• 상하수도학회지
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• 제33권3호
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• pp.225-234
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• 2019

This study is focused on effects of factors that affect the formation of THMs during chlorination in drinking water treatment. During the chlorination, chlorine consumption is increased by increasing the initial chlorine dose, the pH and the total dissolved solid (TDS) concentration. Also THMs formation is increased up to $58.82{\mu}g/L$ and $55.54{\mu}g/L$ by increasing initial chlorine concentration and increasing pH. However, concentration of chloroform is decreased by increasing TDS concentration. This is caused the cation($Na^+$) of the total dissolved solids preferentially reacts with the functional groups of the organic material which influence the trihalomethane formation. But total trihalomethane formation is increased up to $127.46{\mu}g/L$ by $Br^-$ contained in the total dissolved solids. DOC reduction was not influenced by any of the factors.

• 한국환경과학회지
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• 제31권4호
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• pp.341-356
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• 2022

Electrical Conductivity (EC) or Total Dissolved Solids (TDS) has been often used to evaluate the water quality in some water education program for children and youth. This study attempted to find out whether EC (or TDS) can be used as a water pollution criteria in water education program. To clarify it, we used the water analysis data of July 2019 and January 2020 from Water Environment Information System. Data from 332 points in Han-river were used to investigate correlation between the parameters, such as BOD, COD, TN, TP vs EC. Correlation(r) for all data of BOD vs. EC was 0.347 for July 2019 and 0.483 for January 2020. No correlation was observed for BOD Ia and BOD Ib for July 2019 (r=-0.041, -0.030, respectively) and BOD Ia for January 2020 (r=0.041). Better correlation for all data of COD vs. EC was obtained (r=0.543 for July 2019 and r=0.610 for January 2020). However, no correlation was observed for COD Ia for January 2020. High vlaue of EC or TDS does not always mean water pollution, especially for clean water environment. Thus, EC (or TDS) alone can not be used as a water pollution criteria.

• 한국환경과학회지
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• 제24권8호
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• pp.1075-1084
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• 2015

This study was conducted to investigated the changes in the nutrient components ($NO_3{^-}-N$, $NH_4{^+}-N$, $PO_4{^{3-}}P$, $K^+$, $Ca^{2+}$, and $Mg^{2+}$) and environmental parameters (electrical conductivity, total dissolved solids and pH) on the leaf lettuce (Lactuca sativa L.) grown with hydroponics. Recirculating hydroponic cultivation system was consisted of planting port, LED lamp, water tank, and circulating pump for hydroponic. Nutrient solution was used in the standard solution for Japan vegetables experimental station and commercial hydroponic. The result showed that electrical conductivity (EC), total dissolved solids (TDS) and pH, depending on the growth of lettuce decreased continuously. With the growth of the lettuce, nitrate nitrogen, ammonia nitrogen, phosphate phosphorus were required for periodic replacement. The number of pH compensation due to the growth of lettuce are the most high. The concentration of $Ca^{2+}$ and $Mg^{2+}$ during the lettuce growth showed no significant change. However, $K^+$ concentration increased due to the replacement with nitrogen and phosphorus. Electric conductivity and total dissolved solids with total nutrient concentration showed the linear relationship and the correlation coefficient $R^2$ were 0.8601 and the 0.827, respectively.

• 한국물환경학회지
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• 제32권3호
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• pp.303-309
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• 2016

This study aimed to assay the biological removal of TDS (total dissolved solids) from RO (reverse osmosis) rejected water. Following bio-sorption of TDS with AGS (aerobic granular sludge), the effects of TDS on biological nitrogen removal were examined. The bio-sorption of TDS after AGS treatment was confirmed by checking for TDS removal efficiency and surface analysis of microorganisms with SEM and EDS. Then, the effects of TDS on biological nitrogen removal and the denitrification efficiency were evaluated using the MBR reactor. According to the results, the bio-sorption of TDS with AGS was 0.1 mg TDS/mg AGS, and we confirmed that the microorganism surfaces had adsorbed the TDS. Biological nitrogen removal efficiency was measured at inhibiting denitrification at 4,000 mg/L of TDS-injected material. Based on this study, it is necessary to pretreat TDS-containing RO rejected water and to maintain TDS concentration lower than a specific value (≤4,000 mg/L), when considering biological nitrogen removal.

