• 한국농공학회지
• /
• 제28권3호
• /
• pp.99-106
• /
• 1986

This study was carried out to investigate the effects of moisture content, temperature, C/N ratio and pH of the sewage sludge mixed with hulle and sawdusts for making compost under aerobic condition and to improve the defect of the structure of experimental equipment heat lose and handling method. and obtained results were as follows 1.The temperature was reached 73$^{\circ}$ C around 50 hours fermentation in the condition of 0.8 L/min. of air and 60.4% of moisture content. and favorable moisture content of initial condition ranged from 50 to 65% 2.The temperature near bottom of the batch composter was decreased due to evaporate water vapor and lose the heat produced during aeration. and it is required to be improved. 3.The temperature in the batch composter from the center to the inside wall surface was gradually decreased. the temperatures of the points located in r=9cm and the wall surface were 4$^{\circ}$ C and 6$^{\circ}$ C respectively. and therefore it is required to be insulated. 4. The maximum C02 production was obtained as 7.3% per volume in the temperature of 63$^{\circ}$C at the moisture content of 60% 5.The temperature range of active microbes growth was found to be as 20$^{\circ}$C to 40$^{\circ}$C in the case of mesophiles and 50$^{\circ}$C to 65$^{\circ}$C in the case of thermophiles due to increase and decrease C02 production. 6.C/N ratio after decomposition was 1.3 to 2.6 smaller than that of initial one due to increase the amount of nitrogen. The more C/N ratio increased. the less the reaction velocity decresed. The optimum of it as found to be 30. 7.pH values after decomposition were slightly increased than that of initial ones. The reaction velocity was decreased at acid and alkall condition. Therefore it is neseseary to neutralize the medium to improve the reaction.

• Journal of Applied Biological Chemistry
• /
• 제54권4호
• /
• pp.290-295
• /
• 2011

본 연구는 산약(Disocorea batatas)을 대상으로 토양 및 관개용수의 질 평가, 화학비료 및 퇴비의 사용실태 그리고 잡초 및 병해충 실태에 대한 현장 및 설문조사를 통하여 생산단계에서 good agriculture practices (GAP) 기반조성에 유용한 데이터를 제시하고자 하였다. 산약 재배지 토양과 관개용수 중 카드뮴, 납, 구리 및 아연 모두 자연함유량 수준으로 조사되었다. 산약재배지 관개용수 가운데 총질소는 대부분의 조사지점에서 기준치를 초과하였으나 총인은 기준치 이하로 나타났다. 산약 재배지에 화학비료와 퇴비가 복합적으로 과량 투입되고 있음이 현장 설문조사에서 나타나 최적의 양분종합관리 프로그램의 도입이 필요한 것으로 나타났다. 산약 재배지에서 우점 잡초는 바랭이(Digitaria sanguinalis), 쇠비름(Portulaca oleracea) 그리고 깨풀(Acalypha australis)로 나타났으며, 제초제 처리횟수는 1년에 2회 처리가 가장 많았고, 일부 농가에서는 4회까지 처리하는 경우도 있었다. 또한 산약 재배지에서 병해는 탄저병과 잎마름병이 주로 발생하였고, 해충으로는 응애가 주로 출현하는 것으로 조사되었다. 병해충 방제 목적으로 살충제나 살균제를 연 4~5회 처리하고 있었다. 산약의 안전성과 지속적인 농업생산성을 유지하기 위해서는 화학비료와 농약의 저투입이 필요하며, 궁극적으로는 유기농업에 의한 우수 산약의 재배기술 개발이 이루어져야 할 것이다.

• 상하수도학회지
• /
• 제20권3호
• /
• pp.397-402
• /
• 2006

The treatment characteristics of leachate produced from pretreatment facilities like composting and feeding were investigated in a mesophilic anaerobic treatment. Experiments were performed in two phase which were acidification and methane fermentation. The acidification step was optimized for OLR from 1 to $4.5kg\;COD/kg\;VS{\cdot}day$ without adding NaOH. As experiment dates became longer, the solubilization ratio of particles increased up to 30% over 70 days. TVA was generated up to maximum 9,970mg HAc/L at OLR of $2kg\;COD/kg\;VS{\cdot}day$. But TVA was generated to minimum 6,519mg HAc/L at OLR of $4.5kg\;COD/kg\;VS{\cdot}day$. The acidification ratio was analyzed from 10.9% to 3.8% at OLR of $2kg\;COD/kg\;VS{\cdot}day$ and $4.5kg\;COD/kg\;VS{\cdot}day$ respectively. After 55 days, salt contents in the acid fermenter were accumulated and stabilized at the concentration of 3,150mg/L. Sodium ion($Na^+$) concentration was stabilized at 1,300mg/L. At methane fermentation step, biogas was generated up to 750ml and 937.5ml at the feeding volume of 20ml and 25ml respectively for acid fermented liquid during 25 days. About 80% of total biogas was generated during early 15 days and 95% were generated during 18 days respectively. After 25 days of the BMP test, acetic acid was removed approximately 97% and 98%, in case of those two experimental conditions.

