NOVELTY - Metronidazole production wastewater is treated by constructing settling ponds, fish ponds, and biogas digesters around periphery of large farm, directly adding livestock and poultry excrement and urine water to biogas digester, discharging wastewater into settling tank, discharging clean water into dish pond, discharging slag water into biogas digester, using generated biogas for metronidazole wastewater distillation or for energy production, and using deposited sludge in digester by directly sending by pipeline or truck to surrounding farmland as organic fertilizer.    USE - Treatment of metronidazole production wastewater (claimed).    ADVANTAGE - Treatment of metronidazole production wastewater is environment-friendly, reduces biological treatment difficulty in sewage treatment plant, energy consumption, device cost, and operation cost, and does not affect poultry and livestock meat quality.    DETAILED DESCRIPTION - Metronidazole production wastewater is treated by constructing settling ponds, fish ponds, and biogas digesters around periphery of large farm, directly adding livestock and poultry excrement and urine water to biogas digester, discharging wastewater into settling tank, discharging clean water into dish pond, discharging slag water into biogas digester, using generated biogas for metronidazole wastewater distillation or for energy production, using deposited sludge in digester by directly sending by pipeline or truck to surrounding farmland as organic fertilizer or for organic fertilizer production, discharging wastewater into fish pond, producing flushing water using filtration wells set in fish pond, producing biogas heat source using animal manure from large-scale farming and separating metronidazole production wastewater in which metronidazole production wastewater separation processing device comprises evaporation and distillation devices in which generated biogas is used as heat source fuel in evaporator and distillation device boiler, evaporator is connected by pipeline to metronidazole production plant water storage tank, and wastewater is treated by evaporating to concentrate, sending concentrated solution to crystalline precipitate storage tank, performing crystalline precipitation, distilling mother liquor, sending light fraction to water pool, using light fraction as cooling water, using heavy fraction as low-boiling organic chemical raw materials, forming distillation residue into biogas raw material using biological treatment, forming inorganic part into sodium silicate, adjusting pH of heavy-meta-free excess part to neutral, and stacking. An INDEPENDENT CLAIM is included for metronidazole production wastewater treatment distillation device.    DESCRIPTION OF DRAWING(S) - The drawing shows the schematic diagram for the treatment of metronidazole production wastewater. (Drawing includes non-English language text).