• 한국환경농학회지
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• 제4권2호
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• pp.78-87
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• 1985

제지(製紙)슬러지가 논 토양(土壤)의 화학성(化學性)과 수도생육(水稻生育)에 미치는 영향(影響)을 검토(檢討)하기 위하여 슬러지의 시용량(施用量)을 300, 600, 900 및 1,200㎏/10a 으로 달리하고 각(各) 시용수준별(施用水準別)로 C/N 율(率)을 30 : 1 로 조절(調節)하여 pot 시험(試驗)을 실시(實施)함으로써 토양중(土壤中) 질소(窒素)의 형태변화(形態變化), 유기태질소(有機態窒素)의 무기성분(無機成分) 및 중금속함량변화(重金屬含量變化)를 경시적(經時的)으로 조사(調査)한 결과(結果)를 요약(要約)하면 다음과 같다. 1) 토양중(土壤中) amino sugar 및 amino acid 태질소(態窒素), 유기물(有機物) CEC 및 유효규산(有效珪酸)의 함량(含量)은 슬러지구(區)가 3요소구(要素區)에 비(比)하여 증가(增加)하였다. 2) 항온(恒溫) 6주후(週後) 유기태질소(有機態窒素)의 무기화율(無機化率)은 3요소구(要素區)가 12.2%, 슬러지 300㎏/10a 구(區) 12.6%, 슬러지 300㎏/10a의 C/N 율조절구(率調節區) 15.1%, 슬러지 600㎏/10a 구(區) 9.7%, 슬러지 600㎏/10a의 C/N 율조절구(率調節區)는 15.2%로 나타났다. 3) 토양중(土壤中) 동(銅) 및 납의 함량(含量)은 각각(各各) $0{\sim}0.2100$ 및 $0{\sim}0.0013$ ppm 범위(範圍)였으며 크롬 및 카드뮴은 검출(檢出)되지 않았고 토양중(土壤中) 이들 중금속함량(重金屬含量)은 처리간(處理間)에 차이(差異)가 없었다.

• 자원리싸이클링
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• 제21권4호
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• pp.60-68
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• 2012

반도체 및 태양광 산업에서는 반도체 소자 및 솔라셀을 제조하기 위하여 실리콘 웨이퍼가 사용되고 있다. 실리콘 웨이퍼는 실리콘 잉곳의 절단으로부터 만들어지며 이 공정에서 실리콘 슬러지가 발생한다. 반도체 소자의 사용처가 점점 증가함에 따라 실리콘 슬러지의 발생량 또한 증가하고 있는 실정이다. 최근 경제적인 측면과 효율성에 관한 측면에서 실리콘 슬러지의 재활용 기술이 폭넓게 연구되고 있다. 본 연구에서는 실리콘 슬러지의 재활용 기술에 대한 특허와 논문을 분석하였다. 분석범위는 1982년~2011년까지의 미국, EU, 일본, 한국의 등록/공개된 특허와 SCI 논문으로 제한하였다. 특허와 논문은 키워드를 사용하여 수집하였고, 기술의 정의에 의해 필터링하였다. 특허와 논문의 동향은 연도, 국가, 기업, 기술에 따라 분석하여 나타내었다.

• 한국건축시공학회지
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• 제17권1호
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• pp.111-117
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• 2017

Stone powder sludge is a byproduct of the crushed aggregate industry, and most of it is dumped with soil in landfills. The disposal of stone powder sludge presents a major environmental problem. This paper investigates the effects of stone powder sludge on the fluidity, density, strength and micro-structure properties of AAC(autoclaved aerated concrete) samples. Stone powder sludge was obtained from a crushed aggregate factory in order to investigate its applicability as a substitute for quartz sand in AAC. To determine the properties of the AAC samples produced with stone powder sludge, specimens containing different foam ratios were produced. Flow value, density, compressive strength, tensile strength and flexural strength of the samples were tested, and X-ray diffraction (XRD) was performed. The test results indicated that the compressive strength of AAC specimens (F120) with stone powder sludge was higher than that of AAC specimens (Q120) with quartz sand for same foam ratio of 120%. For all XRD diagrams, a higher number of tobermorite peaks was shown for the F120 sample than for the Q120 sample, which may explain the slightly higher strength gain in the F120 sample.

