CAJ | 학술논문

为探究污泥水热炭化工艺中碳和氮固定率与影响因素间的关系，采用三因素三水平Box-Behnken 试验设计，拟合响应面模型，研究了水热温度（150～250℃）、含固率（5%～15%）、反应时间（2～6 h）与污泥水热炭化工艺中碳氮固定率的关系。结果表明，多元二次方程可用于描述碳和氮的固定率与上述影响因素间的定量关系（R2分别为0.9925和0.9903）。污泥水热炭化中碳与氮固定率分别为36.6%～52.9%和20.4%～42.5%。水热温度与反应时间对碳和氮固定率均呈负相关，含固率则呈正相关。3个因素对碳固定率的显著影响（p<0.05）大小依次为：水热温度＞含固率＞反应时间，而氮固定率仅受水热温度的显著影响（p<0.05）。水热温度（≤169℃）与含固率（≥7%）的交互耦合可维持较高的碳固定水平（≥50%），而降低水热温度是获得较高氮固定率的关键。该研究结果可为水热炭化技术应用于污泥处理领域提供参考。
위탐구오니수열탄화공예중탄화담고정솔여영향인소간적관계，채용삼인소삼수평Box-Behnken 시험설계，의합향응면모형，연구료수열온도（150～250℃）、함고솔（5%～15%）、반응시간（2～6 h）여오니수열탄화공예중탄담고정솔적관계。결과표명，다원이차방정가용우묘술탄화담적고정솔여상술영향인소간적정량관계（R2분별위0.9925화0.9903）。오니수열탄화중탄여담고정솔분별위36.6%～52.9%화20.4%～42.5%。수열온도여반응시간대탄화담고정솔균정부상관，함고솔칙정정상관。3개인소대탄고정솔적현저영향（p<0.05）대소의차위：수열온도＞함고솔＞반응시간，이담고정솔부수수열온도적현저영향（p<0.05）。수열온도（≤169℃）여함고솔（≥7%）적교호우합가유지교고적탄고정수평（≥50%），이강저수열온도시획득교고담고정솔적관건。해연구결과가위수열탄화기술응용우오니처리영역제공삼고。
Carbon and nitrogen emissions during sewage sludge treatment are important sources of greenhouse gases and environmental pollutants. The fixation degrees of carbon and nitrogen have been an issue deserving significant attention and consideration when choosing a treatment process for sewage sludge. Hydrothermal carbonization (HTC) is an emerging technology to treat wet biomasses aimed at producing biochar materials. Studies have demonstrated that HTC of wet biomasses including sewage sludge results in the formation of biochar in a relatively cheap and sustainable way. However, the data necessary to understand how multiple processing conditions influence carbon and nitrogen fixed in sludge biochar from HTC are currently lacking. In the present study, the influences of hydrothermal temperature (150-250℃), solid content (5%-15%), and reaction time (2-6 h) on the fixations of carbon and nitrogen in sludge biochar were investigated using a 3-level, 3-factor Box-Behnken experimental design. The results showed that the relationships between the carbon and nitrogen fixation and tested factors can be quantitatively described by multivariate quadratic equations with R2 of 0.9925 and 0.9903, respectively. Carbon and nitrogen fixation rates of 36.6%-52.9%, and 20.4%-42.5%, respectively were obtained under the tested hydrothermal carbonization conditions. Both the maximum carbon and nitrogen fixation rates were achieved at a hydrothermal temperature of 150℃, solid content of 10%, and reaction time of 2 h. The carbon fixation rate was negatively correlated with hydrothermal temperature and reaction time, but positively correlated with solid content. The significant effects (p<0.05) of hydrothermal temperature, solid content, and reaction time on carbon fixation rate were in a decreasing order. Yet, the nitrogen fixation rate was only significantly (p<0.05) and negatively related to hydrothermal temperature. The interaction between hydrothermal temperature and solid content had a significant effect (p<0.05) on carbon fixation, and the coupling of low hydrothermal temperature (≤169℃) and high solid content (≥7%) could maintain a fairly high carbon fixation rate (≥50%). The interactions between hydrothermal temperature and reaction time, and between hydrothermal temperature and solid content significantly (p<0.05) influenced nitrogen fixation. Compared with raising solid content and shorten reaction time, decreasing hydrothermal temperature had a more evident enhancing effect on increasing the nitrogen fixation rate. A low hydrothermal temperature was the key factor in bringing in a higher nitrogen fixation rate. The results from this study can help quantitatively monitor carbon and nitrogen emissions during sludge hydrothermal carbonization.