• Journal of Korean Society of Water and Wastewater
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• v.7 no.1
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• pp.20-28
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• 1993

The Wastewater from the weight reduction process of polyester is more difficult to be treated biologically than the general wastewater from dyeing and finishing processes in textile industries. Above wastewater shows high pH, high organic strength and wide variation of organic loading. These characteristics are due to TPA and EG resulting from alkaline weight-reduction process and make trouble in the operation of activated sludge process. Therefore, the objective of this study is to develop the pretreatment method for the successful operation of treatment process. For the successful pretreatment process, the wastewater from weight-reduction process should be segregated from other wastewater stream and then acidified with concentrated sulfuric acid to precipitate out TPA from DST solution. At the optimum pH of 2. 2, the initial $COD_{cr}$ 60,000mg/l is reduced to 11,500mg/l and the removal efficiency of $COD_{cr}$ is 81.1%. The required amount of sulfuric acid for pretreatment is not greater than the amount for the the existing neutralization process. Moreover, the supernatant of pretreatment process can be reused in acidification of wastewater.

• Journal of environmental and Sanitary engineering
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• v.22 no.1 s.63
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• pp.17-27
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• 2007

This study was conducted the adsorption experiment way of organic wastewater (BOD, COD, TOC, T-N, T-P) by changing the carbonization temperature and the size of adsorbent to examine the adsorption capacity of Korean traditional charcoal which has similar characteristics to activated carbon of organic pollutants. Also, it was performed the basic experiment for pH and inorganic materials. As a result of observing Korean traditional charcoal with has the greatest inorganic contents which are the important factor of chemical adsorption. As the carbonization temperature was better high temperature charcoal than law temperature charcoal to adsorption capacity of pollutant and as the particle was minute (D size : $3.35mm{\sim}2.0mm$), it was most effective. The result of adsorption experiment of organic wastewater show that the elimination ratio of pollutants by bamboo high temperature charcoal was found as BOD(82.1%), COD(91.7%), TOC(52.4%), T-N(66.6%), T-P(83.2%) and it has most excellent adsorption capacity of organic pollutants.

• New & Renewable Energy
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• v.5 no.4
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• pp.80-85
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• 2009

The effects of various organic wastes on anaerobic fermentative hydrogen production were studied using enriched mixed microflora in batch tests. Rotten fruit, corn powder and organic wastewater enriched with sulfate (up to 1,000 mg/L) were used for experiments. Maximum hydrogen production (547.1 mL) was observed from rotten apple with initial substrate concentration of 132.2 g COD/L. The experimental result on sulfate enriched organic wastewater indicated that hydrogen production is not adversely influenced by relatively high sulfate concentration. Residual sulfate content remained at 96-98 % after 75 hours of reaction, which showed that no major sulfate reduction was occurred at pH 5.3-5.5 in the reactor. The volatile fatty acid (VFA) fractions produced during the reaction was in the order of butyrate > acetate > propionate in all experiments. The results of this study would be useful for controlling the conditions on fermentative hydrogen production using different feedstocks.

• Journal of Korean Society of Water and Wastewater
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• v.30 no.1
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• pp.99-104
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• 2016

This study was performed to develop a new process technology for advanced wastewater treatment using a modified Rotating Activated Bacillus Contactor (RABC) process that adopts anoxic-oxic suspended biomass tanks to enhance nutrients removal. A modified lab-scale RABC process was applied to examine its applicability and to obtain the design factors for the optimum operation of the system. The modified RABC process showed a little more stable and high nutrients removal efficiency than the prototype RABC process: about 70% of nitrogen and 55% of phosphorous removal when the low organic loading (influent COD 200mg/L). However, the processing efficiency of nutrients removal rates was enhanced to great extent when high organic loading: nitrogen 90% and phosphorous 85% (influent COD 500mg/L). High organic loading stimulated extremely good biomass attachment on the reticular carrier RABC stage and the excellent nutrients removal, nevertheless with almost no offensive odor.

• Journal of the Korea Organic Resources Recycling Association
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• v.19 no.2
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• pp.22-27
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• 2011

This study was performed to find out the optimum condition for hydrogen production by changing mixture ratio from 3:7(food waste water : swine wastewater) without pre-treatment of food wastewater and swine wastewater using a continuous reaction process. It was confirmed that hydrogen generation according to pH is the highest in a condition of pH 5.5, and that the optimum pH for hydrogen production in case of mixing food wastewater with swine wastewater is 5.5 through this. Hydrogen generation according to HRT showed high hydrogen generation rate in case of 4 days rather than 3 days, and this involves largely in vitality of hydrogen producing bacteria according to variation of the HRT value, so it is judged that HRT also acts as an important factor to hydrogen producing bacteria. The organic removal efficiency recorded a removal efficiency of maximum TS 52%, VS 71%, TSS 83% and VSS 89% at the 6th day of operation, and it was confirmed that organic removal efficiency is possible even through an hydrogen production process.

