Study On The Effect Of HPAM On Wastewater Treatment And Its Degradation Method

Oilfield wastewater is a kind of industrial wastewater produced during the development of oil and gas fields.Oilfield sewage contains a large number of soluble organic matters,suspended solids,charged colloidal particles,heavy metal,all kinds of inorganic salt and chemical additives and so on,which make wastewater composition complex,toxic and refractory.In this paper,the HPAM degradation by ultrasound and its operational parameters,such as ultrasonic time,power,pH,temperature and initial concentration of HPAM were studied,which can get an optimal ultrasonic condition.At the same time,the flocculation of different molecular weight HPAM with single flocculent and compound flocculent was researched,and its influence factors were also studied,such as settling time,pH and temperature.Eventually,the influence of different degradation degree of polyacrylamide on flocculation efficiency was briefly studied,and this paper also researched the flocculation between HPAM and flocculants under these parameters,such as settling time,pH and different temperature.The following conclusions through can be got from these experiments.The ultrasound can degrade the polyacrylamide at some degree,and its removal rate can reach to about89.23%at optimal experimental conditions.When dealing with the wastewater,which the initial concentration of polyacrylamide by ultrasound,its optimal experimental condition is that optimal degradation time is 20 minutes,ultrasonic power is at 75 W,pH of solution is 7.0,and temperature of solution is between 20? and 30?.Under this condition,its degradation rate can be better and reach to 89.23%.Besides,the initial concentration of HPAM has certain effect on the ultrasonic degradation to some extent.The conclusion is that as the initial concentration of HPAM increased,the HPAM removal rate decreased.The orthogonal experiment showed that the influence of ultrasonic time,temperature and power on the degradation was declined one by one.When observing the reactions of different molecular weight HPAM with flocculants(single flocculent and compound flocculent),the following conclusions can be got.As the flocculent increased,the light transmission of different molecular weight HPAM solution had the same changing trend,that is,increased first and then decreased.However,when it came to the best treatment effect,20 million molecular weight HPAM solution required the most amount of flocculent,12 million molecular was the second,4 million molecular need the least.For different molecular weight HPAM solutions,the effect of temperature and pH on flocculation has the same rule:At the temperature between 45 to 55 and neutral and alkaline conditions,the flocculation effect of the experiments is better.With the increase of settling time,the transmittance of HPAM solution with different molecular weight increased,and the transmittance of 20 million molecular weight HPAM solution changed the most.The effect of different HPAM degradation degree on flocculation efficiency was studied,and proper degradation can enhance the effect of flocculation.Compared with the undegraded HPAM solution,when the molecular weight of 20 million HPAM was degraded to 13.97 million,the flocculation effect was better.But when the HPAM molecular weight was degraded to 7.28 million,the effect of flocculation was relatively worse.And for 12 million HPAM and 4 million HPAM,when the molecular weight was degraded to 9.27 million and2.67 million respectively,the flocculation experiments had the better effect.The flocculation effect got worse as their molecular weight degraded to 5.98 million and 2.07 million in the range of molecular weight investigated.The change of pH had the same effect on flocculation experiments of the degraded HPAM solution and undegraded HPAM solution.And the neutral and alkaline conditions are beneficial to the flocculation experiment of degraded and undegraded HPAM solution,and the flocculation effect on the neutral condition is better.In addition to the 20 million molecular weight HPAM solution,the effect of temperature on the flocculation experiment of HPAM solution with different degradation degree was different.For 20 million molecular weight of HPAM solution,the effect of temperature on the flocculation experiment of HPAM solution was roughly same,and the flocculation effect was better between 45? and 55?.However,for the degraded solution of 12 million and 4million HPAM,the flocculation effect decreased with the increase of temperature,and the flocculation effect was better at 35?.