

BACKGROUND: Water quality of rural areas are susceptible to agricultural nutrient input and supply such as chemical fertilizer and livestock manure. This study was conducted to evaluate the usefulness of nutrient (N and P) indices in understanding spatial variations of water quality across Chonnam province which is a typical agricultural region in Korea. METHODS AND RESULTS: The nutrient indices including chemical fertilizer supply, livestock manure production, and nutrient balance were correlated with water quality data (T-N, T-P, BOD, and COD) for the twenty-two districts of the province. Concentration of T-N were positively correlated with chemical fertilizer supply, livestock manure N production, and nutrient balance (P<0.05 or P<0.01). Meanwhile, T-P concentration was not correlated with these nutrient indices; however, there was a tendency that T-P concentration increases with livestock manure P production (P=0.06) and with nutrient balance (P=0.09). These results suggest that T-N concentration is susceptible to both chemical fertilizer and livestock manure; whereas T-P is likely to be affected by livestock manure rather than chemical fertilizer. The concentrations of BOD and COD were also positively (P<0.05 or P<0.01) correlated with livestock manure production. CONCLUSION: This study shows the usefulness of nutrient indices in understanding spatial variations of water quality and suggests that livestock manure rather than chemical fertilizer can be a more critical water pollution source and thus highlights the need for more attention to livestock manure treatments for rural water quality management.

• Journal of Microbiology and Biotechnology
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• v.23 no.1
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• pp.92-98
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• 2013

Microalgal cultivation using wastewater is now regarded as essential for biodiesel production, as two goals can be achieved simultaneously; that is, nutrient removal efficiency and biomass production. Therefore, this study examined the effects of carbon sources, the N:P ratio, and the hydraulic retention time (HRT) to identify the optimal conditions for nutrient removal efficiency and biomass production. The effluent from a 2nd lagoon was used to cultivate microalgae. Whereas the algal species diversity and lipid content increased with a longer HRT, the algal biomass productivity decreased. Different carbon sources also affected the algal species composition. Diatoms were dominant with an increased pH when bicarbonate was supplied. However, 2% $CO_2$ gas led to a lower pH and the dominance of filamentous green algae with a much lower biomass productivity. Among the experiments, the highest chlorophyll-a concentration and lipid productivity were obtained with the addition of phosphate up to 0.5 mg/l P, since phosphorus was in short supply compared with nitrogen. The N and P removal efficiencies were also higher with a balanced N:P ratio, based on the addition of phosphate. Thus, optimizing the N:P ratio for the dominant algae could be critical in attaining higher algal growth, lipid productivity, and nutrient removal efficiency.

• Journal of Animal Science and Technology
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• v.60 no.2
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• pp.3.1-3.9
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• 2018

Background: Poultry breeding has increased by 306% in Korea, inevitably increasing the production of manure which may contribute to environmental pollution. The nutrients (NP) in the manure are essential for crop cultivation and soil fertility when applied as compost. Excess nutrients from manure can be accumulated on the land and can lead to eutrophication. Therefore, a nutrient load on the finite land should be calculated. Methods: This study calculates the nutrient production from Korean poultry by investigating 11 broiler and 16 laying hen farms. The broiler manure was composted using deep litter composting while for layer deep litter composting, drying, and simple static pile were in practice. The effect of weight reduction and storing period during composting was checked. Three weight reduction cases of compost were constructed to calculate nutrient loading coefficients (NLCs) using data from; i) farm investigation, ii) theoretical P changes (${\Delta}P=0$), and iii) dry basis. Results: During farm investigation of broiler and layer with deep litter composting, there was a 68 and 21% N loss whereas 77 and 33% P loss was found, respectively. In case of layer composting, a loss of 10-56% N and a 52% P loss was observed. Drying manure increased the P concentrations therefore NLCs calculated using dry basis that showed quite higher reductions (67% N; 53% P). Nutrient loss from farm investigation was much higher than reported by Korean Ministry of Environment (ME). Conclusions: Nutrients in manure are decreased when undergo storing or composting process due to microbial action, drying, and leaching. The nutrient load applied to soil is less than the fresh manure, hence the livestock manure management and conservation of environment would be facilitated.

• ALGAE
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• v.33 no.4
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• pp.319-327
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• 2018

Ettlia sp. YC001, a highly settleable and productive microalga, was shown to be effective in removing nutrients and capturing suspended solids from eutrophic pond water. The optimum conditions for the Ettlia sp. YC001 cultivation were investigated using water from a landscape pond. The pond water was supplemented with different N : P ratios by weight, and the biomass production and nutrient removal compared in batch cultures. The maximum removal rate of N and P was with an N : P ratio of 16 : 1. Plus, the turbidity dropped to near zero within 4 days. Meanwhile, chemostat cultivation showed that the biomass productivity and nutrient removal rate increased when increasing the dilution rate, where a dilution rate of $0.9d^{-1}$ showed the highest N and P removal rate at $32.4mg\;L^{-1}\;d^{-1}$ and $1.83mg\;L^{-1}\;d^{-1}$, respectively, and highest biomass and lipid productivity at $0.432g\;L^{-1}\;d^{-1}$ and $67.8mg\;L^{-1}\;d^{-1}$, respectively. The turbidity was also reduced by 98% in the chemostat cultivation. Moreover, auto-flocculation and pH were closely connected to the turbidity removal. As a result, this study identified the optimal N : P ratio for small pond water treatment using an Ettlia sp. YC001, while also establishing the optimal conditions for nutrient removal, turbidity reduction, and biomass production.

