경기도 양평군 수입천에서 대형 군락을 형성하여 자생하는 갯버들의 영양염류의 농도와 수리학적체류시간에 따른 질소.인 흡수 실험 결과로서 NH4-N, NO3-N, PO4-P제거효율은 저농도에서 체류 시간이 길 때 높은 경향을 보였고, 제거능은 고농도와 짧은 체류시간에서 높은 경향으로 나타났다. 유입농도와 체류시간에 따른 지상부 1g당 제거능 추정식을 구하였다. 수입천 갯버들의 현존량은 4,880.81g/m2로 추정되었고, 현존량과 제거

The raw drinking water quality is getting worse because of the winter drought and the conventional treatment system is'nt suitable to obtain the satisfied quality of water. So, the advanced water system, BAC(Biological Activated Carbon) process is said to be effective to remove dissolved organics and ammonia nitrogen. In our study, the BAC pilot plant using Nak-dong river water is tested in low temperature. Following results are found from the study. The ammonia nitrogen removal rate of BAC system using wood-based carbon (PICABIOL) was 99% in $6^{\circ}C$ temperature. Chlorine dosage in wood-based BAC effluent was reduced to 67% of that in sand filtered wate. It resulted from the removal of ammonia nitrogen. Also, THM formed by chlorine addition in wood-based BAC effluent was decreased to 65% of that in sand filtered water. In the case of dual-filter, the removal efficiency of ammonia nitrogen was increased 30% more than in conventional sand filter. According to this result, the ammonia nitrogen load to BAC system could be lessened by the use of dual-filter.

호소의 부영양화와 같은 수계오염을 유발하는 질소 및 인에 대한 방류수 수질기준 규제가 점차 강화되고 있으며, 최종 개정된 방류수 수질기준에서는 처리수를 Ⅰ지역에 방류하는 경우, 총 질소 20 mg-N/L, 총 인 0.2 mg-P/L로 규제하고 있다. 이에 따라 대부분의 공공하수처리시설은 고도처리공법을 확보하고 있으며 현재 운영중인 고도처리시설에는 생물학적 고도처리법인 SBR공법과 A O 공법이 가장 많이 적용되고 있다. 그러나 한국 하수 성상의 경우 질소에 대한 유기물의 비율이 낮기 때문에 질소 제거효율이 낮고, 탈질을 위해 외부 탄소원을 추가적으로 주입함에 따라 운영비의 증가 문제가 발생된다. 외부 탄소원의 주입에도 불구하고 2015년 환경부에서 발표한 방류수 수질현황을 참고하면 공공하수처리시설의 T-N 제거효율은 약 70%에 그친다. 이에 본 연구에서는 국내 생물학적 고도처리법으로 가장 많이 적용되고 있는 SBR 공법에 수처리용 스펀지 담체를 투입하였을 때, 폭기구간에서의 질소제거 효율을 평가하고자 하였다. 스펀지 담체와 같이 담체 내외부의 물질전달이 자유로운 담체의 경우, 담체 내외부에 형성되는 산소 농도구배로 인하여 담체 내부에는 국소적인 무산소 조건이 형성되며, 그에 따라 담체 외부에서는 질산화가 내부에서는 탈질이 일어나는 SND(Simultaneous Nitrification and Denitrification) 기작이 일어날 수 있다. 이에 폭기 전･후의 암모니아성 질소와 질산성 질소 측정을 통해 SND 효율을 계산한 결과, 약 30%의 효율을 나타내었으며, 이는 탈질이 유도되는 단위공정에서 탈질에 필요한 외부탄소원의 요구량을 감축시킬 수 있으므로 경제적인 측면에서 긍정적인 영향을 미칠 것으로 사료된다.

