• Proceedings of the Korea Water Resources Association Conference
• /
• 2006.05a
• /
• pp.1400-1404
• /
• 2006

생물학적 질소, 인 제거 공정(이하 BNR)의 운전에 있어서 최적 유입수의 C/N(COD/TKN)비, SRT 및 온도의 범위 및 정량적 수치 등은 유기물 뿐 만아니라 질소, 인의 처리 효율에 있어서 매우 중요하다. 특히, 외국과 다른 저농도 유기물 특성을 보이는 국내 하수에 대해서는 BNR 공정의 선택과 설계 및 운전인자의 선별이 무엇보다도 중요한 역할을 한다. 본 연구에서는 IAWQ에서 제시한 ASM No.2d를 기초로 하여 만들어진 전산모형인 Envirosim사의 Biowin 프로그램을 시뮬레이션 도구로 활용하여, 국내 하수에 비교적 적용하기 용이한 A2/O 공정과 MUCT 공정에 대한 유기물, 질소 및 인처리 효율을 비교하고 유입수의 C/N와 SRT 및 온도에 따른 질소, 인 처리 특성과 유출수의 거동 등을 파악하였다. 시뮬레이션 결과, 국내 하수에서는 A2/O 보다는 MUCT 공정이 질소, 인 처리효율이 더 크게 나타났다. 온도와 SRT가 일정한 상태에서 C/N비는 7이상에서 TKN과 TP제거효율이 양호하게 나타났고, 온도와 C/N비를 일정한 조건에서는 SRT가 7일을 넘어서면 효율이 급격히 낮아지는 현상을 관찰할 수 있었다. 온도조건 실험에서는 $20^{\circ}C$이하, 특히 국내 하수처리장에 BNR 적용시 설게조건인 $13^{\circ}C$에 근접해서는 TKN의 제거효율은 급격히 떨어지는 반면에 인 제거효율이 상승하는 것으로 나타났다.

• Journal of Wetlands Research
• /
• v.19 no.2
• /
• pp.216-222
• /
• 2017

Recently, opinions on the need for revision regarding the nitrogen effluent standard of nitrogen from sewage treatment plant(STP) are consistently suggested. However, it is axiomatic that if nitrogen effluent standard is strengthened without a clear basis, it will cause confusion in domestic STP. In this research, nitrogen fraction was analyzed based on a long-term incubation method, according to STP capacity, and the linked treatment of industrial wastewater. As a result, NBDDON, which is difficult to treat in STP, ranged from 1.0 to 1.9 mg/L. larger DON and NBDDON/DON was detected in small STP (under 10,000 m3 /d) as opposed to the large STP. NBDDON/DON in industrial STP was about 0.7 and it was higher than municipal STP. This research result will be used in the important raw data for revision of nitrogen effluent standard of nitrogen from STP.

• Resources Recycling
• /
• v.16 no.6
• /
• pp.52-60
• /
• 2007

Denitrification from aqueous solution was investigated through patent analysis and electrochemical denitrification experiment. Among several candidates, biological treatment and oxidation/reduction method are mainly discussed. Recently, patent pending concerning to electrochemical treatment is increasing. Based on basic electrochemical study, total nitrogen was removed up 47% by 1-hour galvanostatic electrolysis with Fe cathode and Pt anode. More applicable technique to industry could be mentioned combination of two or more technologies suitable to waste water characteristics. In the case of small and concentrate effluent, combination of chemical and electrochemical treatment would be recommendable because nitrate could be easily converted to nitrite by chemical treatment, and in that case denitrification by electrolysis becomes more efficient and metal ions from chemical treatment can be recovered during electrolysis.

• Journal of Bio-Environment Control
• /
• v.19 no.4
• /
• pp.257-265
• /
• 2010

The objective of study was carried out to investigate the proper nutrient nitrogen concentration and irrigation period for increasing plant growth and flowering in Ardisia pusilla. Nutrient nitrogen concentrations were 120, 150, 180 and $210\;mg{\cdot}L^{-1}$ and they were based on the Sonneveld solution. Irrigation periods were divided into ED (except dormancy) and TG (total growth) according to plant age. The results of plant age and irrigation period, growth of 1 year-old plant was promoted by nitrogen concentration above $150\;mg{\cdot}L^{-1}$ regardless of irrigation period. And plant growth values of 2 years-old in TG treatments were higher than ED treatments, especially TG-180 treatment was best of all. The contents of total nitrogen of leaves after flowering were increased with nutrient nitrogen strength. And the contents of potassium, calcium, magnesium and phosphate slightly were decreased or were no significant differences. Plant growth and flowering decreased when nitrogen concentration was over $210\;mg{\cdot}L^{-1}$. Therefore, TG-150 and TG-180 were supposed to be appropriate treatment for plant growth and flowering of 1year-old plant and 2 years old plant, respectively.

