고령화매립지 침출수 처리에서 발생되는 난분해성물질의 제거 및 탄소원 부족에 의한 탈질의 제한문제를 해결하고자 분리막침지형생물반응기(SMBR)와 역삼투(R/O)공정의 조합공정을 침출수처리에 적용하였다. 먼저 용인시에서 SMBR Pilot 테스트를 약 100일간 수행하였으며 여기서 SMBR 공정에 대한 신뢰성은 확인되었으나 (NH3-N제거율 : 90%) 난분해성물질의 제거와 질산화의 한계는 있었다. 실플랜트 규모에서는 조합공정(SMBR + R/O)의 성능을 관찰하였는데 방류수의 CODCr이 3mg/L 이하(98%), TN이 50mg/L 이하(94%)의 우수한 처리효율을 보였다.

기존의 정수처리 공정인 응집 침전 과정을 대체하여 분리막을 이용한 상수처리 시스템의 개발을 목적으로한다. 따라서 4가지 형태의 정수처리 공정과 분리막의 분획 분자량을 변화시켰을 때 막 투과수의 변화와 안정적이며 높은 투과수를 얻기 위해 필요한 운전 조건의 최적화를 실험하였다 실험결과 한외여과막이 정밀여과막보다 막 투과수 감소경향이 완만했으며 초기 투과수 회복율은 더 높았다. 수질 분석의 결과 한회여과막이 정밀 여과막보다 우수하였지만 전처리에 의한 차이는 나지 않았다. 운전 조건에 따른 flux 는 온도, 선속도가 높을수록 압력이 낮을수록 flux 감소율이 적은 경향을 나타내었다.

알루미늄 전착공정중 도료정제장치에서 발생하는 도료계 폐수(CODMn 1,500~2,000 ppm)를 역삼투압을 이용하여 농축수는 전착조로 보내 재사용하고 반면 투과수는 세정수로 사용할 목적으로 시스템을 설계하여 현장 설치하였다. 역삼투압시스템은 폴리아미드 재질의 나권형 모듈(직경 102 mmtimes 길이 1,016 mm)3개를 직렬로 연결하고 시스템회복율 30%, 운전압력 11.5 kg/cm2, 그리고 실온에서 3일 주기로 발생하는 폐수량 20 m3을 회분식조업으로 처리하였다. 원폐수를 42시간 연속가동하여 5배까지 농축하는 실험기간중 거의 일정한 투과 flux 390 l/m2-hr을 유지하였고 그 투과수질이 CODMn 300 ppm으로 나타났다. 이는 도료정제장치의 잔존 도료성분을 회수하기 위해 사용되는 순수대신 세정수로 사용하기에 적합하였다. 그리고, CODMn 제거율은 83pm5%이었으며, 각 용제성 분별 제거율은 feed 농도의 증가에 따라 감소하였는데 5배 농축시 ethyl cellusolve, butyl cellusolve 그리고 n-butanol은 각각 79, 87 그리고 70%로 나타났다.

혐기-호기의 생물반응조 공정과 막분리 공정을 조합한 막-생물반응조 공정을 이용하여 염색폐수 중의 난분해성 물질들을 제거하였다. 염색폐수 원수를 직접 막분리공정에 적용한 결과 심각한 fouling을 초래하였다. 반면 생물반응조로 1차 처리한 후 막분리공정에 적용한 경우 생물반응조가 막의 오염원을 상당부분 제거하여 fouling현상이 현저리 감소하였으며, 막의 수명도 연장시킬 수 있었다. 염색폐수의 처리효율 및 fouling현상은 막의 기공 크기나 구조보다는 막의 재질에 더욱 의존함을 확인하였다. 중공사막 module의 사용 방법 및 중공사막 내부의 유속에 따라서 제거효율 및 투과유량이 변화하였다. 생물반응조나 막분리 단독공정보다 두공정을 조합한 공정이 보다 효과적으로 염색폐수 처리능력을 보였다.

