• Korean Membrane Journal
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• v.7 no.1
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• pp.58-66
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• 2005

Nanofiltration (NF) of a dyeing wastewater was carried out using polyamide NF-membranes. Before applying the wastewater to the membrane process, it was pretreated with various chemical coagulants such as alum, ferric chloride and HOC-100A. In order to see the effect of the pretreatment of the wastewater using chemical coagulants on the membrane separation process, the optimum conditions for the coagulation and sedimentation process using the chemical coagulants were sought. By the pretreatment, despite the different coagulants used, the chemical oxygen demand (COD) and UV-absorbance of the wastewater were lowered by more than $70\%$. The pretreated wastewater was then applied to the membrane process. The effect of the coagulants used for the pretreatment on the membrane fouling was studied. From this study, it was found that the HOC-100A was the best out of the coagulants used far the removal of the materials that could cause membrane fouling.

• Journal of Korean Society on Water Environment
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• v.23 no.6
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• pp.993-997
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• 2007

The upflow anaerobic sludge blanket (UASB) reactor can be effective for treating simple organic compounds containing high concentration of ammonia nitrogen. The chemical oxygen demand (COD) removal efficiency was about 80% at ammonia nitrogen concentration up to 6,000 mg-N/L. This result also showed that it would be possible to treat propionate effectively at free ammonia nitrogen concentration up to 724 mg-N/L if sufficient time was allowed for adaptation. However the specific methanogenic activity (SMA) of granule was lower than that of granule in the reactor with lower ammonia nitrogen concentration. At 8,000 mg-N/L, the inhibition of high ammonia concentration was observed with evidence of increase of the volatile suspended solids (VSS) concentration in the effluent. It might be ascribed to the decrease in the content of extracellular polymer (ECP), which resulted to the sloughing off of obligated proton-reducing acetogens and heterogenotrophic methanogens from the exterior of granular sludge. This caused a great portion of the finely sludge to be easily washed out. Therefore, failure to maintain the balance between these two groups of microorganism cause accumulation of the hydrogen partial pressure in the reactor, which could have inhibited the growth of acetate utilizing methanogens.

• Journal of Korean Society of Water and Wastewater
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• v.10 no.4
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• pp.45-54
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• 1996

Effects of temperature on the efficiency of the Upflow Anaerobic Sludge Blanket(UASB) process for treatment of wastewater from a starch and related products manufacturing industry were investigated using laboratory scale reactors equipped with two types of Gas-Solid Separator(GSS). Both fresh digested sludge and granular sludge stored nearly for one year at room temperature were good as a seeding material. The reactors seeded with aged granular sludge showed slow start-up, however, lowered activity at the initial period was recovered gradually. The GSS with an inner cylinder was proved to be effective in liquid-solid separation compared to the conventional type. Although the rate of organic removal and gas production per unit volatile suspended solids in the reactor reduced significantly as the temperature varied from 35 to $20^{\circ}C$, possibility of operation at low temperatures was shown as a result of gradual buildup of volatile suspended solids in the bed. Stable operation with a reduced efficiency was possible at a COD loading of $5-8kg/m^3/day$ at a temperature as low as $20^{\circ}C$.

• Journal of the Korean Society of Industry Convergence
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• v.15 no.3
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• pp.83-86
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• 2012

This study have cross checked the change of internal sludge-recycle in Full-scale Anaerobic-Digestion, and researched about not only the improvement of Bio-gas production from the digested sludge but also the efficient method of sludge minimization. Ultimate aim of the study is to reduce the amount of sludge by the improved efficiency of contact with the organic-matter and the microbes in Anaerobic-Digestion. The sludge-recycle fluidized sludge layer and raised the activity of the sludge, The sludge-recycle ratio of optimum was 500%, VS and COD removal ratio respectively appeared with 67.8% and 70.4%. Through these result of this study, it may be positive view to treat waste sludge by the sludge-recycle ratio in terms of minimization and circulation of resources.

• Journal of the Korean Ceramic Society
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• v.45 no.11
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• pp.667-674
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• 2008

In this study, we prepared Fe-activated carbon fiber(ACF)/$TiO_2$ composites with titanium (VI) n-butoxide (TNB) as the titanium source for ACF pre-treated with iron compounds through the impregnation method. In terms of textural surface properties, the composites demonstrate a slight decrease in the BET surface area of the samples and an increase in the amount of iron compounds treated. The surface morphology of the Fe-ACF/$TiO_2$ composites was characterized by means of SEM. The composites have a porous texture with homogenous compositions of Fe and titanium dioxide distributed on the sample surfaces. The phase formation and structural transition of the iron compounds and titanium dioxide were observed in X-ray diffraction patterns of the Fe-ACF/$TiO_2$ composites. The chemical composition of the Fe-ACF/$TiO_2$ composites, which was investigated with EDX shows strong peaks for the C, O, Fe and Ti elements. The photo degradation results confirm that the Fe-ACF/$TiO_2$ composites show excellent removal activity for the COD in piggery waste due to photocatalysis of the supported $TiO_2$, radical reaction by Fe species, and the adsorptivity and absorptivity of ACF.

