Effects of Organic Content on Anaerobic Biodegradability by Agricultural Waste Biomass

신국식,손연규,윤영만 한국토양비료학회 2014 한국토양비료학회지 Vol.47 No.3

Recently interest on production of biogas from biomass resources has increased because of climate change inworldwide. In this study, anaerobic digestion efficiency of 17 different types of agricultural waste wasevaluated using biochemical methane production potential estimated from the International biochemicalmethane potential standard method (Germany VDI4630). As a result, theoretical biochemical methanepotential (Bth) of agricultural waste biomass ranged from 0.266 to 0.488 Nm3 kg-1-Volatile Solid (VS)added. Ultimate biochemical methane potential (Bu) of agricultural waste biomass ranged between 0.176 and 0.417Nm3 kg-1-VSadded. The agricultural waste biomass anaerobic biodegradability with Bu/Bth and VDI4630determined by VS contents was 36.0∼95.9% and 30.8∼91.1%, respectively. Ultimate methane potential andanaerobic biodegradability given by the VS term showed more reasonable results.

농산 바이오매스의 메탄 생산 퍼텐셜

신국식,김창현,이상은,윤영만 한국토양비료학회 2011 한국토양비료학회지 Vol.44 No.5

Recently, anaerobic methane production of agricultural waste biomass has received increasing attention. Until now domestic BMP (Biochemical methane potential) studies concerned with agricultural waste biomass have concentrated on the several waste biomass such as livestock manure, food waste, and sewage sludge from WWTP (Waste water treatment plant). Especially, the lack of standardization study of BMP assay method has caused the confused comprehension and interpretation in the comparison of BMP results from various researchers. Germany and USA had established the standard methods, VDI 4630 and ASTM E2170-01, for the analysis of BMP and anaerobic organic degradation, respectively. In this review, BMP was defined in the aspect of organic material represented as COD (Chemical oxygen demand) and VS (Volatile solid), and the influence of several parameters on the methane potential of the feedstock was presented. In the investigation of domestic BMP case studies, BMP results of 18 biomass species generating from agriculture and agro-industry were presented. And BMP results of crop species reported from foreign case studies were presented according to the classification system of crops such as food crop, vegetables, oil seed and specialty crop, orchards, and fodder and energy crop. This review emphasizes the urgent need for characterizing the innumerable kind of biomass by their capability on methane production.

양돈분뇨 혐기소화액의 액비화 기간에 따른 유기물 분해와 질소 손실 특성

신국식,김창규,오승용,윤영만 한국열환경공학회 2019 한국열환경공학회 학술대회지 Vol.2019 No.-

간척지 토양에서 혐기소화액비 시용에 따른 사료작물의 생산성과 사료가치 평가

신국식,황원재,이승헌,김창현,윤영만,Shin, Kook-Sik,Hwang, Won-Jae,Lee, Seung-Heon,Kim, Chang-Hyun,Yoon, Young-Man 한국유기농업학회 2012 韓國有機農業學會誌 Vol.20 No.4

