• Journal of Korean Society of Environmental Engineers
• /
• v.27 no.2
• /
• pp.130-137
• /
• 2005

This research programme include investigation of the adsorption behavior of heavy metals and VOCs by Pyrolysis char for using landfill cover material. The volatile potions in the sludge gasified during the pyrolysis period and gave birth to porosity throughout the matrix. The result of the ad/desorption experiment of nitrogen to find out the formation of some pore by the gasification of the volatile matter, we can certify that the pyrolysis char($14.56\;m^2/g$) has increased twice more than the organic wasted sludge($6.68\;m^2/g$) in specific surface area. The pyrolysis char has the adsorption characteristic of medium type of Type II and V in BDDT classification, and showed a little micro pore. In the adsorption experiment of ethylbenzene and toluene, as a result of applying the Freundlich adsorption isotherms, the pyrolysis char was higher in the adsorptivity of ethylbenzene and toluene than the granite and the organic wasted sludge. The results of the heavy metal adsorption test for the char indicated that it had some ability of adsorption. It is suggest that pyrolysis char has some advantages for utilizing as landfill covers because the pyrolysis char can adsorb/absorb hazardous substances from the landfill sites and inhibit the ground water and soil contamination.

• Journal of Korean Society of Environmental Engineers
• /
• v.28 no.4
• /
• pp.362-367
• /
• 2006

Waste activated sludge(WAS) collected from domestic wastewater treatment plant is biomass that contains large quantities of organic matter. However, relevant literature show that the bio-hydrogen yield using WAS was too low. In this study, the effect of pretreatment of WAS on hydrogen yield was investigated. Pretreatment includes acid and alkali treatments, grinding, heating, ozone and ultrasound methods. After pretreatment organic matters of WAS were solubilized and soluble chemical oxygen demand(SCOD) was increased by 14.6 times. Batch experiments were conducted to investigate the effects of pre-treatment methods and buffer solution, hydrogen partial pressure, and sodium ion on hydrogen production from WAS by using heated anaerobic mixed cultures. Experimental results showed that addition of buffer solution, efficient pre-treatment method with alkali solution, and gas sparging condition markedly increased the hydrogen yield to 0.52 mmol $H_2/g$-DS.

• Transactions of the Korean hydrogen and new energy society
• /
• v.13 no.1
• /
• pp.52-64
• /
• 2002

유기성 폐기물을 이용하여 생물학적 수소생산 통합화 시스템 연구를 수행하였다. 통합화 시스템은 유기성폐기물의 전처리, 2단계 혐기발효 및 광합성 배양으로 구성된 생물학적 수소생산 공정, 초임계수 가스화 공정, 생산된 가스의 저장, 분리 및 연료전지를 이용한 전력 생산으로 구성되었다. 실험에 사용된 유기성 폐자원은 식품공장 폐수, 과일폐기물, 하수슬러지이며, 전처리는 폐기물에 따라 열처리 및 물리적 처리를 하였으며, 전처리된 시료는 생물학적 수소생산 공정에 직접 적용되었다. Clostridium butyricum 및 메탄 생성조에서 발생하는 하수슬러지중의 미생물 복합체는 수소생산 혐기 발효공정에 사용되었으며, 광합성 수소생산 미생물인 홍색 비유황 세균은 광합성 배양에 사용되었다. 생물학적 공정에서 발생하는 미생물 슬러지는 초임계수 가스화 공정으로 수소를 발생하였으며, 슬러지 중의 COD를 저하시켰다. 생물학적 공정 및 초임계수 가스화 공정에서 발생하는 수소는 가스탱크에 가입상태로 저장한 후, 95%순도로 분리하였으며, 정제된 수소는 연료전지에 연결하여 전력 생산을 하였다.

• Journal of Korean Society of Environmental Engineers
• /
• v.22 no.3
• /
• pp.475-484
• /
• 2000

The purpose of this study was to develop model for estimating biodegrability of organic sludge (sewage and papermill) in various environmental conditions. to assume degradable degree with operating time of SRB reactor. and evaluate duratior of organic sludge as carbon source. Average TCOD was 28.7~63.2mg/L in effluent. organic sludge did not much supply carbon source for experimental period. But in point of durability. it seemed that organic sludge was efficient because it was not consumed by degradation of much organic matter within short period. With increasing $SO_4{^{2-}}$ reduction rate. Pb and Fe was removed 77~82% and 33~59%. respectively. Because Al was precipitated as a hydroxide. its removal rate wa,. about $54{\pm}2%$ in R-l~R-3 maintaining low pH but about 78% in R-4 maintaining high pH. Because Mn was large in solubility. it showed to be much lower than other heavy metals. Considering supportable capacity or durability of orgainc matter for initial SRB mixing ratio of sewage/papermill 0.5 was regarded as appropriate substituting material and at this time. it estimated that carbon source continued about 3.08 year but safety factor must apply to be thought over. because various factors had an effect on degradation of organic sludge.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.9 no.2
• /
• pp.58-65
• /
• 2001

To produce the substitute for farmland were mixed concrete waste and organic wastes. To estirnate the application of the mixture for farmland components in the solid and the leachate from the mixture were analyzed according to the ordinance of the Waste Society in Germany. Plants were cultivated in the mixture and its harvests were measured. The results showed that the mixture from waste may be used for the reclamation of landfill and landscaping according to circumstances, and the best mixture was from 85% of concrete waste, 10% of sewage sludge and 5% of paper mill sludge.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.17 no.1
• /
• pp.96-102
• /
• 2009

