Zhang Zhenchao
College of Chemistry and Chemical Engineering, Northeast Petroleum University, Daqing 163318, China E-mail:
Water Sci Technol. 2017 Nov;76(9-10):2630-2637. doi: 10.2166/wst.2017.414.
In the present study, the performance of compound flocculants composed of different concentrations of polyaluminum chloride (PAC) and cationic polyacrylamide (CPAM), the influencing mechanism of the flocculation process and the effects of temperature, settling time, and speed and time of stirring were investigated. The results show that the poor water quality with high concentrations of oil, suspended solids (SS) and polymer greatly increases the oily wastewater emulsion stability and the difficulty of the flocculation treatment process. The compound flocculant in oily wastewater treatment can achieve best results at optimum conditions of temperature 45 °C, settling time 60 min, and two stirring stages, 250 r·min for 3 min followed by 100 r·min for 7 min. At the PAC dosage of 80 mg·L and the CPAM dosage of 0.8 mg·L, the turbidity of oily wastewater is reduced from 153.8 NTU to 11.2 NTU, and the turbidity removal rate reaches 92.69%. Through further measurements, oil content and SS content are less than 10 mg·L, which meets the requirement of the Daqing oilfield re-injection standard.
在本研究中，研究了由不同浓度的聚合氯化铝（PAC）和阳离子聚丙烯酰胺（CPAM）组成的复合絮凝剂的性能、絮凝过程的影响机制以及温度、沉降时间、搅拌速度和时间的影响。结果表明，含有高浓度油、悬浮物（SS）和聚合物的劣质水质极大地增加了含油废水乳液的稳定性以及絮凝处理过程的难度。在含油废水处理中，复合絮凝剂在温度45℃、沉降时间60分钟以及两个搅拌阶段（先以250转·分钟搅拌3分钟，然后以100转·分钟搅拌7分钟）的最佳条件下可取得最佳效果。在PAC投加量为80毫克·升且CPAM投加量为0.8毫克·升时，含油废水的浊度从153.8 NTU降至11.2 NTU，浊度去除率达到92.69%。通过进一步测量，油含量和SS含量均小于10毫克·升，满足大庆油田回注标准的要求。