This study was carried out to investigate the nutrient value and yield response of corn, barley, and sudangrass by the application of anaerobic liquid fertilizer in two tidal land soil in order to design the resource recycling agricultural system between livestock and forage crop cultivation in a environment friendly agricultural region. Forage crop yields at reclaimed tidal soil during were at the level of 64~76% comparing with forage crop yields at upland soil in the cropping system of corn, barley, and sudangrass. And yields of forage crops were in the order of barley > corn > sudangrass in the cultivated cropping system for 2 year. Relative feed values (RFVs) of forage crops were 88%~106% for corn, 90%~111% for barley, and 91%~113% for sudangrass, and the carrying capacity of beef cattle (Hanwoo) was 5.8~8.6 head/year/ha for the corn-barley cropping system of one year, and 4.8~6.7 head/year/ha for the barley-sudangrass cropping system of one year. Also, carrying capacity of beef cattle (Hanwoo) was highest in the application level of anaerobic liquid fertilizer 200%. 본 연구는 간척농경지에 경 축 순환단지 구축을 목적으로 2년 3작기 작부체계로 혐기소화액비를 시용하고 사료작물 재배를 실시하여 수량반응과 사료가치분석을 하였으며, 이를 토대로 연간 한우 사육 용량을 추정 하였다. 2년 3작기 동안의 사료작물의 생산성은 전체 혐기소화액비 시비구에서 대조토양에 비해 간척지 토양에서 약 64~76% 수준을 보였으며, 사료 작물별 수확량은 보리 > 옥수수 > 수단그라스 순으로 나타났다. 사료작물의 상대적 사료가치(RFV)는 옥수수가 88~106%, 청보리는 90~111%, 수단그라스는 91~113%이었으며, 한우의 사육용량을 추정 하였을 때 1년 2작기 옥수수-청보리 작부체계에서 5.8~8.6 두/년/ha, 청보리-수단그라스 작부체계에서는 4.8~6.7 두/년/ha로 추정되었고, 혐기소화액비 시비율 200% 처리구에서 가장 높은 연간 한우 사육용량을 보였다. 따라서 결론적으로 간척지토양 같은 조건 불리지라 하더라도 가축분뇨액비를 시용하여 사료작물을 재배하는 것은 생초수량은 감소하였지만 연간한우 사육용량과 사료가치 면에서 크게 뒤지지 않는 결과를 보여 주었다.

The Estimation of Water Balance at Regional Upland According to RCP8.5 Scenario from 2011 to 2020

신국식,서명철,조현숙,박태선,강항원,성기영 한국토양비료학회 2014 한국토양비료학회지 Vol.47 No.1

In order to evaluate water balance at upland according to RCP8.5 climate change scenario distributed byKorean Meteorological Administration (KMA), we simulated soil moisture using estimation model, calledAFKAE0.5 for 66 sites from 2011 to 2020, and established the water balance maps. The amount of annualaverage precipitation by RCP8.5 scenario was highest in 2016 as recorded 2,062 mm and lowest in 2011 with1,134 mm. As result of analysis for monthly precipitation and runoff, the amounts of precipitation and runoffhave been especially intensive in July in 2014, 2016, 2019, and 2020. Overall, the area of Kyeongbuk andGyeonggi was estimated more dried status of soil compared with precipitation. Except 2015 and 2020, soilwater balance was recorded as negative value in other years which was calculated by subtracting output frominput. The status of soil moisture was the most dry in 2020 among those in other years.

The Determination of Anaerobic Biodegradability Rates Livestock Byproducts Using Double First-Order Kinetic Model

신국식,윤영만,정하일,현병근,조현준,손연규 한국토양비료학회 2015 한국토양비료학회지 Vol.48 No.5

This study investigated methane productions and a degradation rate of organic matters by German standard method, VDI4630 test. In this study, 4 livestock byproducts from livestock farm were selected for the investigation. The objective of this study was to estimate a distribution of organic matters by using the double first-order kinetics model in order to calculate the rate of biodegradable organic matters which degrade rapidly in the initial stage and the persistently biodegradable organic matters which degrade slowly later. As a result, all the byproducts applied in this study showed rapid decomposition in the initial stage. Then the decomposition rate began to slow down for a certain period and the rate became 5 times slower than the initial decomposition rate. This trend of decomposition rate changes is typical conditions of organic matter decompositions. The easily degradable factors (k1) ranged between 0.145 ~ 0.257 day-1 and persistent degradable factors (k2) were 0.027 ~ 0.080 day-1. Among these results, greater organic matter decomposition rates from VDI4630 had greater k1 values (0.257, 0.211 day-1) and smaller k2 values (0.027, 0.030 day-1) for dairy wastewater and forage byproduct, respectively.