자체적으로 설계한 막분리 장치 시스템을 사용하여 먼저 순수한 물(3차 처리수)을 대상으로 polysulfone 재질의 중공사형 한외여과막에 대한 분리 성능을 조사하였다. 분획분자량(Molecular cutoff) 5,000 및 10,000 두 종류의 한외여과막에 대하여 실험한 결과, 온도가 증가함에 따라 공급량에 대한 투과량의 비인 회수율이 증가하는 경향을 보였다. 또한, 다양한 분자량의 polyethylene glycol 및 dextran 2,000 ppm 수용액으로 분획분자량을 확인한 결과, 표시된 값보다 다소 큰 값을 얻을 수 있었다. 이러한 기초 실험결과를 토대로 하여, 최종적으로 생활하수의 유입으로 수질이 악화되고 있는 춘천시 공지천의 물을 처리 대상으로 선정하여 원수의 성분을 분석하고, 한외여과 실험을 실시하였다. 그 결과, 생물학적 산소요구량(BOD) 및 총고형물(TS), 탁도가 모두 처리수에서 원수보다 탁월한 감소를 나타내었다. 따라서, 중공사형 한외여과막을 사용한 생활하수 처리에 가능성을 본 연구를 통하여 확인할 수 있었다.

The dewatering characteristics of the sewage sludge was investigated through the experimental observations and model simulations. The activated sludge and the anaerobically digested sludge were examined for the dewaterability evaluation within the pressure range of $0{\sim}10^6N/m^2$. Modified Buchner funnel test and compression test by the consolidometer were conducted to evaluate average specific resistance, porosity, and moisture percentage of filter cake. Shirato's technique of compression-permeability test was followed for the pressure range lower than about $10^2N/m^2$. The flocculation effects on sludge dewatering was also examined for ferric chloride and polymeric flocculant. The application of hydrated lime which can be used for flue-gas desulfurization showed improved moisture percentage, and was thought to have positive feasibility in combined system of sludge dewatering and incineration. Determined characteristic constants were applied to Tiller's cake filtration model to simulate liquid pressure distribution and porosity distribution in cake. Model simulations showed a sharp drop of the porosity close to the cake-medium interface for the highly compressible material such as the activated sludge and the anaerobically digested sludge.

This study was conducted to develop a new RBC process available for the effective removal of organic matters and nitrogen in sewage. The RBC process for the oxidation organic compounds and nitrification was designed to occur at the 1st-stage and next-stage RBC respectively. Then nitrified water was recycled to the denitrifying RBC located at the lower part of the 1st-stage RBC. Some results were summarized as follows. 1. The loading limitation was represented as $60g{\cdot}COD/gm^2/day$ in experiment of simultaneous removal of organic matter and nitrogen. The maxmum COD % removal was 85% at the load $35g{\cdot}COD/m^2/day$. 2. The $NO_3-N$ % removal was approximately 80% at the load $60g{\cdot}COD/m^2/day$ and the maximum $NO_3-N$ remaval rate was $3.9g{\cdot}COD/m^2/day$ and the overall C/N ratio of 11.0 as required to achive 80% of $NO_3-N$% removal. 3.$NO_3-N$ removal rate was rapidly decreased above the load $7g{\cdot}NH_4{^+}-N/m^2/day$ and the maximum $NO_3-N$ removal rate was $3.7g{\cdot}NO_3-N/m^2/day$. 4. Irrespective of the recycle ratio, the COD % removal at the system of 2-stage RBC unit was nearly constant as 89% while the maximum one in the 1st-stage unit was 77% in the case of 50% recycle. 5. The maximum COD % removal in the 3-stage RBC system was 93% while 1st-stage one being 80%, under the $NH_4{^+}-N$ load of $7.4g/m^2{\cdot}d$. Also maximum percentage of nitrification and denitrification was 69% and 41% respectively, under the same $NH_4{^+}-N$ load.