The use of Soluble Cutting Fluids (SCF) is essential in the development of industrial technology. However, it is difficult to decompose biologically due to its high concentrations of organic substances and nitrogen compounds, which interfere with microbial growth. Recently, Advanced Oxidation Processes are being studied both domestically and internationally. Electrolysis is highly adaptable industrial wastewater treatment because it has high removal efficiency and short processing time, regardless of the contaminant’s biodegradable nature. Accordingly, this study shows the characteristics of total nitrogen removal in SCF on the operating time, current density, and electrolytes when using aluminum in a batch-type reactor. The results are as follows: ① Under the condition of without the electrolyte when the current density was adjusted to 40 A/m2, 60 A/m2, or 80 A/m2, the respective T-N removal efficiencies were 71.7%, 80.6%, and 87.2% at 60 min. ② In the comparison for the condition of whether NaCl was added, the removal efficiency of adding NaCl (5 ~ 10 mM) was higher than non-addition at 60 min for all current densities. ③ In the comparison for the condition of whether Na2SO4 (5 ~ 10 mM) was added, the removal efficiency when adding Na2SO4 showed no significant difference compared to non-addition at 60 min for all current densities.

As industry continues to develop, the contents of various recalcitrant substances that are not removed by conventional wastewater treatment have increased in modern society. The metal working fluids (MWFs) used in the metal working process contain chemical substances, such as mineral oils, anticorrosive agents, extreme-pressure additives, and stabilizers, as well as high concentrations of organics and ammonia-nitrogen. Accordingly, MWFs are required to develop advanced treatments to conserve hydro-ecological resources. This study investigated the removal efficiency of ammonia nitrogen from MWFs according to operating time, applied voltage, and NaCl concentration using a Ti/IrO2 electrode in a batch-type reactor. The experimental results showed that ammonia-nitrogen removal efficiencies without NaCl were 89% and 92% when voltage was adjusted to 15 and 20 V for 60 min and removal efficiency was 90% at 25 V for 40 min. Removal efficiencies of 10 mM NaCl were 4% and 2% greater than those of not adding NaCl at 15 V for 50 min and 20 V for 30 min.

2012년 현재, 국내 광공업 중 자동차 및 트레일러 제조업, 금속가공제품 제조업 등 금속가공을 필요로 하는 사업체는 전체 광공업 사업체 중 약 40%를 차지하고 있으며, 이와 같은 금속가공 과정에서 필요로 하는 것이 절삭유이다. 그러나 절삭유 내에는 50~80% 정도의 미네랄 오일 외에 amins, carboxylates, chlorine, glycols와 같은 부식방지제, 안정제, 습윤제, 극압 첨가제 등 20여종 이상의 화학성분이 다량 함유되어 있으며, 인체에 지속적으로 노출 시 호흡기 자극, 천식, 폐렴, 피부염, 모낭염 및 피부암 등을 일으키게 된다. 또한 고농도의 유기성분이 함유되어 있으며 유기성분 외에도 금속가공유 내 함유된 암모니아성 질소는 수생태계에 방류되면 부영양화 및 녹조현상과 같은 문제를 일으키며, 수중에서 산화반응을 하여 아질산성 질소와 질산성 질소로 변화되면서 수계의 용존산소를 감소시켜 수계 내 오염을 일으켜 각별한 처리가 필요하다. 따라서 본 연구에서는 수용성 절삭유의 효율적인 처리를 위해 용성전극인 알루미늄과 SUS316전극을 이용하여 전극간격, 전압, NaCl 농도변화를 통해 암모니아성 질소 제거 효율에 미치는 영향을 검토하여, 전극 특성과 각 인자에 따른 제거양상을 비교하였다. 본 연구에서 사용한 시료는 수용성 절삭유 W1-1종을 초순수와 함께 5%(V/V) 희석하여 사용하였으며 성상은 Table 1과 같다. 장치구성은 반응조, 전극, 전원공급장치, 전압안정기(AVR)로 진행하였으며, 장치모식도는 다음 Fig. 1에 나타내었다.