The Determination of Anaerobic Biodegradability and Organic Fractionation of Agricultural Byproducts by Biochemical Methane Potential Assay Using Double First-Order Kinetic Model

신국식(Kook-Sik Shin),윤영만(Young-Man Yoon) 유기성자원학회 2021 유기물자원화 Vol.29 No.4

본 연구는 독일 유기물분해율 표준시험법인 VDI4630 시험을 통해 메탄 생성 및 유기물의 분해율을 조사하였으며 시험을 위해 농업 분야의 11개의 폐기물 바이오매스를 공시재료로 선택하여 시험하였다. 본 연구의 목적은 초기에 빠르게 분해되는 생분해성 유기물과 이후 천천히 지속적으로 분해되는 유기물의 비율을 계산하기 위해Double first-order kinetics 모델을 이용하여 유기물의 분포를 추정하고자 하였다. 그 결과로 본 연구에 적용된 모든 바이오매스는 초기 단계에서 빠른 분해를 보이다가 이후 분해 속도가 일정 시간 느려지기 시작하여 초기 분해 속도보다 10배 이상 느려지는 결과를 보였다. 이러한 분해율 변화 경향은 바이오매스 분해의 전형적인 형태이며 쉽게 분해되는 인자(k1)는 채소 작물에서 0.097~0.152 day-1 범위였고, 분해에 저항성을 가지는 인자(k2)는 0.002~0.024 day-1 사이에 위치하였다. 유기물 분해율이 높을수록 k1 상수 값이 더 크게 나타났으나 (0.152, 0.144day-1) 오이와 파프리카 열매와 같이 표면에 왁스층이 존재하는 부산물은 k1 값이 오히려 줄기보다 낮았고 (0.002, 0.005day-1), 무와 귤껍질도 k1 각각 0.097과 0.094 day-1로 낮은 분해율과 k1 값을 보여 유기물의 분해율은 이분해성 유기물 분해 상수인 k1 값에 크게 영향을 미치는 것으로 분석되었다. This study investigated methane productions and a degradation rate of organic matters by German standard method, VDI4630 test. In this study, 11 waste biomasses from agricultural fields were selected for the investigation. The objective of this study was to estimate a distribution of organic matters by using the Double first-order kinetics model in order to calculate the rate of biodegradable organic matters which degrade rapidly in the initial stage and the persistently biodegradable organic matters which degrade slowly later. As a result, all the biomasses applied in this study showed rapid decomposition in the initial stage. Then the decomposition rate began to slow down for a certain period and the rate became 10 times slower than the initial decomposition rate. This trend of decomposition rate changes is typical conditions of biomass decompositions. The easily degradable factors (k1) were raged between 0.097~0.152 day-1 from vegetable crops and persistent degradable factor (k2) were 0.002~0.024 day-1. Among these results, greater organic matter decomposition rates from VDI4630 had greater k1 values (0.152, 0.144day-1) and smaller k1 values (0.002, 0.005day-1) from cucumbers and paprika. In a meanwhile, radishes and tangerine rinds which had low decomposition rates showed 0.097 and 0.094 day-1 of k1 values and decomposition rates seems to affect k1 values.

CNC선반 C축 밀링 원호가공에서 절삭조건이 표면 거칠기에 미치는 영향

신국식(Kuk-sik Shin) 한국기계가공학회 2014 한국기계가공학회지 Vol.13 No.4

The domestic airline industry undertakes the production of finished products by assembling existing self-described components via a design process which involves assembly and production steps, after which many of the finished products are exported. However, high reliability and stability must be guaranteed, because customers require high-precision components at the time of manufacturing. In the aircraft parts industry, the mass production of high-value-added parts in limited. Therefore, a small production scale depending on the part is used, as many types of conventional CNC lathe machines with X-axis and Z-axis as well as Z-axis and C-axis CNC milling are used. The parts also rely on high-pressure air to increase production. The most important factors are good stability during processing, as high-precision parts are required, as noted above. It was found that as the C-axis rotation speed increased, the diameter of the cutting tool decreased with a decrease in the surface roughness, while the workpiece rotation speed increased with an increase in the surface roughness.

CNC선반 C축 밀링가공에서 표면 거칠기에 미치는 절삭조건의 영향

신국식(Kuk-Sik Shin) 한국기계가공학회 2012 한국기계가공학회지 Vol.11 No.3

For domestic aircraft industry, not mass production of components is limited, small production scale of the order is made by part because many kinds of hundreds of thousands of kinds of small quantity batch production system are taking. But the high reliability and stability are required during the processing because they require high precision parts are required. It is found that when C-axis rotation speed was increased, the diameter of the cutting tool decreased with increasing surface roughness, while the turn-mail feed rate was increased with increasing the surface roughness.

