폐수슬러지의 효율적 처리 방안

이정임,조영무,정혜윤,홍이슬 경기연구원 2018 정책연구 Vol.- No.-

As the policies banning the ocean dumping of waste gradually become effective, ocean dumping of industrial sewage sludge is prohibited from 2014 with temporary allowance until 2015 in the case of being unable to treat it on the ground. While various recycling methods including composting and vermicomposting of sewage sludge are being explored, the cost of recycling treatment is increasing in trend. The amount of sewage sludge in Gyeonggi Province is the highest in Korea with 3,838.3 tons per day and the average treatment cost per ton at public sewage treatment facilities increased compared to 2015 to 107,148 Korean Won per ton, highlighting the need for consideration of efficient treatment methods through process innovation and treatment method in sewage treatment. In the case of sewage sludge resulting from industrial facilities, recycling and utilization are difficult due to harmfulness or securing location for final treatment facility for industrial waste is hampered by opposition from local communities. Therefore, it is necessary to consider alternative treatment methods such as incinerating, reutilizing after consolidation, or turning into fuel. Based on survey results about waste treatment facility, 90% of the respondents answered to have no improved operation to promote recycling of sewage sludge, suggesting little efforts to reutilize after the ban on ocean dumping and highlighting the need for further efforts on reutilization of sewage sludge. The survey indicated that the respondents desire “installation and management of treatment facility at the regional- and community-levels” for treating sewage sludge and showed that they prefer “connected treatment with private recycling operators,” “connected treatment at public environmental facility,” and “connected treatment with cogeneration power plants.” For efficient treatment methods in the future, “turning into fuel after drying” and “composting” received a high number of responses. Accordingly, it is necessary to prepare appropriate recycling plans for different types of sewage sludge depending on the characteristics of harmful substances in emission, and to revitalize related industries by securing recycling treatment facilities. In addition, as reduction in costs of collection and transportation, fuel utilization in adjacent areas and reductions in greenhouse gas are possible when turning sewage sludge into fuel at combined power plant facilities adjacent to industrial complexes, it is necessary to consider plants for turning sewage sludge into fuel at combined power plant facilities. As the combined utilization of regular and industrial wastes at public waste treatment facilities has been proposed based on the principles of “Optimization Plan for Waste Treatment Facility” by Ministry of Environment, it is possible to consider plans for utilizing slack capacity at public waste incineration and landfill facilities. As a result of survey on the treatment cost of sewage sludge, it was shown that current treatment costs of sewage sludge are over 120,000~140,000 Korean Won per ton in 42.4% of the responses and that appropriate treatment costs for incineration and landfill are below 200,000 Korean Won per ton in many cases. Therefore, it is possible to consider calculation based on “Treatment Costs of Types of Wastes for Calculation of Fulfillment Guarantee Payments for Waste Treatment.”

폴리프로필렌의 용융특성을 이용한 하수슬러지 연료화 및 열적 특성 변화

정왕석,이병규 한국폐기물자원순환학회 2009 한국폐기물자원순환학회지 Vol.26 No.5

This study has developed a technology on solid fuel, composed of polypropylene (PP) and sewage sludge, with drying water in sludge with water content of 83.4%. The fuel was prepared by coating or impregnating liquid phase PP, obtained using melting characteristics of thermoplastic, on the sewage sludge. After PP was put into the reaction vessel designed in this study, the reactor was heated up to 250 ± 10℃ and then solid phase PP was turned into liquid phase with lower viscosity and high fluidity. After the external heat source was got rid of, and then the sewage sludge (3 g, 7 g) was put into the liquid phase PP solution with minimizing exchange of external heat or air into the reactor. The PP-sewage sludge fuel was prepared with increasing contact time (5, 10, and 15 min) between the liquid phase PP and the sludge. The heat content and proximate components of the PP-sewage sludge fuel were examined. When tested the sewage sludge of 3 g, the obtained PP-sewage sludge fuel in a contact time for 15 min showed heat content of 8,575 kcal/kg and moisture content of 3% which can satisfy the criteria of refused plastic fuel. In case of the sewage sludge of 7 g, the heat content and the water content of the fuel obtained in a contact reaction for were 7,798 kcal/kg and 11.6% which cannot satisfy the criteria. The smaller size of the sewage sludge, the higher heat content and water removal effects were obtained.