• Membrane and Water Treatment
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• v.6 no.6
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• pp.489-499
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• 2015

In this work, treatment of real hypersaline refinery wastewater by hollow fiber membrane bioreactor coupled with reverse osmosis unit was studied. The ability of HF-MBR and RO developed in this work, was evaluated through examination of the effluent properties under various operating conditions including hydraulic retention time and flux. Arak refinery wastewater was employed as influent of the bioreactor which consists of an immersed ultrafiltation membrane. The HF-MBR/RO was run for 6 months. Average elimination performance of chemical oxygen demand, biological oxygen demand, total suspended solids, volatile suspended solids, total dissolved soild and turbidity were obtained 82%, 89%, 98%, 99%, 99% and 98% respectively. Highly removal performance of oily contaminant, TDS and the complete retention of suspends solids implies good potential of the HF-MBR/RO system for wastewater refinement.

• Journal of Environmental Science International
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• v.16 no.6
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• pp.699-706
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• 2007

Many lakes or irrigative reservoirs in Korea are rapidly contaminated due to the ever increasing pollutants. Although lots of treatment processes have been recommended and practiced, economical and technical improvement is currently needed. In this study, contaminated irrigation reservoir was treated using the proposed process which is consisted of fine air bubbles, coagulation and flotation. Fine bubbles, approximate diameter of 3 to $10{\mu}m$, were generated using cavitation in the pressurized tank and polyaluminum chloride was used as coagulants. This fine bubbles, coagulation and flotation effectively controlled the low density algae, for example, Chlorophyll-a was removed more than 97 %. Removal efficiency of COD, SS, T-N and T-P were 80.7%, 94.3%, 64.1 % and 92.4%, respectively. Pollutants released from the sediments was removed more than 80% of organics and 60-70 % of nutrients. Consequently, fine bubbles coagulation and flotation process could be effectively used as an alternative treatment method for the purpose of control of lake water quality.

• Journal of Environmental Health Sciences
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• v.31 no.4 s.85
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• pp.294-300
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• 2005

Food waste can be a valuable carbon source in biological nutrient removal (BNR) systems because of high C/N and C/P ratios. However, food waste should be pretreated to promote its hydrolysis rate because hydrolysis reaction would be a rate-limiting step. This study investigates the influence of the enzymatic pretreatment on acid fermentation of food waste. Solubilization of particulate matter in food waste by using commercial enzymes was examined. The acidification efficiency and the volatile fatty acids (VFAs) production potential of enzymatically pretreated food waste were also examined. The highest volatile suspended solids (VSS) reduction was obtained with an enzyme mixture ratio of 1:2:1 of carbohydrase:protease:lipase. An optimum enzyme dosage for solubilization of food waste was $0.1\%$(V/V) with the enzyme mixture ratio of 1:2:1. In the acid fermentation of enzymatically pretreated food waste, $0.1\%$(V/V) enzyme mixture dosage for pretreatment result in the maximum VFAs production and the best VFAs fraction in soluble COD(SCOD). The VFAs production at this addition level was 3.3 times higher than that of no-enzyme added fermenter. The dominant VFAs present was n-butyrate followed by acetate.

• Advances in environmental research
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• v.2 no.2
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• pp.131-141
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• 2013

Agricultural practice and improper waste disposal in developing regions have resulted in environmental degradation in land and waters, for which low-cost, proven solutions are needed. We demonstrate in the laboratory the applications of composting and trickling filter techniques to treat olive mill wastes that can be implemented in the West Bank and other regions of the world. To a pomace waste sample from a California mill, we amended with saw dust (wood carbon source) and baking soda ($NaHCO_3$ alkalinity) at weight ratios of waste/wood/$NaHCO_3$ at 70:27:1 and composted it for periods of 11 and 48 days; the compost was used as an additive to potting soil for transplanting. The pomace sample was also blended into slurry and introduced to a water-circulating pond and trickling filter system (P/TF) to examine any inhibitive effect of the pomace on biological removal of the organic waste. The results showed the compost-amended potting soil supported plant growth without noticeable stress over 34 days and the P/TF system removed BOD and COD by >90% from the waste liquid within 2 days, with a first-order rate constant of 1.9 $d^{-1}$ in the pond. An onsite treatment design is proposed that promises implementation for agricultural waste disposal in developing regions.

• Journal of Navigation and Port Research
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• v.34 no.5
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• pp.375-381
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• 2010

This study was carried out for advanced treatment development on shipboard sewage. We employed SBR process using Bacillus sp. to remove Organic compounds, Nitrogen and Phosphorus simultaneously. Based on Res. MEPC.159(55) the system was qualified. From the results it was suggested that SBR system might be suitable process for shipboard sewage treatment in terms of pollutant removal efficiency, maintenance and special environmental conditions of ship. More than 90% of COD and BOD were removed. In addition, aover 50% of T-N and T-P were reduced.