The Research Of Backflow Based On Guar Gum For Reinjection Treatment In Lake Ma

The backflow based on guar gum has high viscosity,complex composition and is difficult to treat.At present,a mature treatment process has not yet been formed in Xinjiang Oilfield.When the backflow was introduced to the existing oilfield wastewater treatment system,the water quality compliance rate was seriously affected.Further researches on the backflow and exploration of the reinjection treatment process are extremely urgent.This study simulated the process of the backflow affecting the existing sewage treatment system in Xinjiang Oilfield,and explained the reasons why the backflow seriously affected the water quality compliance rate with the stability analyzer.The guar gum molecular weight measurement method(gel chromatography)and the guar gum concentration measurement method(anthrone detection method)were used to evaluate the degradation results on guar gum of chemical oxidation,hydrolysis acidification and enzymatic hydrolysis.Then,a set of economical treatment process was proposed,that was,flocculation after enzymatic hydrolysis.And two different backflow fluids were treated indoors,and the effluent water quality reached the standard.The main results were as follows:(1)During the flocculation process,potassium chloride,calcium chloride,magnesium chloride and fungicide in the backflow inhibited the adsorption and bridging process of PAM,so that there were more micro-size flocs.And the sinking speed of the flocs decreased by 84% because of guar gum;(2)During the degradation process of guar gum,the following data were obtained,by using 50g/L sodium hypochlorite degrading 4g/L guar gum,and the proportion of macromolecules of guar gum decreased to 58%,COD decreased to 3620,the proportion of sugar still accounted for above 80%;by using 10g/L activated sludge degrading 4g/L guar gum,macromolecules were completely degraded,the proportion of sugar accounted for 42.58%,COD decreased to 4265;by using 10mg/L enzyme degrading 4g/L guar gum,the proportion of macromolecules decreased to 0%,the proportion of sugar was still 96%,and COD remained unchanged at 6150.It is confirmed that the oxidant had no selectivity for substance in the backflow,and the enzyme had strong selectivity to the macromolecular guar gum in the backflow,and the degradation results were ideal.(3)After the treatment process of enzymatic hydrolysis and flocculation,the effluent water quality met the standard.In the process,the influences of components such as calcium chloride,magnesium chloride and guar gum on flocculation were confirmed.