• KSBB Journal
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• v.22 no.4
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• pp.244-248
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• 2007

The treatment of a model wastewater containing high concentration, 10 $g/{\ell}$, of phenol in an integrated wet oxidation-aerobic biological treatment was investigated. Partial wet oxidation under mild operating conditions was capable of converting the original phenol to biodegradable organic acids such as maleic acid, formic acid and acetic acid, the solution of which was subjected to the subsequent aerobic biological treatment. The wet oxidation was carried out at 150$^{\circ}C$ and 200$^{\circ}C$ and the initial pH of 1 to 12. The high temperature of 200$^{\circ}C$ and the acidic initial condition in the wet oxidation led to effluents of which biodegradability was higher in the subsequent biological oxidation process, as assessed by chemical oxygen demand (COD) removal. Homogeneous catalyst of $CuSO_4$ was also used for increasing the oxidation rate in the wet oxidation at 150$^{\circ}C$ and initial pH of 3.0. However, the pretreatment with the catalytic wet oxidation resulted in effluents which were less biodegradable in the aerobic biological process compared to those out of the non-catalytic wet oxidation at the same operating conditions.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2002.05b
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• pp.209-212
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• 2002

The heavy use of petroleum products in modern livings has brought ubiquitous environmental contaminants of aromatic compounds, which persist in aquatic and geo-environment without the substantial degradation. The persistence and accumulation of the aromatic compounds, which include xylene, phenol, toluene, phthalate, and so on are known to cause serious problems in our environments. Some of soil and aquatic microorganisms facilitate their growth by degrading aromatic compounds and utilizing degrading products as growth substrates, the biodegradation helps the reentry of carbons of aromatic compounds, preventing their accumulation in our environments. The metabolic studies on the degradation of aromatic compounds by microoganlsms were extensively carried out along with their genetic studies. A Rhodococcus sp. isolated in activated sludges has shown the excellent ability to grow on phenol as a sole carbon source. In the present study investigated a gene encoding phenol-degrading enzymes from a Rhodococcus sp.

• Membrane Journal
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• v.6 no.2
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• pp.109-116
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• 1996

This work is a fundamental study for applying hybrid process coupling adsorption with microfiltration to waste-water treatment. Phenol was separated by adsorption on powdered activated carbon, adsorbed phenol with activated carbon was separated by microfiltration. As the particle size in suspension increased, filtration resistance decreased, and effect of particle concentration on resistance was less pronounced. The rate of uptake was greatly dependent on the degree of phenol loading. For a smaller amounts of activated carbon, the change of permeate concentration before break point and phenol loading with time were steeper than in the case of large amounts. Permeate concentration before break point decreased with decreasing particle size, this could be due to the increase of outer surface of particle and film mass transfer coefficient.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.7
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• pp.1213-1223
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• 2000

The adsorption characteristics of phenol has been studied by using CDQ (Cokes Drying Quenching) dust as an adsorbent. The adsorption capacity of CDQ dust was shown to be 42% about removal for 300 ppm phenol solution at the equilibrium adsorption time of 60 min. Removal percentage of phenol increased as the initial phenol concentration was raised in the experimental conditions and the adsorption behavior was explained well by Freundlich adsorption isotherm. Kinetic study showed that the adsorption followed 1st, 1.5th, and 2nd-order rate equation in the sequence as the adsorption time passed. Since the adsorption amount of phenol was increased as the adsorption temperature was raised, the adsorption was thought to be endothermic, and several thermodynamic parameters have been calculated based upon experimental data. Adsorbed amount of phenol on CDQ dust changed little according to the variation in the solution pH except for the slight decrease under the strong alkaline condition.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.4
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• pp.797-806
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• 2000

The objectives were to compare the biodegradable threshold concentrations of phenol with the different composition of the influent carbon source and examine the SMA (Specific Methanogenic Activity)and the possibility of simultaneous removal of high-strength organics and nitrogen compounds in UASB(Upflow Anaerobic Sludge Blanket) - PBR(Packed Bed Reactor) process. The results showed that UASB reactors were efficient to remove phenol and phenol + glucose from synthetic wastewater. At phenol conc, of 600 mg/L and SCOD conc. of 2100 mg/L in UASB reactor(with only phenol as substrate), the removal efficiencies of phenol and SCOD were over 99% and 93% respectively, under MLVSS of 20 g. The activity of microorganism was $0.112g\;phenol/g\;VSS{\cdot}d$, $0.351g\;SCOD/g\;VSS{\cdot}d$. The gas production rate was $0.115L/g\;VSS{\cdot}d$ and $CH_4$ content in gas was about 70%. At phenol conc. of 760 mg/L and SCOD conc. of 4300 mg/L in UASB reactor( with phenol + glucose as substrates), the removal efficiencies of phenol and of SCOD were over 99% and 90% respectively, under MLVSS of 20 g. The activity of microoganism was $0.135g\;phenol/g\;VSS{\cdot}d$, $0.696g\;SCOD/g\;VSS{\cdot}d$. The gas production rate was $0.257L/g\;VSS{\cdot}d$ and $CH_4$ content in gas was about 70%. Serum bottle test showed that the activity of granule was inhibited over 1600 mg/L phenol conc, and denitrification and methanogenesis simultaneously took place in UASB granules under co-substrates conditions. PBR reactor packed with cilium type media, was efficient in nitrification. In condition of $0.038kg\;NH_4-N/m^3-media{\cdot}d$. 10~12 mg/L phenol conc. and 200~500 mg/L SCOD conc., nitrification efficiency was over 90% and phenol removal efficiency was over 98%.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.2
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• pp.214-219
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• 2007