• Journal of the Korean GEO-environmental Society
• /
• v.4 no.3
• /
• pp.61-67
• /
• 2003

A new precess which consists of pre-dewatering device, post composting for solid phase and post sequencing batch reactor(SBR) for liquid phase was designed. Nitrogen in supernatants of dewatering device was removed by sequencing batch reactor. Experiments were carried out to investigate the SBR operation modes such as fill ratio, SRT, and operation cycle. The optimum fill ratio, SRT and aeration/non-aeration time were 1/12, 15days, and 2hr aeration / 1hr non aeraion, respectively. Methanol as an external carbon source increased denitrification when step feeding method was applied, not single feeding method.

• Korean Journal of Organic Agriculture
• /
• v.17 no.3
• /
• pp.381-391
• /
• 2009

Crop production can be secured by the cycle of green manure crops as an alternative of the chemical fertilizer. Recently, rapeseed (Brassica napus L.) has been cultivated in the south part of Korea for the production of biodiesel. In this research, we focused on recycling rapeseed residue, which is produced after harvesting the rapeseed for biodiesel, as a potential source of nitrogen to the succeeding crop. Pot experiment was conducted to evaluate the effects of winter rapeseed as green manure on mineralization and uptake of nitrogen to the succeeding corn (Zea mays L.). Result showed that total nitrogen and C/N ratio of rapeseed at the harvesting stage was 0.54% and 63, respectively. The incorporation of rapeseed without decomposition period slightly inhibited nitrogen uptake to the succeeding corn compared to those with 30 days decomposition period. The pH and EC values of soils increased by increasing the period of decomposition of rapeseed from 5.2 to 6.4 and from 0.05 dS/m to 0.21 dS/m, respectively. Significant amounts of $NH_4^+$ and $NO_3^-$ are released by incorporation of rapeseed. The succeeding corn took up 86% and 88% of inorganic nitrogen released from the rapeseed with and without decomposition period, respectively. The overall results suggested that the utilization of rapeseed residue as green manure can be an alternative source of nitrogen in corn-rapeseed double cropping system.

• Applied Chemistry for Engineering
• /
• v.33 no.6
• /
• pp.624-629
• /
• 2022

Formaldehyde is an indoor pollutant that is harmful to humans, such as causing respiratory and skin diseases. Nitrogen plasma treatment was performed to introduce nitrogen groups on the surface of the activated carbon fibers (ACFs), and the adsorption characteristics of formaldehyde for the surface-modified ACFs were considered. As the nitrogen gas flow rate increased, the content of nitrogen functional groups introduced to the surface of the ACFs increased by about 7%, and the ratio of nitrogen functional groups to each type present was similar. Ultramicropores increased on the ACFs surface due to the etching effect of plasma treatment. The adsorption efficiency of formaldehyde on the modified ACFs surface was also enhanced. However, under the nitrogen flow rate of 120 sccm or more, the surface of the ACFs was excessively etched, and the specific surface area and the formaldehyde adsorption capacity decreased. Therefore, the content of the nitrogen groups is the main factor in the adsorption of formaldehyde on the nitrogen plasma-treated ACFs, but it can be found that the adsorption efficiency of formaldehyde is improved when the ACFs have a suitable pore structure.

• Korean Journal of Soil Science and Fertilizer
• /
• v.33 no.1
• /
• pp.8-14
• /
• 2000

Long term cultivation crops like tomato, capsicum, melon etc. demand much amount of continuous supplying of nutrition during the whole growing periods. It is not easy to cover satisfactorily the nutritional demands for them by splitted top dressings, slow release fertilizer applications and fertigation systems. To overcome these problems, the "CULTAN" (Controlled Uptake Long Term Ammonium Nutrition) Beaker Deposit techniques have been developed and it was put into PVC beaker with the combined nitrogen fertilizer type mixed with the ratio of one-third of ammonium sulfate-N and two-thirds of urea-N, in which nitrogen was loaded on the demanding amount of a tomato plant during the growing period. Gypsum was mixed as a binder, and loamy soil and compost were used as a diffusion regulator. It was placed upside down into root zone of tomato at the transplanting. Tomato roots were spreaded into the Deposit beaker by ammonium ions which attract root growth. The tomato fruit yield and nitrogen uptake by plant were increased by application of $NH_4$-Beaker deposit fertilizer rather than those of common fertilizer treatment. In conclusion, it was able to improve economic and ecological benefits through CULTAN system compared with common fertilization systems. CULTAN system was estimated as a prospective alternative to enhance productivity and minimize nutrient lose. In addition, it shows further developing possibility of CULTAN system by the supplement of micro-nutrients and pesticides in the macro-nutrient beaker deposits.

