生物活性炭运行过程中的强度变化规律及机理  

Rule and Mechanism of Strength Variation for Biological Activated Carbon during Operation

作　　者：冯昌龙 庄星宇 王慕 张晶晶 刘成[1] FENG Changlong;ZHUANG Xingyu;WANG Mu;ZHANG Jingjing;LIU Cheng(College of Environment,Hohai University,Nanjing 210098,China;Wuxi Municipal Research Institute of Public Environment Testing Co.,Ltd.,Wuxi 214063,China)

机构地区：[1]河海大学环境学院,江苏南京210098 [2]无锡市政公用环境检测研究院有限公司,江苏无锡214063

出　　处：《净水技术》2022年第12期37-45,85,共10页Water Purification Technology

基　　金：国家科技重大专项(2012ZX07403-001)。

摘　　要：长期运行过程中,生物活性炭(BAC)强度下降会形成“炭粉层”,引发生物泄露和浑浊度反弹现象。在已有的BAC池失效研究中,强度并未引起足够的重视。文中对使用压块破碎炭、柱状炭和再生柱状炭的3座自来水厂的BAC池进行了长期跟踪监测,并建立中试装置进行累积反冲试验。监测结果表明,投入运行的前24个月,BAC强度降低速度最快。3种炭中,柱状炭的平均强度下降最快,再生柱状炭的平均强度下降最慢。炭池表层BAC强度低,底层BAC强度高,运行10年后两者差距为5%~15%,且随运行时间增加而增大。粒度的变化规律表明,强度的减小与运行中的颗粒碰撞、迁移有关;中试试验论证了反冲碰撞、污染物的吸附加快了强度的衰减。在此基础上,应用材料力学及经典赫兹弹性理论分别解释了炭粒耐磨强度、耐压强度的衰减机理,并考虑了包括微生物在内的其他因素造成的强度衰减及安全隐患。综合以上结论,提出了强度评价的建议及针对“炭粉”现象及“刮炭”操作的指导。After long-term operation, the strength of biological activated carbon(BAC) decreases and forms "powdery carbon layer", which will cause biological leakage and turbidity rebound. In previous research on the failure of BAC filter, the strength has not attracted enough attention. BAC at different depths of filters in three water treatment plants(WTPs) were monitored for a long time, which used broken briquetting carbon, columnar carbon and regenerated columnar carbon respectively. And a pilot test facility was set up for cumulative backwash simulation. The results showed that strength of BAC decreased fastest in the first 24 months after operation. Among the 3 kinds of carbon, the average strength of columnar carbon decreased the fastest, and the average strength of regenerated columnar carbon decreased the slowest. The strength of BAC in the surface layer was the lowest, while that in the bottom layer was the highest. The difference between them after 10 years’ operation was 5%~15%, and it increased with the increased of operation time. The rule of particle size variation showed that the decreased of strength was related to the impact and movement of particles in operation. The pilot test showed that the impact of backwashing and the adsorption of pollutants accelerated the strength attenuation. On this basis, material mechanics and classical Hertz elastic theory were applied to explain the mechanism of the decrease in frictional strength and abrasive resistance of carbon particles respectively.Meanwhile, the strength reduction and safety risks caused by other factors including microorganisms were considered. In view of the above conclusions, the suggestions of strength evaluation and monitoring were put forward, and the guidance of "charcoal powder" phenomenon and "scraping" operation was given.

关 键 词：饮用水 生物活性炭 耐压强度 耐磨强度 粒度 变化规律 

分 类 号：TU991[建筑科学—市政工程]