66 micropollutants analyses in 9 wastewater treatment plants(WWTPs) along Nak-dong river were implemented to identify the concentrations and removal efficiencies before and after treatment processes. As a result of study, the concentration levels discharged from WWTP effluents to water system were below the water quality criteria and the levels of other studies. The removal efficiencies were 84.6%(DAF/CCR) and 81.6%(AC) for 1,4-dioxane. Phenol, Clphs and PAHs were removed 94.6%, 66.4% and 80.6% respectively by the activated sludge(AS) process. The removal efficiencies of Clbzs were 45.3% for the activated sludge(AS) process and 60.6% for the activated carbon(AC) process. However, other processes besides AS and AC, the removal efficiencies of Clbzs were very low(<20%). The sand filtration(SF) process that could remove particle matters showed the best efficiency for PCDDs / Fs removal$(\geq99%)$. However, in case of relatively low PCDDs/Fs concentration level in influent, the removal efficiency was not so high$(\leq50%)$.

• Clean Technology
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• v.5 no.1
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• pp.49-61
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• 1999

Fenton's oxidation can improve the biodegradability of refractory organic wastewater by generating $OH{\cdot}$ which is one of the most reactive species. Fenton's reagent is used to treat a variety of industrial waste containing a range of toxic organic compounds. But this process cannot be economical because of high chemical cost of $H_2O_2$, ferrous ion solution and high sludge disposal cost. In this study, we proposed a modified Fenton's oxidation process which can reduce the reagent cost and obtain better removal efficiencies with less Fenton's reagents, and have a good potential of sludge recycling. In modified Fenton reaction, ferrous ion solution is adjusted to optimal pH with NaOH. Then it added to the sample and reacted to $H_2O_2$. For the experiment, synthetic wastewater made of phenol, which is one of the typical water pollutants, was used and the ionic strength of this wastewater was controlled by adding $NaHCO_3$. The effects of DO, ionic strength, and $H_2O_2$ dosing methods were investigated. As a result, modified Fenton's treatment efficiencies are better than conventional Fenton's reaction treating leachate and dyeing wastewater. And modified Fenton's treatment efficiencies combined to the sludge recycling for a half of Iron dosage are as good as the conventional Fenton's for a normal Iron dosage.

• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.431-434
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• 2002

Effect of various factors on the phenol degradation by activated sludge immobilized with the photocrosslinked resin were investigated. The optimum pH on the degradation of phenol in both free and immobilized activated sludge was 7. A higher rate of phenol degradation was observed when a bead size, vas smaller. The phenol degradation in the free activated sludge was inhibited at the 3000 mg/L of phenol, while that in the immobilized activated sludge was maintained at the same concentration for 28 hrs without an inhibition.

• Journal of Environmental Science International
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• v.10 no.3
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• pp.239-245
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• 2001

This research was performed to investigate the dynamics of microbial community by RBC (Rotating Biological Contactor) using Rhodococcus sp. EL-GT and activated sludge. Cell counts revealed by DAPI were compared with culturable bacterial counts from nutrient agar. Colony counts on nutrient agar gave values 20~25% and 1~15% of cell counts (DAPI). The cell counts for the dynamics of bacterial community were determined by combination of in situ hybridization with fluorescently-labelled oligonyucleotide probes and epifluorescence microscopy. Around 90~80% of total cells visualized DAPI were also detected by the bacteria probe EUB 338. For both reactors proteobacteria belonging to the gamma subclass were dominant in the first stage (1 and 2 stage) and proteobacteria belonging to the gamma subclass were dominant in the last stage (3 and 4 stage).

• Journal of Environmental Health Sciences
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• v.22 no.3
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• pp.72-80
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• 1996

This study was carried to investigate the biodegradability of phenol wastewater in the sluge blanket-packed bed reactor(SBPBR). The reactor consisted of two regions. The lower region was a sludge blanket of 0.5 m height and the upper region was a packed-bed. The phenol and COD concentration of the effluent, the gas production and the composition of gas were measured to determine the performance of the anaerobic wastewater treatment system as the phenol concentration of the influent was increased from 600 to 1800 mg/l. Stable biodegradation of phenol wastewater could be achieved with the anaerobic treatment system from 600 to 1200 mg/l of the influent phenol concentration. But the SBPBR system was getting more serious at 1800 mg/l of influent phenol concentration. At the steady state of the influent phenol concentration of 600-1200 mg/l, the treatment performance showed the phenol removal efficiency of 94.5~96.3%, the COD removal efficiency of 93.3~96% and the gas production of 4.94~9.64 l/day.