关键词: 沼液, 热处理, 消毒, 温度, 时间

Abstract: Farmland application and backwash of pig house are the main ways to utilize  swine manure based digested slurry from swine manure. However, the potential risk of pathogenic microorganisms exists in digested slurry produced by psychrophilic and mesophilic biogas digesters. Referring to the pasteurization technology after anaerobic fermentation in the European Union, the heat treatment disinfection method was used to disinfect the digested slurry from swine manure. In order to optimize heat treatment disinfection parameters of digested slurry, the number of coliform bacteria and fecal coliform were used as indicators to evaluate the key factors and disinfection effects of heat treatment. Based on the preliminary test of heating temperature of 50～80 ℃, the experiments were carried out using digested slurry with 3 total solids (TS) content (2%, 4%, 6%), 4 heating temperatures (525, 55, 575, 60 ℃), 3 heating time (the time from 35 ℃ to heating temperature, 15 min, 30 min), respectively. The Results showed that the heating temperature and heating time had an significant influence on the disinfection efficiency of swine manure digested slurry (P< 001), while the TS of digested slurry had no significant effect (P>005). In addition, the temperature growth rate of digested slurry decreased with the increase of total solids content in digested slurry. For digested slurry from swine manure used in this study, the average group number of coliform and fecal coliform in digested slurry were less than 1 CFU·mL-1 and 003 MPN·mL-1 after continuous heating time for 15 min at 60 ℃, respectively, which could meet the requirements of reclaimed water quality standard (SL368-2006) for pathogenic microorganisms disinfection in the reuse of reclaimed water for agriculture. The present research provided a reference for the development of disinfection technology of digested slurry from swine manure.

Key words: digested slurry, heat treatment, disinfection, temperature, time