• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.1
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• pp.116-123
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• 2023

Flow-through aquaculture systems generate large amounts of wastewater containing compounds such as solids that can settle near aquafarms and cause eutrophication. The settled solids are often reintroduced into flow-through systems, and aquatic animals can be affected by the solids and pathogens associated with these solids. For a sustainable aquaculture operation, adequate wastewater treatment is required. Hydrocyclones are one of the most promising technologies for the removal of solids in aquaculture wastewater. In this study, a model for performance prediction of hydrocyclones was investigated under three different operating conditions: water temperature, solids concentration, and water inlet velocity. The synthetic solids solution was prepared using settled solids from abalone aquaculture farms. The daily solids removal rates of the tested hydrocyclones ranged from 0.18 to 26.0 g solids-m^-3-day^-1, and removal efficiency ranged from 5.1 to 34.4%. The inlet water velocity had the greatest effect on solids removal and hydrocyclone efficiencies. The following multiregression model equation was derived from the daily solids removal rate (g solids-m^-3-day^-1) results for water temperature (T, ℃), solids concentration (SS, mg-L^-1), and tangential inlet water velocity (TIV, m-sec^-1): daily solids removal rate: f(z)=4.465+0.809TIV-0.375T+0.217SS (r²=0.976).

• Journal of Environmental Impact Assessment
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• v.9 no.2
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• pp.127-142
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• 2000

This research was performed for analyzing the transport of suspended solids during the harbor construction. In behalf of the research, we have analyzes the characteristics of suspended solids movement in sand reclamation of breakwater according to age of tide and tidal period at the construction spot of Pusan new harbor. In the process of sand reclamation, soil was dumped by a dumping device which direct soil from the barge to the bottom of the sea. According to the results from this research, suspended solid concentration was very high in the range of 5m from the dumping point right after the dumping. However these suspended solids settled very quickly and the solids concentration was very beyond 10m from the dumping point. It is deduced that the movement of solids dumped from barge has the tendencies as following; 1) Most of the dumped solids precipitated quickly after the dumping 2) The rest of the suspended solids are diffused slowly toward the bottom of the water being figured smoothing curve 3) The diffusion movement of suspended solids tend to proceed toward the shore line in a parallel motion with tidal current at the sea-bottom That is to say, most of the suspended solids precipitated very quickly even though highly concentrated solids produced at the bottom of the solids which did not precipitated spread with the tidal current horizontally along the bottom of the sea.

• Korean Journal of Plant Resources
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• v.28 no.3
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• pp.329-332
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• 2015

The effect of storage temperature and the storage period of hardy kiwifruits on the fruit firmness, soluble solids and fruit weight were studied in this work. The investigation was carried out on the Sae-Han cultivar of Actinidia arguta. It has an edible smooth skin and contains high amounts of sugar and vitamin C (ascorbic acid). In this research, the measurement of fruit firmness, soluble solids, and fruit weight were carried out at various temperatures (5, 10, 15, and 20℃) during 14 days. Fruit firmness rapidly decreased and soluble solids content increased at 15 and 20℃. We also investigated the correlation between fruit firmness and soluble solids content. There was a strong correlation between fruit firmness and soluble solids content. That means that fruit firmness affect the soluble solids content of hardy kiwifruit.

• Journal of Korean Society on Water Environment
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• v.29 no.6
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• pp.739-745
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• 2013

This paper investigated the runoff characteristics of different properties of suspended solids in streams according to the watershed characteristics and dry/rainy season. Suspended solids were divided into VSS and NVSS depending on volatilization. The main results of this study were as follows. TSS were more correlated with NVSS than VSS. Suspended solids were positively related with the proportion of urban > paddy > upland, negatively related with forest cover. VSS were positively correlated with POP and POC. VSS, measured in dry season, would partly result from autochthonous production and could be an indirect indicator of organic suspended solids.

• Advances in environmental research
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• v.3 no.3
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• pp.199-206
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• 2014

Dewatering is an extremely important step in wastewater treatment process to reduce the final sludge volume in order to minimize the cost of sludge transportation and disposal. In the present study, the effect of different sludge solids content (1, 2 and 3.8%) on the dewaterability of anaerobically digested sludge using Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans was studied. The pH reduction rate was higher during initial process in the sludge having low solids content, but after 48 h of bioleaching, similar pH of below 3 was observed with all the different solids content. Bio-oxidation rate of $Fe^{2+}$ was initially higher in sludge with low solids content, but 100% $Fe^{2+}$ was oxidized within 60 h in all the three treatment levels. Compared to the control, specific resistance to filtration was reduced by 75, 78 and 80% in the sludge with a solids content of 1, 2 and 3.8% respectively, showing improvement in dewaterability with an increase in sludge solids content. Sludge effluent quality and sludge settling rate were also improved in treatments with higher solids content after the bioleaching process.

