New Materials Research Institute of Shandong Academy of Sciences, Jinan, People's Republic of China
J Air Waste Manag Assoc. 2013 Aug;63(8):997-1002. doi: 10.1080/10962247.2013.788458.
In China, over 17 million tons dewatered sewage sludge cake (DSSC), with about 80% water content, was generated from wastewater treatment plants in 2010. High water content is the bottleneck of sludge treatment and disposal. In this study, the combination of hydrothermal and mechanical treatments has been chosen in order to improve sludge dewaterability. Sludge thermogravimetry analysis was conducted to determine 180 degrees C as the upper-limit hydrothermal temperature. Five temperatures (60, 80, 120, 150, 180 degrees C) were chosen to study the effects of hydrothermal treatment temperature and the holding time on dewaterability. The higher the hydrothermal temperature, the better was the dewaterability character. The water contents of solid products were positively correlated with the hydrothermal holding time at predetermined temperatures in this study. Degradation of macromolecules into acidic compounds could be the reason of pH decrease of separated liquid. Destruction of zoogloe and decomposition of organic matters improved the sludge dewaterability. Sludge dewaterability experiencing hydrothermal processes in this study was negatively correlated with extracellular polymeric substance (EPS) content. With the rising temperature, sludge flocculate disaggregated to small particles generally, this could also be one of the important reasons for sludge dewaterability.
High water content is the bottleneck of sludge treatment and disposal. Up to now, only a small amount of research has been conducted to determine whether the dewaterability of dewatered sewage sludge cake can be improved by hydrothermal pretreatment. The mechanism of sludge dewaterability by hydrothermal pretreatment is uncertain. In this study, a new sludge disposal method and corresponding parameters were given. The mechanism of sludge dewaterability was analyzed extensively by extracellular polymeric substances, scanning electron microscope images, element contents, and caloric values, etc. This study will be helpful for knowing about sludge hydrothermal pretreatment technology and its mechanism.
2010 年，中国污水处理厂产生了 1700 多万吨含水率为 80%的脱水污水污泥饼（DSSC）。高含水率是污泥处理和处置的瓶颈。在本研究中，选择了水热和机械处理的组合，以提高污泥的脱水性能。进行了污泥热重分析，以确定 180°C 为上限水热温度。选择了五个温度（60、80、120、150 和 180°C）来研究水热处理温度和保持时间对脱水性能的影响。水热温度越高，脱水性能越好。在本研究中，在预定温度下水热保持时间越长，固体产物的含水量越高。大分子物质降解为酸性化合物可能是分离液体 pH 值下降的原因。菌胶团的破坏和有机物的分解提高了污泥的脱水性能。本研究中水热过程经历的污泥脱水性能与细胞外聚合物（EPS）含量呈负相关。随着温度的升高，污泥絮体通常会分散成小颗粒，这也是污泥脱水性能提高的重要原因之一。
高含水率是污泥处理和处置的瓶颈。到目前为止，只有少量研究确定水热预处理是否可以提高脱水污水污泥饼的脱水性能。污泥水热预处理的脱水机制尚不确定。在本研究中，提出了一种新的污泥处理方法和相应的参数。通过细胞外聚合物、扫描电子显微镜图像、元素含量和热值等对污泥脱水性能的机理进行了广泛分析。本研究将有助于了解污泥水热预处理技术及其机理。