The Wastewater from the weight reduction process of polyester is more difficult to be treated biologically than the general wastewater from dyeing and finishing processes in textile industries. Above wastewater shows high pH, high organic strength and wide variation of organic loading. These characteristics are due to TPA and EG resulting from alkaline weight-reduction process and make trouble in the operation of activated sludge process. Therefore, the objective of this study is to develop the pretreatment method for the successful operation of treatment process. For the successful pretreatment process, the wastewater from weight-reduction process should be segregated from other wastewater stream and then acidified with concentrated sulfuric acid to precipitate out TPA from DST solution. At the optimum pH of 2. 2, the initial $COD_{cr}$ 60,000mg/l is reduced to 11,500mg/l and the removal efficiency of $COD_{cr}$ is 81.1%. The required amount of sulfuric acid for pretreatment is not greater than the amount for the the existing neutralization process. Moreover, the supernatant of pretreatment process can be reused in acidification of wastewater.

This article analyzes the structural characteristics and working principles of heat treatment equipment while considering the possibility of “zero-carbon manufacturing.” It integrates the concepts of material flow, energy flow, and waste recycling, and, by following the life cycle theory, constructs a system boundary model for heat treatment equipment to track the direction of carbon emissions throughout various stages. It identifies the sources and forms of carbon emissions in the entire process of heat treatment equipment and proposes carbon emission estimation models for each stage, upon which a comprehensive data inventory for heat treatment equipment is established.

The purpose of this study was to develop a recycling system for ozone off-gas. Although the ozone transmission rate of the injector method differs slightly depending on the ozone injection rate, it reaches approximately 99%, which is very high. During the increase in water inflow to the ozone recycling system from 2 L/min to 10 L/min, the average ozone recycling rate was 99.4% at a 1 ppm ozone injection rate, 98.6% at a 2 ppm ozone injection rate, 98.1% at a 3 ppm ozone injection rate. Ozone treatment facility operating costs can be divided into the costs of pure oxygen production, ozone production, and maintenance. The annual operating costs of ozone treatment facilities in Korea are estimated to be approximately 38.9 billion won. The annual savings are estimated to be approximately 5.8 billion won when the ozone transfer rate of the diffuser method, which is mostly employed in domestic water treatment plants, is 85% and 15% of the ozone is recycled.

The purpose of this study was to evaluate the operational characteristics of wastewater treatment using Sequencing Batch Reactor (SBR) with Aerobic Granular Sludge (AGS) separator in the pilot plant. Pilot plant experiments were conducted using SBR with AGS separator and pollution removal efficiencies were evaluated based on the operational condition and surface properties of AGS. The results of the operation on water quality of the effluent showed that the average concentration of total organic carbon, suspended solids, nitrogen, and phosphorus was 6.89 mg/L, 7.33 mg/L, 7.33 mg/L, and 0.2 mg/L, respectively. All these concentrations complied the effluent standard in Korea. The concentration of mixed liquor suspended solid (MLSS) fluctuated, but the AGS/MLSS ratio was constant at 86.5±1.3%. Although the AGS/MLSS ratio was constant, sludge volume index improved. These results suggested that the particle discharged fine sludge and increased the AGS praticle size in the AGS. Optical microscopy revealed the presence of dense AGS at the end of the operation, and particles of > 0.6 mm were found. Compared to those of belt-type AGS separator, the required area and power consumption of the hydrocyclone-type AGS separator were reduced by 27.5% and 83.8%, respectively.

Various treatment modalities for vocal process granuloma include simple observation, antireflux therapy, voice therapy, botulinum injection, and steroid inhalation, but recurrence rates are high. Surgical excision can be considered in refractory and recurrent cases. In this study, the authors report the effectiveness of surgical excision using a carbon-dioxide laser with topical Mitomycin-C for the treatment of recurrent vocal process granuloma. The study included 28 patients with recurrent vocal process granuloma despite various treatments. The vocal process granuloma was excised using a carbon-dioxide laser and 1 cc of 0.4 mg/mL topical Mitomycin-C was applied for 4 minutes. Follow-up duration was 13-33 months (mean, 21.8 months). Of 28 patients, 19 (67.9%) were cured. Two who received surgical excision as a first-line treatment, 2 who used a steroid inhaler as a first-line treatment, and 5 who previously took antireflux medication as initial treatment showed recurrence. Surgical excision using a carbon-dioxide laser with topical application of Mitomycin-C is considered effective for recurrent vocal process granuloma.