Generally, metal working fluids (MWFs) are used to reduce friction in metalworking processes. In addition to mineral oils, MWFs contain many chemical substances, such as anticorrosive agents, extreme-pressure additives, and stabilizers, as well as high concentrations of organics and ammonia nitrogen. Accordingly, MWFs must be managed to advanced treatment for hydro-ecological conservation. This study investigated the removal efficiency of ammonia nitrogen from MWFs according to operating time, applied voltage, distance between electrodes, and NaCl concentration using aluminum in a batch-type reactor. The experimental results were as follows: First, without NaCl, removal efficiencies of ammonia nitrogen were 69.6%, 37.9%, and 22.7%, when the distance between electrodes was adjusted to 1, 4, and 7 cm, respectively, at 15 V for 60 min. Secondly, without NaCl, removal efficiencies of ammonia nitrogen were 49.5 and 90.9% when the voltage was adjusted to 5 V and 10 V, respectively, for 60 min and 94.6% at 15 V for 40 min. Lastly, with the addition of NaCl 10 mM, the removal efficiency of ammonia nitrogen was 40.3% and 11.5% greater than that of no addition of NaCl at 5 V for 60 min and at 10 V for 30 min.

There are two treatment processes that are currently applied to ships are the biological treatment process using the activated sludge and the electrochemical treatment. However, neither of them are able to remove both nitrogen and phosphorus due to their limited ability to remove organic matters, which are main causes of the red tide. This study was conducted to identify the characteristics of nitrogen removal factors from manure wastewater by replacing the final settling tank in SBR (Sequencing Batch Reactor) process and applying immersion type hollow fiber membrane. SBR process is known to have an advantage of the least land requirement in special environment such as in ship and the immersion type hollow fiber membrane is more stable in water quality change. As the result, the average in the cases of DO (Dissolved Oxygen) is 2.9(0. 6∼3.9) mg/L which was determined to be the denitrifying microorganism activity in anaerobic conditions. The average in the cases of ORP (Oxidation Reduction Potential) is 98.4∼237.3 mV which was determined to be the termination of nitrification since the inflection point was formed on the ORP curve due to decrease in the stirring treatment after the aeration, same as in the cases of DO. Little or no variation in the pH was determined to have positive effect on the nitrification. T-N (Total Nitrigen) removal efficiencies of the finally treated water were 71.4%, 72.3% and 66.5% in relatively average figures, thus was not a distinct prominence. In being applied in ships in the future, the operating conditions and structure improvements are deemed necessary since the MEPC (Marine Environment Protection Committee). 227(64) ship sewage nitrogen is less than the standard of 20 Qi/Qe mg/L or the removal rate of 70%.

Livestock wastewater has high potential as one of energy resources because this wastewater is including high organic matter. Therefore the studies attempting to bio-gasification and bio-electricity generation using livestock wastewater is being tried. The pre-treatment system used in this study was the purpose to control the ammonia nitrogen in conjunction with the system and the microbial fuel cell. Because ammonia nitrogen is to inhibit the electricity generation efficiency of microbial fuel cell. These studies were to ascertain the effect of oxidants on the nitrogen removal in the pre-treatment system using catalyst and microbubbles to treat the ammonia nitrogen. The three kinds of oxidant such as air, oxygen (O2), and hydrogen peroxide (H2O2) were used to know the ammonia and nitrate nitrogen removal. This system was operated with four kinds of conditions. First method is O2 gas with 100 mL/min with 1ml of 30% H2O2 was supplied to the wastewater. A second method, the O2, with 400 and 1,000 mL/min was supplied through the flow meter before livestock wastewater was flow in the reactor. The last method, air was supplied 800 mL/min. The nitrate removal had no significant difference all conditions except the air supply. On the other hand, the ammonia and nitrate nitrogen removal when oxygen was supplied with 1000 mL O2/min was higher than that of the other conditions. The removal rate when air was supplied 800 mL/min was similar to the value in the supplied with 400 ml O2/min. This result showed that oxidant was important factor to improve the ammonia nitrogen removal rate.