• Journal of Microbiology and Biotechnology
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• 제20권7호
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• pp.1128-1133
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• 2010

The diversity and abundance of ammonia-oxidizing bacteria (AOB) in activated sludge were compared using PCR-DGGE and real-time PCR assays. Activated sludge samples were collected from five different types of wastewater treatment plants (WWTPs) mainly treating textile, paper, food, and livestock wastewater or domestic sewage. The composition of total bacteria determined by PCR-DGGE was highly diverse between the samples, whereas the community of AOB was similar across all the investigated activated sludge. Total bacterial numbers and AOB numbers in the aerated mixed liquor were in the range of $1.8{\times}10^{10}$ to $3.8{\times}10^{12}$ and $1.7{\times}10^6$ to $2.7{\times}10^{10}$ copies/l, respectively. Activated sludge from livestock, textile, and sewage treating WWTPs contained relatively high amoA gene copies (more than $10^5$ copies/l), whereas activated sludge from food and paper WWTPs revealed a low number of the amoA gene (less than $10^3$ copies/l). The value of the amoA gene copy effectively showed the difference in composition of bacteria in different activated sludge samples and this was better than the measurement with the AOB 16S rRNA or total 16S rRNA gene. These results suggest that the quantification of the amoA gene can help monitor AOB and ammonia oxidation in WWTPs.

• 한국응용과학기술학회지
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• 제27권4호
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• pp.437-444
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• 2010

Dry Process(natural drying, hot-air drying, oil fry drying), optimized mixture ratio and the condition of carbonization was carried out in order to improve the product durability develop eco-friendly solid fuel mixing food waste and paper sludge. As a result of the experiment, oil fry drying process was the fastest method for drying food waste and paper sludge mixture that contains 80% water inside, and the optimized mixture ratio to minimize the generating concentration of chlorine gas against caloric value of mixture ratio was 7:3. Additionally proper temperature of product carbonization was about $200^{\circ}C$ and shown increasing product durability through the carbonization. Therefore, the pelletized solid fuel be shaped diameter around 0.5cm, length 2cm under which was pulverized and molded using 7:3 mixture of food waste, and paper sludge was the eco-friendly solid fuel possible to be industrialized which is consist of chlorine concentration of below 2.0wt% and the lowest caloric value of over 5,000kcal/kg. In conclusion, this developing manufacturing process of the solid fuel can be interpreted to contribute alternative energy development in accordance with low carbon and green growth era.

• 농업과학연구
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• 제19권2호
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• pp.153-160
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• 1992

잔디상토로서 제지슬러지와 연탄재의 이용 가능성을 구명하기 위해 들잔디(Zoysia japonica Steud.)를 공시재료로하여 모래와 슬러지, 연탄재와 슬러지의 배합비율을 각각 3:1, 2:1, 1:1, 1:2, 1:3(V/V)으로 혼합하여 잔디의 생육과 적정 배합비율 등을 조사한 결과는 아래와 같다. 1. 활성슬러지는 대조구에 비해 초장, 생체중, 건물중을 2배이상 증가시켰으며, 모래와의 혼합비율간에는 슬러지가 67%혼합된 1:2구에서 가장 생육이 좋았다. 2. 단위면적당 shoot의 밀도는 모래와 활성슬러지의 혼합비율간에 큰 차이가 없이 대조구에 비해 모든 처리구에서 많았으며, 엽록소함량은 활성슬러지가 적게 혼합된 3:1, 2:1구에서는 대조구와 차이가 없었으나 슬러지의 함유량이 50%이상인 1:1, 1:2, 1:3구에서는 증가를 보였다. 3. 생슬러지는 대조구에 비해 잔디 생육이 저조하고 슬러지가 많이 함유된 1:3구에서는 파종잔디의 생육이 어려웠으나 엽록소함량은 큰 차이가 없었다. 그러나 영양번식을 하였을 경우 분얼증가는 대조구와 차이가 없거나 약간 저조한 경향을 보였다. 4. 연탄재와 활성슬러지의 혼합구는 모래 혼합구에 비해 잔디의 초장이 다소 적었으나 shoot의 밀도는 비슷하였고, 대조구에 비해 초장, 단위면적당 밀도, 생체중, 건물중, 분얼수가 월등히 증가하였다. 5. 연탄재와 생슬러지의 혼합토양은 파종된 잔디의 생육에는 불량하였으나 영양번식 잔디의 분얼을 대조구보다 증가시켰다.

