加热对餐厨垃圾生物干化能效及氮损失的影响

针对餐厨垃圾生物干化处理周期长、脱水效率低的问题,基于外源辅助加热的生物干化机,比较不同加热温度(加热板设置温度)/加热时间(分别记为CK、JR 55-30、JR 75-30、JR 95-30、JR 105-20、JR 105-30、JR 105-40、JR 115-30)对餐厨垃圾生物干化过程系统脱水能效及氮素损失的影响.结果 表明:CK、JR 75-30和JR 105-30的单位质量水分去除能耗较低,分别为0.58、1.24和1.34 kW·h/kg,其余处理在1.42～1.61 kW·h/kg;JR 105-30、JR 105-40、JR 115-30的水分去除效率较高,别为84.22％、92.27％、84.77％;其余处理均在26.86％ ～76.82％;加热温度越高、加热时间越长,总氮(TN)和铵态氮损失率越大,8个处理的TN损失了6.16％ ～ 22.03％,铵态氮损失了19.15％ ～60.87％.Pearson相关性分析结果表明TN、铵态氮与含水率(MC)呈现显著正相关(P＜0.05),与电导率(EC)呈现显著负相关(P＜0.05).JR 105-40处理的单位质量水分去除能耗为1.52 kW· h/kg,比CK(0.58 kW·h/kg)高0.94 kW· h/kg;水分去除效率为92.27％,比CK(26.86％)高65.41％;TN损失了19.49％,比CK(6.16％)高13.33％;铵态氮损失了57.45％,比CK(19.15％)高38.30％.在保障快速干化效率的基础上,建议采用JR 105-40对餐厨垃圾进行生物干化;4 d内可以使餐厨垃圾含水率下降到28.56％.研究结果为餐厨垃圾快速生物干化处理外源加热温度/时间的选择提供了参考.

Effects of External Heating on Energy Consumption, Water Removal Efficiency and Nitrogen Loss of Kitchen Waste Bio-drying

Aiming at the problems of long treatment cycle and low water removal efficiency of kitchen waste biological drying, the effects of different heating temperature and heating time (signed as CK, JR 55-30, JR 75-30, JR 95-30, JR 105-20, JR 105-30, JR 105-40, JR 115-30, respectively) on water removal efficiency, energy consumption and nitrogen loss of kitchen waste biological drying, on the biological drying machine with external auxiliary heating. The results showed that: (1) The energy consumption of water removal per unit mass of CK, JR 75-30 and JR 105-30 were 0.58, 1.24 and 1.34 kw.h.kg^-1, respectively, which were lower than other treatments (1.337 - 1.613 kw.h.kg^-1); (2) The water removal efficiencies of JR 105-30, JR105-40 and JR 115-30 were 84.22%, 92.27% and 84.77%, respectively, which were higher than other treatments (26.86% - 76.82%); (3) The higher the heating temperature and the longer the heating time, the greater the loss rate of TN and ammonium nitrogen; The loss rate of TN was 6.16% - 20.03% and the loss rate of ammonium nitrogen was 19.15% - 60.87% of all treatments. The pearson correlation results show that TN and ammonium nitrogen were positively correlated with moisture content (p<0.05), and negatively correlated with EC (p<0.05). The results showed that the energy consumption of water removal per unit mass of JR 105-40 was 1.52 kw.h.kg^-1, which was higher 0.94 kw.h.kg^-1 than CK (0.58 kw.h.kg^-1); the water removal efficiency was 92.27%, which was higher 65.41% than CK (26.86%); the loss of TN was 19.49%, which was higher 13.33% than CK (6.16%); and the loss of ammonium nitrogen was 57.45%, which was higher 38.30% than CK (19.15%), respectively. On the premise of ensuring the drying efficiency, JR 105-40 is recommended for biological drying of kitchen waste, and can reduce the water content to 28.56% on day 4. The results provide a reference for the selection of external heating temperature and heating time for the treatment of kitchen waste by external auxiliary heating biological drying machine.