This research investigated the feasibility of rice husk as a biosorbent for removal of ammonium ion from aqueous solutions. To improve the sorption functionality of rice husk, the carboxyl groups were chemically bound to the surface of the rice husk by graft polymerization of acrylic acid using potassium peroxydisulphate as a redox initiator. The removal of ammonium ion by rice husk grafted with acrylic acid (RH-g-AA) was studied in a batch mode and fixed bed columns. The kinetic and equilibrium data obtained from batch experiments follow the second-order kinetics and fit well with the Langmuir isotherm model. The sorption energy determined from D-R model was 8.61 kJ/mol indicating an ion-exchange process as the primary sorption mechanism. To determine the characteristic parameters of the column useful for process design, four mathematical models; Bed Depth Service Time (BDST), Bohart-Adams, Clark and Wolborska models were applied to experimental data obtained from the fixed bed columns with varying bed heights. All models were found to be suitable for simulating the whole or a definite part of breakthrough curves, but the Wolborska model was the best. The fixed bed sorption capacity determined from the Wolborska model was in the range 33.3 ~ 40.5 mg/g close to the value determined in the batch process. The thickness of mass-transfer zone was calculated to be approximately 40 mm from DBST model. The RH-g-AA sorbent could be regenerated by a simple acid washing process without a serious lowering the sorption capacity or physical durability.

도계량을 현재의 2배까지 증가시킬 예정인 닭 가공 업체인 A사의 생물학적 처리조를 대상으로 하여 처리효율을 2배까지 높이는 방안을 모색하였다. 이를 위해 MLSS 농도가 증가할 경우 이에 따른 유기물 및 질소 제거 효율 증가에 대한 근거를 확보하고자 연구를 진행하였다. 연구는 닭 가공 폐수를 1차 화학 처리한 가압부상처리수를 대상으로 진행되었으며 SBR 형태로 진행되어 호기조 상태 25시간 운전 후, 무산소조 상태 5시간으로 운전되었다. MLSS 12,700mg/L로 진행된 실험 결과 호기조 상태 25시간 이내에 질산화가 완벽하게 일어났으며 C/N비 3:1 이상 실험군에서의 탈질 효율도 90%를 초과하였다. 후에 진행된 MLSS 농도 대비 유기물 및 질소 제거 효율 비교에서는 MLSS 농도를 5,600에서 12,700mg/L까지 변화시켰으며 MLSS 농도 10,800mg/L 실험군에서 유기물과 총 질소 농도 모두 배출허용기준치를 만족하는 결과를 보였다.

하수처리장은 인간의 생활에 있어서 중요한 공공시설이다. 하수에 포함되어 있는 유기물, 질소, 인 등의 오염물질이 함유되어 아무런 처리없이 수계로 방류 될 경우 수계에 심각한 오염을 야기 할 수 있다. 특히 질소(Nitrogen)와 인(Phosphorus) 경우 수계에 부영양화(Eutrophication)를 일으키는 주요 원인으로 알려져 있다. 이 중 질소를 제거하는데에는 생물학적 방법이 대부분의 하수처리에 쓰이는데 이는 물리적 및 화학적 방법에 비하여 경제적, 환경적 장점을 가지고 있기 때문이다. 질소 제거방법에는 아질산화-탈질 공정이 사용 되는데, 기존에 쓰이는 질산화-탈질 공정에 비하여 25%의 산소량과 40%의 탄소원 절감이 가능하여 탈질의 고효율을 얻을 수 있기 때문이다. 본 연구에서는 이러한 아질산화를 혐기 소화 상징액을 이용하여 SRT가 암모니아 제거율과 아질산화율에 미치는 영향에 대한 연구를 하였다. 서울 H 하수처리장의 혐기 소화액을 대상으로 실험실 규모의 아질산화 반응조 운전결과 SRT 6일 이상에서 대부분 60%이상의 효율을 보였다. 또한 아질산화율의 경우 SRT 4일에서 고효율의 아질산화율을 보였다. SRT 16일에 낮은 아질산화율이 나타났는데, 이는 아질산성 질소가 질산성 질소로 완전한 질산화가 이루진 것으로 사료된다. 이러한 결과로 볼 때 SRT가 아질산화 반응에 영향을 미치는 인자로 판단된다.

The pilot plant experiment was performed to investigate phosphorus and nitrogen removal from domestic wastewater by MLE process combined with aluminum corrosion reactor. When operating 0.5Q and 1Q to internal recycle and sludge recycle in the MLE process, the effluent CODMn concentration of internal recycle 0.5Q were higher than internal recycle 1Q, the removal efficiency rates of NH3-N in the internal recycle 0.5Q were was higher than internal recycle 1Q. Denitrification rates were about 86.8% in internal recycle and sludge recycle 0.5Q. When operating 0.5Q to internal recycle and sludge recycle in the MLE process, the removal efficiency rates of total nitrogen was the highest. The removal efficiency rates of total phosphorus was about 91.5% in the aluminum corrosion reactor.

