본 연구는 통상 muntz metal로 불리는 구리와 아연의 합금 금속의 산화 환원 반응을 이용한 폐수 중 탈인 처리에 관한 연구이다. 연구를 위하여 200 ㎛ 두께의 극세사 형태로 제조된 구리 아연 금 속합금이 수용액 중에서 산화 환원 반응 작용으로 인하여 발생하는 OH radical을 이용하여 금속과 phosphate의 공침 반응에 의해 탈인 처리되는 원리를 이용한 인 처리법에 관한 연구이다. 인 제거 효율은 장시간의 순환 처리보다는 1회 처리에서 가장 제거 효율이 높았으며, 1시간 이후의 순환처리에서는 더 이 상의 제거효율을 보이지 않았다. 이는 금속합금 물질은 표면적이 넓어서 1회 처리만으로도 수용액의 pH 를 평형에 도달하게 하여 반응 효율이 높은 것으로 나타났다. 제조한 합성폐수의 pH 조건은 pH 5 에서 pH 9 사이이며, pH 8일 때 제거 효율이 가장 높았으며 pH 8 이상에서는 효율 증가를 보이지 않았다. 이때 인산염은 H2PO4 -, HPO4 2-의 형태로 가장 많이 존재하는 것으로 조사되었으며, 온도에 따른 인 제 거는 온도만의 영향이 아닌 타 영향인자와의 관계를 고려해야 하며 본 연구에서는 온도가 낮을수록 높은 인 제거 효율을 보였다.

This study were performed to control color and satisfy discharge permission standard of effluents operating a small dyeing factory based on a fiber. The color removal efficiency was very high when the injection site of Sodium Hypochlorite(NaOCl) was more discharge site of second sedimentation tank than of first sedimentation tank. Although NaOCl usages was reduced from 1.0 ㎥/day to 0.8 ㎥/day, the removal efficiency of BOD, COD and SS were similar. At the time, the optimal Hydraulic Retention Time(HRT) was calculated to twenty five minute after NaOCl injection until effluent discharged finally. After controlling NaOCl usages and HRT, the effluent quality of BOD, COD, SS, Color and Chloroform were 8.6 mg/L, 24.7 mg/L, 43.3 mg/L, 191.2 degree and 0.346 mg/L, respectively, so that was satisfied to discharge permission standard.

This paper presents PKES(PuKyung -Excel based Simulator) for WWTPs(wastewater treatment plants) by using MS Excel and VBA(Visual Basic for Application). PKES is a user-friendly simulator for the design and optimization of the whole plant including biological and physico-chemical processes for the wastewater and sludge treatment. PKES calculates the performance under steady or dynamic state and allows changing the mathematical model by the user. Mathematical model implemented in PKES is a improved integration model based on ASM2d and ADM1 for simulation of AS(activated sludge) and AD(anaerobic digestion). Gaseous components of N2, N2O, CO2 and CH4 are added for estimation of GHGs(greenhouse gases) emission.The simulation results for comparison between PKES and Aquasim(EAWAG) showed about the same effluent concentrations. As a result of verification using by measured data of BOD, TSS, TN and TP for 2 years of operation, calculated effluent concentrations were similar to measured effluent concentrations. The values of average RMSE(root mean square error) were 1.9, 0.8, 1.6 and 0.2 mg/L for BOD, TSS, TN and TP, respectively. Total GHGs emission of WWTP calculated by PKES was 138.5 ton-CO2/day and GHGs emissions of N2O, CO2 and CH4 were calculated at 21.7, 28.9 and 87.9 ton-CO2/day, respectively. GHGs emission of activated sludge was 32.5 % and that of anaerobic digestion was 67.5 %.

This study investigated the effect of a co-culture of Scenedesmus dimorphus and nitrifiers using artificial wastewater on the removal of ammonium, nitrate and phosphate in the advanced treatment. To test the synergistic effect of the co-culture, we compared the co-culture treatment with the cultures using S. dimorphus-only and nitrifiers-only treatment as controls. After 6 days of incubation, nitrate was removed only in the co-culture treatment and total amount of N removal was 1.3 times and 1.6 times higher in the co-culture treatment compared to those in the S. dimorphus- and nitrifiers-only treatments, respectively. In case of total amount of P, co-culture treatment removed 1.2 times and 12 times more P than the S. dimorphus -and nitrifiers-only conditions, respectively. This indicates that the co-culture improved removal rates for ammonium, nitrate, and phosphate. This further implies that there was no need for denitrification of nitrate and luxury uptake of P processes because nitrate and phosphate can be removed from the uptake by S. dimorphus. In addition, co-culture condition maintained high DO above 7 mg/L without artificial aeration, which is enough for nitrification, implying that co-culture has a potential to decrease or remove aeration cost in the wastewater treatment plants.

