• Food Science and Preservation
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• v.8 no.1
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• pp.102-108
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• 2001

Flow properties of the concentrated pigment solutions extracted from purple-fleshed sweet potatoes were determined using a cone and plate rotational viscometer for soluble solids concentration range of 25 to 65% at temperature range of 20 to 60 $^{\circ}C$. The purple-fleshed sweet potato pigment solutions exhibited Newtonian behavior. Temperature dependency for the viscosity of the solution followed the Arhenius relationship with activation energy values between 14.23 and 43.00 kJ/mol, which increased linearly with soluble solids concentration. A relationship between viscosity, temperature and soluble solids concentration was investigated. At the same temperature, the viscosity of the concentrated pigment solutions increased exponentially as the concentration increased with higher degree of such phenomena at lower temperatures.

• Membrane and Water Treatment
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• v.7 no.1
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• pp.11-22
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• 2016

The characterization of treatment performance with respect to mixed liquor suspended solids (MLSS) concentration enables greater control over system performance and contaminant removal efficiency. Hybrid membrane bioreactors (HMBRs) have yet to be well characterized in this regard, particularly in the context of greywater treatment. The aim of this study, therefore, was to determine the optimal MLSS concentration for a decentralized HMBR greywater reclamation system under typical loading conditions. Treatment performance was measured at MLSS concentrations ranging from 1000 to 4000 mg/L. The treated effluent was characterized in terms of biochemical oxygen demand ($BOD_5$), chemical oxygen demand (COD), turbidity, ammonia ($NH_3$), total phosphorus (TP), total kjeldahl nitrogen (TKN), and total nitrogen (TN). An MLSS concentration ranging from 3000 to 4000 mg/L yielded optimal results, with $BOD_5$, COD, turbidity, $NH_3$, TP, TKN, and TN removals reaching 99.2%, 97.8%, 99.8%, 99.9%, 97.9%, 95.1%, and 44.8%, respectively. The corresponding food-to-microorganism ratio during these trials was approximately 0.23 to 0.28. Operation at an MLSS concentration of 1000 mg/L resulted in an irrecoverable loss of floc, and contaminant residuals exceeded typical guideline values for reuse in non-potable water applications. Therefore, it is suggested that operation at or below this threshold be avoided.

• Journal of Korean Society of Water and Wastewater
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• v.33 no.3
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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.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.3
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• pp.645-654
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• 1994

Photocatalytic oxidation conditions of reactant recirculation flow rate 275 mL/min, aeration rate 2 LPM and $UV+TiO_2+H_2O_2$(500 mg/L) proved to be appropriate for water including organic materials treatment. With increasing turbidity and suspended solids concentration, at turbidity 10 NTU-suspended solids concentration 29 mg/L the phenol degradation efficiency increased, which in turn decreased at turbidity 50 NTU-suspended solids concentration 170 mg/L, however no significant differences were observed, demonstrating similar results with those obtained at zero turbidity and suspended solids concentration. The degradation efficiency of phenol decreased with increasing influent phenol concentrations. The $UV+TiO_2+H_2O_2$ photocatalytic advanced oxidation process conducted is considered to be possibly applied to the drinking water treatment, and the post-treatment process of biological wastewater treatment.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.2
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• pp.257-264
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• 2011

Recycling of industrial products as the stabilizers can be proper handling of industrial products and has positive side in terms of recycling of wastes. In this study, the final aims were to evaluate the usability as stabilizer of Bio-solids which was generated from contaminated soil with heavy metals after primary process and to compare the treatment efficiency with slag being currently applied in many existing sites. Soluble and exchangeable forms have closely related to pollution of groundwater and plant growth and they can be used to determine the effect of the stabilization efficiency. Slag and Bio-solids were tested to investigate the capacity of stabilizing arsenic. Slag treatment process 4 (PS-ball 5%) showed higher leachate concentration rather to 0.84% compared to treatment 1 (blank) based on an average of 0.63%. The other hand treatment 4 (Bio-solids 5%) showed the lowest soluble and exchangeable forms to 0.57% when Bio-solids was applied to stabilize arsenic. Thus, the leaching of arsenic will be more reduced if the Bio-solids are used as stabilizer in stead of slag which is being currently used in many fields.

