• 한국환경과학회지
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• 제9권1호
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• pp.81-88
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• 2000

Every year, 1.1 million tons of rice-hull are produced in South Korea by the by-product in pounding rice. But they has mainly been utilized as a fuel, agricultural compost and moisture proofs. So, it's very valuable to use waste rice-hull for activated carbon manufacture. SiO2 content was the highest among inorganics in rice-hull. Therefore, the SiO2 extraction experiments were carried out under the various conditions of pH 9 to 14, reaction time from 2 to 24 hrs and various temperature of 20 to 100℃. The results showed that increase in pH and temperature enhanced SiO2 extraction from the carbonized rice-hull. The surface area of the carbonized rice-hull indicating activated carbon adsorption capacity was very small as 178∼191 m2/g at first. However, it was increased to 610∼675 m2/g when extracted in alkali solution at 100℃. When the mixing rate of carbonized rice-hull and NaOH was 1:1.5, iodine No. and surface area of activated rice-hull during 10 min at 700℃ were 1,650 mg/g and 1837 m2/g, respectively. Subsequently, an activated carbon with specific surface area of 1,300∼1,900m2/g was manufactured in a short contact time of 10∼30 min with a mixing rate of 1:1.5 in carbonized rice-hull and NaOH, and iodine No. and specific surface area increased as the amount of SiO2 removal increased.

• 한국유기농업학회:학술대회논문집
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• 한국유기농학회 2009년도 하반기 학술대회
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• pp.317-317
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• 2009

The effects of environment-friendly materials carbonized rice hull and wood vinegar on the improvement of rice quality and soil fertility were investigated. Combined application of carbonized rice hull and chemical fertilizer resulted in lower protein in rice, similar amylose content and generally higher palatability values. Combined application of wood vinegar and chemical fertilizer obtained high protein and amylose contents, and palatability values. However, both carbonized rice hull and wood vinegar did not exhibit weed control. In the carbonized rice hull treatments, soil K was high during heading stage while soil pH during harvest stage was low. In the case of wood vinegar treatments, clear distinction between total K and Ca was observed. K was high during tillering stage while Ca was high until harvest stage.

• 한국토양비료학회지
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• 제14권3호
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• pp.130-136
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• 1981

Rice hull was reduced to ash by carbonization grades to illcuidate alkalinity increase and extract of inorganic nutrients in the rice hull charcoal. Alkaline reaction of water extraction was neutral at less carbonized charcoal, but much carbonized ash from 65% weight loss reached over 10 of pH value, also origin shape of rice hull was maintained until near 65% carbonized grade. Therefore, physical properties sustained good condition for seedling bed. The more charcoal carbonized to ash, the pH value and concentration of inorganic nutrient in their extracts were increased gradually. Nitric acid concentrations for neutralizing extract from charcoal were stronger in proportion to the carbonized grade but 0.1 N nitric acid solution was very reasonable to neutralize the 65% carbonized charcoal for mixing with heavy texture acidy soil(pH 5.3) of uncultivated deep horizon to transplant the tobacco seedlings. Volume ratio mixing for seedling bed is adequate at five of ash to one of acid solution. Neutralization with nitric acid solution also accelerated extraction of the inorganic nutrient in rice hull ash. Tobacco seedlings grown on bed mixed with neutralized rice hull charcoal and soil had shown better results on the agronomic measurement than alkaline ash bed, and phosphorus and cations were uptaken more amounts.

• 한국토양비료학회지
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• 제48권5호
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• pp.340-350
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• 2015

This experiment was carried out to find out the mitigation of greenhouse gases (GHGs) emission and changes of soil carbon contents in the cropland. In order to minimize the soil disturbance, this study was conducted without crop cultivation at the pots treated with different biomass. Different biomass was buried in the soil for 12 months. Decomposition rates of expander rice hull, pig manure compost and carbonized rice hull were 18%, 11~11.5% and 0.5~1.2%, respectively. It was appeared that carbonized rice hull was slightly decomposed. No difference was shown between chemical fertilizer treatment plot and non-application plot. It was appeared that soil carbon content in the non chemical fertilizer application plot was high when compared to its chemical fertilizer. Its content at soil depth of 20 cm more decreased than the upper layer of soil. Accumulative emission of $CO_2$ with different treatments of biomass was highest of 829.0~876.6 g $CO_2m^{-2}$ in the application plot of PMC (Pig Manure Compost) regardless of chemical fertilizer treatment during 16 months of experiment. However, the emission for expander rice hull treatment plot was lowest of 672.3~808.1 g $CO_2m^{-2}$. For application plot of the carbonized rice hull, it was shown that non chemical fertilizer plot, 304.1 mg $N_2Om^{-2}$, was higher than the chemical fertilizer treatment, 271.6 mg $N_2Om^{-2}$. Greenhouse gas emissions in the PMC treatment were highest of 0.94 ton $CO_2eqha^{-1}yr^{-1}$. However, it was estimated to be the lowest in the expander rice hull treatment.