A fixed biofilm reactor system composed of anaerobic, anoxic(1), anoxic(2), aerobic(1) and aerobic(2) reactor was packed with synthetic activated ceramic (SAC) media and adopted to reduce the inhibition effect of low temperature on nitrification activities. The changes of nitrification activity at different wastewater temperature were investigated through the evaluation of temperature coefficient, volatile attached solid (VAS), specific nitrification rate and alkalinity consumption. Operating temperature was varied from 20 to 5 ℃. In this biofilm system, the specific nitrification rates of 15 ℃, 10 ℃ and 5 ℃ were 0.972, 0.859 and 0.613 when the specific nitrification rate of 20 ℃ was assumed to 1.00. Moreover the nitrification activity was also observed at 5 ℃ which is lower temperature than the critical temperature condition for the microorganism of activated sludge system. The specific amount of volatile attached solid (VAS) on media was maintained the range of 13.6-12.5 mg VAS/g media at 20~10 ℃. As the temperature was downed to 5 ℃, VAS was rapidly decreased to 10.9 mg VAS/g media and effluent suspended solids was increased from 3.2 mg/L to 12.0 mg/L due to the detachment of microorganism from SAC media. And alkalinity consumption was lower than theoretical value with 5.23 mg as CaCO3/mg NH4 +-N removal at 20 ℃. Temperature coefficient (θ) of nitrification rate (20 ℃ ~ 5 ℃) was 1.033. Therefore, this fixed film nitrogen removal process showed superior stability for low temperature condition than conventional suspended growth process.

For the cost-effective biological nitrogen removal (BNR) process whose characteristics of influent have low COD/N ratios, the automatic control system for the addition of external carbon based on oxidation-reduction potential (ORP) data in an anoxic reactor has been developed. In this study, it was carried out with a pilot-scale Bardenpho process which was consisted of anoxic 1, aerobic 1, aerobic 2, anoxic 2, aerobic 3 tank and clarifier. Firstly, the correlation coefficient (R2) of the dosage of external carbon source and ORP value was about 0.97. Consequently, the automatic control system using ORP showed that the dosage of external carbon source was decreased by about 20% compared with a stable dosage of 75 mg/L based on the COD/N ratio of the anoxic influent.

하수에는 유기물, 질소, 인, 중금속 등 다양한 종류의 오염물질이 함유되어 있으며, 수계로 미처리하여 방류되게 되면 수계 수질을 악화시키게 된다. 그 중 질소(Nitrogen)와 인(Phosphorus)은 영양염류(Nutrient)로 분류되며 수계 부영양화(Eutrophication)의 주요한 원인으로 알려져 있다. 생물학적 영양소 제거 방법은 화학적 처리 방법에 비해 경제적, 환경적 및 운영적 장점을 가지고 있어 대부분의 하수처리에 적용되고 있다. 하지만, 현재 적용되는 기술에서는 암모니아성 질소를 질산성 질소 상태로 산화시킨 후 탈질 반응을 거치는 완전질산화(Nitrification)반응이 적용되고 있다. 만약 아질산성 질소 상태에서 탈질을 유도하는 아질산화 반응(Nitritation)을 적용하게 된다면, 완전질산화에 비해 이론적으로 약 25%의 산소를 절감할 수 있는 효과를 기대할 수 있다. 본 연구에서는 하수처리장에서 슬러지 처리 공정 중 혐기 소화단계에서 발생하는 고농도 질소를 함유한 혐기 소화 상징액을 대상으로 하여, SRT가 암모니아성 질소 제거율(Ammonium nitrogen removal rate)와 아질산화율(NItrite conversion rate)에 미치는 영향에 대한 연구를 수행하였다. 서울 A 하수처리장의 혐기 소화 상징액을 대상으로 한 실험실 규모 아질산화 반응조 운전 결과 안정적인 암모니아성 질소 제거율을 기대하기 위해서는 SRT 0.5d 이상, 고효율의 아질산화율을 기대하기 위해서는 SRT 1d를 유지해야 하는 것으로 나타났다. 이는 암모니아성 질소 제거율의 경우 일정한 SRT 이상 유지시켜 주면, 안정적인 효율을 기대 할 수 있는 반면, 아질산화율의 경우에는 일정한 SRT를 유지시켜 주어야만 안정적인 효율을 얻을 수 있는 것으로 해석 할 수 있다. 따라서 암모니아성 질소 제거 및 아질산화 반응에 서 SRT는 그 효율 및 유도에 있어 매우 중요한 인자로 작용하는 것을 확인 할 수 있다.

