含聚污水双层级配过滤工艺反冲洗特征及影响

Backwashing Characteristics of Double-Layer Graded Filtration Process of Polymer-Bearing Wastewater

为进一步提高含聚污水过滤反冲洗工艺运行效果,以下层磁铁矿与上层石英砂的双层级配滤料过滤工艺为基础,开展滤料反冲洗工艺过程数值模拟研究,以反冲洗过程压力场分布特征、滤料层空间膨胀特征及滤料颗粒表面吸附与截留粒子的脱附情况为依据,对反冲洗性能进行评价,由此研究反冲洗工艺运行特征及影响因素。研究结果表明:以反冲洗强度15 L/(s·m^(2))时滤料不同填充高度比级配模式的压力场波动程度表现最强,相同反冲洗强度下,则以填充高度比为1.28~1.67时压力场波动程度表现最强;在含聚质量浓度为300~500 mg/L的一级过滤工况中,推荐使用1.28~1.67的填充高度比与20 L/(s·m^(2))的反冲洗强度进行反洗,可使滤层中油滴与悬浮固体脱附率均达到70%以上。研究结论可为油田含聚污水处理提供工艺与技术参考。

In order to further improve the performance of filtration backwashing process for polymer-bearing wastewater,on the basis of the filtering technology of double-layer graded filter material(magnetite in the lower layer,quartz sand in the upper layer),the numerical simulation was performed on the backwashing process of filter material.Then,based on the distribution characteristics of pressure field in the backwashing process,the spatial expansion characteristics of the filter material layer,and the particle surface adsorption and entrapped particle desorption of filter material,the backwashing performance was evaluated.Finally,the operating characteristics and influential factors of the backwashing process were studied.The results show that when the backwash intensity is 15 L/(s·m^(2)),the pressure field fluctuation degree of different grading modes is the strongest.Under the same backwash intensity,the pressure field fluctuation degree is the strongest when the packed height ratio is 1.28~1.67.In the first grade filtration condition with polymer concentration of 300~500 mg/L,the 1.28~1.67 packed height ratio and 20 L/(s·m^(2))backwash intensity are proposed for backwashing,which can make the desorption rate of oil droplets and suspended solids in the filter layer exceed 70%.The research conclusions provide process and technical reference for the treatment of polymer-bearing wastewater in oilfields.