稠油污水蒸发冷凝水除有机物及脱盐的实验研究

Experimental Research of the Organic Matter Removal and Desalination from Heavy Oil Wastewater Evaporation Condensate

针对稠油污水蒸发冷凝水中有机物含量较高、电导率和二氧化硅含量也未达到火力发电机组锅炉补给水水质要求问题,采用上向流曝气生物滤池(UBAF)-浸没式超滤(SUF)-反渗透(RO)工艺进行了蒸发冷凝水除有机物和脱盐实验,并通过GC-MS测定了蒸发冷凝水中有机物的组成,研究了工艺参数变化对有机物去除和脱盐性能的影响。结果表明,蒸发冷凝水中有机物主要是烷烃类、酯类、苯类,且以C_8和C_(12)小分子有机物为主。蒸发冷凝水直接RO处理时,膜被有机物快速污堵。UBAF-SUF-RO组合工艺能有效去除蒸发冷凝水中的有机物,出水TOC的质量浓度低于0.4 mg/L,且RO的污染趋势大大降低;RO处理出水电导率平均约30μS/cm,平均脱盐率达到95%左右,脱盐性能稳定。

Aiming at solving the problems that the organic matter content in heavy oil wastewater evaporation condensate is comparatively high and the conductivity and silica content do not meet the makeup water quality required by coal fired electricity generation boiler as well, the up-flow biological aerated filter （UBAF） - submerged ultrafiltration （SUF） - reverse osmosis （RO） process was selected to study the organic matter removal and desalination performance from the evaporation condensate. The organic compounds in the evaporation condensate were analyzed using GC-MS and the effect of process parameter variation on the organic matter removal and desalination performance was investigated. The results showed that the primary organic compounds in the evaporation condensate were alkanes, esters and benzenes, and they were mainly composed of small molecule organic matter containing C8 and C^2. When the evaporation condensate was treated directly using RO process, the membrane was fouled rapidly by organic matters. The organic matters in the evaporation condensate could be eliminated efficiently using UBAF-SUF-RO integrated process and the effluent mass concentration of TOC of RO was below 0.4 mg/L with the dramatically reduced RO fouling tendency. The average effluent conductivity of RO system was about 30 μS/cm, the average desalination rate was about 95% and the desalination performance was stable.