This study examined a feasibility of coagulation as post-treatment to remove sulfide and phosphorus for the effluent of anaerobic fluidized bed reactor (AFBR) treating domestic wastewater. Removal efficiencies of sulfide, phosphorus and COD by coagulation were not affected by pH in the range of 5.9 to 7.2. Alkalinity requirement could be estimated by the amount of Fe3+ to form Fe(OH)3(S) and to remove sulfide and phosphorus. At coagulant aid dosage of 2 mg/L, anionic polymer showed best results regarding size and settleability of flocs. Sulfide removal for the AFBR effluent at the Fe3+/S2- ratio of 0.64, close to the theoretical value of 0.67 found with a synthetic wastewater, was only 75.2%. One of the reasons for this low sulfide removal is that the AFBR effluent contains, phosphorus, hydroxide and bicarbonate which can react with Fe3+ competitively. Concentrations of sulfide and phosphorous reduced to below 0.1 and 0.5 mg/L, respectively, at the Fe3+/S2- ratio of 2.0. Average effluent COD of 80 mg/L, mostly soluble COD, was obtained at the dosage 50 mg Fe3+/L (Fe3+/S2- ratio of 2.0) with corresponding COD removal of 55%. For better removal of COD, soluble COD removal at the AFBR should be enhanced. Coagulation with Fe3+ removed sulfide, phosphorus and COD simultaneously in the AFBR effluent, and thus could be an alternative process for the conventional wastewater treatment processes where relatively high quality effluent is not required.

A coagulation-flocculation (CF) process using aluminum sulfate as a coagulant was employed to treat highly suspended solids in tunnel wastewater. Response surface methodology (RSM) based on a Box-Behnken design was applied to evaluate the effects of three factors (coagulant dosage, pH and temperature) on total suspended solids (TSS) removal efficiency as well as to identify optimal values of those factors to maximize removal of TSS. Optimal conditions of coagulant dosage and pH for maximum TSS removal changed depending on the temperature (4 ~ 24°C). As temperature increased, the amount of coagulant dosage and pH level decreased for maximum TSS removal efficiency during the CF process. Proper adjustment of optimal pH and coagulant dosage to accommodate temperature fluctuations can improve TSS removal performance of the CF process.

The object of this study is to investigate the relationship between the air dilution sensory test and the threshold odor number (TON) method for evaluating the odor of domestic wastewater, plating plant wastewater, food plant wastewater and lake water. The dilution factor of raw wastewater evaluated by the air dilution sensory test was in the order of food plant > plating plant > domestic > lake, and that evaluated by the threshold odor number method was in the order of food plant > domestic > plating plant > lake. The same results were obtained when the raw wastewater and lake water were diluted 2 and 5 times with pure water. The relative geometric standard deviation determined from the threshold values of each panel on the air dilution sensory test was much larger than that calculated from results derived from the threshold odor number method. The relative geometric standard deviation obtained from samples with a low dilution factor was greater. There was a very good linear correlation (correlation coefficient = 0.968~1.000) between the air dilution sensory test and the threshold odor number method. But, the reduction in odor intensity (the slopes of regression curves) by dilution was dependent on the types of the odor-emission sources.

Microalgae is known as one alternative energy source of the fossil fuel with the small size of 5 ~ 50 µm and negative charge. Currently, the cost of microalgae recovery process take a large part, about 20 - 30% of total operating cost. Thus, the microalgae recovery method with low cost is needed. In this study, the optimum current for Scenedesmus dimorphus recovery process using electrocoagulation techniques was investigated. Under the electrical current, Al metal in anode electrode is oxidized to oxidation state of Al3+. In the cathode electrode, the water electrolysis generated OH- which combine with Al3+ to produce Al(OH)3. This hydroxide acts as a coagulant to harvest microalgae.Before applying in 1.5 L capacity electrocoagulation reactor, Scenedesmus dimorphus was cultured in 20 L cylindrical reactor to concentration of 1 OD.The microalgae recovery efficiency of electrocoagulation reactor was evaluated under different current conditions from 0.1 ~ 0.3 A. The results show that, the fastest and highest recovery efficiency were achieved at the current or 0.3 A, which the highest energy efficiency was achieved at 0.15 A.

The predictive capacity of wastewater treatment facility in the industrial park was estimated by the traditional method and on-the-spot survey such as certification of wastewater report and the invoices of water supply and ground water supply. The ratios of a converted wastewater to supplied industrial water between traditional method and on-the-spot survey in the estimation methods were different. By using traditional method, the business type of clothes, accessary and fur production had 77.18 % of waste ratio of wastewater and 10.72 m3/day·1000 m2 unit mass of wastewater as the highest among 9 business types. With the respect to the on-the-spot survey, food manufacturing business type had 75 % of waste ratio of wastewater and 8.35 m3/day·1000 m2 unit mass of wastewater as the highest values. The amount of wastewater from on-the-spot survey method was 541 m3/day less than one from traditional method.