Leaching Characteristics of Slag from the Melting Treatment of Industrial Sewage Sludge

( Yeong-su Park ),( Dong-kyu Park ),( Young-sik Yoon ),( Dong-ju Kim ),( Bup-mook Jeong ) 한국폐기물자원순환학회(구 한국폐기물학회) 2019 ISSE 초록집 Vol.2019 No.-

In South Korea, the ocean dumping of industrial sewage sludge is prohibited from 2014. Therefore, it is necessary to find an alternative process for disposal of industrial sewage sludge. The physicochemical characteristics of the sludge generated from wastewater treatment process depend on the type of industry, wastewater treatment method and treatment intensity. Various recycling methods of industrial sewage sludge have been studied, but recycling cost is increasing in trend. In 2015, the amount of industrial sewage sludge is 18,276 t/d and the average treatment cost is 107,148 won/t. Since the heavy metal content of industrial sewage sludge is high, it cannot be directly utilized as solid refuse fuel. Then the stabilization of heavy metals in industrial sewage sludge is necessary for reuse. In this study, three kinds of industrial sewage sludge were tested. The evaluation items are melting temperature, heavy metal concentration and heavy metal leaching. The bottom ash of dried industrial sewage sludge was melted in a furnace and then slowly cooled to form slags. In order to evaluate the hazard of slag, the concentration of heavy metal leaching was analyzed. In case of slags, most heavy metals were not detected, and the leaching concentration of slag was lower than that of sludge.

하수슬러지와 음식물쓰레기 침출수슬러지 또는 제지슬러지를 혼합하여 부숙시킨 먹이에 대한 줄지렁이(Eisenia fetida )개체군의 섭식률 및 생장률

김병우,배윤환 유기성자원학회 2008 유기물자원화 Vol.16 No.3

Aged sewage sludge with food waste leachate sludge or paper mill sludge was fed to earthworm(Eisenia fetida) populations and the effect of it on feeding and growth rate of earthworm population was investigated. Feeding rate of earthworm population on sewage sludge aged with food waste leachate sludge for 30 days was higher than that aged for 10 and 20 days. At 90 days after feeding, the density of earthworm population decreased regardless of aging period. And earthworm population growth to next generation was blocked by sewage sludge. The feeding rate and the density of earthworm population aged with paper mill sludge for 20 days were higher than that on sewage sludges aged for 10 and 30 days. Until 90 days after feeding, the density of earthworm population increased regardless of aging period of sewage sludge, however, since then decreased. There were comparatively higher feeding rate and growth rate of earthworm population on the sewage sludge which had been mixed with paper mill sludge and aged for 20 days, which rendered the probable pretreating method for vermicomposting sewage sludge.

Hyrothermal carbonization of sewage sludge for energy recovery

( Gabin Kim ),( Donghwan Sohn ),( Jongkeun Lee ),( Seunghyun Lee ),( Kyung Jin Min ),( Ki Young Park ) 한국폐기물자원순환학회(구 한국폐기물학회) 2019 한국폐기물자원순환학회 심포지움 Vol.2019 No.1

