【摘要】 该文分别设置不同反应温度（120、150、180、210、240℃）和不同反应停留时间（0.5、1.0、2.0、4.0、8.0 h）,采用控制变量法对污泥进行水热处理。研究水热处理对污泥中氮、磷、钾含量及重金属形态分布的影响,且对重金属进行风险评估。结果表明,随着水热处理温度升高和时间延长,滤液的p H值逐渐降低,溶解性COD（SCOD）浓度逐渐升高。此外,液相中总氮（TN）、氨氮（NH₄⁺-N）、总磷（TP）、磷酸盐(PO₄^3-)浓度呈现递增趋势,而固相中总氮和钾呈现递减趋势。固相产物中OP向IP转化,NAIP向AP转化,TP、IP和AP含量升高,OP和NAIP含量下降。水热处理对Cu、Ni、Zn、Pb 4种重金属具有稳定化作用,Zn由极高污染风险等级降为高污染风险等级,Cu由中度污染风险降为低污染风险,Ni和Pb的风险值都有所下降。总体来说,水热温度对污泥的影响效果比水热时间更显著。更多还原

【Abstract】 This paper described a laboratory experiment conducted for studying hydrothermal treatment of sewage sludge by using the control variate method, in which various reaction temperatures（120, 150, 180, 210 and 240 ℃） and different reaction retention time（0.5, 1.0, 2.0, 4.0 and 8.0 hours） were respectively set for the hydrothermal treatment, and the effects on concentration of nitrogen, phosphorus, and potassium and heavy metal morphology in sludge were investigated. Besides, the environmental risk assessment of heavy metals was also carried out. Consequently, it was showed that with the increase of the hydrothermal temperature and the extension of the retention time, pH of the filtrate decreased gradually as well, meanwhile the concentration of SCOD（dissolved COD） increased gradually; and the concentrations of TN, NH₄⁺-N, TP and PO₄^3- in the liquid phase tended to increase, while the concentrations of TN and potassium in the solid phase tended to decrease. It was also showed that in solid phase, OP（organic phosphorus） was converted to IP（inorganic phosphorus）, NAIP（non-apotite phosphorus） was converted to AP（apatite phosphorus）, and the concentraions of TP, IP and AP increased, but concentrations of OP and NAIP decreased. As for heavy metals, hydrothermal treatment of sludge can stabilize Cu, Ni, Zn and Pb in sludge, so environmental risk of Zn could be reduced from the extremely high level to high level, while that of Cu reduced from moderate level to low level, and the risk values of Ni and Pb both declined to a certain extent. As to the efficiency of hydrothermal treatment,in general the influence of reaction temperature was bigger than retention time.更多还原