This study was carried out to investigate the response characteristics of a hydrogen sulfide electrochemical gassensor for several wastewater odors. At first, it was found that bubbling sampling method was superior toheadspace sampling method in terms of sensor sensitivity. High correlation between odor concentration and sensorresults was shown for two wastewater which were r=0.977 for food-waste recycling wastewater and r=0.997for food industry wastewater. On the other hand, no correlation (r=0.258) was found for plating wastewater,because hydrogen sulfide was not the main odorant for that.

Capacitive deionization(CDI) has many advantages over other desalination technologies due to its low energy consumption, less environmental pollution and relative low fouling potential. The objectives of this study are evaluate the performance of CDI which can be used for dissolved salts removal from sewage. To identify ion selectivity of nitrate and phosphate in multi-ionic solutions and adsorption/desorption performance related to applied potential, a series of laboratory scale experiments were conducted using a CDI unit cell with activated carbon electrodes. The CDI process was able to achieve more than 75 % TDS and NO3-, NH4+ removals, while phosphate removal was 60.8 % and is inversely related in initial TDS and H3- concentration. In continuous operation, increasing the inner cell pressure and reduction of TDS removal ability were investigated which are caused by inorganic scaling and biofouling. However a relative mild cleaning solution(5 % of citric acid for calcium scaling and 500 mg/L of NaOCl for organic fouling) restored the electrochemical adsorption capacity of the CDI unit to its initial level.

우리나라는 겨울철에 미세조류가 성장하기에 적합하지 않은 기후조건을 가진다. 따라서, 차세대 바이오매스의 공급원료로서의 미세조류 배양을 겨울철에 이룩하기는 쉽지 않다. 본 연구에서는 적은 에너지를 이용하여 미세조류가 성장이 불가한 영외환경에서 미세조류를 성장시키기 위해서, 삼중막의 비닐하우스를 설치하였다. 또한 투명한 아크릴 재질로 수조를 제작하여 빛을 수조의 모든 면에서 받을 수 있게 함으로써, 빛의 이용성을 최대화하였다. 6가지의 다양한 실험조건을 설정하여 겨울철 영하의 기후조건에서 최소한의 비용으로 하수종말처리장 폐수를 사용하여 미세조류를 배양하였다. 또한 미세 조류 바이오매스를 증가시킴과 동시에 환경오염의 원인이 될 수 있는 영양염류 성분 중 질소를 최대 92%, 인을 최대 99%까지 제거시켰다. 본 연구에서 바이오디젤의 원료가 될 수 있는 가장 주된 지방산은 리놀렌산(C18 : 3n3)으로 총 지질량의 최대 61%까지 차지했다. 지방산의 생산성은 2.4 g m-2 day-1이었다. 결론적으로, 본 연구를 통하여 차세대 바이오매스 생산을 위한 미세조류 배양을 저온 시기에서도 이룩하였으며, 그에 따른 폐수처리에서도 좋은 성과를 이루었다.

본 연구는 시설하우스에서 비점오염원으로 인해 배출되는 오염된 농업배수를 인공습지에서 효과적으로 처리하기 위한 기초자료를 확보하기 위해 인공습지에서 여재종류, 조합방법 및 부하량에 따른 오염물질 정화효율을 평가하였다. 인공습지의 조합방법은 수직-수평흐름조, 수평-수직흐름조, 수평-수직-수평흐름조 및 수직-수평-수평흐름조로 구분하여 설계 및 시공하였으며, 여재는 왕사, 쇄석, 방해석 및 혼합여재로 구분하여 각 조에 충진하였다. 또한 농업배수 부하량을 150, 300, 600 L m-2 day-1으로 달리하여 오염물질의 처리효율을 조사하였다. 조합방법별 수처리효율은 HF-VF-HF 조합방법이 다른 조합방법에 비해 높은 처리효율을 보였으며, 최적여재는 COD 처리효율은 왕사가 가장 높았고, T-N은 쇄석, T-P는 방해석이 가장 높았다. 하지만 모든 처리효율과 경제성 부분을 고려하였을 때 최적여재는 혼합여재가 가장 효과적일 것으로 판단된다. 농업배수의 부하량에 따른 처리효율 결과 COD는 농업배수 부하량 600 L m-2 day-1까지 안정적인 처리효율을 보였으나, T-N 및 T-P는 150 L m-2 day-1≒300 L m-2 day-1¤600 L m-2 day-1의 순으로 농업배수의 부하량이 증가함에 따라 약간 감소하는 경향이었다. 따라서 시설하우스 농업배수 처리를 위한 인공습지 농업배수처리장의 최적조건은 HF-VH-HF 조합형 인공습지에 왕사, 쇄석 및 방해석이 혼합된 혼합여재로 충진하고 부하량 300 L m-2 day-1 이하의 농업배수를 주입하는 것이 최적일 것으로 판단된다.

