• 공업화학
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• 제33권5호
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• pp.532-537
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• 2022

The need for obtaining treated wastewater that meets high quality standards for discharge or reuse necessitates the use of highly efficient wastewater treatment techniques. In the present study, experiments have been carried out to reduce the concentration level of biological oxygen demand (BOD), chemical oxygen demand (COD), and total dissolved solids (TDS) from the wastewater sample. Treatment of sample of a real municipal wastewater collected from a sewage treatment plant (STP) was carried out in an electrochemical membrane bioreactor (EMBR). The EMBR was operated continuously for five days, and readings were taken at regular intervals. This paper has experimental results conducted in EMBR that indicate reduction of BOD, COD, and TDS levels of up to 32.25%, 29.25%, and 31.93%, respectively. Further, it was observed that a current of magnitude of 0.00752 mA was generated due to the metabolic activities of bacteria present in municipal wastewater, which gradually decreased day by day due to the decay of bacteria.

• 상하수도학회지
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• 제35권4호
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• pp.293-300
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• 2021

Recently, various researches have been studied, such as water treatment, water reuse, and seawater desalination using CDI (Capacitive deionization) technology. Also, applications like MCDI (Membrane capacitive deionization), FCDI (Flow-capacitive deionization), and hybrid CDI have been actively studied. This study tried to investigate various factors by an experiment on the TDS (Total dissolved solids) removal characteristics using MCDI module in aqueous solution. As a result of the TDS concentration of feed water from 500 to 2,000 mg/L, the MCDI cell broke through faster when the higher TDS concentration. In the case of TDS concentration according to the various flow rate, 100 mL/min was stable. In addition, there was no significant difference in the desorption efficiency according to the TDS concentration and method of backwash water used for desorption. As a result of using concentrated water for desorption, stable adsorption efficiency was shown. In the case of the MCDI module, the ions of the bulk solution which is escaped from the MCDI cell to the spacer during the desorption process are more important than the concentration of ions during desorption. Therefore, the MCDI process can get a larger amount of treated water than the CDI process. Also, prepare a plan that can be operated insensitive to the TDS concentration of backwash water for desorption.

• Membrane and Water Treatment
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• 제14권4호
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• pp.163-173
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• 2023

The presence of high amounts of organic and inorganic contaminants in textile wastewater is a major environmental concern. Therefore, the treatment of textile wastewater is an urgent issue to save the aquatic environment. The disposal of large quantities of untreated textile wastewater into inland water bodies can cause serious water pollution. In this study, synthetic dye wastewater samples were prepared using orange dye in the laboratory. The synthetic samples were then treated by a batch adsorption process using the prepared activated carbon (AC) from date pits. The wastewater parameters studied were the pH, total dissolved solids (TDS), total suspended solids (TSS), electrical conductivity (EC) and salinity. The activated adsorption process showed that the maximum removal efficiencies of electric conductivity (EC), salinity, TDS and TSS were 65%, 92%, 89% and 90%, respectively. The removal efficiencies were proportional to the increase in contact time (30-120 min) and AC adsorbent dose (1, 3 and 5 g/L). The adsorption profile indicates that 5 g/L of adsorbent delivers better results for TDS, EC, TSS and salinity at contact time of 120 min. The adsorption characteristics are better suited to the pseudo-second-order kinetic model than to the pseudo-first-order kinetic model. The Langmuir and Freundlich isotherms were well suited for describing the adsorption or contact behavior of EC and TSS within the studied system.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2012년도 학술발표회
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• pp.1-10
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• 2012

Throughout much of the world, many ecological problems have arisen in watersheds where a significant portion of stream flows are diverted to support agriculture production. Within endorheic watersheds (watersheds whose terminus is a terminal lake) these problems are magnified due to the cumulative effect that reduced stream flows have on the condition of the lake at the stream's terminus. Within an endorheic watershed, any diversion of stream flows will cause an imbalance in the terminal lake's water balance, causing the lake to transition to a new equilibrium level that has a smaller volume and surface area. However, the total mass of Total Dissolved Solids within the lake will continue to grow; resulting in a significant increase in the lake's TDS concentration over time. The ecological consequences of increased TDS concentrations can be as limited as the intermittent disruption of productive fisheries, or as drastic as a complete collapse of a lake's ecosystem. A watershed where increasing TDS concentrations have reached critical levels is the Walker Lake watershed, located on the eastern slope of the central Sierra Nevada range in Nevada, USA. The watershed has an area of 10,400 sq. km, with average annual headwater flows and stream flow diversions of 376 million $m^3/yr$ and 370 million $m^3/yr$, respectively. These diversions have resulted in the volume of Walker Lake decreasing from 11.1 billion m3 in 1882 to less than 2.0 billion $m^3$ at the present time. The resulting rise in TDS concentration has been from 2,560 mg/l in 1882 to nearly 15,000 mg/l at the current time. Changes in water management practices over the last century, as well as climate change, have contributed to this problem in varying degrees. These changes include the construction of reservoirs in the 1920s, the pumpage of shallow groundwater for irrigation in the 1960s and the implementation of high efficiency agricultural practices in the 1980s. This paper will examine the impacts that each of these actions, along with changes in the region's climate, has had on stream flow in the Walker River, and ultimately the TDS concentration in Walker Lake.

