Enhanced solid-Liquid separation of kitchen waste hydrolysate using polyacrylamide:efficiency and mechanism
Kitchen waste hydrolysate(KWH),characterized by high COD and high C/N ratio,can be utilized as an additional carbon source in the biological treatment unit of wastewater treatment plants.Nevertheless,the organic matter present in KWH with larger particles may not be readily metabolized by microbes,leading to elevated concentrations of suspended solids and COD in the effluent.This limitation hinders its widespread application.To address this issue,this study proposed the sequential use of anionic-cationic polyacrylamide(PAM)to enhance the removal of large-particle organic matter from KWH.Experimental results indicated that,at pH=5,sequential addition of 3.2 mg·gTSS-1 anionic PAM(APAM)and 4.0 mg·gTSS-1 cationic PAM(CPAM)reduced the normalized capillary suction time(CSTn)of the hydrolysate from 19.12 s·L·gTSS-1 to 0.61 s·L·gTSS-1,achieving effective solid-liquid separation.Under this condition,the removal efficiency of the soluble COD(SCOD)in supernatant of KWH reached 52.81％,while the concentration of BOD5 remained unchanged.As a result,the ratio of BOD5/SCOD increased from 0.12 to 0.26,significantly improving the biodegradability of KWH.In addition,the efficient removal of proteins in KWH was the main reason for promoting solid-liquid separation of the hydrolysate,as indicated by the analysis of two-dimensional infrared correlation spectra.The results of this study may contribute to promoting the resource utilization of KWH.
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维普
