| 水热改性污泥的水分布特征与脱水性能研究 |
| 摘要点击 3015 全文点击 1734 投稿时间：2008-04-09 修订日期：2008-07-21 |
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| 中文关键词 污泥 水热改性 水分布 脱水性能 |
| 英文关键词 sludge hydrothermal conditioning water distribution dewaterability |
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| 中文摘要 |
| 采用差示扫描量热法（DSC）考察了水热改性污泥束缚水含量及水热改性影响下的污泥固体颗粒对水的束缚强度，分析了水热改性污泥水分布特征与脱水性能变化的关系.结果表明，水热处理将污泥的束缚水含量由3.6 g/g降低至1.0 g/g以下，随着热处理时间的增加束缚水含量降低，在水热处理条件为170℃/90 min时束缚水含量降低至0.592 g/g.水热处理将污泥中大部分的束缚水转变为可被机械力去除的自由水，污泥中自由水、束缚水及固体含量发生变化.泥饼中自由水的含量基本不变，约为10%.对污泥中的水分进行热力学分析发现，污泥脱水泥饼的水分束缚强度约为65 kJ/kg，机械脱水不能再进行.在170℃下进行水热改性污泥压滤脱水的含水率从80%降低至50%左右. |
| 英文摘要 |
| Water distribution within sludge is an effective means of characterizing its ability to dewater. The bound water content and water bond strength in hydrothermal treated sludge were investigated based on differential scanning calorimetry (DSC), and sludges were dewatered by expression tests. Hydrothermal treatment of sludge resulted in a decrease of bound water content from 3.6 g/g dry solid to lower than 1.0 g/g. The lowest bound water content was 0.592 g/g at 170℃ and 90 min. The results indicated that the hydrothermal treatment of the sludge changed the bound water into free water which could be mostly removed during the mechanical dewatering performance, and improved the dewaterability of sludge. The residual free water in the dewatered cake was basically keeping unchanged about 10% depending on the dewatering operation system error. The thermodynamic interpretation showed that the water bond strength in the dewatered cake was at the same level, and it was about 65 kJ/kg, which determined the dewatering process. There was a reduction of water content in dewatered cake from 80% to 50% with hydrothermal conditioning at 170℃. |
