Technique for biological treatment of mine acidic wastewater

[0040] Embodiment 1. Sulfate biological reduction reactor, sulfate load is 7.0kgSO 4 2 /m 3 ·D, the temperature is 35℃, COD/SO 4 2- The value is 1.2, the pH value of the inlet water is 6.5, and the rising flow rate of EGSB in the anaerobic expanded granular sludge bed reactor v up The reflux ratio is 3.0m/h, the reflux ratio is 80:1, the hydraulic retention time HRT is 0.2d; the AF reflux ratio of the anaerobic biological filter is 20:1, HRT is 0.25d; the anaerobic baffle reactor ABR, HRT is 0.2d; Anaerobic fluidized bed reactor AFBR, HRT is 0.02d; colorless sulfur bacteria CSB biological oxidation S 2- The reactor has a pH of 8.0, a temperature of 15°C, and a sulfide load of 12.0kg/m 3 ·D, DO in the reactor ≈ 5.5mg/L; slow sand filter, filtration rate of 0.1m/h, filtration cycle of 25d, intercepting elemental sulfur S in the sand layer of 6cm on the surface; particle size of the sand filter layer is 1.2mm , Thickness 25cm; supporting layer sand grains from bottom to top, particle size 5.0mm, 2.5mm, 1.2mm, height of each layer 3cm; extraction equipment, with carbon disulfide CS 2 As the extractant, the scraped sand filter material and the extractant CS 2 Full contact of the solution to make CS 2 Fully dissolve elemental sulfur particles; solid-liquid separation equipment, the extractant CS is separated by filtration 2 Phase separation of solution, sand filter material and shedding biofilm; distillation equipment, temperature 48℃, distillation extractant CS 2 Solution, the elemental sulfur is precipitated, and the extractant is reused; the drying equipment, the temperature is 175°C, the precipitated elemental sulfur is dried for 1 hour to recover the elemental sulfur.

[0041] Embodiment 2. Sulfate biological reduction reactor with a sulfate load of 4.0kgSO 4 2 /m 3 ·D, Anaerobic expanded granular sludge bed reactor EGSB, HRT is 0.5d; anaerobic biological filter AF, HRT is 0.75d; anaerobic baffled reactor ABR, HRT is 0.6d; anaerobic fluidized bed The reactor AFBR and HRT are 0.16d, and the others are the same as in Embodiment 1.

[0042] Embodiment 3, sulfate biological reduction reactor, sulfate load is 1.0kgSO 4 2 /m 3 ·D, Anaerobic expanded granular sludge bed reactor EGSB, HRT is 0.85d; anaerobic biological filter AF, HRT is 1.25d; anaerobic baffled reactor ABR, HRT is 1.0d; anaerobic fluidized bed The AFBR and HRT of the reactor are 0.3d, and the others are the same as in Embodiment 1.