http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
응집에 의한 생물학적 처리수의 색도 및 난분해성 유기물 제거
서태경, 박상민, 박노백, 임지영, 전항배 충북대학교 건설기술연구소 2008 충북대학교 건설기술연구소 논문집 Vol.27 No.1
This study was to evaluate the optimum conditions for chemical coagulation to remove color and non-biodegradable organic matters from the biologically treated water of piggery wastewater. Raw water was fractionated by characteristics of dissolved organic matter. The fractions of hydrophilic substance and molecular weight cut-off(MWCO) below 500 in raw water were 51% and 74%, respectively. SC(streaming current) was measured to find out the optimum pH values and dosages for aluminium sulfate[Al₂(SO₄)₃·14H₂O] and ferric chloride[FeCl₃·6H₂O] as a coagulant, which was compared with color and turbidity removal efficiencies followed by coagulation, flocculation and sedimentation. From several jar tests, optimum pH values and dosages of coagulants were well matched with the results of SCD analyses. The optimum dosages(pH values) of aluminium and ferric were 5.84 mM(pH 4.0) and 7.03 mM(pH 5.6), respectively. At optimum conditions of coagulation, color removal efficiencies for aluminium sulfate and ferric chloride were as high as 89.3 and 97.9%, respectively. Chemical coagulation showed good performance to remove color and non-biodegradable organic matters from biologically treated water.
노태희,전경문,여경희 한국과학교육학회 1999 한국과학교육학회지 Vol.19 No.4
본 연구에서는 분자 수준의 그림을 강조하고 4단계 문제 해결 전략을 제시하는 수업에서 협동학습의 효과를 조사하였다. 고등학교 세 학급(130명)을 선정하여 개별적으로 전략을 사용하는 집단(St : Strategy), 협동학습 환경에서 전략을 사용하는 집단 (St-Co: Strategy-Cooperative learning), 그리고 통제 집단으로 무선 배치하였다. 수업 처치 후 학생들의 객관식 문제 해결력, 전략 수행 능력, 수업 참여도에 대한 인식을 비교하였고, 학생들이 선호하는 수업 유형도 조사하였다. 객관식 문제 해결력에서는 집단간에 유의미한 차이가 없었으나, 전략 수행 능력에서는 수업 처치와 사전 성취 수준 사이의 상호작용 효과가 유의미하였다. 단순 효과를 분석한 결과, St 집단의 중위 수준 학생들이 St-Co 집단보다 전략을 더 잘 수행한 것으로 나타났다. 그러나 수업 참여도에 대한 인식 검사에서는 St 집단의 점수가 통제 집단보다 유의미하게 낮았고, 학생들이 가장 선호하는 수업도 St-Co인 것으로 조사되었다. The effect of cooperative learning in a heuristic approach (four stage-problem solving strategy) that also emphasized molecular level representation was studied. Three high school classes (N=130) were randomly assigned to St group (using strategy individually), St-Co group (using strategy in cooperative group), and control group. After instruction, students' multiple-choice problem solving ability, strategy performing ability, and the perception of involvement were compared. Students' preferred instruction type was also examined. Although multiple-choice problem solving ability were not different significantly, a significant interaction between the treatment and the previous achievement level was found in strategy performing ability. Analysis of simple effects indicated that the medium-level students in the St group performed better than those in the St-Co group. In the perception questionnaire of involvement, however, the scores of the St group were significantly lower than those of the control group. The instruction type that students most preferred was also St-Co.