Abstract: The study on the secondary biochemical effluent of agricultural pharmaceutical factory by using pretreatment, ultrafiltration and nano-filtration technology are carried out. By changing the dosage, pressure and recovery rate, the optimum process conditions of the secondary biochemical effluent of agricultural pharmaceutical factory discussed by using pretreatment and double-membrane process technology. The results show that the pretreatment effluent effect meet ultrafiltration water requirements under the condition of PFS dosage 300 mg/L. The membrane system runs stably when the ultrafiltration operating pressure control in 0.1~0.2 MPa, recovery rate 90% and nano-filtration operating pressure control in 2.0~2.2 MPa, recovery rate 80%. After the double-membrane treatment, wastewater TP decreases to 8 mg/L, the removal rate of COD is above 90%, the effluent turbidity is less than 0.1 NTU. Effluent quality reaches the level of new emission standards.

Key words: pretreatment, double-membrane method, depth processing, phosphorus-containing wastewater