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 ㎡/g at first. However, it was increased to 610∼675 ㎡/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 ㎎/g and 1837 ㎡/g, respectively. Subsequently, an activated carbon with specific surface area of 1,300∼1,900㎡/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.

수발아가 벼의 품질 및 정현 비율 감소에 미치는 영향, 수발아성의 품종간 차이 및 왕겨로부터 발아 억제물질을 추출하여 수발아 방제를 위한 기초자료를 얻고자 실시한 결과는 다음과 같다. 1. 현미중은 무처리에 비하여 수발아 처리일수가 길어질수록 감소되는 경향으로 6일 처리시 약 20% 감소되었다. 2. 수발아 처리일수에 따른 완전립 비율은 무처리가 99.5%인데 반해 6일 처리시 41.3%로 현저히 저하되었다. 3. 인디카품종은 대부분 난수발아성이었으나 자포니카(9.2∼79.7%) 및 통일형 품종(2.1∼63.7%)은 품종간 차이가 현저히 나타났다. 4. 난수발아성인 IR36, 신운봉벼 및 중원벼의 왕겨를 메탄올을 이용하여 추출한 물질이 발아억제에 효과가 있었다.