Study On Optimization Techniques Of Flocculant In Coal Mine Drainage Treatment

The development and utilization of coal mine drainage is an effective way to reduce the degree of water shortage in water stress area.The abundance discharge of coal mine water and easily treated due to having less organic pollution,which make it feasible to develop and utilize.At the same time,it is necessary to recycle coal mine drainage in the area which is shortage of water resources,especially in the severe water shortage area such as northern Shaanxi coal mine,It will have good social, environmental and economic benefits.In this paper,high suspended solids mine drainage which accounted for about 60%in the part of northern China coal mine was studied,and the main treatment process for the coagulation was done in the laboratory.Representative of the five kinds of flocculants were selected,such as PAC,PFS,PAFC,PAM and CTS.A series of coagulation experiment was carried out but PAFC was optimum.The removal efficiency of turbidity and chemical oxygen demand were more than 90%and 60% when the dosage of PAFC and pH were 15 mg/L,7-9,respectively.Natural organic polymer flocculant chitosan has unique advantages in drinking water treatment due to it's natural,non-toxic and safe.In this paper,preliminary study of chitosan used in coal mine drainage was tried out.The optimum dosage was 1.5 mg/L,meanwhile the removal efficiency of turbidity and chemical oxygen demand was 46.5%and 66.7%respectively.The optimum pH was about 5.Under optimum conditions,the removal efficiency of turbidity and chemical oxygen demand was up to 67.2%and 64.8%.Meanwhile,the complex experiments which PAFC was separately combined with PAM and CTS were carried out.Through the two L₉(3⁴) orthogonal experimental design,the optimum dosage and pH value were determined.In the compound experiment of PAFC and PAM,the primary and secondary factors of which impacted on turbidity removal rate was obtained through visual analysis.They were followed by PAFC dosage,pH value,PAM dosage.The appropriate conditions were PAM dosage of 0.2mg / L,PAFC dosage of 15mg / L,pH value of 9.In the compound experiment of PAFC and CTS,the relationship between the primary and secondary factors was: PAFC dosage,CTS dosage,pH value.The optimum conditions were CTS dosage of 1.5mg / L,PAFC dosage of 15mg / L,pH value of 9.The coagulation mechanisms of chose coagulants were analyzed simultaneously.