Study On High Efficiency Coagulation Theory And Treatment Technology Of Conventional Mine Water

Aiming at the problems of conventional coagulation technology in treating mine water,such as relatively low efficiency,high treatment cost,process to be optimized,high investment in project construction,and easy secondary pollution of chemicals,In this thesis,the conventional mine water is taken as the main body,and the basic hydrochemical and physical properties of mine water are studied as the starting point,and the characteristics of floc size,particle size distribution,Zeta potential and so on in the process of micro-flocculation of mine water are analyzed.Development of micro-flocculation（tubular reactor）+ultrafiltration process for mine water treatment provides technical support for efficient treatment and utilization of mine water.Take conventional mine water of a mining area（No.1 to No.4 mine）in the south of Hebei province is taken as the research object,and the hydrochemical characteristics of suspended particle content,particle size distribution,Zeta potential and wetting contact Angle are analyzed,and the conventional coagulation experiment is carried out.The results showed that the content of suspended solids was below 100 mg/L,the median diameter of particles was evenly distributed around 10μm,and the Zeta potential was between-20 m V and-30 m V,and PAC showed good coagulation effect,the Zeta potential of coagulation and sedimentation effluent was all below-5 m V,and the turbidity of supernatant was all below 4 NTU when PAC-PAM was added.According to the characteristics of suspended particles in mine water,the floc characteristics of mine water in pipe microflocculation reaction are explored.The results showed that the electric double layer compression and electric neutralization mainly occurred at this stage.When the dosage is 6 mg/L and the flow rate is 1.0 m/s,the particle size of the flocs formed is between 10 and 40μm,and the average particle size is about 20μm.The fractal dimension is between 1.0 and 1.3,and the structure is relatively loose.The effluent Zeta potential is-1.75 m V,which is mainly affected by the dosage of coagulation.The experimental results of pipeline micro-flocculation-ultrafiltration process show that when PAC 6 mg/L is added,the pipe diameter combination isΦ4,20+Φ6.4,12,and filtration for 30 min,the membrane flux J/J₀is 0.882,the effluent turbidity is below0.08 NTU,and the transmembrane pressure difference is 0.18 MPa.The water yield is93.8%,and the filtration cycle is 30 min,and the membrane pollution is small when the hydraulic washing method of forward flush+recoil+forward flush is adopted.Compared with the direct filtration process,the micro-flocculation-ultrafiltration process can reduce the particles blocking the membrane pores,reduce the irreversible pollution and slow down the membrane pollution by forming the filter cake layer on the membrane surface.