• Journal of Korean Society of Water and Wastewater
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• v.18 no.1
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• pp.22-28
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• 2004

The fate and transport mechanism of pollutants which have affinities to particles, such as trace metals and some petroleum product based compounds, can be effectively explained by the movement of sediment. The sediment release from lands to adjacent water bodies due to rainfall events was investigated in an effort to predict the total suspended solids (TSS) concentrations in runoff. The contribution of sediment from land origin to the river TSS can be better understood by the relationship between TSS concentration and particle size in runoff. The sieve analysis was used to determine the particle size distribution and these results were incorporated into statistical models. The critical size of particles was set to $74{\mu}m$ which contributes to the river TSS concentration since fine particles (wash load) of the sediment in the runoff play the key role in constituting TSS in a water column of the river. Empirical relationships were developed to predict TSS in runoff from the percentage of the critical particle size and were proven statistically to be valid.

• Journal of Korean Society of Water and Wastewater
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• v.17 no.4
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• pp.559-566
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• 2003

From this research, the performances of a sludge reduction in the sewage sludge aerobic digestion was experimented by using a sludge pretreatment and membrane bioreactor. The submerged plate membrane was used as the solid-liquid separation membrane. After drawing small amounts of sludge in a bioreactor and then doing the alkaline treatment and ozone treatment, the sludge was sent to back to the reactor. The HRT in the reactor was set as 5 days and the operation in the reactor was carried out at the DO of 1mg/L on average. After 100 days of operation in the reactor, it was shown that the reduction efficiency of total solids was more than 83%. Most of volatile solids were removed through mineralization, and the considerable portion of the non-volatile solids was dissolved and then flowed out with the effluent. Only about 16.3% of total solids in the sludge was accmulated in the reactor even without the loss of volatile fraction. Also, by deriving nitrification and denitrification in one reactor simultaneously, more than 90% of nitrogen removal effect was realized and the experiment was run smoothly without fouling of membrane, even in the high concentration of MLSS. Based on this experiment, sludge can be reduced considerably at a low HRT by these two newly suggested approach.

• Membrane and Water Treatment
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• v.8 no.4
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• pp.337-353
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• 2017

Membrane fouling at different solids retention times (SRT) (7, 12 and 20 days) was studied under well-controlled conditions in a laboratory-scale aerobic submerged membrane bioreactor under constant biomass concentration using a synthetic high strength wastewater. An increase in SRT was found to improve membrane performance and this correlated to changes in the total production of bound extracellular polymeric substances (EPS), and the composition and properties of bound EPS using X-ray photoelectron spectroscopy (XPS) and Fourier transform-infrared spectroscopy (FTIR) and floc sizes. A larger amount of total bound EPS was found at the lowest SRT (7 days) tested but the ratio of proteins (PN) to carbohydrates (CH) in bound EPS increased with an increase in SRT. Similarly, the quantity of soluble microbial products (SMP) decreased with an increase in SRT and the SMP PN/CH ratio increased with an increase in SRT. SMP concentrations positively correlated to the percentage of membrane pore blocking resistance. The quantity of total bound EPS and total SMP positively corresponded to the membrane fouling rate, while the PN/CH ratio in the bound EPS and SMP negatively correlated to the membrane fouling rate. The results show that both the quantity and composition of bound EPS and SMP and floc sizes are important in controlling membrane fouling.

• Journal of Aquaculture
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• v.16 no.4
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• pp.216-222
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• 2003

In a simulated seawater aquaculture system, effects of different operating factors like the superficial air velocity (SAY), hydraulic residence time (HRT), protein concentration and foam overflow height on the removal of total suspended solids (TSS) by a foam fractionator, with 20 cm diameter and 120 cm height, were investigated. This experiment was performed on batch and consecutive modes for different combinations of the tested factors, using synthetic wastewater. In 5 consecutive trials, TSS concentration in culture tank water decreased faster, when the foam fractionator was operated at higher SAV and lower HRT. In batch trials, with increasing SAV, TSS removal rate increased, but decreased with increasing HRT. Higher protein concentration in the bulk solution resulted in higher TSS removal rate. TSS concentration in the collected foam condensates increased but the foam overflow rate decreased with increasing foam overflow height. Foam fractionation was effective for removing TSS in seawater aquaculture systems and its performance largely depended on the operating parameters, especially superficial air velocity.

• Journal of Environmental Science International
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• v.24 no.8
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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.