The performance of inorganic sludge separation system is evaluated. Anaerobic digester effluent sludge is used for feed sludge of this system and hydrocyclone is used for inorganic sludge separation. For phosphorus removal and recovery MgCl2 is pumped into MAP growth tank, a component of inorganic sludge separation system. Using this system inorganic sludge which contained less than 40 % of organic matter can be discharged stably and the maximum amount of separated inorganic sludge is 13.4 % of influent sludge based on dry solid. The amount of phosphorus recovered as MAP(as P) is 16.7 % to influent T-P.

Study on effluent organic matter (EfOM) characteristic and removal efficiency is required, because EfOM is important in regard to the stability of effluents reuse, quality issues of artificial recharge and water conservation of aqueous system. UV technology is widely used in wastewater treatment. Many reports have been conducted on microbial disinfection and micro pollutant reduction with UV treatment. However, the study on EfOM with UV has limited because low/medium pressure UV lamp is not sufficient to affect refractory organics. The high intensity of pulsed UV would mineralize EfOM itself as well as change the characteristics of EfOM. Chlorine demand and DBPs formation is affected on the changed amounts and properties of EfOM. The objective of this study is to investigate the effect on EfOM, chlorine residual, and chlorinated DBPs formation with low pressure and pulsed UV treatment. The removal of organic matter through low pressure UV treatment is insignificant effect. Pulsed UV treatment effectively removes/transforms EfOM. As a result, the chlorine consumption is changed and chlorine DBPs formation is decreased. However, excessive UV treatment caused problems of increasing chlorine consumption and generating unknown by-products.

Most small laundry factory has been operated without not only environmental expertise but also technical process. The objective of this study is to get the optimal coagulation dosage for satisfaction of discharge permission standard of laundry wastewater treatment plant(WTP) effluents by jar test.The coagulants are alum and sodium hydroxide(NaOH), coagulants aids is polymer. Also, the best coagulation reaction was shown in the following conditions ; Alum 4.13g/L, NaOH 1.03g/L, Polymer 0.27g/L on average. The optimal coagulation dosage could be reduced costs to 4.43 million won a year. It was considered that operating a small WTP was an important technical data in same industry.

주류를 제외한 과일 및 탄산음료 등을 제조하는 비알코올성 음료품 제조시설에서 발생되는 폐수는 높은 농도의유기물과 낮은 농도의 질소, 인 등을 함유한다. 이러한 폐수의 처리 시설은 주로 호기성 공정과 약품응집 공정으로 구성하고 후단에 사여과지 또는 활성탄 공정을 추가하기도 한다. 하지만 이러한 방식은 긴 체류시간과 침전지 설치로 인해 많은 부지를 필요로 하는 문제가 있다. 본 연구에서는 부지소요 문제와 슬러지 유출로 인한 수질저하 문제를 해결하고자 W식품공장 폐수처리장 인근에 MBR pilot plant를 설치하고 장기간 운영을 통해 데이터를 확보하고 처리 효율을 평가하였다. 약 3개월간음료수 제조공정 폐수를 평막을 적용한 MBR pilot plant로 운전조건을 변화하며 처리한 결과, 처리유량 20 m3/day, HRT 29hr, 4Q 반송조건까지는 유기물 제거율 97% 이상으로 안정적인 처리가 가능했다. 하지만 그 이상의 운전조건에서는 생물반응조의 오염물질 제거율이 감소하였고 TMP가 급격히 증가하는 모습을 보였다.

The purpose of this study is to get basic data for the application of coagulants for treating an industrial wastewater containing NBD COD. The NBD COD concentration of the target wastewater was calculated to be 61 mg/L, which was about 72% of the first stage treated water, and this shows that there must be advanced wastewater treatment process. When Alum(8%) was injected in raw the water, 150ppm was the best dosage and 41% CODmn removal efficiency was obtained. When Alum(8%) was injected in the discharge water, 150ppm was the best dosage, and 19% CODmn removal efficiency was obtained. When powdered activated carbon was injected, 40ppm was the best dosage, 26% CODmn removal efficiency was obtained. The method of injecting Alum(8%) in the discharge water was suitable, when the effluent exceeds the water quality standard by 20%, and the method of injecting the powdered activated carbon was suitable, when the effluent exceeds the water quality standard by 20~40%.