电子束辐照结合低温热水解协同提高污泥破解率

Improvement of sludge disintegration by electron beam radiation in combination with low temperature thermal treatment

以城市污水处理厂脱水污泥为供试材料,通过比较电子束辐照、热水解及组合工艺对污泥破解率的影响发现:随着热水解温度从90℃提高到120、140和160℃,污泥破解率分别从14.82%升高至19.97%、23.16%和33.28%。当热水解温度低于140℃时,氨氮/溶解性总氮的比值(NH_3-N/TSN)在0.14~0.17之间波动,而温度达160℃时,NH_3-N/TSN升高至0.22。另一方面,当污泥吸收剂量由5 k Gy增加至10、15、20 kGy时,污泥破解率分别由3.77%缓慢上升到4.87%、5.01%、5.42%。但是,NH_3-N/TSN维持在0.32~0.33之间,比热水解处理约提高1倍。在组合工艺中,15 kGy+90℃热水解30 min污泥破解率最高,达25.1%,NH_3-N/TSN≈0.22。实验证明:热水解对污泥破解效果显著,但电子束辐照可进一步将大分子有机物质降解为小分子物质。

The effects of thermal hydrolysis （TH）, electron beam （EB） radiation, and combined process of EB-TH on sludge disintegration were investigated. It indicated that sludge disintegrations were improved with the increasing TH temperature from 90 to 120, 140, 160 ℃. The sludge solubilization were achieved from 14. 82% to 19.97% , 23. 16% and 33.28% , respectively. Another key data of NH3-N/TSN ranged between 0. 14 and 0. 17 when TH temperature was below 140 ℃. However, this ratio increased up to 0.22 when TH operated at 160 ~C. On the other side, the sludge solubilization were 3.77% , 4.87% , 5.01% and 5.42% when absorbed dose increased from 5 to 10,15,20 kGy, respectively. The ratio of NH3-N/TSN ranged from 0. 32 to 0.33, which were almost double times higher than that treated with thermal hydrolysis. The most promising result was obtained by EB radiation （ 15 kGy） in combination with thermal treatment （90 ℃/30 min）. The sludge solubili- zation and NH3-N/TSN were 25. 1% and 0.22, respectively. The results demonstrated that thermal hydrolysis was far more effective in sludge disintegration while electron beam radiation was better in degradation of high mol- ecule organic compounds into lower molecule compounds.