• Journal of Korean Society of Forest Science
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• v.94 no.5 s.162
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• pp.302-306
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• 2005

Litterfall and nutrient inputs were measured in even-aged coniferous plantations (a 31-year-old Pinus rigida and a 31-year-old Larix leptolepis) on a similar site condition in the Forest Practice Research Center, Gyeonggi Province. Litterfall was collected monthly from circular littertraps (collecting area: $0.50m^2$) for three years between April 1997 and February 2000. Average total annual litterfall was significantly higher for pine (5,802 kg/ha/yr) than for larch (4,562 kg/ha/yr) plantations. Needle litter in both plantations accounted for about 63% of total litterfall. Litterfall in the larch was distributed as follows: needle > other leaf > branch > miscellaneous > bark, while it was needle > miscellaneous > other leaf > branch > bark in the pine plantation. There was no temporal variation in needle litter, other leaf and bark during the 3 year study period. The concentrations of all nutrients (N, P, K, Ca, Mg) in needle litter were significantly higher in the larch than in the pine plantations. The annual nutrient concentration of needle litter in the larch varied among the years, whereas no year variation of needle litter was in the pine except for phosphorus (P). Nitrogen (N) and P inputs by needle litter were significantly higher for larch than for pine plantations established on a similar soil. The differences in N and P inputs were attributed to lower nutrient concentration in pine needle litter compared with larch needle litter, not to total needle litter mass. Annual inputs of nutrient in both plantations were not significantly different among years except for K of the larch although there was yearly different in needlefall mass and nutrient concentration during the 3-year observed period. The results indicate that the mechanisms of litterfall and nutrient inputs vary considerably between pine and larch plantations established on a similar site condition.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.5
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• pp.272-279
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• 2003

This study was performed to develop a more rapid and simple nutrient diagnosis method of plants than the conventional leaf analysis method. Cucumber (Cucumis sativus L. cv. jangil banbaek) was planted in the mixed media produced by mixing perlite and rock wool at 1:1 (v/v) ratio. The Yamazakki nutrient solution for cucumber was supplied to the media using micro-drip irrigation system. Experimental plots were consisted of no fertilization, deficient fertilization, adequate fertilization, and surplus fertilization for N, P and K. Specific color difference sensor value (SCDSV) measured by chlorophyll meter was closely related to total-N concentration in leaves measured by the conventional method. Nitrate, $PO_4$ and K concentration in petiole sap measured by test strips showed a significant relationship with total-N, P and K concentration in leaves. Linear regression equations between $NO_3$, $PO_4$ and K concentration in petiole sap and total-N, P and K concentration in the leaves were prepared. Optimum levels of $NO_{3}$, $PO_{4}$ and K in petiole sap were obtained by plugging the optimum concentrations of total-N, P and K in the leaves by other researchers into the equations. In conclusion, the SCDSV measured by chlorophyll meter and the concentration of $NO_3$, P and K in petiole sap measured by the test strips would be suitable for rapid estimation of plant nutrient status.

• Journal of Korean Society of Forest Science
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• v.99 no.2
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• pp.186-196
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• 2010

Fertilization increases the crop productivity and produces high quality seedlings for plantation. We quantitatively measured both physical performances and nutrient responses of Fraxinus rhynchophylla, Fraxinus mandshurica, Pinus koraiensis, and Abies holophylla seedlings, which are commercially planted species in Korea, to nitrogen, phosphorus, and potassium fertilization. We analyzed the growth performances by using Dickson's quality index (QI) and the nutrient status by using vector diagnosis. Nitrogen or phosphorus treatment increased height and root collar diameter growth of F. rhynchophylla and F. mandshurica, however, did not increase those of P. koraiensis and A. holophylla. The order of QI was N > P > K > control for F. rhynchophylla, P ${\geq}$ N > Control ${\geq}$ P for F. mandshurica, P > Control ${\geq}$ K > N for P. koraiensis and A. holophylla. In F. rhynchophylla, fertilization diluted N concentration in tissues by 5-25% because growth responses were higher than fertilization uptake. P. koraiensis and A. holophylla showed N excess showing "toxic accumulation". F. rhynchophylla and F. mandshurica showed P deficiency with P fertilization, however, P. koraiensis and A. holophylla showed "luxury accumulation". Vector diagnosis indicated that more fertilization was applicable for F. rhynchophylla and F. mandshurica, and high fertilization rates were inefficient for P. koraiensis and A. holophylla. Both QI and vector diagnosis can be applied to verify seedling quality in the light of growth responses and nutrient status in fertilization trials.