• Membrane and Water Treatment
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• 제6권6호
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• pp.489-499
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• 2015

In this work, treatment of real hypersaline refinery wastewater by hollow fiber membrane bioreactor coupled with reverse osmosis unit was studied. The ability of HF-MBR and RO developed in this work, was evaluated through examination of the effluent properties under various operating conditions including hydraulic retention time and flux. Arak refinery wastewater was employed as influent of the bioreactor which consists of an immersed ultrafiltation membrane. The HF-MBR/RO was run for 6 months. Average elimination performance of chemical oxygen demand, biological oxygen demand, total suspended solids, volatile suspended solids, total dissolved soild and turbidity were obtained 82%, 89%, 98%, 99%, 99% and 98% respectively. Highly removal performance of oily contaminant, TDS and the complete retention of suspends solids implies good potential of the HF-MBR/RO system for wastewater refinement.

• 청정기술
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• 제10권1호
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• pp.37-45
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• 2004

본 연구는 섬유산업에서 많이 사용되고 있는 주요염료인 분산성, 반응성, 산성염료를 대상으로 일반적인 수질오염항목인 COD, T-N, TOC, color, SS, TDS, conductivity 등을 분석하여 각각의 염료용액의 성상을 비교 분석하였고, NF막을 투과시켰을 경우 투과 flux와 배제율이 염료용액 종류에 따라서 어떻게 다른 양상을 나타내는지를 연구하였다. 결과적으로, 염료종류별 화학적 성질 및 구조적인 차이에 의하여 염료용액의 용해도 및 유기물부하 등이 달라짐을 알 수 있었고, 특히, 분산성 염료와 반응성염료는 이들 화학적 성질의 차이가 매우 현격하게 달라서 투과 flux 감소현상과 유기물, color, 부유물 및 용존 고형물, 이온성 물질 등의 배제율이 다른 양상을 보임을 알 수 있었다. 반응성염료 용액은 분산성염료 용액에 비하여 투과 flux는 높지만, TDS의 배제율이 낮은 반면, 분산성염료 용액은 부유성 고형물 농도가 높아 투과 flux가 낮고, 유기물질의 배제율이 낮은 특성을 나타낸다.

• 대한환경공학회지
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• 제38권1호
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• pp.34-41
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• 2016

UF (ultrafiltration)-SWRO (seawater reverse osmosis) 공정을 이용하여 해수와 기수의 유입수 블렌딩(pre-blending)이 보론(boron)과 휴믹산(humic acid)의 제거에 미치는 영향을 조사하였다. 유입수 블렌딩은 TDS (total dissolved solids) 농도를 기준으로 15,000 mg/L~27,000 mg/L까지 설정하였으며, RO에서의 보론 제거특성을 분석하였다. 또한, 동일한 TDS 농도범위에서 휴믹산을 주입하여 유기물 제거 특성을 알아보았다. 보론은 TDS 농도가 높아질수록 제거율은 76.60% - 83.27%로 높게 나타났지만, 최종 생산된 생산수의 보론 농도는 0.48 mg/L-0.69 mg/L로 높아져 유입수 내 보론 농도가 다량 유입될 시 유입수 블렌딩이 필요할 것으로 판단된다. 휴믹산의 경우 10 mg/L 수준일 경우 TDS 농도 22,500 mg/L가 27,000 mg/L 보다 제거율이 높게 나타났지만, 휴믹산이 5 mg/L 수준일 경우 TDS 농도 18,000 mg/L가 15,000 mg/L보다 높게 나타났다. 한편, 휴믹산이 주입되었을 때 UF-SWRO 공정에서는 오히려 플럭스(flux)와 회수율(recovery rate)이 증가하는 효과를 나타내었는데, 이는 파울링 물질이 $Ca^{2+}$와 휴믹산의 결합에 의해 대부분 제거되어 나타난 것으로 판단된다. 따라서 UF-SWRO를 이용한 해수 담수화 시 보론 농도와 휴믹산 제거측면에서 TDS 농도가 낮을수록 유리하다고 판단된다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 추계학술발표회
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• pp.435-437
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• 2003