One way to recover energy from sewage sludge is to use it as fuel through drying and carbonization. Although this method accounts for 43.8% (w/w)of sludge recycling rate, however, it consumes much energy in the fueling process due to the high water content of sewage sludge. In order to overcome this problem, a hydrothermal carbonization method which can carbonize sewage sludge at a lower temperature by using water in sewage sludge is being used as a new treatment method. In this study, to increase the efficiency of the sewage sludge fueling method for the energy independence of the sewage treatment plant, the primary sludge generated in the sewage treatment plant and the digested sludge are converted into fuel through hydrothermal carbonization, and the solid fuel characteristics of the product are analyzed Sludge selection and optimum treatment conditions for solid fuel production. In this study, sludge generated in J wastewater treatment plant in Seoul was used. Experimental conditions were as follows: 300 mL of feedstock and the same amount of distilled water was added to the reactor and heated to 180~270℃. The reaction time was the same for 30 minutes and aimed at the optimum temperature was obtained. Both the primary sludge and the digested sludge showed an increase in carbon content, a decrease in oxygen and hydrogen content, and an improvement in coal quality as the water temperature increased. However, as the treatment temperature increased, the calorific value of the primary sludge improved, but the calorific value of the digested sludge decreased. This phenomenon is considered to be the result of increased ash content in the carbonization process. In order to use sewage sludge generated from sewage treatment facilities as solid fuel, primary sludge with high heating value is more suitable than digestion sludge and 210℃ with high energy recovery efficiency is suitable because the treatment temperature is the highest.

난지도 하수슬러지 매립지의 슬러지 성상분석

남궁완(Wan Namkoong),황선숙(Seon Suk Hwang),김철수(Chul Soo Kim),윤범한(Bum Han Yeun),류범수(Bum Su Ryu) 유기성자원학회 1996 유기물자원화 Vol.4 No.2

난지도 하수슬러지 매렵지 내 슬러지의 적정 처리방안을 검토하기 위한 기초조사로서 슬러지의 매립량 빛성상을 조사하였다. 보링시험을 통하여 매렵지의 깊이를 측정하였고 슬러지성상분석을 위한 시료를 채취하였다. 주요 분석내용은 슬러지의 화학적 특성, 중금속함량 그리고 용출시험이었다. 조사결과 슬러지 매립지는 펑균 15m 깊이에 약 5만 평방미터 넓이로 총 매렵량은 60만톤 정도로 추정되었다. 슬러지의 성상을 분석한 결과 일반적인 하수슬러지에 비하여 상당히 안정화된 슬러지임을 알 수 있었다. 또한 중금속 함량 시험에서 구리를 제외한 모든 항목에서 미국 캘리포니아주의 일반폐기물기준을 만족하였으며, 외국의 퇴비내 중금속허용기준치와 비교한 결과 대부분 기준치 이내 이었다. 슬러지의 용출시험결과 난지도 하수슬러지매렵장의 슬러지는 일반폐기물로 분류되었다. This study was carried out to estimate the amount and the characteristics of sewage sludge dîsposed of in the Nanjido sludge landfill sîte. Borîng test was conducted to estimated the landfîll volume and to get sludge samples to be analyzed. Total analysis and leaching test were performed to find the characteristics of sewage sludge. The Nanjido sludge landfill site had the surface area of 50,000 m2 and the average depth of 15 m. The estimated sludge volume was 600 ,000 ton. Sewage sludge in Nanjido sludge landfill site was very stable. Results of total analysis of heavy metals indicated that the sludge could be classified as a non - hazardous waste according to the California state regulation. The sludge also could be used as compost based on compost quality criteria of foreign countries. Results of Korea Extraction Procedure showed that sewage sludge in Nanjido sludge landfill site was not a hazardous waste.

