• Journal of the Korea Organic Resources Recycling Association
• /
• v.5 no.1
• /
• pp.15-23
• /
• 1997

Commercial inocula and mature compost were added separately to food wastes in order to compare the inoculating effect on garbage decomposition. Among commercial inocula available in the market, GM (Green Microorganisms) and EM (Effective Microorganisms) were selected as test inocula. Garbage decompostion were evaluated in Volatile Solid (VS) reduction and FDA (Fluorescein DiAcetate) hydrolysis activity. VS reduction with mature compost experiment was higher than that with GM-added one. VS reduction rates were about 32% with mature compost and 27% with GM. When food wastes were treated with GM and EM based on the manufacturer's specifications, GM-added and EM-added food wastes showed only 8% and 9% of VS reduction respectively, which are much lower than those with the mature compost. FDA hydrolysis activity increased during the first 10 days of active composting periods for the composting experiments, while it decreased continuously for the experiments based on manufacturer's specifications.

• Journal of environmental and Sanitary engineering
• /
• v.12 no.3
• /
• pp.139-147
• /
• 1997

펄프폐수 내에 존재하는 대표적인 수지 구성성분의 일종인 wood resin 화합물이 메탄생성균에 미치는 독성을 평가하기 위한 회분식 독성실험을 수행하였다. 수지는 극성용매로 추출가능한 몇몇 wood 구성성분의 혼합물로서 수지의 주요 구성성분은 긴 사슬 휘발성유기산, terpenes, resin acids, 리그난과 극성 페놀류들이다. 메탄생성균의 독성실험은 $30^{\circ}C$에서 표준회분식 실험방법을 채택하였고 식종물질로서는 입상슬러지를 사용하였다. 극성페놀의 한 종류인 4-hydroxystilbene가 가장 높은 독성을 나타내었으며, 50% 저해를 일으키는 농도는 $20mg/\ell$이었다. Resin acid와 휘발성 terpene 역시 메탄생성균에 독성을 나타내었으며, 50% 독성을 일으키는 농도는 $43{\;}~{\;}330mg/\ell$이었다. 반면에 triterpenes은 1,000 to $1,300{\;}mg/\ell$의 상대적으로 높은 농도에서도 메탄생성균에 독성을 일으키지 않았다. 따라서 wood resin의 구성성분이 몇몇 펄프폐수의 혐기성 처리에 있어서 독성을 일으키는 주요물질이었다.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.28 no.1
• /
• pp.65-72
• /
• 2020

The aims of this study were to compare the biomethanation of CO₂ through specific methanogenic activity (SMA) test which was inoculated with four different types of mixed microbial culture obtained from full-scale anaerobic digestion (AD) plants. The experimental results showed that CH₄ conversion was the highest in the samples inoculated by seed sludge taken from ADs of food waste and brewery; under this condition, the produced biomethane contains 89.3-91.9% of CH₄. Meanwhile, the lowest level was obtained in the sample from sewage sludge. The measured ratio of CH₄ production rate to CO₂ consumption rate in all reactors was higher than the theoretical value (1) in the middle of the period and soon dropped to 0.7-0.8. It might be due to changed metabolic pathways in the reactor by the degradation of residual organic matter and the increased activity of homoacetogenic bacteria.

• Korean Journal of Environmental Agriculture
• /
• v.23 no.1
• /
• pp.1-6
• /
• 2004

The seeding sources and concentration of ammonia on anaerobic digestion were investigated by batch culture bioreactors. The sources of seeding on anaerobic digestion were from swine wastewater collection pit of a hog raising farm and from anaerobic digestion sludge of a municipal sewage treatment plant. The inhibition of ammonia on anaerobic microorganisms was initiated at ammonia concentration of $1,500\;mgNH_4-N/L$ and it's effect was increased by increased by increasing ammonia concentration up to $3,500\;mgNH_4-N/L$ regardless the sources of seeding as evidenced by decreases in COD removal efficiencies and biogas yields. The inhibition occurred to not only methanogens but also acidogens since the concentration of volatile fatty acids was maintained at 50 mg/L The COD removal efficiency and biogas yield were Maintained constantly while increasing ammonia concentration up to $3,500\;mgNH_4-N/L$ when swine wastewater collection pit was used as a seeding; however, those were decreased while increasing ammonia concentration when anaerobic digestion sludge was used as a seeding. The results indicate that the seeding acclimated to high concentrations of ammonia for long time was easy in adaptation to high ammonia concentration and less subjective to ammonia inhibitory effects.

