摘要
超滤技术的膜污染问题已成为制约其推广应用的关键,针对这一现状,提出对超滤组合工艺的整体参数进行系统性、科学性的优化。构建了混凝沉淀-膜前预加氯-超滤一体化工艺装置并开展中试,通过单因素分析考察了混凝单元(速度梯度)和膜前预加氯(Na Cl O投率)对膜污染的影响,提出了最大可工作通量这一概念,并针对膜比通量(SF)衰减速率采用响应面法对各单元的工艺参数进行了整体优化。结果表明,当混合絮凝池中机械搅拌转速为40 r/min时,膜组件的最大可工作通量达到峰值;在混凝沉淀后、超滤前设置预加氯装置是不可取的,会降低膜的最大可工作通量。通过因素的优化分析、回归方程的预测,得到的最优参数值如下:机械搅拌器的转速为40 r/min,膜前Na Cl O投率为零,膜的运行通量为100 L/(m^2·h)。在此条件下,SF衰减速率最小,为48.58 L/(h·m^5·MPa),重复验证值为47.37 L/(h·m^5·MPa),试验值和预测值较吻合。由此可见,响应面分析法可科学地优化组合工艺的整体运行参数。
Irreversible membrane fouling has been the major impediment in the application of UF technology; therefore, systematic and scientific optimization of general operational parameters of the hybrid process based on uhrafihration （UF） was proposed to solve this issue. A device integrating coagulation-sedimentation, pre-chlorination, and UF was developed, and a pilot-plant test was carried out to treat water from the Minjiang River. Impacts of the velocity gradient of the coagulation unit and the dosage of NaClO on the membrane fouling were assessed in single factor experiments; in addition, the concept of ＂maximum feasible flux＂ was proposed. Thereafter, in each processing unit of the combined process, the decay rate of the membrane specific flux （SF） in each filtration cycle was optimized using the response surface methodology （RSM）. The results showed that the maximum feasible flux of the UF module was achieved under an agitator rotational velocity of 40 r/min in the coagulation unit. The usage of the pre-chlorination unit between the coagulation unit and the UF unit was unsuitable in the proposed process. Through the optimization analysis of the optimized parameters of agitator rotational 0 and 100 L/（ m^2 ·h）. Under this condition, each factor and the prediction of the regression equation, velocity, NaClO dosage and operating flux were 40 r/min, the SF decay rate reached the minimum during a single filtration, with a predicted value of 48.58 L/（ h · m^5 · MPa）, and was verified at 47.37 L/（h · m^5· MPa）. RSM was proved to successfully optimize general operation parameters in integrated processes.
出处
《中国给水排水》
CAS
CSCD
北大核心
2018年第3期42-47,共6页
China Water & Wastewater
基金
福建省住房和城乡建设系统科学技术项目(2014-K-05
2016-K-42)
国家自然科学基金资助项目(51778146
51308123)
中国博士后科学基金资助项目(2014M561856)
关键词
超滤
组合工艺
混凝
预氯化
膜污染
响应面分析
ultrafiltration
combined process
coagulation
pre-chlorination
membrane fouling
response surface methodology