• Membrane and Water Treatment
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• 제6권4호
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• pp.339-349
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• 2015

Experiments were carried out using granular activated carbon (GAC) adsorption techniques to treat wastewater contaminated with organic compounds caused by diverse human activities. Two techniques were assessed: adsorbent GAC prepared from coconut shell (GACC) and adsorbent GAC from palm shell (GACP). A comparison of these two techniques was undertaken to identify ways to improve the efficiency of the treatment process. Analysis of the processed wastewater showed that with GACC the removal efficiency of biochemical oxygen demand (BOD), chemical oxygen demand (COD), turbidity, total suspended solids (TSS) and total dissolved solids (TDS) was 65, 60, 82, 82 and 8.7%, respectively, while in the case of GACP, the removal efficiency was 55, 60, 81, 91 and 22%, respectively. It can therefore be concluded that GACC is more effective than GACP for BOD removal, while GACP is better than GACC for TSS and TDS removal. It was also found that for COD and turbidity almost the same results were achieved by the two techniques. In addition, it was observed that both GACC and GACP reduced pH value to 7.9 after 24 hrs. Moreover, the optimal time period for removal of BOD and TDS was 1 hr and 3 hrs, respectively, for both techniques.

• 멤브레인
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• 제34권2호
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• pp.132-139
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• 2024

Total dissolved solids (TDS) 제거에 이용되는 이온교환수지는 컬럼에 충진시켜 사용하게 되는데, 이온교환 과정에서 이온성 물질과 이온교환수지의 충분한 접촉시간을 필요로 한다. 본 연구에서는 이온교환수지의 분체화를 통하여 짧은 접촉시간으로도 높은 TDS 제거 성능을 보이는 이온교환수지의 특성을 연구하였다. 흐름성 등을 고려한 분체의 최적 크기는 100 ㎛ 이상임을 확인하였고, 250~500 ㎛d와 100~250 ㎛ 크기의 최대 분쇄 수율은 각각 67.3%와 36.9%였다. 또한 100~500 ㎛ 크기의 분쇄 수율은 분쇄 시간 2분에서 87.1%로 나타났다. 회분식(batch) 실험 조건에서 250~500 ㎛ 크기의 분체가 95%와 99%의 제거율에 도달하는 시간은 분쇄 전(non-pulverized) 이온교환수지에 비해 각각 1.82배와 1.96배 더 빨랐다. 100~250 ㎛ 크기의 분체는 각각 15.9배와 6.18배 더 빨랐다. 컬럼 테스트의 경우 분쇄 전 이온교환수지는 총 1.74 g, 250~500 ㎛ 크기의 분체는 1.83 g, 100~250 ㎛ 크기의 분체는 1.63 g의 NaCl을 제거하였다. 분체의 크기가 작아질수록 용량(capacity)이 약간 감소한 것으로 나타났다. 결과적으로 분체화된 이온교환수지를 사용하는 것이 접촉시간 대비 높은 TDS 제거 성능을 얻을 수 있는 방법임을 확인하였다.

• 한국막학회:학술대회논문집
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• 한국막학회 1996년도 제5회 산학협동 심포지움 (먹는 물과 막분리공정)
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• pp.39-64
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• 1996

Probably over most of recorded time, the quality of drinking water has been praised for good health and blamed for bad health. Certainly it is true, considering pathogenic organism that cause typhoid fever, giardiasis, etc., or considering chemical contaminants suspected of causing cancer. Drinking "natural" waters with a high mineral content is generally accepted to be healthy. Water containing very low levels of total dissolved solids (TDS), such as distilled water, is believed by some to help "cure" arthritis by "washing out" calcium from deposits in joints. Along with this reasoning, many believe that drinking very tow TDS water, treated by distillation, reverse osmosis (RO) or deionization (DD, "leaches" minerals from the body and causes mineral deficiencies with subsequent ill health effects.cies with subsequent ill health effects.