집적형 이온선택성 미세전극 센서에 적합한 토양화학 분석용 침출액 종 개발

신국식(Kook-Sik Shin),임우진(Woo-Jin Lim),이상은(Sang Eun Lee),이재선(Jae Seon Lee),차근식(Geun Sig Cha) 한국토양비료학회 2009 한국토양비료학회지 Vol.42 No.6

본 연구는 현장에서 신속히 토양양분을 측정하기에 적합한 집적형 미세 이온선택성 전극을 토양화학성분석에 이용하기 위하여, 이에 적합한 침출액의 종류와 양과 같은 분석방법을 개발 하는 데에 목적을 두었다. 대상 토양화학성들은 교환성 양이온들(K?, Ca²?, Mg²?, Na?)과 무기태 질소들(NH₄?, NO₃?) 이었으며, 분석법 개발의 목표는 다 성분 동시침출액 종 선발에 있었다. 침출액 자체에 존재하는 화학종들은 이온간 방해작용으로 이온선택성 전극의 분석능에 영향을 미친다. 순수용액 내에서는 0.01M HCl 과 1M LiCl 이 모든 분석대상 화학종과 그들의 존재 농도범위(10?¹M~10?⁴M)에 대하여 가장 Nernst 이론값에 근접하였다. 그러나 실제 토양 침출용액에서 1M LiCl은 고농도(1M)의 Li? 존재로 말미암아 분석대상 화학성분의 선택성이 현저히 낮아짐을 알 수 있었다. 반면에, 0.1M HCl로 침출하여 10배 희석 측정하거나 또는 0.01M HCl로 직접 침출하여 측정하는 것은 표준분석 방법과 고도의 유의성이 있는 상관관계를 보이므로 최적 분석 방법으로 밝혀졌다. 토양에 대하여 집적형 이온선택성 미세 전극을 사용한 분석치와 표준분석법 분석치의 사이의 회귀상관에서는 K?, Na?, Ca²?, NO₃?가 매우 우수한 회귀상관 관계를 보였다. 그러나 NH₄?이온은 K?이온과 혼재할 때 K?이온의 간섭으로 매우 낮은 선택성을 나타내었다. 또한, Mg²?이온은 현재까지 이온선택성 막을 위한 최적의 Ionophore(이온투과 담체)가 개발되어 있지 않아 분석의 어려움이 있었다. The primary goal of this research was to develop an optimized analytical procedure for soil analysis based on ion-selective microelectrodes for agricultural purposes, which can perform on-site measurement of various ions in soil easily and rapidly. For the simple and rapid on-site diagnosis, an analysis of soil chemicals was performed employing a multicomponent-in-situ-extractant and an evaluation of ionselective microelectrodes were conducted through the regressive correlation method with a standard analytical approach widely employed in this area. Examination of sensor responses between various soil nutrient extractants revealed that 0.01M HCl and 1M LiCl provided the most ideal Nernstian response. However, 1M LiCl deteriorated the selective response for analytes due to high concentration (1M) of lithium cation. Thus, employing either 0.1M HCl as an extractant followed by 10 times dilution, or 0.01M HCl as an extractant without further dilution was chosen as the optimal extractant composition. A study of regressive correlation between results from ion-selective microelectrodes and those from the standard analytical procedure showed that analyses of K?, Na?, Ca²?, and NO₃? showed the excellent consistency between two methods. However, the response for NH₄? suffered the severe interference from K?. In addition, the selectivity for Mg²? over Ca²? was not sufficient enough since available ionophores developed so far do not provide such a high selectivity for Mg²?. Therefore, as an agricultural on-site diagnostic instrument, the device in development requires further research on NH₄? analysis in the soil sample, development of Mg²?-selective ionophore, and more detailed study focused on potassium, one of the most important plant nutrients.