不同条件下污泥水热液相产物的生成特性

Character analysis of liquid products from hydrothermal treatment of sludgeunder different conditions

将城市污水污泥作为研究对象进行水热处理,目的是得到可以改性成为聚集介质的水溶性有机聚合物(soluble organic polymers,SOP)。研究了不同温度(150、175、200和225℃)、反应时间(0.5、1和1.5 h)和碱性添加剂用量等水热条件下SOP的生成特性。结果表明,随着温度和反应时间的增加,SOP产率逐渐下降,由28.5%(150℃、0.5 h)降低至14.73%(200℃、0.5 h)。碱的投加提高了SOP产率,且NaOH的效果优于Na_(2)CO_(3)。元素分析表明,温度升高导致SOP的O/C和H/C下降,腐殖化、芳香化程度均增加。红外光谱和X射线光电子能谱表明,温度的升高导致SOP中改性可利用的含氧基团减少。因而150℃、0.5 h、NaOH投加量为污泥干重的10%时,水热反应条件是最适宜的,可以得到更适合作为聚集介质前体物的SOP。本研究结果可为污水污泥资源化利用提供参考。

Municipal sewage sludge was used as raw substrate for hydrothermal treatment in order to obtain soluble organic polymers(SOP),which can be modified to aggregation media.The characteristics of SOP were investigated under various hydrothermal conditions with different temperatures(150,175,200 and 225℃),reaction times(0.5,1 and 1.5 h)and amounts of alkaline additives.The results showed that the SOP yield decreased gradually with increasing temperature and reaction time,from 28.5%(150℃-0.5 h)to 14.73%(200℃-0.5 h).The alkali addition boosted the SOP yield,besides,NaOH had a better effect than Na_(2)CO_(3).Elemental analysis demonstrated that the increase of temperature led to the decrease of O/C and H/C of SOP,which meaned the increase of humification and aromatization.Results of infrared spectroscopy and X-ray photoelectron spectroscopy indicated that the increase in temperature led to a decrease in the oxygen-containing functional groups.Thus,the hydrothermal conditions at 150℃,0.5 h,and NaOH dosing of 10%(w/w of dry weight)were optimal to obtain SOP as precursors for aggregation media preparation.This study can provide a reference for the reuse of sewage sludge.