• Journal of Environmental Health Sciences
• /
• v.24 no.1
• /
• pp.70-79
• /
• 1998

본 실험의 목적은 다양한 펄프제조 조건과 여러 형태의 리그노 셀루로우스 성분이 펄프폐수의 혐기성 생분해에 미치는 영향을 규명하는 것이다. 실험에 사용된 폐수는 일반적으로 펄프 제조시에 발생되는 폐수를 대상으로 하였으며, 펄프제조 조건은 TMP공정과 소다 펄프공정을 적용하였다. 혐기성 생분해 가능성 시험 및 독성실험은 $35\pm 2\circ$C의 중온상태에서 입상슬러지를 식종물질로 사용한 회분식 반응조를 이용하였다. TMP공정의 배출되는 폐수는 산으로의 전환율이 총 COD기준으로 68-87%로 매우 높은 혐기성 생분해 가능성을 보였다. 그리고 TMP공정폐수는 일반적으로 제지폐수 처리시 독성농도라고 알려진 농도에서도 메탄생성균에 독성을 주지 않았고, 또한 COD 10g/l의 농도에서도 처리에 저해가 일어나지 않았다. 반면에, 알카리성 상태에서 준비된 펄프폐수의 경우는 생분해성이 매우 낮아서 대략 50%정도의 산전환율을 보였으며, 메탄생성균에 상당한 저해를 주었다. 메턴생성균의 활성도에 50%저해를 주는 농도는 2.1~5.4 gCOD/l였다. 알카리성 펄프폐수의 독성에 대한 추가 실험결과 펄프내 wood resin이 산이나 중성 pH부근에서는 잘 용해가 되지 않고 알카리성 상태에서 쉽게 용해되어 메탄생성균에 저해를 나타내는 것으로 밝혀졌다. 따라서 펄프제조시 나무성분이 알카리성분과 접촉할 경우 후속하는 혐기성 처리공정의 메탄생성균에 심각한 저해를 줄 수 있다.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.9 no.3
• /
• pp.77-87
• /
• 2001

Composting is a cost-effective and environmentally-sound technology to treat soils contaminated with hazardous organic pollutants. Pollutants to be treated are as follows: explosives, phenolic compounds, PAHs, petroleum hydrocarbons, pesticides, and etc. Composting systems are windrow, static pile, and in-vessel. Design and operational parameters of composting are aeration modes, temperature, moisture content, nutrient supplement, amendment added, and etc. Appropriate oxygen concentration of composting for contaminated soils are 5~15%, while some compounds are degraded well at the low $O_2$ concentration of 2~5%. The most diverse microorganisms live in the temperature of $25{\sim}40^{\circ}$. 50~90% of the soil field capacity is the moisture content not to make a problem in composting. Assuming a bacterial chemical equation is $C_{60}H_{87}O_{23}N_{12}P$, theoretical C : N : P from bacterial chemical portion is approximately 20 : 5 : 1. It should be noted that the ratio does not apply to the total organic carbon measured in a waste because not all carbon metabolized by bacteria is synthesized to new cellular material. Initial C/N ratio of 25~40 is optimum. It is more economical to recycle soils or composts than to add commercial microbes.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.15 no.3
• /
• pp.113-120
• /
• 2007

Anaerobic batch tests were performed to evaluate the characteristics of methane production from piggery manure such as the ultimate methane yield (UMY), the kinetic constant and the maximum methane production rate. The kinetic behavior of anaerobic degradation of piggery manure was assumed as a first order reaction. The UMY, the first order kinetic constant and the maximum methane production rate were 0.27~0.44L $CH_4/gVS$, $0.161{\sim}0.280d^{-1}$ and 0.043~0.120L $CH_4/d$, respectively. Reactor of piggery manure as the self-seed source of anaerobic digestion resulted in longer acclimation time than reactors seeded with anaerobic digested sludge (ADS). But there was no little difference in the UMY between the two seed materials. The anaerobic digestion can be effective for the treatment of piggery manure containing high concentration of solids, the two-stage anaerobic digestion is, however, thought to be more effective than the traditional single one.

