• Environmental Engineering Research
• /
• v.16 no.2
• /
• pp.97-102
• /
• 2011

This study investigates the treatment of pigment wastewater using a sequential batch reactor (SBR) followed by dissolved ozone flotation-pressurized ozone oxidation treatement (DOF-$PO_2$). The process efficiency has been evaluated at the lab scale on the basis of water quality parameters. In addition, the effect of pure oxygen and air was investigated on the removal of COD, BOD, and TN in the SBR process. It was observed that under comparable conditions the removal efficiencies of these water quality parameters using pure oxygen and air were similar. The effect of the recycle rate was also investigated for its impact on the water quality parameters using different ozone dissolving pressures in a DOF process in order to optimise conditions. The results conclude that the use of an SBR and ozone contact by DOF-$PO_2$ is a highly effective treatment for pigment wastewater and aids in the achievement of effluent discharge criteria.

• Environmental Engineering Research
• /
• v.19 no.4
• /
• pp.395-399
• /
• 2014

Operation characteristics of the sequencing batch reactor (SBR) process with electro-flotation (EF) as a solid liquid separation method (EF-SBR) were investigated. EF-SBR process showed excellent solid-liquid separation performance which enabled to separate biosolids from liquid phase within 30 min and to extend cyclic reaction time. Although influent organic loading rate was increased stepwise from 5 to 15 g COD/day, food to microorganisms (F/M) ratio could be maintained about 0.3 g COD/g VSS/day in EF-SBR because biomass concentration could be easily controlled at desired level by EF. However, it was impossible to increase biomass concentration at the same level in control SBR (C-SBR) process because solid-liquid separation by gravity settling showed a limitation at higher mixed liquor suspended solids (MLSS) concentration with 60 min of settling time. Total chemical oxygen demand (TCOD) removal efficiency of EF-SBR process was not decreased although influent organic loading rate became 3 times higher than initial value. However, it was seriously deteriorated in C-SBR process after increasing the rate over 10 g COD/day, which was accounted for insufficient organic removal by relatively higher food to microorganisms (F/M) ratio as well as biosolids wash-out by a limitation of gravity sedimentation.

• Resources Recycling
• /
• v.21 no.4
• /
• pp.44-52
• /
• 2012

The purpose of this study is to confirm the possibility of obtaining high grade coal from fixed carbon 20.68% coal. Also, the mineralogical, physical/chemical and liberation characteristics was found with the aim of decrease in ash amount, during the pre-processing of clean coal technology. In this study, batch flotation and microbubble column flotation that was appropriate for the processing of fine particles was used with the variation in kinds and quantity of frother, collector and depressant. Also grinding time, air flow rate and feeding rates were examined. As a result of batch flotation, using pulp density 20%, collector DMU-101+dodecyl amine(100 mL/ton), frother pine oil (200 mL/ton), depressant sodium silicate(1 kg/ton), obtained the result of ash rejection 81.55% and combustible recovery 70.23%. In result of microbubble column flotation, the result was ash rejection 83.85% and combustible recovery 70.42% under the condition of pulp density 5%, grinding time 5 min. collector DMU-101+DDA(100 mL/ton), frother AF65(5.4 L/ton), depressant SMP(3.5 kg/ton), wash water(360 mL/min.) and air flow rate(1,197 mL/min.).

• 한국지구물리탐사학회:학술대회논문집
• /
• 2003.11a
• /
• pp.581-589
• /
• 2003

The variable flotation response ores from different deposits results basically from mineralogical association and their differences. Development of new techniques for analyzing the metallurgical performance of flotation and other concentration processes is demanded even in the treatment of rather simple ores such as porphyry ores. Diagnostic metallurgical analysis can be used to quantify the most possible recovery processes. Several porphyry copper/gold ores around the world were used to examine the responses in flotation, gravity separation and cyanidation in order to define the linkage between the recovery processes for both copper and old values. Laboratory batch flotation, gravity separation and cyanidation tests were carried out on these samples. All results were used to correlate the relative recovery of copper and gold, and to predict the highest possible metal recovery in the system. The metallurgical predictions were made according to the flotation conditions used and gravity separation. The results of various concentration processes on each porphyry ore samples are presented and discussed. All seven samples have shown significantly different gold/copper metallurgy. The grade/recovery relationships of gold and copper in the laboratory batch tests for the best results and the plants are given in the Figures below. The results of laboratory tests show that the copper recoveries converged to about $90\%$, but the gold recoveries were spread over $55-80\%$, except the K S ore. Series of standard cyanidation tests on the flotation concentrate samples and gravity separation using Knelson Separator on heads ores were carried out to cross-link the metallurgy and mineralogy of gold in the porphyry ores.

• Journal of Korean Society of Water and Wastewater
• /
• v.19 no.2
• /
• pp.155-160
• /
• 2005

Gravity thickening process has been widely used in WTP sludge thickening at domestic water treatment plant. The operation method of the process is very simple, however, the process requires long detention time about 24~48 hours for sludge thickening, uses polymer, and low total solids of thickened sludge to increase sludge thickening efficiency. To solve there problems, we studied about flotation process, especially, electro-flotation (EF) process in WTP sludge thickening. Electro-flotation process is simpler than dissolved-air-flotation(DAF) process because EF needs only electrode and current to generate micro-bubbles and the operation is easy. This study was performed at two batch columns to compare interface height, total solids, effluent turbidity between an electro-flotation thickening and a gravity thickening. According to the result, an electro-flotation thickening was that interface height was decreasing, total solids had high concentration, and effluent turbidity was low in comparison with a gravity thickening. Also, it will make the high efficiency of following process, such as a dehydrating process and digestive process. because of high total solids and low moisture content in the sludge.