• 상하수도학회지
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• 제13권4호
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• pp.27-34
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• 1999

An experimental study on improvement of the paper-mill wastewater treatment using the pure oxygen activated sludge process was conducted. The effects of hydraulic retention time(HRT) and BOD loading on organic removal efficiency were investigated. The BOD removal efficiencies were above 90% under all examined HRTs except for HRT of 3 hours. The increase of HRT from 3 hours to 6 hours, and to 12 hours significantly improved BOD and COD removal efficiencies, respectively. However, additional increase of HRT did not affect organic removal efficiency. F/M ratio change at fixed HRT did not affect organic removal efficiency. However, F/M ratio investigated in this study(0.11~1.98kgBOD/kgMLVSS/day) was 5 times greater in maximum than that of conventional activated sludge process, which implies that pure oxygen activated sludge process can treat wastewater with high organic strength. Under the same HRT, the volumetric BOD loading change cause no effect on organic removal efficiency also.

• Geomechanics and Engineering
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• 제13권1호
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• pp.25-41
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• 2017

In recent years, the amount of sludge ash (SA) has considerably increased due to rapid urbanization and population growth. In addition, its storage in landfills induces environmental pollution and health problems. Therefore, its disposal in an environmentally friendly way has become more important. The main goal of this study is to investigate the reusability of sludge ash as an additive with polypropylene fiber (PF) to stabilize marginal sand based on the compressive strength performances from UCS tests. For this purpose, a series of UCS tests was conducted. Throughout the experimental study, the used inclusion rates were 10, 15, 20 and 30% for sludge ash and 0, 0.5 and 1% for polypropylene fiber by total dry weight of the sand+sludge ash mixture and the prepared samples were cured for 7 and 14 days prior to the testing. Freezing and thawing resistance of the mixture including 10% sludge ash and 0, 0.5 and 1% polypropylene fiber was also examined. On the basis of UCS testing results, it is said that sludge ash inclusion remarkably enhances UCS performance of sand. Moreover, the addition of polypropylene fiber to the admixtures including sand and sludge ash significantly improves their stress-strain characteristics and post-peak strength loss as well as UCS. As a result of this paper, it is suggested that sludge ash be successfully reused with polypropylene fiber for stabilizing sand in soil stabilization applications. It is also believed that the findings of this study will contribute to some environmental concerns such as the disposal problem of sludge ash, recycling, sustainability, environmental pollution, etc. as well as the cost of an engineering project.

• 한국물환경학회지
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• 제22권5호
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• pp.905-912
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• 2006

In this paper, simulation methods of the system dynamics model developed by Das et al. (1997) for activated-sludge wastewater treatment plants are illustrated in an attempt to determine the operating rules and the policies related to capacity expansion of an activated-sludge wastewater treatment plant. For existing conditions, the analyses were performed by varying activated-sludge return rate to observe changes in effluent water quality and treatment efficiency. The effluent water quality is also analyzed for various average daily inflow conditions and activated-sludge return rates. As a result, without expanding the aeration tank, maximum average daily inflow that can satisfy the effluent water quality standard of BOD $0.02kg/m^3$ was determined as $2,840m^3/hr$, subject to 100% of activated-sludge return rate while other factors remain constant. When the activated-sludge return rate is less than 100%, expansion of the aeration tank is necessary and minimum sizes of the aeration tank to satisfy the effluent water quality standard were determined for various activated-sludge return rates. In addition, the total operating and maintenance as well as unit treatment cost regression equations for activated-sludge wastewater treatment plants are suggested by using the cost data that are obtained from Water and Wastewater Division, Ministry of Environment. The regression analyses showed that the economies of scale phenomena exist in the operating and maintenance costs of activated-sludge wastewater treatment plants.

• 펄프종이기술
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• 제34권3호
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• pp.32-37
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• 2002

The paper mill wastewater actually generating bulking was used to apply to the spot. Batch and continuous type pilots were used in this study. Optimal time after propagating generation of activated sludge in aeration basin by adding Hoc forming microorganism was 24 and 36hours while optimal time of activated sludge in original aeration basin was 60hours. Showing the difference of sedimentation velocity at 7th day after operating a pilot continuously, SV30 was decreased to 50% at 13th day. COD value in aeration basin with floe forming microorganism was 35mg/L while COD value in original aeration basin was 52mg/L. It was indicated that application of Hoc forming microorganism can control the bulking of paper mill wastewater by shortening of recovery time and improving of pollution removal efficiency.