Abstract:

Significant amounts of oil-containing waste water are discharged in industrial processes, and it is difficult to separate the oil/water mixture. In this paper, a concept of air-lift loop was introduced to traditional flotation process to treat oil-containing water. In the experiment, oil-in-water emulsion was produced by ultrasound, and the flotation agent for this system was optimized first, as poly(acrylamide-co-diallyldimethyl ammonium chloride) (PDA). Then, the effect of different conditions in the loop flotation process was investigated. When air flow rate was 250 L·h^-1, liquid flow rate was 10 L·h^-1, liquid level was 6 cm, amount of PDA was 20 mg·L^-1, oil removal rate was the highest. Concentration of oil was reduced from 900 mg·L^-1 to 100 mg·L^-1 and the highest efficiency was 90.48%. Compared with the traditional column flotation under the same condition, loop flotation was more effective and quick, with increased oil removal by 10%. The loop flotation concept would have great industrial application value.

Key words: flotation, air-lift loop column, separation, waste water, technological conditions

摘要：

工业生产中会产生大量结构稳定的含油废水,将环流的概念引入传统的空桶式柱气浮工艺来处理含油水体,以克服空桶式浮选柱液体停留时间短、碰撞效率低的缺点,达到提高油水分离效果、深度净化水体的目的。实验中以超声乳化柴油水溶液作为原料,优选出适合本体系的气浮药剂二甲基二烯丙基氯化铵/丙烯酰胺共聚物(PDA),考察了环流气浮法中各工艺条件的影响。结果表明,当气体流量为250 L·h^-1,液体流量为10 L·h^-1,液位高度为6 cm,PDA用量为20 mg·L^-1时,气浮效果最好,最高除油率可达90.48%。对比相同工艺条件下的空桶式柱气浮法,除油效率提高了10%以上,且气浮速度更快,具有很高的工业应用价值。

关键词: 浮选, 环流浮选柱, 分离, 废水, 工艺条件