• 펄프종이기술
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• 제43권2호
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• pp.72-76
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• 2011

Antimicrobial activities of the Acidic Liquid originated from Carbonized Rice Hull(ALCRH) and the paper treated with ALCRH were investigated to apply ALCRH to functional paper products as a natural antimicrobial agent. ALCRH showed antimicrobial activity for bacteria and yeast, with higher performance for bacteria than for yeast. Antimicrobial activity was not developed on paper coated with ALCRH by bar coater probably due to the evaporation of antimicrobial compounds of ALCRH from the paper surface with time. Saturation of paper with ALCRH was essential to develop antimicrobial activity on the paper. Dipping paper in ALCRH solution was recommended as one of the effective ways to make antimicrobial paper.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2011년도 추계학술발표회 논문집
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• pp.335-343
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• 2011

We examined the effect of the acidic liquid from carbonized rice hull(ALCRH) treatments to molded fiber packages(MFP) on weight, Haugh unit, pH and microbial activity of egg to extend the shelf life in egg packaging. Higher concentration and surface spray treatment of the acidic liquid extended the shelf life of egg. ALCRH treatment to MFP improved the performance of the packaging for egg in terms of decreased weight loss and retarded microorganism growth of eggs during storage.

• 생물환경조절학회지
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• 제7권2호
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• pp.151-158
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• 1998

본 실험은 오이 고형배지경 재배시 펄라이트 단용 및 혼합배지를 이용한 다양한 배지조건하에서 적합한 관수방법을 찾고자 수행하였다. 배지는 펄라이트 단용배지와 펄라이트 70%에 왕겨, 훈탄 및 코코피트를 각각 30%씩 섞은 혼합배지를 비교하였으며 관수방법은 일반적인 점적관수, 점적튜브 아래에 부직포를 깔아 상면의 물퍼짐을 개량한 변형점적급액법, 그리고 미스트노즐을 이용한 분무관수를 비교하였다. 엽면적은 펄라이트 단용처리구가 51.6dm$^2$으로 가장 낮은 엽면적을 나타냈으며 혼용처리구의 경우 60.0dm$^2$이상이었고. 특히, 코코넛 피트를 흔용한 처리구에서는 66.2dm$^2$의 엽면적을 나타냈다. 순동화율(NAR)은 펄라이트와 코코넛피트를 혼용한 처리구에서 가장 높았으며. 엽면적지수(LAI)와 개체생장율(CGR)도 높게 나타났다. T/R율의 경우 펄라이트 단용 처리와 왕겨혼용처리구에서 높게 나타났다. 펄라이트 단용배지와 코코넛피트 흔용배지의 경우 점적튜브 저면에 부직포를 펼친 변형점적 급액법이 주당 2140g과 2175g으로 가장 많았고, 왕겨혼용배지는 분무급액법이 우수하였다. 훈탄흔용배지는 일반적인 점적급액법이 가장 좋았다. 상품과수와 상품과수량은 코코넛피트 혼용패지의 변형점적급액법이 가장 많았고 기형과율도 낮게 나타났다.

• 생물환경조절학회지
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• 제4권2호
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• pp.159-166
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• 1995

