高盐度化学制药废水预处理试验研究

采用蒸馏+铁炭内电解+絮凝工艺对某制药企业排放的废水进行预处理。经过蒸馏脱盐后,综合废水盐度(质量分数,下同)由7.4%降至0.15%;再采用铁炭内电解+絮凝工艺进行处理,内电解试验最佳工艺条件:进水pH值为3.0、铁炭比为4∶1(体积比)、停留时间为6 h,COD去除率达到26.5%;絮凝试验最佳pH值为9.0,COD去除率达到1.5%。废水经过预处理后,COD去除率达到28.0%,出水COD质量浓度(下同)降至20 988 mg/L,ρ(BOD)5/ρ(COD)由0.28提高至0.41。预处理出水厌氧可生化性试验表明,当进水COD质量浓度为9 000 mg/L左右时,容积负荷(COD)为1.0 kg/(m3.d),出水COD质量浓度降低至2 100 mg/L左右,COD去除率达到75.0%。说明该制药废水经过预处理后可生化性显著提高,为后续的生化处理创造了有利条件。

Pretreatment of chemical pharmaceutical wastewater with high salinity

The chemical pharmaceutical wastewater was pretreated by ＂distillation＋ ferric-carbon microelectrolysis＋ flocculation＂ process. The results indicate that the salinity of the integrated wastewater falls from 7.4% to 0.15% after distillation. Then it was treated by ＂ferric-carbon microelectrolysis ＋ flocculation＂, and the optimized conditions of ferric-carbon microelectrolysis are pH=3.0, V（Fe）/V（C）=4 ： 1 and HRT=6 h. COD removal rate is 26.5%. The optimized pH value of flocculation are 9.0 and COD removal rate are 1.5 %. After these pretreatment processes, COD removal rate reaches 28.0 %, COD is decreased to 20 988 rag/L, and the ratio of BODs/COD of wastewater increased from 0.28 to 0.41. Then the effluent of the pretreatment process was treated by anaerobic digestion. The results show that COD decreases from 9 000 mg/L to 2 100 mg ·L^-1 and COD removal rate is 75.0%, The volumetric COD loading rate is 1.0 kg/（m3 ·d）. Then it could be concluded that after pretreatment, the biodegradability of the chemical pharmaceutical wastewater is improved and suitable for the following biotreatment.