• 멤브레인
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• 제32권2호
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• pp.126-132
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• 2022

정수기는 일반적인 산업용 막여과 수처리 공정과 다르게 운전과 휴지를 반복하는 특성이 있다. 이러한 특징 때문에 역삼투막을 사용하는 정수기의 경우, 재정수시에 정수수의 농도가 정상적인 값보다 높게 나오는 현상(제거율이 정상값보다 낮게 나오는 현상)이 있는데, 이를 "TDS creep"이라고 한다. 본 연구에서는 휴지시간과 농도에 따른 TDS creep 정도를 관찰하였다. 또한, TDS creep 현상을 저감하기 위해 원수 세척, 정수부의 부피 증가 및 정수 세척 방법 등을 시험하였고 이에 대한 실질적인 효과를 관찰하였다. 이러한 방법들 중에 정수수의 세척과 같이 역삼투막의 feed side와 permeate side의 농도차를 최소화하는 것이 TDS creep 현상을 해소하는 궁극적인 해결책임을 확인하였다.

• Environmental Engineering Research
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• 제21권4호
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• pp.333-340
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• 2016

An Artificial Neural Network including a Radial Basis Function (RBF) and a Time Delay Neural Network (TDNN) was used to predict total dissolved solid (TDS) in the river Zayanderud. Water quality parameters in the river for ten years, 2001-2010, were prepared from data monitored by the Isfahan Regional Water Authority. A factor analysis was applied to select the inputs of water quality parameters, which obtained total hardness, bicarbonate, chloride and calcium. Input data to the neural networks were pH, $Na^+$, $Mg^{2+}$, Carbonate ($CO{_3}^{-2}$), $HCO{_3}^{-1}$, $Cl^-$, $Ca^{2+}$ and Total hardness. For learning process 5-fold cross validation were applied. In the best situation, the TDNN contained 2 hidden layers of 15 neurons in each of the layers and the RBF had one hidden layer with 100 neurons. The Mean Squared Error and the Mean Bias Error for the TDNN during the training process were 0.0006 and 0.0603 and for the RBF neural network the mentioned errors were 0.0001 and 0.0006, respectively. In the RBF, the coefficient of determination ($R^2$) and the index of agreement (IA) between the observed data and predicted data were 0.997 and 0.999, respectively. In the TDNN, the $R^2$ and the IA between the actual and predicted data were 0.957 and 0.985, respectively. The results of sensitivity illustrated that $Ca^{2+}$ and $SO{_4}^{2-}$ parameters had the highest effect on the TDS prediction.

• 한국습지학회지
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• 제11권3호
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• pp.89-103
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• 2009

필리핀은 많은 섬들로 이루어진 국가로 물 뿐만 아니라 각종 자연환경이 풍부한 국가이나, 금세기 들어 필리핀의 농업활동 및 빠른 도시화로 인한 도시 및 산업지역으로부터 야기되는 수질오염이 심각해지고 있다. 필리핀 국가 환경관리국은 수질 모니터링과 수계오염원인 조사 등을 책임지고 있는 최고의 국가기관으로 수질오염원 원인분석과 해결방안을 모색하기 위하여 다양한 노력을 하고 있다. 그러나 DO, BOD, TSS, TDS, 중금속, coliform 등에 대해 년간 4회 이상의 모니터링 수행과정을 통해 수질관리를 하고 있기에 수질개선에 애로사항이 많다. 현재 필리핀의 각종 수질은 도시하수, 산업폐수, 농업폐수 및 비점오염원에 의해 영향을 많이 받고 있는 것으로 나타났으며, 도시 하수관거의 불량도 수질에 크게 영향을 끼치는 것으로 나타났다. 본 연구의 목적은 필리핀의 수질오염원인 및 정도를 분석하고 그 결과를 제시함으로써 향후 국가적으로 관심을 가져야 할 분야가 어디인지를 명시하기 위하여 수행되었다.