• Journal of Korean Society on Water Environment
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• v.26 no.1
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• pp.81-88
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• 2010

This study was conducted to find the capability of comparison of overall oxygen transfer coefficient in the membrane coupled high performance reactor (MPHCR) in treating high organic loading wastewater. Effluent quality had been analyzed while the influent organic loading rate was changed from 2 to $7kg\;COD/m^3{\cdot}day$. The oxygen transfer coefficients had been investigated using two-phase nozzle for operating variables which were internal circulation flowrate (5~8 L/min), air flow rate (0.0125~0.2 L/min), liquid temperature ($10{\sim}20^{\circ}C$), and pure-oxygen flow rate (0.0125~0.2 L/min). The overall oxygen transfer coefficient was increased with flowrate of internal circulation and air and high temperature. Especially, internal circulation flow rate showed distinct effect on overall oxygen transfer coefficient due to an increase of gas holdup and air-liquid contract area by two-phase nozzle. In the high range of organic loading rate from 4 to $7kg\;COD/m^3{\cdot}day$, the removable efficiency of COD was 91%. Conventional activated sludge process usually treat organic loading from 0.32 to $0.64kg\;COD/m^3{\cdot}day$ however, the MPHCR can treat 10 to 20 times higher if it would be compared to the conventional activated sludge process. Foaming problem often happened and caused biomass wash out of the reactor, therefore, the foaming should be controlled for the enhanced operation.

• Journal of Korean Society of Water and Wastewater
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• v.21 no.5
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• pp.641-647
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• 2007

This study aims to find out optimum condition for hydrogen production and organic removal when treating food and swine wastewater together. For this purpose, various batch tests were conducted by changing mixture ratio from 6:4 (food wastewater:swine wastewater) to 1:9 without pretreatment process. For hydrogen production through anaerobic fermentation, the mixture ratios of R-1 (6:4), R-2 (5:5) and R-6 (1:9) were out of pH range appropriate for hydrogen production and mixture ratios of R-3 (4:6), R-4 (3:7), and R-5(2:8) showed appropriate hydrogen production where their pH ranges were 5.1~5.5. Especially in case of R-3, it consistently maintained appropriate pH range for hydrogen production for 72hr and produced maximum hydrogen. The characteristics of hydrogen production and cumulative hydrogen production according to each mixture ratio showed that R-1, R-2 and R-6 did not produce any hydrogen, and maximum hydrogen productions of R-3, R-4 and R-5 were 593ml, 419ml and 90ml, respectively. Total cumulative hydrogen productions of R-3, R-4 and R-5 were 1690ml, 425ml and 96ml, respectively. Based on previous results, it was concluded that, the most appropriate mixture ratio of food wastewater and swine wastewate rwas 4:6 (R-3). The experiment for COD removal rate to evaluate organic removal efficiency revealed that R-3, R-4 and R-5 showed high removal efficiencies during the highest hydrogen production amount and the highest efficiency was 41% with R-3.

• Environmental Engineering Research
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• v.25 no.3
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• pp.324-334
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• 2020

Tannery wastewater is known to contain high concentrations of organic compounds, pathogens, and other toxic inorganic elements such as heavy metals, nitrogen, sulfur, etc. Biological methods such as aerobic and anaerobic processes are unsuitable for tannery wastewater treatment due to its high salinity, and electrochemical oxidation offers a promising method to solve this problem. In this study, raw tannery wastewater treatment using DSA® Ti/RuO₂, Ti/IrO₂ and Ti/BDD electrodes with continuous flow systems was examined. Effects of current densities and electrolysis times were investigated, to evaluate the process performance and energy consumption. The results showed that a Ti/BDD electrode is able to reach higher treatment efficiency than Ti/IrO₂, and Ti/RuO₂ electrodes across all parameters, excluding Total Nitrogen. The main mechanism of tannery wastewater oxidation at a Ti/BDD electrode is based on direct oxidation on the electrode surface combined with the generation of oxidants such as °OH and Cl₂, while at DSA® Ti/RuO₂ and Ti/IrO₂ electrodes, the oxidation mechanisms are based on the generation of chlorine. After treatment, the effluents can be discharged to the environment after 6-12 h of electrolysis. Electrooxidation thus offers a promising method for removing the nutrients and non-biodegradable organic compounds in tannery wastewater.

• Journal of Industrial Technology
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• v.16
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• pp.61-70
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• 1996

This research aims to find granulation and organic removal of the piggery wastewater with the upflow blanket filter(UBF) reactor. UASB process had the effect of high pH on the granulation phase. But teh effect was decreased after the granule formation. The filter zone of the UBF reactor had the function of GSS and contributed to removing the organic because of its biofilm formation. The removal rates of total COD and soluble COD were 70% ~ 80% and 60 ~ 80% at an influent organic loading range of $2{\sim}17.4kgCOD/m^3{\cdot}d$, respectively. The methane production rate with the organic removal was $0.21{\sim}0.34{\ell}CH_4/gCOD_{rem}$ and the maximum methan production rate was $0.34CH_4{\ell}/gCOD_{rem}$ at the volumetric loading $5kgCOD/m^3{\cdot}d$.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.2
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• pp.171-176
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• 2011

Organic matters that comprise a tiny part of seawater generally occur over 50% of membrane fouling in Reverse Osmosis Process. This study evaluates Foundation efficiency of reverse osmosis membranes under brackish and seawater conditions and resistance of organic fouling. Moreover, analyzing the membrane surface through roughness, contact angle and zeta potential results in roughness and contact angle are proportional to flux decline rate (FDR), yet FDR has high value when zeta potential is low level. Furthermore, with various membrane fouling of different raw water conditions, the flux tends to improve when pH value is high and raw water which is complex with organic and cation pollutes membrane faster than organic separated raw water condition.