• Journal of Korea Soil Environment Society
• /
• v.5 no.2
• /
• pp.99-105
• /
• 2000

The purpose of this study was to show the application of the Biofilter for treatment of the soil contaminated by lead and to investigates the effect of the biofilter on the retardation of lead with pilotplants that were simulated with different media and the number of bed. and to testify the inoculation by seeding microbes. The ratio of the degradation of soil contaminant was verified as CODcr/TOC in order to find a variation of the stabilization index in soil. The Biofiltration was one of biological processing methods for treatment. The contaminants were transported through the biofilter that was filled with the media. The surface of media formed biofilm which was surrounded by microbes and through its boundary, some materials were exchanged and migrated into the cell of microbes in an orderly manner. To investigate the effect of the Biofiltration, contaminated soil with lead nitrate of 1000mg/kg in dry was made artificially. The tests were simulated such as compost, Bioceramic and compost with bioceramic by 7:3 in weight. The bed consisted of three layers in order to find effect of the number of bed. Aspergillus niger was used as a biosorbent could probe the effect on the retardation of lead.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.16 no.4
• /
• pp.91-97
• /
• 2008

The objective of this research is to investigate the effect of the addition of granular activated carbon (GAC) and granular sludge on the performance of upflow anaerobic sludge blanket (UASB) reactors for treating leachate. For the control reactor, sludge obtained from an anaerobic digester was used as a seed material. On the other hand, GAC and granular sludge were incorporated with the seed sludge in the GAC reactor and the Granule reactor, respectively. The shortest acclimation period was observed in the Granule reactor. The GAC reactor also gave comparable performance to the Granule reactor at the beginning of operation. However, as the adsorptive capacity of GAC was exhausted, the effluent COD concentration increased gradually. Once the systems were stabilized, the GAC reactor showed slightly better results than the other two reactors in terms of chemical oxygen demand (COD) removal. COD removal in all reactors was more than 90% at hydraulic retention time of 1.0 day. Furthermore, GAC reactor showed little variation in COD removal rate and remained at 95% with organic loading rate (OLR) of 4.0 to $8.2kg\;COD/m^3.d$. Initial operating period was reduced by the addition of granular sludge, while the treatment efficiency was enhanced by the addition of GAC.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.8 no.1
• /
• pp.90-96
• /
• 2000

The composition of leachates varies depending on the waste characteristics, landfill age and landfilling method. Generally, leachates contain high dissolved organic substance and ammonia nitrogen whereas phosphorus concentration was very low. Leachate A produced from young landfill is characterized by high BOD5/COD ratio (0.8) whereas leachate C produced from old landfill has lower BOD5/COD ratio (0.1). Maximum biochemical methane potential of leachate A, B (from medium landfill) and C were 271,106 and 4 ml CH4/g-COD, respectively. On the other hand, the maximum biodegradability of leachate A, B, and C were 75,30, and 1%, respectively. These results indicated that anaerobic treatment of leachate from young landfill was effective in removing organic pollutants. In case of leachate C, carbon might reside in the form of large molecular weight organic compounds such as lignins, humic acids and other polymerized compounds of soils, which are resistant to biodegradation. The lag-phase period increased with the increasing organic concentration in leachate. In case of leachate A of concentration greater than 25%, the lag-phase period increased sharply. This implied that the start-up period of anaerobic process using an unacclimated inoculum could be extended due to the higher concentration of leachate. This relatively long lag-phase is probably related to the fact that most of the inhibitory compounds have been diluted beyond their inhibitory concentrations of less than 50%. Furthermore, the ultimate methane yield and methane production rate decreased as leachate concentration increased. It was anticipated the potential inhibition was related with the steady-state inhibition as well as the initial shock load.