• Polymer(Korea)
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• v.29 no.6
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• pp.549-556
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• 2005

Effects of the dimensionless variables on the heat transport phenomena in the extrusion process of a single screw extruder have been studied numerically. Based on the understanding of the solids conveying related to the geometrical structure and characteristics of the screw, the heat balance equation for the solids conveying zone was established and normalized. The finite volume method and power-law scheme were applied to derive a discretized equation and the equation was solved using the alternating direction iterative method with relaxation. Effects of the dimensionless parameters, Biot and Peclet numbers, that define the heat transfer characteristics of the solids conveying zone have been investigated with respect to the temperature of the feeding zone and the length of the solids conveying zone. As the Biot number is increased, the heat loss by cooling dominates to decrease the temperature of the barrel but it has little effects on the temperature of the solids bed and the length of the solids conveying zone. On the other hand, if the Peclet number is increased, the convection term dominates to decrease the temperature of the solids bed and it results in an increase in the length of the solids conveying zone.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.3
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• pp.328-337
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• 2022

This study investigated the removal performance of a foam fractionator under seawater conditions. The foam fractionator was tested using a 3×3×3 factorial design for operating conditions by combining different solids concentrations (SS; 1, 5, and 10 mg·L^-1), surface air velocities (SAV; 1.1, 1.5, and 2.1 cm·sec^-1), and hydraulic residence times (HRT; 1, 3, and 6 min) at 16℃. Performance parameters such as daily solids removal rate and efficiency were measured, and a multi-regression model equation was developed accordingly. The daily solids removal rate and removal efficiency varied with the experimental conditions and ranged from 0.14-2.33 g-solids·m^-3-air·day^-1 and 8.9-96.7 %, respectively. Overall, the daily solids removal rate increased with increasing SS and SAV and decreasing HRT, whereas the removal efficiency increased with increasing SAV and HRT and decreasing SS. The daily solids removal rate (g-solids·m^-3-air·day^-1) of the foam fractionator for SAV (cm·sec^-1), SS (mg·L^-1) and HRT (min) were described by the following multi-regression model: Daily solids removal rate [f(z)]=-0.118+0.422SAV+0.094HRT+0.141SS (r²=0.873).

• Environmental Engineering Research
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• v.16 no.1
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• pp.41-45
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• 2011

The aim of this investigation was to demonstrate a rapid bioluminescence bioassay for comparison of the toxicity of whole solids and the aqueous extracts of various environmental solid samples. With regard to the toxicities, those for the soil extracts were mostly found to be lower than those of whole soils, which may have been caused by un-extracted pollutants or dilution during the extraction process. Solid samples from dam-reservoir sediments and municipal refuses were also tested. The toxicities of the solid extracts (0-34%; refuses and sediments) were much lower than those of the whole solids (13-91%). The bioluminescence inhibition test indicated that the harmful effects of the contaminated solids samples were greater than those of the solid extracts.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.04a
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• pp.118-121
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• 2002

The kinetics and stoichiometry of the reduction of hexavalent chromium (Cr(Ⅵ)) with ferrous iron (Fe(II)) were examined in systems with and without aquifer solids. Cr(Ⅵ) reduction was rapid in the absence of solids, but demonstrated slower and more complex kinetics in the presence of aquifer solids. The aquifer solids removed Fe(II) from solution and a portion of the reducing capacity of Fe(II) was transferred to the aquifer solids. The solid phases were then able to continue to remove Cr(Ⅵ). This suggests in-situ treatment of Cr(Ⅵ) by Fe(II) injection would be feasible in the aquifer environment. In general, re-oxidation of reduced chromium by molecular oxygen was not observed in our systems over time periods of nearly one year.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.1
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• pp.109-118
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• 2015

In order to obtain basic informations about impact assessment of marine life by suspended solids in coastal waters, the survey about recent study related with suspended solids effects on exploitable marine life (shellfish, fish, seaweed.) was tried. 1) The paper concerning impacts of suspended solids on marine life has been mainly focused on shellfish. 2) Effects of suspended solids on marine life mainly investigated for acute toxicity. 3) Experiments with suspended solids are intended on adult and juvenile in shellfish, egg and juvenile in fish, and spores in seaweed. Biological impacts of suspended solids can vary depending on concentrations, duration, and life stage, and these informations would improve a knowledge of the effects of suspended solids on marine life.