하수 슬러지 건조장치 운전시 하수슬러지 함수율 및 조성 분석연구

이건주 유기성자원학회 2014 유기물자원화 Vol.22 No.3

In this study, the sewage sludge dryer is installed before and after dehydration of the sludge and aqueous phase composition, the heavy metal content, and measurement and analysis were investigated. The removal efficiency of water content of sewage sludge was about 95.7% in the sewage sludge dryer. The removal efficiency of water content for primary dryer was designed for 35% of primary drying, secondary drying to remove the water content to 10%, but as the measurement revealed that 20.8% of primary drying, the second dryer 3.3% a better effect to the actual operation respectively. Before the installation of the sewage sludge dryer, the content of heavy metal was as follows, Cu:352~614 ppm, Hg: 1.3~1.44ppm, Cd : 1.1~1.86ppm, Pb : 17.25~ 28.93 ppm, As : 1ppm. And after the installation of the sewage sludge dryer, the content of heavy metal changed to as follows, Cu : 340~350 ppm, Hg : 0 ppm , Cd : 0~0.021 ppm, Pb : 0 ppm, As : 0~0.043 ppm which is Also below the legal limits. Also, the sewage sludge dryer produce 1/4 of the sewage sludge into dried sludge. 본 연구에서는 A 지역의 하수슬러지 건조장치가 설치되기 전과 후 탈수슬러지의 조성 및 성상, 중금속함유량 등을 측정 및 조사 분석을 하였다. 분석결과 건조로 설치전보다 약 95.7%의 제거효율을 보였으며, 설계값으로 1차건조로 35%, 2차건조로 10% 함수율을 제거하지만, 측정해본결과 1차건조로 20.8%, 리본 3.3%로 실제 운전효과가 더 좋은 것으로 나타났다. 중금속 함유량은 건조장치 설치 전 Cu : 352~614ppm, Hg : 1.3~1.44ppm , Cd : 1.1~1.86ppm, Pb : 17.25~ 28.93 ppm, As : 1ppm 이고 설치 후 Cu : 340~350 ppm, Hg : 0 ppm , Cd : 0~0.021 ppm, Pb : 0 ppm, As : 0~0.043 ppm으로 건조장치설치 전과 후 모두 법정 기준치에 초과하지 않음을 확인하였다. 또한건조장치를 통과한 하수슬러지는 평균적으로 ¼의 건조슬러지가 발생하였다

Ecotoxicological Evaluation of Sewage Sludge Using Bioluminescent Marine Bacteria and Rotifer

Park, Gyung-Soo,Chung, Chang-Soo,Lee, Sang-Hee,Hong, Gi-Hoon,Kirn, Suk-Hyun,Park, Soung-Yun,Yoon, Seong-Jin,Lee!, Seung-Min The Korean Society of Oceanography 2005 Ocean science journal Vol.40 No.2

Bioassay using the marine bacteria, Vibrio fischeri and rotifer, Brachionus plicatilis, and chemical analyses were conducted to assess the toxicity of the various sewage sludges, one of the major ocean dumped materials in the Yellow Sea of Korea. Sludge elutriates extracted by filtered seawater were used to estimate the ecotoxicity of the sludge. Chemical characterization included the analyses of organic contents, heavy metals, and persistent organic pollutants in sludge. Bacterial bioluminescent inhibition (15 min), rotifer mortality (24 hr) and rotifer population growth inhibition (48 hr) assay were conducted to estimate the sludge toxicity. EC50 15 min (inhibition concentration of bioluminescence after 15 minutes exposed) values by Microtox(R) bioassay clearly revealed different toxicity levels depending on the sludge sources. Highest toxicity for the bacteria was found with the sludge extract from dyeing waste and followed by industrial waste, livestock waste, and leather processing waste. Clear toxic effects on the bacteria were not found in the sludge extract from filtration bed sludge and rural sewage sludge. Consistent with Microtox(R) results, rotifer neonate mortality and population growth inhibition test also showed highest toxicity in dyeing waste and low in filtration bed and rural sewage sludge. High concentrations of persistent organic pollutants (POPs) and heavy metals were measured in the samples from the industrial wastes, leather processing plant waste sludge, and urban sewage sludge. However, there was no significant correlation between pollutant concentration levels and the toxicity values of the sludge. This suggests that the ecotoxicity in addition to the chemical analyses of various sludge samples must be estimated before release of potential harmful waste in the natural environment as part of an ecological risk assessment.