Renewable energy resources from foodwaste have attracted significant interest and, consequently, many alternatives are considered for large-scale biogas treatment processes and small-scale onsite drying processes (heat source: electricity, gas, and dried foodwaste by-product). The pre-treatment process for foodwaste consists of the following sequential steps: collection, transportation, shredding, segregation, and dehydration. After this pre-treatment, the dried foodwaste by-product is recycled into (among others) animal feed, fertilizer/compost or biomass solid fuel. In addition, the leachate?liquid generated by squeezing the foodwaste is used for bio-gasification, achieved through an Anaerobic Digestion (AD) process associated with a sewage co-digestion treatment. In this study, the operation cost and greenhouse gas (GHG) emissions of an improved and simplified small-scale onsite drying treatment are compared with those of a large-scale biogas treatment. The pre-treatment can be improved and simplified via this drying treatment. Through this treatment, operationcost reductions of 45.4%, 50.5%, and 89.6% are achieved when electricity, liquified natural gas (LNG), and biomass solid fuel (dried foodwaste by-product), respectively, are employed as drying heat sources. Furthermore, if the annual amount of foodwaste (5 million ton) is recycled into biomass solid fuel, then significant reductions (7.5 million tCO2-e per annum) in GHG emissions can be realized. Therefore, this study demonstrates that improvement and simplification of the smallscale drying process (i) reduces the operation cost as well as GHG emission levels (to levels lower than those achieved via the large-scale biogas treatment process) and (ii) offers a practical solution for foodwaste treatment and a renewable energy resource.

In this research, the target process was a modified type of a conventional aeration tank with four different influent feeding points and alternated aeration to obtain nitrogen removal. For more accurate switching of influent feeding, the process was operated under a designed control strategy based on monitoring of NH4-N and NOX-N concentrations in the tank. However, the strategy did have some limitations. For example, it was not sensitive to detecting the end of each reaction when losing the balance between nitrification and denitrification of each opposite part of biological tank. To overcome the limitations of the existing control strategy, a diagnosis-based control strategy was suggested in this research using the diagnosis results classified as normal (N), ammonia accumulation (AA) and nitrate accumulation (NA). Using the pre-designed rules for control actions, the aeration and volume of the aerated part of the reactor could be increased or decreased at a fixed mode time. In simulations of the suggested diagnosis-based control strategy, the NH4-N and NOX-N removal rates in the reactor were maintained at higher levels than those of the existing control strategy.

This study discusses regeneration of mercury-contaminated, activated carbon from adsorption in the mercuryrecovery process. Mercury in activated carbon was desorbed by thermal treatment, and the regeneration efficiency was confirmed by mercury content and iodine adsorption comparing new and spent activated carbon. Up to 95% of mercury desorbed and up to 86% adsorption performance regenerated at 673 K. Therefore, it is expected that activated carbon can be reused many times by regenerating it through thermal treatment without disposing of mercury-containing activated carbon.

The purpose of this study was to confirm the applicability of aerobic granular sludge (AGS) in the advanced sewage treatment process. Simulated influent was used in the operation of a laboratory scale reactor. The operation time of one cycle was 4 h and the reactor was operated for six cycles per day. The volume exchange ratio was 50%. The influent was injected in divisions of 25% to increase the removal efficiency of nitrogen in every cycle. As a result, the removal efficiencies of CODCr and TN in this reactor were 98.2% and 76.7% respectively. During the operation period, the AGS/MLVSS concentration ratio increased from 70.0% to 86.7%, and the average SVI30 was 67 mL/g. The SNR and SDNR were 0.073 0.161 kg NH4 +-N/kg MLVSS/day and 0.071 0.196 kg NO3 --N/kg MLVSS/day respectively. These values were higher or similar to those reported in other studies. The operation time of the process using AGS is shorter than that of the conventional activated sludge process. Hence, this process can replace the activated sludge process.