• Resources Recycling
• /
• v.1 no.1
• /
• pp.69-77
• /
• 1992

In this study, a talc flotation was fundamentally carried out with dolomite origin talc ore produced in Dong Yang Talc Mine at Chung-Ju. This ores are mainly composed with talc as a valuable mineral, dolomite as a gangue mineral and other minor minerals of hornblende, tremolite, actinolite, chlorite, calcite, epidote and iron oxide. In order to obtain some of fundamental data for the talc flotation from low grade dolomitic talc tailings which were abandoned -25mm +17 mm size, after the treatment of crude talc ores by screening and hand -picking at the mine, flotation characteristics of the pure talc and dolomite in this ores were first investigated by measuring floatability of the minerals at some experiment conditions. Furthermore, Several times of batch flotations for talc were performed experimentally to recover talc from the low grade dolomitic talc tailings. From the results obtained in this experiment, the conclusions can be summarized as follows ; 1) In the flotation of pure talc, the use of Dowfroth 250 as frother was the most effective in various kinds of frother and the proper addition amount was about 50 mg/${\ulcorner}$(200g/t) at the condition of this experiment. 2) In the flotation of pure talc, the use of kerosene as collector was not adequate, at the addition over 50mg/l of Dowfroth 250. 3) The adequate pH of pulp ranged from pH6 to pH9 in the talc flotation using Dowfroth 250 as frother. 4) The use of Quebracho as depressant for dolomite was not adequate for the recovery of talc, and more selective depressant was required. 5) In the talc flotation on D sample(dolomitic talc tailing), the suitable number of cleaning time was about 3. 6) At this experimental conditions for the talc flotation on D sample, the talc flotation concentrates of 1. 40% CaO and 84.5 whiteness could be recovered with the talc recovery of about 53%.

• Resources Recycling
• /
• v.8 no.3
• /
• pp.43-48
• /
• 1999

The pupose of h s study was to develop a process for removal of unburnzd carbon li-om fly ash by froth flotation. "Carbon zero (C.Z)" develqcd by KIGAM, gave the best results, praduci112 cleaned fly ash containing abom 0.1% FC with 72% yieldBased on the results of batch flotation tests, the pilot-scale tests wcre conducted. The result showed that cleaned fly ash with 0.1% FC could be recovered by about 73% yield.t 73% yield.

• Journal of Korean Society on Water Environment
• /
• v.24 no.3
• /
• pp.340-344
• /
• 2008

Electro-flotation (EF) was applied to a sequencing batch reactor process (SBR) in order to enhance solids-liquid separation. Solids-liquid separation was good enough in the SBR coupled with EF (EF-SBR) and it was possible to maintain the concentration of mixed liquor suspended solids (MLSS) high in the EF-SBR. Under moderate organic loading condition (COD loading rate: 6 g/day), control SBR (C-SBR) showed similar treatment efficiencies with the EF-SBR. Under high organic loading condition (COD loading rate: 9.6 g/day), the solids-liquid separation in the C-SBR was deteriorated due to proliferation of filamentous bulking organisms at high F/M ratio. However, the EF-SBR was operated stably and with the high MLSS concentration (above 4,000 mg/L) regardless of the organic loading conditions during overall operating period leading to the satisfactory effluent quality. Gas production rate of the electrodes was gradually decreased because of anodic corrosion and scale build-up at the surface of cathode. However it could be partially overcome by use of corrosion-proof electrode material (SUS-316 L) and by periodic current switching between the electrodes.

• Journal of Korean Society on Water Environment
• /
• v.23 no.2
• /
• pp.244-250
• /
• 2007

This study was carried out to obtain the optimum design factors for an eletrolytric flotation reactor. When the effluent of the leachate treatment facility was treated under the condition of 10 volts, 30 minutes, at the Al-Al electrode system; COD removal efficiency was 45%, and total phosphorus removal efficiency was 98%. The high removal efficiency was caused by the fact that phosphate was removed by leaching $Al^{3+}$ from two electrodes. The leachate containing high ammonium nitrogen concentration was treated by a batch test under the condition of 60 minutes reaction time and added chloride ion; ammonium nitrogen removal efficiency was 89%. This high efficiency was affected by added chloride ion to wastewater. To find the optimum current density and voltage of the leachate containing chloride ion (ratio of $Cl^-/NH_4-N$ is 11) a electrochemical polarization curve was used. These values were found to be $4.5mA/cm^2$ and about 2.1 V, respectively. When C-Al electrode system was used at a batch test, the total nitrogen removal efficiency was increased by 1.8 to 3.3 times, compared to Al-Al electrode system due to high $Cl_2$ gas production.

• Journal of Environmental Science International
• /
• v.32 no.5
• /
• pp.355-363
• /
• 2023

This study used a batch DAF (dissolved air flotation) jar tester to evaluate the algae removal efficiency of alum and PAC coagulants during coagulation, flocculation, and flotation. Optimal coagulant dosages were 0.06 ~ 0.15 mL/L (12.0 ~ 26.0 mg Al/L,17%), 0.08 ~ 0.20 mL/L (10.0 ~ 24.0 mg Al/L, 12%), 0.25 ~ 0.30 mL/L (25.0 ~ 30.0 mg Al/L, 10%) for PAC, and 3.0 ~ 5.0 mL/L (81.0 ~ 135.0 mg Al/L, 2.7%) for alum. Turbidity of treated water was 1.0 ~ 2.0 NTU in optimal coagulation, flocculation, and flotation conditions for the four coagulants types. The amount of coagulant injected tended to decrease with increasing Al content in the coagulant, as follows : 17% PAC < 12% PAC < 10% PAC < 2.7% alum. Turbidity removal efficiencies were in the order of 12% PAC (93.6%) > 10% PAC (92.7%) > 17% PAC (91.3%) > 2.7% Alum (88.1%).