본 실험은 배수성과 통기성이 우수한 양액 재배 배지로써 perlite와 구입이 용이한 왕겨 및 훈탄의 혼합배지를 이용하여 스티로폼 성형베드 및 상자, 플라스틱 자루, 폿트 등의 재배용기의 차이와 배지의 종류에 따른 양액재배 오이의 생육 및 수량반응을 구명하고자 수행하였 다. 1. 스티로폼베드와 상자가 다른 용기보다 초장이 높게 나타났으며, 스티로폼 상자를 용기로 사용할 때 펄라이트 단용처리구가 275.5cm, 왕겨 혼합처리구가 277.0cm로 초장이 가장 높았다. 2. 엽면적은 스티로폼 성형베드와 상자가 가장 높게 나타났고, 자루재배, 폿트재배의 순으로 나타났다. 스티로폼 성형베드와 상자의 경우에는 펄라이트 단용>왕겨 혼합배지>훈탄 혼합배지의 순으로 나타났으나, 자루재배에서는 왕겨, 폿트재배에서는 왕겨 혼합배지에서 엽면적이 높게 나타났다. 3. 과실수량은 스티로폼 상자를 용기로 한 펄라이트 단용구가 2097.1g으로 가장 많았으며 과수도 13.4개로 높게 나타났다. 4. 상품과율은 스티로폼 베드와 상자에서 70%이상을 나타냈으나 자루재배와 폿트재배에서는 70%이하로 나타났다. 5. 곡과율과 선세과는 자루재배에서 10%이상으로 높게 나타난 반면 스티로폼 상자에서는 낮게 나타났다.

• 한국토양비료학회지
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• 제49권2호
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• pp.181-193
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• 2016

This experiment was conducted to evaluate the effect of carbonized rice hull (CRH) application on soil carbon storage and $N_2O$ emissions from upland soil. It was used at different rates of 0, 5, 10 and $20Mg\;ha^{-1}$. During the Chinese cabbage cultivation, several soil chemical characteristics such as soil moisture, temperature and soil carbon were observed. Also, $CO_2$ and $N_2O$ emissions were monitored. Soil organic matter contents slightly increased with carbonized rice hull applied in all the treatments. The soil carbon contents with application rate of 0, 5, 10 and $20Mg\;ha^{-1}$ were 0, 1.3, 1.2 and $2.6g\;kg^{-1}$, respectively. It was observed that soil carbon content was higher with increasing CRH application rate. Total nitrogen contents of soil applied with CRH relatively decreased with the course of time. However, $NO_3$-N contents in the soil with CRH application rate of 5, 10 and $20Mg\;ha^{-1}$ were 28.6, 25.7 and $21.5mg\;kg^{-1}$ at the end of experiment, respectively. $CO_2$ emission at the $5Mg\;ha^{-1}$ application of CRH was higher about 18.9% than non-treatment, whereas those of $10Mg\;ha^{-1}$ and $20Mg\;ha^{-1}$ treatment were lower 14.4% and 11.8% compared to non-treatment, respectively. Also, it was shown that $N_2O$ emission reduced by 19.9, 28.3 and 54.0% when CRH was applied at 5, 10 and $5Mg\;ha^{-1}$, respectively.

• 한국환경농학회지
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• 제39권3호
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• pp.171-177
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• 2020

BACKGROUND: Recently, biomass conversion from agricultural wastes to carbon-rich materials such as biochar has been recognized as a promising option to maintain or increase soil productivity, reduce nutrient losses, and mitigate greenhouse gas emissions from the agro-ecosystem. This experiment was conducted to select an optimum conditions for enhancing the NH₄-N adsorption capacity of rice hull activated biochar. METHODS AND RESULTS: For deciding the proper molarity of KOH for enhancing its porosity, biochars treated with different molarity of KOH (0, 1, 2, 4, 6, 8) were carbonized at 600℃ in the reactor. The maximum adsorption capacity was 1.464 mg g^-1, and an optimum molarity was selected to be 6 M KOH. For the effect of adsorption capacity to different carbonized temperatures, 6 M KOH-treated biochar was carbonized at 600℃ and 800℃ under the pyrolysis system. The result has shown that the maximum adsorption capacity was 1.76 mg g^-1 in the rice hull activated biochar treated with 6 M KOH at 600℃ of pyrolysis temperature, while its non-treated biochar was 1.17 mg g^-1. The adsorption rate in the rice hull activated biochar treated with 6 M KOH at 600℃ was increased at 62.18% compared to that of the control. Adsorption of NH₄-N in the rice hull activated biochar was well suited for the Langmuir model because it was observed that dimensionless constant (R_L) was 0.97 and 0.66 at 600℃ and 800℃ of pyrolysis temperatures, respectively. The maximum adsorption amount (q_m) and the bond strength constants (b) were 0.092 mg g^-1 and 0.001 mg L^-1, respectively, for the rice hull activated biochar treated with 6 M KOH at 600℃ of pyrolysis. CONCLUSION: Optimum condition of rice hull activated biochar was 6M KOH at 600℃ of pyrolysis temperature.