Application Research Of API Piracetam Production Wastewater Treatment Engineering

A pharmaceutical and chemical enterprise in Jiangxi produces wastewater with high concentration and complex composition when it produces piracetam,α-pyrrolidone,sodium methanol,silicone oil and other products.The wastewater produced by the pharmaceutical enterprise has the characteristics of high COD and high ammonia nitrogen,and the wastewater contains toluene,pyrrolidone and some accessory intermediate products,which are difficult to decompose ring organics.According to the characteristics of the wastewater,the combined treatment process of"air flotation+iron-carbon micro-electrolysis+Fenton oxidation+coagulation precipitation+UASB+A/O+biological aerated filter"is determined to treat the production wastewater.（1）In this paper,the combined pretreatment process of"air flotation+iron carbon micro-electrolysis+Fenton oxidation+coagulation precipitation"is used to open the rings and chains of annular organic matter in the production wastewater,so that the biodegradability of the wastewater is greatly improved to biodegradability.The optimal reaction conditions of the combined process of"iron-carbon micro-electrolysis+Fenton oxidation"are determined by orthogonal experiment and single factor experiment.The experimental results show that:The addition amount of Fe powder is 3 g/L,the addition amount of C powder is 3 g/L,the addition amount of30%H₂O₂is 2.5 ml/L,the addition amount of Fe SO₄is 2 g/L,the reaction time is 2 h,the reaction p H value is 3,the removal rate of COD is 41.35%,NH₃-N is 36.21%.After the effluent from the pretreatment process was stable,the biochemical treatment system of the project"UASB+A/O+biological aerated filter"was debugaged and studied,and the running debugging results were as follows:（2）At the beginning of UASB startup,keep the influent COD concentration between 1000～1500 mg/L,C:N:P=300:5:1,water temperature between 25～35℃,p H normal value between 6.5～7.5,and the final influent concentration is about 4200mg/L.The removal rate of effluent COD is stable between 70%and 80%,and the effluent COD concentration is between 1000-1200 mg/L.（3）When the dissolved oxygen in pool A and Pool O were controlled to be0.2-0.4 mg/L,2-4 mg/L,p H between 7 and 8,and nitrification reflux ratio was 100%,the final removal rates of COD and NH₃-N in Pool A/O were 89%and 82%,respectively.（4）The biological aerated filter works stably after on-site commissioning.The effluent COD concentration is about 45～55 mg/L,the COD removal efficiency is basically stable between 55%～60%,the ammonia nitrogen concentration is about 3mg/L,and the ammonia nitrogen removal rate is about 60%.After commissioning,the wastewater treatment project runs stably.The removal rate of COD,NH₃-N and toluene is 99.6%,97.5%and 99.9%,respectively.The effluent COD is 48 mg/L,ammonia nitrogen is 3 mg/L and toluene is about 0.06mg/L.The effluent quality meets the level 1 standard in Table 4 of Discharge Standard for Water Pollutants of Chemical Synthetic Pharmaceutical Industry（GB21904-2008）and Comprehensive Sewage Discharge Standard（GB8978-1996）.The comprehensive treatment cost of the combined treatment process for piracetam API production was 24.5 RMB/tonne,with good treatment effect and high environmental and economic benefits,which has good reference significance for other pharmaceutical production wastewater treatment.