• 유기물자원화
• /
• 제13권2호
• /
• pp.98-106
• /
• 2005

지렁이 사육상으로부터 지렁이를 분리, 수확할 수 있는 지렁이 유인장치를 개발하기 위해서 사육상에서의 지렁이 개체군 동태, 유인물질 및 유인틀내 철망의 mesh 크기, 덮개재질 등에 따른 지렁이 유인효율을 조사하였다. 지렁이 사육상에서 줄지렁이의 최고밀도는 약 $5kg/m^2$이었으며 최고밀도 도달한 이후에는 $4.4{\sim}5.0kg/m^2$의 밀도를 유지하였다. 유인틀내 철망의 mesh 크기는 7mm정도가 적정하였으며 유인틀 덮개는 표면은 매끄럽고 수분을 잘 머금을 수 있는 재질이 적당하였다. 유인틀내에 유인제를 사용하는 경우가 사용하지 않는 경우보다 유인효과가 현저히 높았으며, 유인틀내 유인제량이 많을수록, 유인틀 설치 기간이 길어질수록 지렁이 유인량이 많아졌다. 유인제로서는 분쇄된 배껍질이 제지슬러지보다 우수하였는데 이는 유인제내 당도의 차이에 기인하는 것으로 판단된다. 그러나 현장에서 사용할 수 있을 만큼 충분한 량의 배껍질을 공급하기가 어려우므로 그 대용으로서 설탕물(10%)을 유인물질로 이용하는 방안이 제시될 수 있었다.

• 유기물자원화
• /
• 제12권4호
• /
• pp.130-138
• /
• 2004

서로 다른 지역에서 발생한 음식물 쓰레기에 제지슬러지, 인분케익을 혼합하여 부숙시킨 후, 부숙기간에 따른 음식물 쓰레기의 이화학적 성상 및 줄지렁이의 섭식반응 및 생체량 변화를 조사하였다. 발생지역에 따른 음식물 쓰레기의 이화학적 성상은 큰 차이가 없는 것으로 나타났으며, 지렁이가 섭식하기에는 음식물 쓰레기내의 염분 농도가 전반적으로 높게 나타났다. 음식물 쓰레기에 인분케?을 혼합하여 부숙시켰을 때보다 제지슬러지를 혼합, 부숙시켰을 경우 염류농도 저하효과가 높게 나타났으나, 지렁이의 섭식효율과 생장률을 크게 개선시킬만큼 효율적이지는 않은 것으로 나타났다. 따라서 음식물 쓰레기에 대해서 지렁이 처리법을 적용시키기 위해서는 음식물 쓰레기내의 염류농도를 저하시키는 방법의 개발이 선행되어야 할 것으로 판단된다.

• 농업과학연구
• /
• 제42권3호
• /
• pp.177-181
• /
• 2015

Food waste has been widely considered as a recycling resource to be applied to agricultural lands due to the effects of organic matter and nutrient for plant productivity. but the maturity and salt concentration in the compost produced from food waste processing facilities should be considered firstly, which was little information on compost quality produced from food waste treatment facility. In this study, we examined actual situation of food waste processing facility on the composting of food waste and evaluated the characteristics of composts produced from food waste processing facilities. The quality of composts was analyzed on the basis of the criteria of fertilizer processing manual. The 46% of food waste treatment facility registered composting produced actually the compost mixed with food waste or animal waste. The compost maturity and salt concentration as indicators of the quality of compost were not met 46.8% of composts collected from food waste processing facilities to the criteria of fertilizer processing manual. Also, 15.6%(moisture) were not satisfied with the criteria. In conclusion, the compost produced from food waste processing facilities is firstly required with better compost maturity and reduced salt concentration in order to use to agricultural lands as an amendment.