In order to design the improvement process for T-N removal, the treatment process of Suyoung, Gangbyeon, and Noxan sewage treatment plants (STP) in Busan was anlayzed. Suyoung STP shows a T-N removal efficiency of about 69.8% with MLE(Modified Ludzack ettinger) and A2O+MBR. However, it is necessary to improve the process to maintain over DO of 1 mg/L and is required to install a flow control tank to minimize the rainfall effect. Gangbyun STP shows a about 70.2% T-N removal efficiency with A2O+GFF(gravity fiber filtration). However, in order to improve T-N removal efficiency, it is needed to install MLE process to treat recycle water. Noksan STP shows a T-N removal efficiency of about 71.0% with MLE+Chemical treatment and shows stable T-N concentration in effluent. However, it is required a toxic chemical management process because bad wastewater flows into the STP, also is necessary a process improvement in order to increase internal recycling ratio. Especially, it is required a process improvement to increase HRT of nitrification tank because Suyoung and Gangbyeon STPs shows low nitrification efficiency during winter season.

A continuous process of persulfate oxidation and citric acid washing was investigated for ex-situ remediation of complex contaminated soil containing total recoverable petroleum hydrocarbons (TRPHs) and heavy metals (Cu, Pb, and Zn). The batch experiment results showed that TRPHs could be degraded by Fe2+ activated persulfate oxidation and that heavy metals could be removed by washing with citric acid. For efficient remediation of the complex contaminated soil, two-stage and three-stage processes were evaluated. Removal efficiency of the two-stage process (persulfate oxidation - citric acid washing) was 83% for TRPHs and 49%, 53%, 24% for Cu, Zn, and Pb, respectively. To improve the removal efficiency, a three-stage process was also tested; case A) water washing - persulfate oxidation - citirc acid washing and case B) persulfate oxidation - citric acid washing (1) - citric acid washing (2). In case A, 63% of TRPHs, 73% of Cu, 60% of Zn, and 55% of Pb were removed, while the removal efficiencies of TRPHs, Cu, Pb, and Zn were 24%, 68%, 62%, and 59% in case B, respectively. The results indicated that case A was better than case B. The three-stage process was more effective than the two-stage process for the remediation of complex-contaminated soil in therms of overall removal efficiency.

국내 하수처리장에서는 방류수에 총인 규제의 강화에 대응하기 위해 응집제와 여과 혹은 가압 부상 등의 방법을 이용하여 인을 물리·화학적으로 처리고 있으며, 사용되는 응집제는 주로 황산반토, PAC(poly aluminum chloride)등을 이용되고 있다. 그리고 처리 과정에서 발생되는 슬러지(이하에서는 총인 슬러지라고 함)는 별도로 탈수하거나 처리장의 여건에 따라 소화 슬러지와 통합하여 탈수하여 처분되고 있는 실정이다. 총인 슬러지에는 다량의 알루미늄과 인이 함께 함유되어 있으며, D시 하수처리장에 발생되는 총인 슬러지를 대상으로 하여 분석한 결과, 알루미늄이 150~220g/kg, 총인이 16~23g/kg정도 함유되어 있는 것으로 나타났다. 이와 같은 함유량은 다량의 응집제를 사용하는 정수 공정에서 발생되는 슬러지의 알루미늄 함유량(110~140g/kg)에 비해서도 높은 값임을 알 수 있다. 따라서 본 연구에서는 D시의 하수처리장 중에서 총인 슬러지를 별도로 탈수 처리하고 있는 처리장의 슬러지를 대상으로 비료의 원료로 사용할 수 있는 인과 응집제로 재사용을 위한 알루미늄의 회수를 위한 기초적 조건을 검토하고 회수한 응집제의 인의 회수능과 분리 회수한 인의 순도에 대한 검토를 실시하였다. 회수한 응집제의 경우는 황산반토와 유사한 인의 제거능을 보였으나, Hydroxylapatite의 형태로 회수한 인의 경우는 알루미늄과의 완전한 분리가 이루어지지 않아 중량 단위로 인에 비해 3배 이상의 알루미늄이 되어 있는 것으로 나타났지만, 총인 슬러지에 있어서 인의 함유량이 알루미늄의 약 10배 정도임을 감안한다면, 약 70%의 알루미늄을 제거한 알루미늄과 결합되어 있을 가능성이 높은 Hydroxylapatite를 얻을 수 있었다.