市政污泥水热炭化废水组成成分特征

污泥水热炭化处理被认为是极具潜力的污泥安全处置与资源化利用的技术措施之一。为了解废水中碳、氮、磷、钾和重金属含量随水热炭化反应温度和反应时间的变化规律,对市政污泥190℃和260℃水热炭化不同时间（1、6、12、18和24 h）后的废水组成成分进行了研究。结果表明,水热炭化处理后,废水颜色由黑色变成浅黄色;pH由6.40提高到9.14;TOC、COD和BOD5最高分别增加了13 175 mg/L、55 998 O2mg/L和31 723 O2mg/L;氮和钾含量显著提高,但磷含量降低;Cd、Cr含量由未检测到分别增加到0.060 mg/L和2.326 mg/L,As、Pb含量均由0.032 mg/L分别增加到1.408 mg/L和0.590 mg/L,但Cu、Mn及Zn含量降低。比起反应时间,反应温度对废水组成成分的影响更大。

Characteristics of wastewater from municipal sludge after hydrothermal carbonization treatment

Hydrothermal carbonization is considered as a potential approach for safe disposal and resource utilization of municipal sewage sludge.The research was conducted,by analyzing the wastewater produced at 190℃ and 260℃ for 1 h,6 h,12 h,18 h and 24 h of municipal sludge,to investigate the changes of C,N,P,K and heavy metal concentrations with reaction temperature and duration.The results showed that the color of wastewater changed from black to pale yellow.The acidity increased from pH 6.40 to pH 9.14.The concentrations of TOC,COD and BOD 5 increased by maximal values of 13 175 mg / L,55 998 O 2 mg / L and 31 723 O 2 mg / L,respectively.The hydrothermal carbonization of municipal sludge increased N and K contents of wastewater,but reduced P concentration.The heavy metals of Cd,Cr,As and Pb contents increased from 0 mg / L,0 mg / L,0.032 mg / L and 0.032 mg / L to 0.060 mg / L,2.326 mg / L,1.408 mg / L and 0.590 mg / L,respectively.However,the heavy metals of Cu,Mn and Zn contents decreased.The temperature had the larger impact on properties of wastewater than reaction duration.