摘要
油田为提高原油采收率而采用聚合物驱油作业,产生的采出水中残留着阴离子型高分子质量聚丙烯酰胺(PAM)。废水中PAM和淀粉共存时PAM可发生碳链断裂和生物降解,然而以PAM作为唯一碳源的生物降解性还不清楚。利用好氧悬浮污泥和厌氧升流式反应器,分别处理PAM为唯一碳源的模拟废水(水力停留时间(HRT)为2 d,PAM浓度为200 mg·L-1),结果表明,好氧反应器出水的PAM浓度和黏度均没有降低,同时运行84 d后污泥流失,造成系统崩溃。而厌氧反应器出水PAM浓度和黏度分别降为169.81 mg·L-1和1.50 mPa·s,流场流分离耦合多维角度激光光散射分析发现PAM的分子质量从2.17×107Da降低到3.35×106Da,表明厌氧条件下可以利用PAM作为唯一碳源进行生物降解,并发生碳链断裂。延长HRT从2~8 d可以提高利用PAM作为唯一碳源的厌氧处理效果,出水分子质量进一步降低到1.60×106Da,同时黏度也从1.50 mPa·s降低到1.21 mPa·s。串联生物膜反应器也可以提高利用PAM作为唯一碳源的厌氧生物处理效果,在HRT为4 d条件下PAM的分子质量和黏度降低到1.87×106Da和1.26 mPa·s。
Polymer flooding was used to enhance the oil recovery in the oilfield,and the partial hydrolyzed anionic high molecular weight polyacrylamide(PAM)would remained in the produced wastewater.It was found the cleavage of the main carbon backbone and biodegradability of PAM will occur under aerobic and anaerobic conditions using the PAM and coexisting starch as the carbon sources,while the biodegradability of PAM is uncertainty when it was used as the sole carbon source.Aerobic suspended sludge reactor(ASSR)and upflow anaerobic sludge blanket(UASB)were used to treat the synthetic wastewater containing PAM as the sole carbon source(hydraulic residence time(HRT)2 d,PAM concentration 200 mg·L-1),respectively.The results indicated that PAM concentration and viscosity of ASSR effluent did not decrease,after 84 d running,the biomass was washed out and ASSR system collapsed.However,PAM concentration and the viscosity of UASB effluent decreased to 169.81 mg·L-1 and 1.50 mPa·s,respectively.Through the analysis of the flow field fractionation coupled with multi-angles laser lights method,the molecular weight of PAM decreased from 2.17×107 Da to 3.35×106 Da by.This indicated that the anaerobic biodegradation of PAM could occur when it was used as the sole carbon source,as well as the disruption of its main carbon backbone.Extending the HRT from 2 d to 8 d could improve the anaerobic biodegradation of PAM as the sole carbon source,and PAM molecular weight in UASB effluent further declined to 1.60×106 Da.At the same time,the viscosity of UASB effluent decreased from 1.50 mPa·s to 1.21 mPa·s.The tanks-in-series biofilm reactors could also improve the anaerobic biodegradation of PAM as the sole carbon source,and PAM molecular weight and the viscosity of reactor effluent were 1.87×106 Da and 1.26 mPa·s at the HRT of 4 d,respectively.
作者
宋文哲
张昱
杨敏
SONG Wenzhe;ZHANG Yu;YANG Min(State Key Laboratory of Environmental Aquatic Chemistry,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085,China;University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《环境工程学报》
CAS
CSCD
北大核心
2019年第7期1513-1519,共7页
Chinese Journal of Environmental Engineering
基金
国家自然科学基金资助项目(21590814)
国家高技术研究发展计划(863项目)(2012AA063401)
关键词
聚丙烯酰胺
采出水
唯一碳源
延长水力停留时间
polyacrylamide
produced wastewater
sole carbon sources
extension of the hydraulic residence time