Determination and characterization of pharmaceuticals in sludge from municipal and livestock wastewater treatment plants

Ekpeghere, Kalu Ibe,Lee, Ji-Woo,Kim, Hee-Young,Shin, Sun-Kyoung,Oh, Jeong-Eun Elsevier 2017 CHEMOSPHERE - Vol.168 No.-

<P><B>Abstract</B></P> <P>This study investigated 24 pharmaceuticals compounds belonging to the classes of analgesics, stimulants, anti-seizures, non-steroidal anti-inflammatory drugs (NSAIDs), and antibiotics in the sludge of 12 municipal sewage treatment plants (S-sludge) and 4 livestock wastewater treatment plants (L-sludge) located across Korea. Over 70% of the target compounds were detected in at least one sample of S-sludge and L-sludge. The total concentration of the target pharmaceutical compounds detected in S-sludge was 2.622–422.8 mg kg<SUP>−1</SUP>and the most dominant compound was acetylsalicylic acid (ASA: 0.374–367.0 mg kg<SUP>−1</SUP>) whereas in L-sludge, the total concentration was 43.87–156.8 mg kg<SUP>−1</SUP>and the most abundant compound was oxytetracycline (OTC: 34.54–86.39 mg kg<SUP>−1</SUP>). Cluster analysis revealed two distinct groups: group A, which were S-sludge samples including ASA, carbamazepine (CBM), and others, and group B were L-sludge samples, dominated by antibiotics (CTC, OTC, LIN). The total daily load amount of the target pharmaceuticals in S-sludge was 0.010–268.9 kg day<SUP>−1</SUP> while the L-sludge was 0.021–0.529 kg day<SUP>−1</SUP>. The estimated amounts of the target pharmaceutical discharged from S-sludge and L-sludge into the Korean environment were 150.2 ± 47.94 ton yr<SUP>−1</SUP> and 15.05 ± 5.671 ton yr<SUP>−1</SUP> respectively, but the discharged amount of antibiotics from S-sludge (6.945 ton yr<SUP>−1</SUP>) was lower than that from L-sludge (9.234 ton yr<SUP>−1</SUP>).</P> <P><B>Highlights</B></P> <P> <UL> <LI> Pharmaceuticals in sewage and livestock sludge were studied. </LI> <LI> Acetylsalicylic acid was the most abundant pharmacuetical in the sewage sludge. </LI> <LI> Over 80% of the pharmacueticals observed in the livestock sludge were antibiotics. </LI> <LI> Estimated annual discharge amount of antibiotics from livestock sludge was 25% greater than sewage sludge. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

유온감압증발을 이용한 농축슬러지와 소화슬러지의 건조 특성 비교

김석환,임병란,이수구 한국폐기물자원순환학회 2013 한국폐기물자원순환학회지 Vol.30 No.5

The drying and fuel technologies for sewage sludge have been developed due to the prohibition of ocean dumping and new renewable portfolio standard. This study was performed to enhance the quality of sludge derived fuel and compare drying characteristics for thickened and digested sewage sludge at different temperature, pressure and mixing oil conditions in oil vacuum evaporation system. In addition to investigate calorific value and characteristic analysis of dried sludge. The thickened and digested sludge used in this study were taken from municipal sewage treatment plant and coagulated using polymer (C-310P) in laboratory. The drying rate was increased with temperature and degree of vacuum and it was 25 mL/kg-sludge·min at 110oC and -450 mmHg. The moisture content of dried sludge products showed very low within 1% in the range of 0.4 ~ 0.8%. The evaporation rate of thickened sludge was lower than digested sludge and the constant evaporation period was also shorter. Compared the effect of waste cooking oil and refined waste petroleum oil on drying efficiency, the waste cooking oil showed more effective than refined oil in evaporation rate and drying time. The carbon and hydrogen contents of dried sludge with refined oil were higher than waste cooking oil. The low heating value of thickened dried sludge was higher than digested dried sludge about 400 kcal/kg and both of dried sludge showed high calorific value more than 4,000 kcal/kg.