Abstract
Chemical characteristics of paper sludge, degradation of the sludge in soil and $CO_2$ generation, and changes of nitrogen and heavy metals in soil treated with the sludge were investigated. The results obtained was summarized as follows: 1. Degradation rate of paper sludge in soil was 19% at room temperature, and 28% at $incubation(30^{\circ}C)$ temperature after 12-weeks treatment. 2. T-C, T-N and the C/N ratio of the sludge in soil at room temperature were 15.5%, 0.22% and 71 respectively, and 14.5%, 0.24% and 60, respectively, at $incubation(30^{\circ}C)$ temperature after 12-week treatment. 3. $CO_2$ genaration in soil treated with 1%, 3% and 5% of the sludge was 247mg/100g, 334mg/100g and 458mg/100g, respectively, at room temperature, and 385mg/100g, 550mg/100g and 618mg/100g, respectively, at incubation temperature after 12 weeks treatment. 4. Mineralization ratio of organic nitrogen in soil treated with 1%, 3% and 5% of the sludge was 8.7%, 13.4% and 16.2%, respectively, at $incubation(30^{\circ}C)$ temperature after 12-weeks treatment. 5. The amounts of DTPA-extractable Cu, Cd, Zn, Pb, and Cr in Soil treated with paper sludge were $0.7{\sim}2.2$, $0.1{\sim}0.17$, $1.4{\sim}2.8$, $1.4{\sim}2.8$, and $0{\sim}0.7mg/kg$, respectively. Mean while, those of $HNO_3$ extractable Cu, Cd, Zn, Pb, and Cr were $7.9{\sim}10.0$, $0.6{\sim}0.9$, $17.6{\sim}34.4$, $14.7{\sim}18.5$, and $5.8{\sim}9.0mg/kg$, respectively.
제지슬러지의 농업적 이용 가능성을 검토하기 위하여 이들 슬러지의 이화학적 특성, 슬러지의 토양 중 분해율, 토양중 $CO_2$발생량, 질소 변화 등 분해 특성 및 토양중 추출용액별 중금속함량을 조사한 결과를 요약하면 다음과 같다. 1. 제지슬러지를 토양에 매립했을 경우 슬러지의 분해율은 매립 12주 후 실온에서 약 19%이었고, 항온$(30^{\circ}C)$하에서는 약 28%이었다. 2. 슬러지를 토양중에 매립했을때 T-C, T-N 및 C-N율은 실온에서는 매립 12주 후 각 각 약 15.5%, 0.22% 및 71이었고, 항온$(30^{\circ}C)$하에서는 매립 12주 후 각각 약 14.5%, 0.24% 및 60이었다. 3. 토양중 슬러지를 1%, 3% 및 5%로 처리했을 경우 처리 12주 후 $CO_2$발생량은 실온에서 각각 약 247mg/100g, 334mg/100g 및 458mg/100g이었고, 항온$(30^{\circ}C)$하에서는 각각 약 385mg/100g, 550mg/100g 및 618mg/100g이었다. 4. 토양중 슬러지를 1%, 3%, 5%로 처리했을 경우 항온$(30^{\circ}C)$하에서 처리 12주간 유기태질소의 무기화율은 각각 약 8.7%, 13.4% 및 16.2%이었다. 5. 토양중 슬러지를 1%, 3%, 5%로 처리했을 경우 토양중 DPTA 추출 Cu, Cd, Zn, Pb 및 Cr 농도는 각각 약 $0.7{\sim}2.2mg/kg$, $0.1{\sim}0.17mg/kg$, $1.4{\sim}2.8mg/kg$, $1.4{\sim}2.8mg/kg$ 및 $0{\sim}0.5mg/kg$이었고, $HNO_3$추출 Cu, Cd, Zn, Pb 및 Cr농도는 각각 약 $7.9{\sim}mg/kg$, $0.6{\sim}0.9mg/kg$, $17.6{\sim}34.4mg/kg$, $14.7{\sim}18.5mg/kg$ 및 $5.8{\sim}9.0mg/kg$이었다.
(Dept. of Agricultural Chemistry, Gyeongsang National University)