With the rapid growth in population and urbanization, sustainable disposal of sewage sludge has become a prominent problem worldwide. Therefore, an adequate treatment is required to reduce the environmental impacts created from traditional methods such as incineration, landfill, etc. In this context, sewage sludge was liquefied hydrothermally under sub-supercritical conditions with and without catalyst (K₂CO₃). The effect of temperature and alkali catalyst on product distribution was investigated. Obtained results showed that the temperature had a negligible influence, whereas catalyst slightly improved the bio-crude yield and quality for both sub-supercritical conditions (350 and 400 °C). Bio-crude contained N-containing compounds, ketones, phenols, acids, and long-chain hydrocarbons. Carbon and nitrogen recoveries revealed that 58–67% of the carbon went into bio-crude, while the majority of the nitrogen was transferred to the aqueous phase. ICP-AES analysis indicated that approximately 80% of the heavy metals were concentrated in the solid phase. The leaching action of citric acid with sewage sludge not only removed 40% of ash content but also reduced 38% of the fat content.

随着人口的快速增长和城市化，污水污泥的可持续处置已成为世界范围内的突出问题。因此，需要采取适当的处理措施，以减少传统方法（如焚化，垃圾掩埋等）对环境的影响。在这种情况下，污水污泥在有和没有催化剂（K ₂ CO ₃）。研究了温度和碱催化剂对产物分布的影响。所得结果表明，温度对温度的影响可以忽略不计，而催化剂在亚超临界条件下（350和400°C）均略微提高了生物粗品的收率和质量。生物原油中含有含氮化合物，酮，酚，酸和长链烃。碳和氮的回收率表明，58-67％的碳进入了生物原油，而大部分氮则转移到了水相中。ICP-AES分析表明，大约80％的重金属集中在固相中。柠檬酸与污水污泥的浸出作用不仅去除了40％的灰分，而且减少了38％的脂肪。