The effect of ultrasonic and alkaline pre-treatments on waste activated sludge (WAS) disintegration was investigated for improved anaerobic digestion. As WAS was treated by either methods, longer capillary suction time (CST) was required due to the break-up of cell walls, and its supernatant demonstrated increase in soluble chemical oxygen demand (SCOD), protein content and turbidity. Ultrasonic process combined with alkaline pre-treatment demonstrated higher SCOD and protein content in the supernatant as compared with ultrasonic pre-treatment only. However, the degree of disintegration (DDCOD) of WAS decreased with increasing solid concentration as both WAS disintegration methods employed simultaneously.

• Journal of Korean Society of Environmental Engineers
• /
• v.29 no.9
• /
• pp.1044-1050
• /
• 2007

In this study, Bio-hydrogen is produced from organic waste mixtures containing food waste and waste activated sludge (WAS). The effects of different operational factor on hydrogen production, including various solubilization methods for pretreatments of WAS, pH and different ratios of food waste and WAS, were investigated. The highest hydrogen production values are obtained as 4.3 mL $H_2/g$ $VS_{consumed}$ in the case of applying the mixed pre-treatments of alkali and ultrasonic. The pH value in bio-reactor increased from 4 to 8 after the ultrasonic treatment with alkali and the hydrogen yield touched its highest value in the pH range of 5.0 to 5.5. Similarly, the hydrogen production reached the level of 13.8 mL $H_2/g$ $VS_{consumed}$ using the same pre-treatment method from the mixture of food waste and WAS. The ratio of 2 : 1 produced a maximum amount of hydrogen of 5.0 L $H_2/L/d$. The amount of volatile fatty acids(VFAs) including acetate, propionate and butyrate, were also varied considerably. Propionate decreased consistently with rising of hydrogen while butyrate comparing to acetate relatively increased in the effluent.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.13 no.3
• /
• pp.71-81
• /
• 2005

Anaerobic digestion is employed worldwide as the oldest and most important process for sludge stabilization. An additional advantage is the production of methane during anaerobic digestion. However, the waste activated sludge(WAS) has poor anaerobic degradability and less gas production due to the cell wall of bio-solid. In order to improve and enhance stabilization and dewatering of the WAS, a number of pretreatment processes have been developed and investigated. In this research, a pilot-scale study of pulse power pretreatment was performed to improve anaerobic degradability and dewaterability of the WAS. A pilot plant was designed and operated based on a previous laboratory study. Change of the sludge characteristics by pulse power pretreatment was estimated to assess the increasing soluble organics. The increased soluble organics could be used as a good substrate in the anaerobic digesion process. Gas production and methane potential of the anaerobic digestion were estimated as the parameters of anaerobic degradability. For evaluation of the dewaterability of pretreated WAS, capillary suction time(CST) and specific resistance were measured. The efficiency of energy recovery was also estimated by calculating energy balance.

• Journal of Korean Society of Environmental Engineers
• /
• v.36 no.9
• /
• pp.641-647
• /
• 2014

In this study, sludge waste which has a difficulty in treating it was used to manufacture a fiber type of biosorbent. To solve the problems such as the release of organic pollutants and the difficulty in separating solid from treated water, entrapment method using Ca-alginate was used to immobilize sludge waste. Considering ease of manufacture as well as improvement of adsorptive ability, the biosorbent was manufactured in the form of fiber type. Optimum immobilization condition for minimizing the amount of alginate used and maximizing the performance of biosorbent was determined to be 10 g/L alginate concentration, 40 g/L sludge concentration, and 0.3-0.4 mm fiber diameter. The maximum Cd(II) uptake of the biosorbent was 60.73 mg/g. Pseudo-second-order kinetic model and Langmuir isotherm model adequately described the dynamic and equilibrium behaviors of Cd(II) biosorption onto the biosorbent, respectively. In conclusion, sludge waste generated from wastewater treatment process is a cheap raw material for the manufacture of biosorbent which can be used to remove toxic heavy metals from industrial wastewaters efficiently.

• Journal of Korean Society of Environmental Engineers
• /
• v.28 no.12
• /
• pp.1347-1351
• /
• 2006

It was tried to utilize organic waste sludge from wastewater treatment plant as a starting material to produce a solid fuel by vacuum flying. The effects of decompression levels, frying time and temperature on the calorific value and moisture of vacuum fried sludge were systematically investigated. Dewatered raw sludge used in this study had a moisture of 81.1% and calorific value of 2,930 kcal/kg. Based on the experimental observation, it was identified that the decompression level and frying time have the greatest influence on the calorific value of vacuum fried sludge. Moistures of the fried sludge at $180^{\circ}C$ for 25 min in 760 mmHg, 684 mmHg and 630 mmHg were 32.4%, 14.2% and 11.6%, respectively. Calorific values of the vacuum fried sludge at $140^{\circ}C$ for 15 min and 25 min were 5,400 kcal/kg and 5,540 kcal/kg in 684 mmHg and 5,520 kcal/kg and 5,660 kcal/kg in 630 mmHg, respectively.