Abstract: Microwave and low-alkali were integrated for waste activated sludge pretreatment with NaOH dosage ≤15mg/(gTS). The influences of this technology on the sludge disintegration and sludge characteristics were investigated by comparing the variation of SCOD,soluble protein,soluble total sugar,ammonia nitrogen,pH value and conductivity with increasing microwave time whether adding alkali. The results showed that the combined microwave and low-alkali pretreatment was more effective than microwave or alkali pretreatment alone in cracking sludge. The technology can further improve the ratio of cell lysis and increase the amount of soluble organic matter. The protein dissolution was especially more remarkable. Higher microwave power was beneficial to enhance the synergistic effect. The addition of alkali maintained the pretreated sludge pH value at 9.1-9.5,which helped reduce the decrease of sludge conductivity. However,sludge pretreatment did not change much of the ammonia nitrogen concentration. Therefore,the combined microwave and low-alkali pretreatment would help to improve sludge degradation and electricity production in MFC.

Key words: microwave, low-alkali, combination, waste activated sludge, pretreatment

摘要： 采用微波协同低碱技术预处理剩余污泥[NaOH投加量≤15mg/(gTS)]。通过对比加碱前后污泥溶液溶解性化学需氧量(SCOD)、溶解性蛋白质、溶解性总糖、氨氮、pH值、电导率等随微波处理时间的变化,考察该技术对污泥破解以及污泥特性的影响。结果表明,微波协同低碱对污泥的破解效果明显优于单独微波和单独碱处理。二者的协同作用进一步提高了污泥溶胞率,增大了有机物的溶出量,尤其以蛋白质的溶出更为显著,而且较高的微波功率与碱的协同效果更好。碱的加入使预处理后的污泥pH值维持在9.1~9.5的偏碱性条件,同时减少了污泥电导率的减小量。而污泥溶液氨氮浓度在预处理前后变化不大。因此,微波协同低碱预处理剩余污泥将有助于改善后续微生物燃料电池(MFC)的污泥降解和产电性能。

关键词: 微波, 低碱, 协同, 剩余污泥, 预处理