• 한국환경보건학회지
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• 제27권4호
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• pp.79-83
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• 2001

The sludge wastes fermentation process reactors were operated to produce the VFAs(volatile fatty acids) as supplemental carbon sources and to determine the optimum operating conditions. The experiment was carried out by varied mixture ration of 400:0 350:30 300:100 200:200 and operating temperature 2$0^{\circ}C$ 3$0^{\circ}C$ and 4$0^{\circ}C$ The results were as follows: Higher VFAs production rate observed at higher mixed ratio of primary sludge. When the mixed ratio of primary sludge and return sludge were 400:0 350:50 300:100 200:200 respectively. VFAs production are were 829.6mg/l 944.2 mg/l 597.9mg/ml an d441.6 mg/l , respectively. the yield of VFAs increased with temperature, but decreased with initial TSS concentration Because fermented sludge has relatively low nitrogen and phosphorus and relatively high VFAs it can be used as a substitute for external carbon in biological nutrient removal process.

• 자원리싸이클링
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• 제5권3호
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• pp.31-36
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• 1996

The metallic copper was recovered from sludge of the copper electro-plating plant by pyrometallurgical process. The reducing agent was Pyrolysized from waste tires and the flux was a mixture $Na_2CO_3$, $NaB_4O_7$, and glass. The green sludge contained 87.5% moisture and 12.5% solid with 56.5% Cu and 1.59% Fe. The sludge dried at $100^{\circ}C$ was analyized to be $Cu_4SO_4(OH)_6{\cdot}2H_2O$ and CuO by XRD analysis. The former was 84% and the latter 16%, However, the calcined sludge at $500^{\circ}C$ was 49% $Cu_2O(SO_4)$ and 51% CuO. The sludge could by smelted at $1100^{\circ}C$ for two hours with 6 to 8 moles carbon with respect to copper to produce metallic copper (>90%) with recovery of 9% above.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 추계학술대회 논문집
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• pp.145-148
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• 2008

Fuel flexibility of CFBC boiler was examined. Combustion characteristics of low grade coal, coal sludge, coal RDF mixture and RDF were compared. The operation result of a commercial 130TPH CFBC co-generation boiler burning a low grade Chinese coal were analysed. Burning characteristics of coal/RDF mixture and coal and industrial sludge mixture were studied in a 0.1MWth scale CFBC test rig. Also RDF fuel were tested in a 8TPH CFBC test facility. Though fuel characteristics were different, the combustion modes were all very stable. The temperature were maintained in between $800-950^{\circ}C$.

• 수도
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• 제24권5호통권86호
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• pp.29-44
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• 1997

Sewage sludge produced in Korea was 1,275,800 tons (dewatered sludge cake) per year in 1996, which is 3,495 tons per day, 0.303% of 11,526,100 tons per day of sewage treated in 79 sewage treatment plants. Sludge production has been and will be increasing in accordance with construction of new facilities for sewage treatment. Most of the sludge is currently disposed by landfill and ocean dumping, but it is becoming difficult to find suitable sites for landfill, particularly in big cities such as Seoul. In addition, rapid increase of landfill cost is anticipated in a near future. Current trend for sludge disposal in advanced countries is land application. Over the past 10 to 20 years in the United States, sludge management practices have changed significantly, moving from disposal to beneficial use. They use biosolid for utilization instead of sludge for disposal. Under the Clean Water Act of 1972, amended in 1987 by Congress, the U.S. EPA was required to develop regulations for the use and disposal of sewage sludge. The EPA assessed the potential for pollutants in sewage sludge to affect public health and the environment through a number of different routes of exposure. The Agency also assessed the potential risk to human health through contamination of drinking water sources or surface water when sludge is disposed on land. The Final Rules were signed by the EPA Administrator and were published (Federal Register, 1993). These rules state that sewage sludge shall not be applied to land if the concentration of any pollutant in the sludge exceeds the ceiling concentration. In addition, the cumulative loading rate for each pollutant shall not exceed the cumulative pollutant loading rate nor should the concentration of each pollutant in the sludge exceed the monthly average concentration for the pollutant. The annual pollutant loading rate generally applies to applications of sewage sludge on agricultural lands. The most popular beneficial use of sewage sludge is land application. The sludge has to be stabilized for appling to land. One of the stabilization process for sewage sludge is lime stabilization process. The stabilization process is consisted of the stabilizing process and the drying process. Stabilization reactor can be a drum type reactor in which a crossed mixer is equipped. The additive agents are a very reactive mixture of calcium oxide and others. The stabilized sludge is dried in sun drier or rotary kiln.

• 유기물자원화
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• 제28권3호
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• pp.45-49
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• 2020

본 연구는 하수슬러지와 건조연료를 혼합한 혼합물에 대해 토지개량효과를 검토하기 위한 연구이다. 혼합물은 하수슬러지와 건조연료를 중량대비 1:1 비율로 혼합하여 만들었다. 1개의 대조군(0 %)부지와 혼합물을 10 %, 20 %, 30 % 시비한 3개의 비교군을 조성하였다. 토양의 유효인산 함량변화는 혼합물을 시비한 비율에 따라 상관관계가 높은 것으로 확인되었다(P<0.05). 케나프를 90일 재배 후 수확량을 비교한 결과 10 %투입된 배지에서 줄기의 길이가 대조군 대비 73 %증가를 보였으며, 잎 수확량의 경우 20 %배지에서 227 % 가장 높은 증가율을 보였다. 30 %에서는 다른 배지보다 꽃의 개화가 먼저 된 것으로 보아 성장률이 다른 배지보다 빠른 것으로 판단되며 엽록소 함량은 71.6(SPAD)으로 가장 높은 수치를 보여 조단백질의 함량이 다른 배지에 비해 높을 것으로 판단된다. 따라서 건조연료 혼합물의 투입을 통해 전체적으로 식물이 생육하기 좋은 토질로 개선하는데 효과가 있는 것으로 사료된다.

