Enhanced DAF in breaking up oil-in-water emulsions
Enhanced DAF in breaking up oil-in-water emulsions
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DOI：
10.1016/j.seppur.2013.11.007
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发表时间：
2014-02
影响因子：
8.6
通讯作者：
M. Karhu;T. Leiviskä;J. Tanskanen
中科院分区：
文献类型：
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作者：
M. Karhu;T. Leiviskä;J. Tanskanen
将阳离子表面活性剂十六烷基三甲基溴化铵(CTAB)、混凝剂聚二烯丙基二甲基氯化铵(PolyDADMAC)(也用于含油废水)或环氧氯丙烷-二甲胺共聚物(Epi-DMA)以两种不同的浓度直接加入饱和器(PosiDAF)中，或在饱和器(PosiDAF)中直接加入阳离子表面活性剂CTAB(十六烷基三甲基溴化铵)、混凝剂PolyDADMAC(聚二烯丙基二甲基氯化铵)或Epi-DMA(环氧氯丙烷-二甲胺共聚物)，对合成油制备的2%O/W乳状液进行了溶解气浮(DAF)处理研究。通过测定化学需氧量(COD)和总表面电荷(TSC)来评价不同DAF处理方法的处理效果。用流式细胞仪(FCM)检测所选样品中疏水颗粒的数量。结果表明，与PolyDADMAC和Epi-DMA相比，使用CTAB的PosiDAF的性能较差。对于O/W乳状液的处理，PosiDAF使用PolyDADMAC(剂量334ppm，最高COD下降率为100%)优于Epi-DMA(剂量596ppm，最高COD下降率为93%)。当饱和器中PolyDADMAC和Epi-DMA的浓度均较高时，COD降解率较高。结果表明，加入PolyDADMAC的PosiDAF对O/W乳状液的破乳效果优于传统混凝-絮凝再DAF的效果。采用PolyDADMAC的POsiDAF对实际含油废水也有很好的处理效果；在最佳的PolyDADMAC投加量为200ppm的情况下，COD降低了70%，TSC值完全中和。在O/W乳状液和含油废水样品上进行的FCM研究成功，结果重复性好，是一种很有前途的含油乳状液的分析方法。
Dissolved air flotation (DAF) was studied for treatment of 2 m-% oil-in-water emulsions (O/W emulsions) prepared from synthetic oils by adding chemicals such as the cationic surfactant CTAB (cetyltrimethylammonium bromide), the coagulant PolyDADMAC (polydiallyldimethylammonium chloride) (also studied for oily wastewaters) or Epi–DMA (epichlorohydrin–dimethylamine copolymer) directly into the saturator (PosiDAF) in two different concentrations, or by performing coagulation–flocculation followed by DAF. The efficiencies of various DAF treatments were evaluated by measuring the chemical oxygen demand (COD) and total surface charge (TSC). Flow cytometry (FCM) was used to measure the number of hydrophobic particles in the selected samples. According to the results, the performance of PosiDAF with CTAB was poor compared to that with PolyDADMAC and Epi–DMA. PosiDAF performed better with PolyDADMAC (with a dose of 334 ppm, the highest COD reduction was 100%) than with Epi–DMA (with a dose of 596 ppm, the highest COD reduction was 93%) for the treatment of O/W emulsions. The COD reduction was higher when the concentration of both the PolyDADMAC and Epi–DMA was higher in the saturator. The efficiency of PosiDAF with PolyDADMAC proved to be better than the efficiency of the conventional coagulation–flocculation followed by DAF for breaking up O/W emulsions. PosiDAF with PolyDADMAC also proved to perform very well for treatment of real oily wastewaters; the COD reduction was 70% with an optimal PolyDADMAC dosage of 200 ppm with the TSC value totally neutralized. FCM studies performed on O/W emulsions and oily wastewater samples were successful with repeatable results, thus proving to be a promising analysis method for waters containing oil emulsions.