Study Of The Treatment Process Of Pharmaceutical Secondary Effluent

Water is the source of life, which plays an important role in daily life as well as in many industrial processes. However, drought and water shortage is serious in China, especially in Shanxi Province. Water shortage and water pollution being increasingly serious has become an social universal problem. Pharmaceutical waste water is one of main pollution source of fresh water. Study of high-efficient and low-energy pharmaceutical waste water treatment technology is the emphasis and difficulty of environmentalists.Numerous studies on CODcr removal of biochemical treatment effluent of pharmaceutical waste water have appeared recently. But in the process of pharmaceutical waste water treatment used biochemical method, the CODcr removal was difficult to achieve the national emission standards. Hence, in order to seek achieve the national emission standards in advanced treatment of pharmaceutical waste water treatment, to seek a kind of coagulation process which is more economically feasible, to achieve economic efficiency, environmental benefits and social benefits maximized, coagulation sedimentation of the secondary effluent of pharmaceutical wastewater using coagulant have been researched in this topic. The secondary effluent of pharmaceutical waste water of Taiyuan pharmaceutical factory was coagulated through static single factor test and orthogonal experiment methods, respectively. Optimum removal efficiency and reaction conditions were obtained. The results were as following: effect of five kinds of coagulant of dosing quantity, pH, temperature and coagulant aid on coagulation efficiency were analyzed. The suitable conditions for coagulant using were obtained under each single factor. The dosage of aluminium-based and iron-based coagulants was generally 120 mg/L and 140 mg/L around, respectively. It is appropriate to use the two kinds of coagulant at pH=6～8, temperature of around 25℃. When coagulant aid of PAM was used, the suitable adding ratio PAM and coagulant was among 1:20~1:60.Based on static single factor test, orthogonal experiment methods were adopted. Optimum conditions and removal efficiency of various coagulants were obtained. The results showed that the removal rate of CODcr and turbidity using PAC was highest and remarkable effect in the secondary effluent of pharmaceutical waste water; the removal rate of CODcr and turbidity were 74.12% and 89.98%, respectively; the effluent CODcr and turbidity were between 38.83~90.58 mg/L and 2.00~10.02NTU, respectively; removal effect of PAFC and PFS took second place; AS and FC were inferior to three former; significance of factor for removal of CODcr and turbidity using PAFC was in sequence of RpH> R温度> R投加量and RpH> R投加量> R温度, respectively; considering that CODcr was main pollutant in secondary effluent of pharmaceutical waste water, the optimal coagulation conditions for PAC were the dosage of 120mg/L, pH=8 and temperature t=25℃.Through analysing and comparing the coagulation effect, although the removal rate of pollutants of pharmaceutical waste water using PAC, PFS and PAFC coagulants was higher, but economy of PAC was more reasonable from economic analysis. For AS and FC, to achieve emission standards, coagulant aid PAM must be used. However, the cost of PAM-based various types of pharmaceutical are very considerable. Therefore, non-necessary, coagulant aid PAM generally did not choose to use in coagulation and sedimentation to remove pollutants from waste water.In view of the comprehensive performance and economy of various coagulants, PAC was the better scheme for the treatment of secondary effluent of pharmaceutical waste water. This coagulant is technically reliable, higher popular rate in chemical market, meeting the economic requirements of advanced treatment and the most reasonable coagulant in technological and economic. If the filtration-adsorption process was adopted after coagulation, the quality of effluent water could be improved further, which can provide some reference for the choice of coagulation process in this plant.