수질오염원에 속하는 비점오염원은 불특정한 장소에서 불특정하게 수질오염물질을 배출하는 배출원으로서 지점이 불명확하여 관리가 어렵다. 또한, 비점오염물질은 대부분 강우 유출수와 함께 수계로 유입되는데, 이 중 검출되는 TN과 TP는 영양염류로써 수계에 악영향을 초래한다. 이에 대한 대책으로 비점오염저감시설들이 설치되어 모니터링 및 유지관리 되고 있다. 본 연구에서는 비점오염저감시설 중 자연형에 속하는 식생수로에서 2년에 걸쳐 모니터링하고, TN, TP에 대한 저감효율을 산정하여 결과에 나타내었다. EMC를 산정하고, ER의 방법으로 저감효율을 계산한 결과, TN은 85.2%, TP는 77.9%로 나타났다.

The purpose of this study is to investigate the effect of influent phosphorus concentration on the nitrogen and phosphorus removal in sequencing batch reactor(SBR) and sequencing batch biofilm reactors(SBBRs) in order to recover the enhanced biological phosphorus removal (EBPR) capacity at the sludge of the deterioration of EBPR capacity. In SBBRs, comparing to SBR, the organic removal was occurred actively at the 1st non-aeration period because of the active phosphorus release at this period. However, the variation of TOC removal according to the decrease of influent phosphorus concentration was not clearly shown both in SBR and SBBRs. In case of SBR losing EBPR capacity, the EBPR capacity was not recovered by the decrease of the influent phosphorus concentration from 7.5 mg/L to 0.9 mg/L. The nitrogen removal increased by the decrease of influent phosphorus concentration both in SBR and SBBRs.

Lab-scale Electrodialysis(ED) system with different membranes combined with before or after pyroma process were carried out to remove nitrate from two pickling acid wastewater containing high concentrations of NO3-(≈150,000 mg/L) and F-(≈160,000 mg/L) and some heavy metals(Fe, Ti, and Cr). The ED system before Pyroma process(Sample A) was not successful in NO3- removal due to cation membrane fouling by the heavy metals, whereas, in the ED system after Pyroma process(Sample B), about 98% of nitrate was removed because of relatively low NO3- concentration (about 30,000 mg/L) and no heavy metals. Mono-selective membranes(CIMS/ACS) in ED system have no selectivity for nitrate compared to divalent-selective membranes(CMX/AMX). The operation time for nitrate removal time decreased with increasing the applied voltage from 10V to 15V with no difference in the nitrate removal rate between both voltages. Nitrate adsorption of a strong-base anion exchange resin of Cl- type was also conducted. The Freundlich model(R2 > 0.996) was fitted better than Langmuir model(R2 > 0.984) to the adsorption data. The maximum adsorption capacity (Q0) was 492 mg/g for Sample A and 111 mg/g for Sample B due to the difference in initial nitrate concentrations between the two wastewater samples. In the regeneration of ion exchange resins, the nitrate removal rate in the pickling acid wastewater decreased as the adsorption step was repeated because certain amount of adsorbed NO3- remained in the resins in spite of several desorption steps for regeneration. In conclusion, the optimum system configuration to treat pickling acid wastewater from stainless-steel industry is the multi-processes of the Pyroma-Electrodialysis-Ion exchange.