In order to investigate processes and factors controlling the chemical and isotopic compositions of the Han River, seasonal studies were carried out. The North Han River was much lower in the concentrations of total dissolved solids (TDS), dissolved inorganic carbon (DIC) and major ions than the South Han River, but higher in $SiO_2$ concentration, $\delta$$^{34}$ $S_{so4}$ value and $^{87}$ Sr/$^{86}$ Sr ratio. This indicates that the chemical and isotopic compositions of the Han River were strongly controlled by the geology of their drainage basins: silicate rocks in the North Han River and carbonate rocks in the South Han River. The $\delta$$^{34}$ $S_{so4}$ values were relatively higher in the North Han River (5.90$\pm$1.46$\textperthousand$)) than in the South Han River (3.48$\pm$0.73$\textperthousand$). This implies that dissolved S $O_{4}$$^{2-}$ in the North Han River might be mostly derived from deposition of atmospheric sulfates, whereas in the South Han River from oxidation of sulfide minerals in the abandoned poly-metallic deposits and the coal-bearing sedimentary rocks distributed over the upstream as well as deposition of atmospheric sulfates. The $^{87}$ S $r^{86}$ Sr ratios in the North Han River were distinctly higher than those in the South Han River, reflecting water-rock interaction with different rock types.pes.

• 한국농공학회논문집
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• 제47권5호
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• pp.3-13
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• 2005

The present study examined the 3 dimensional space distribution characteristics of sea water intrusion using data available from previous observations. For this study, we used 3D FEMWATER, which is a 3 dimensional finite element model. The target area was around Daechang-ri, Gimje-si, Jeollabuk-do. The area is relatively easy to formulate a conceptual model and has observation wells in operation for surveying sea water intrusion. Considering the uncertainty of numerical simulation, we analyzed sensitivity to hydraulic conductivity, which has a relatively higher effect. According to the result of the analysis, the variation of TDS concentration had an error range of $-1,336{\~}+107 mg/{\iota}$. Taking note that the survey data from observation wells were collected when the boundary between fresh water and sea water in the aquifer was in equilibrium, we set the range of time for numerical simulation and estimated the spatial distribution of TDS concentration as the range of sea water intrusion. According to the result of estimation, the spatial distribution of TDS concentration calculated when 1,440 days were simulated was taken as the range of sea water intrusion. Using the result of calculation, we can draw not only vertical views for a certain section but also horizontal views of different depth. These views will be greatly helpful in understanding the spatial distribution of the range of sea water intrusion. In addition, the result of this study can be used rationally in proposing an optimal quantity of water pumping through investigating the moving route of sea water intrusion over time in order to prevent excessive water pumping and to maintain an optimal number of water pumping wells per interval.

• 대한환경공학회지
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• 제38권2호
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• pp.79-86
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• 2016

본 연구의 목적은 RO 농축수 내 TDS 제어에 따른 고농도 질산성 질소의 효율적인 생물학적 처리에 있다. 실험실 규모의 실험에서는 연속회분식 반응기를 이용하여 연구를 수행하였으며 TDS의 주입조건에 따른 비탈질율, 비산소소비율 분석을 수행하였다. 연구결과, 연속회분식 반응기를 이용한 운전에 따라 탈질 공정 내 고농도 TDS 주입에 따라 탈질 반응이 지연되어 SDNR이 감소하는 것으로 나타났으며 미생물 활성도가 또한 감소하는 것으로 나타났다. 따라서 질산성 질소의 원활한 처리를 위하여 TDS 제어가 수반되어야 하며 특히, $Ca^{2+}$의 중점적인 처리가 필요할 것으로 판단된다. 또한 본 연구를 통하여 도출된 SDNR, SOUR 값은 호기성 그래뉼 슬러지를 이용한 RO 농축수의 생물학적 처리를 위한 공정 설계인자로 활용이 가능할 것으로 판단된다.