• Applied Biological Chemistry
• /
• v.11
• /
• pp.173-184
• /
• 1969

To elucidate the effect of Amo-1618(4-hydroxyl-5-isopropyl-2-methlphenyl trimethyl ammonium chloride, 1-piperidine carboxylate) known as a kind of growth retardant, on the growth, grain yield, increasing the efficiency of nitrogen fertilizer, behavior of mineral nutritions and the rate of phosphorus utilization, this experiment was conducted pot culture method in a vinyl house. Two nitrogen level, namely, practical nitrogen level(1 N) and three times nitrogen level(3 N) was made and labelled double-calcium-superphosphate $Ca(H_2P^{32}O_4)_2.\;2H_2O)$ as a source of radioactive phosphorus(P-32) was employed $80\;{\mu}c/pot$, respectively. Rice seedlings, variety 'Suwon No. 82', was transplanted to a 1/50,000 a china pot on June 13 in 1968. For treatment, at early stage of tillering, 10,000 ppm solution of Amo-1618 was foliar sprayed only one time. The Duncan's new mutiple-range test was adopted for statistical analysis evaluating experimental data at 5% level significance. The results obtained may be summarized as follows; 1) No significant difference was found among the treatments in plant height, but in plot of Amo-1618 treatment and 3 N level, number of tillers was significantly increased than that of others. 2) Weight of 10,000 kernels and seed-setting rate was also remarkably increased in same treatment above. 3) Grain yield per pot was significantly increased in Amo-1618 and 3 N level application. This results seemed to be due to the increased the factors on the yield. 4) Contents of nitrogen and phosphorus per cent in the grain was likewise increased in Amo-1618 and 3 N application. There is, however, no difference among treatments in the content of nitrogen and phosphorus in the leaves and culms of rice plants. 5) On the other hand, the contents of potassium and magnesium, no distinctly tendeny showed among treatments. 6) The rate of phosphorus utilization was significantly increased in the plot of Amo-1618 and 3 N application.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.42 no.5
• /
• pp.515-521
• /
• 1997

Tobacco plant was grown for 40 days hydroponically in nutrient solutions composed of different forms of nitrogen, like NO$_3$$^{[-10]}$ -N, NH$_4$$^{＋}$-N, and a mixed formulation of NO$_3$$^{[-10]}$ -N and NH$_4$$^{＋}$-N. Uptake response, nitrate reductase, and glutamine synthetase activity at growth stage were investigated to understand the basic knowledge of nitrogen metabolism. The better growth of shoot and root was observed in the mixed nutrient solution than NO$_3$$^{[-10]}$ -N or NH$_4$$^{＋}$-N, alone. The plant growth in NH$_4$$^{＋}$-N nutrient solution was poor due to ammonium toxicity. The pH of nutrient solution containing NO$_3$$^{[-10]}$ -N increased up to 40 days after transplanting. But the pH of solution containing NO$_3$$^{[-10]}$ -N decreased drastically to 3.42 at 20 days after transplant. The pH in the mixed formulation dropped to pH 3.64 at 30 days after transplant and showed re-increase. It is assumed that nitrogen of NH$_4$$^{＋}$-N form was taken up preferentially at early stage and NO$_3$$^{[-10]}$ -N form was taken up preferentially at middle stage in the treatment with the mixed solution. The result indicates that the relative proportion of nitrogen forms affected the uptake patterns at each growth stages. The contents of chlorophyll and soluble protein were high with the mixed solution. Total nitrogen content was the highest in NH$_4$$^{＋}$-N solution and the content also increased by the application of the mixed type of nitrogen. The amount of nitrate in leaves was high in NO$_3$$^{[-10]}$ -N treatment and the amount of ammonium was high in NH$_4$$^{＋}$-N treatment. The activity of nitrate reductase or glutamine synthetase was highest in the leaves grown in mixed nutrient solution than in those with any other single of nitrogen form.