• 유기물자원화
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• 제9권2호
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• pp.58-65
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• 2001

매립지의 재자연화와 조경을 위한 토양을 폐기물을 원료로 하여 생산하기 위해서 폐 콘크리트에 여러 가지 유기성 폐기물을 혼합하였다. 이 혼합물이 식물의 성장토로 사용될 수 있는 지의 여부를 알기 위해서 혼합물의 고형물과 침출수에 함유된 물질을 독일의 폐기물학회에서 규정한 항목에 따라서 분석, 평가하였고, 이 혼합물에 식물실험을 하여 수확량을 측정하였다. 실험의 결과 이 혼합물은 매립지의 재자연화를 위한 최종복토용으로, 경우에 따라서는 공원이나 정원의 조경용으로 사용될 수 있고, 폐 콘크리트 85%, 하수슬러지 10% 그리고 제지슬러지 5%의 혼합물이 가장 효과적이었다.

• The Korean Journal of Ecology
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• 제28권4호
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• pp.189-192
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• 2005

We tested the field adaptation of Betula schmidtii on the abandoned coal-mine soil with sludge amendment methods for promoting physiological activity of B. schmidtii seedlings under several environmental stress. Sewage sludges were amended to coal-mine soil with B. schmidtii seedlings which grown in the mixture of artificial soil and composted sludge soil before transplanting (before-fertilized treatment, BF) and fertilized with composted sludge after transplanting (after-fertilized treatment, AF). The percent of establishment of seedlings for AF (80.7%) was lower than that for BF (92.7%). Nitrate reductase activity and photosynthetic pigment content were higher in AF than in BF, but malondialdehyde (MDA) content and superoxide dismutase (SOD) activity were lower in AF than in BF These results represent that after-fertilized seedlings increase resistance against physiological stress at field condition using nitrogen source of composted sludge. On the contrary, before-fertilized seedlings were susceptible to environmental stress on abandoned coal-mine soil by exhausting of nitrogen source from composted sludge.

• 한국환경과학회지
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• 제13권2호
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• pp.161-165
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• 2004

This study has been conducted to develop a new recycling technology of sewage sludge using a carbonization process. The carbonizing yield, the calorific value and EC(electric conductivity) of carbonized sewage sludge had a tendency to be decreased with increase of the carbonizing temperature and time, but pH and the C/N were increased with increase the carbonizing temperature and time. The whole pore volume of carbonized sludge processed in the carbonizing furnace was /g, which was smaller than that in the electric furnace. But, the rates of mesopore and macropore were found to account for 100% therein. Rate of color and organic materials removal for dyeing wastewater were determined 70~97%, 78~83% on cotton yarn, 88~96%, 69~80% on wool wastewater and 77~89%, 77~87% on towel compared with powder activated carbon. Effect of carbonized sludge on chrysanthemum growth was investigated. Plant height and number of leaves was better mixture of carbonized sludge than comparison.

• Journal of Korean Society for Atmospheric Environment
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• 제21권E2호
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• pp.41-48
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• 2005

A novel hybrid system composed of a biotrickling filter and an activated sludge reactor was investigated under the conditions of four different SRTs (sludge retention times). The performance of the hybrid reactor was found to be directly comparable among the four different sludge ages. Discernible differences in the removal performance were observed among four different SRTs of 2, 4, 6, and 8 days. High removal efficiency was achieved by continuous circulation of activated sludge over the immobilized mixture culture, which allowed on pH control, addition of nutrients, and removal of paint VOCs (volatile organic compounds). The results also showed that the removal efficiency for a given pollutant depends on the activity of microorganisms based on the SRT. As the SRT increased gradually from 2 to 8 days, the average removal performance decreased. The highest removal rate was achieved at the SRT of 2 days at which the highest OUR (oxygen uptake rate), $6.1mg-O_2/liter-min$ was measured. Biological activity in the recycle microbes decreased to a much lower level, $3.6mg-O_2/liter-min$ at a SRT of 8 days. It is thus believed that young microorganisms were more active and more efficient for the VOCs removal of low concentrations and high flow rates. The apparent correlation of $R^2=0.996$ between the average removal efficiency and the average OUR at each SRTs suggests that VOCs degradation by young cells significantly affected the overall removal efficiency for the tested SRTs.

• 한국방재안전학회논문집
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• 제10권1호
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• pp.55-60
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• 2017

슬러지를 매립하는 경우 빗물의 유입이나 주변 지하수의 수분을 흡수하여 지반이 전체적으로 연약해 지는 경우가 발생한다. 본 연구에서는 탈수한 염색슬러지를 매립한 경우의 문제점을 확인하기 위해 염색슬러지와 염색슬러지-토사 혼합샘플에 대한 시험을 수행하였다. 염색슬러지가 배수가 원활하지 못한 매립지 내부에서 함수비가 높은 상태로 장기간 방치되면, 염색공장의 염색슬러지와 비교하여 투수성이 약 3/100 수준으로 낮아지고 압축성이 1.4배 증가하는 것으로 나타났다. 매립지의 안정성 확보를 위해 매립지 내부 함수비를 저하시키는 것이 중요하며, 배수로의 확보와 침출수 배제시설을 통한 관리가 필요할 것으로 판단된다.