• 한국환경보건학회지
• /
• 제32권4호
• /
• pp.353-358
• /
• 2006

This study was performed to evaluate the effects of input ratios of bulking material in aerobic composting of food wastes on variation of colony forming units of heterotrophic bacteria. Wood chips were used as a bulking material. Volume ratios of food wastes to wood chips in reactor of Control, WC-1 and WC-2 were 10/0, 10/5 and 10/10, respectively. Reactors were operated for 24 days with 1hour stirring by 1rpm and 2 hours of the forced aeration per day. WC-2 reached high temperature range faster than WC-1, and the maximum temperature of WC-2 was higher than that of WC-1. This means that the reaction velocity of composting of WC-2 was faster than that of WC-1. Judging from the profile of pH changes, composting of WC-1 proceeded slowly and continuously. Composting of WC-2 proceeded rapidly in the former half reaction period, and kept steady state of high pH in the latter half reaction period. Namely, composting of WC-2 was nearly completed in the former half reaction period. In the case of WC-1 and WC-2. the maximum temperature was followed by the rapid pH increase in 2-3 days, and this was followed by the maximum Colony Forming Units(CFU) in 3 days. But, these three items of WC-2 always appeared faster and higher than those of WC-1.

• 한국환경보건학회지
• /
• 제29권3호
• /
• pp.28-34
• /
• 2003

This study was performed to compare the effects of chaff and sawdust as bulking materials on temperature, pH, weight and volume reduction and salinity in aerobic composting of food wastes. Volume ratios of food wastes to chaff in reactor of Control, Ch-l, Ch-2, Ch-3 and Ch-4 were 4:0, 4:1, 4:2, 4:3 and 4:4, respectively. Volume ratios of food wastes to sawdust in reactor of Control, Sd-l, Sd-2, Sd-3 and Sd-4 were 4:0, 4:1, 4:2, 4:3 and 4:4, respectively. Reactors were operated for 24 days with 1 hour stirring by 1 rpm and 2 hours aeration per day. The lowering of the volume ratio of food wastes to chaff and sawdust resulted in the reaction at higher reaction temperature and the elongation of the high temperature reaction period. The lowering of the volume ratio of food wastes to chaff and sawdust resulted in faster pH increase. In the volume ratio of 4:3 and 4:4, pH increased faster in food-chaff mixtures than in food-sawdust mixtures. The lowering of the volume ratio of food wastes to chaff and sawdust resulted in faster steady state in the weight reduction rate and the volume reduction rate. The weight reduction rates of chaff mixtures were higher than those of sawdust mixtures, but the volume reduction rates of sawdust mixtures were more higher than those of chaff mixtures. Salinity increased as composting reaction proceeded, due to reduction in mass weight. The final salinity of Control was 2.79%, and the final range of salinities of chaff and sawdust mixtures were 2.18∼2.37% and 1.86∼2.05%, respectively.

• 한국축산시설환경학회지
• /
• 제8권2호
• /
• pp.115-118
• /
• 2002

This study was conducted to determine the effects of pig manure composting on emission of dinitrogen oxide ($N_2O$) that is greenhouse gas. Fresh pig manure was mixed with sawdust as bulking agent and moisture content of mixed compost was adjusted by 61.9%. After mixing bulking agent with pig manure that was left to compost with aeration in composting chamber for an initial period of 30 days. At the end of this period, that was decomposed and a second period of composting was conducted without aeration for 60 days. Temperature during the initial composting period was above $55^{\circ}C$ for 7 days. Moisture reduction rate by composting pig manure was 36.7%. $N_2O$ Produced during composting was 0.043g/T-Ng.

• 한국축산시설환경학회지
• /
• 제8권2호
• /
• pp.119-124
• /
• 2002

To evaluate composting process of piggery slurry, we made $1m^3$ bench scale composting reactor, and investigated the input and output of mass, moisture evaporation, volatile solid degradation, and running cost. For 15 days experimentation the results was as followed, The quantity of sawdust used was 0.47ton(18,000won) per 1ton slurry. The amount of moisture evaporated was 16.8kg/kg VS degradated. Total evaporation and VS degradation were 24.8%, 5.7% respectably. To analysis the running cost of that, we included only two factors, sawdust cost and compost income. The compost price to sell was 63won/kg(50% of market price) it made 8,694won income to 756 won loss, but 25won/kg, it was $13,650{\sim}23,100won$ loss per 1 ton slurry in the current pig farmer's condition. This cost was $8.5{\sim}14.4%$ of pig production cost and damage strongly to pig farmers to treat it.