Hengyang In Pharmaceutical Pilot Study, The Technological Transformation Of The Wastewater Treatment Station

Traditional Chinese medicine wastewater has the main characteristic of wide variety of flow rate and quality, complicated ingredients, higher SS and color, more inhibitors that is difficult to biodegrade. It has been one of the difficult issues on wastewater treatment. An integrated treatment process of traditional Chinese medicine wastewater in Heng Yang Traditional Chinese Medicine Plant had been put forward in this study, which consisted of hydrolysis acidification and two-stage biological aerated filter. The COD, BOD5, NH3-N, TP (as PO43-), SS, color and pH of influent were 800~1600mg/L, 400-850 mg/L, 10-13 mg/L, 2.0-3.0 mg/L, 100-250 mg/L, 150-200 and 5-7, respectively. During the course of hydrolysis acidification, the macromolecular and bio-refractory organisms in wastewater were degraded into micro-molecular and soluble substances so as to enhance the biodegradability of wastewater, which could benefit the subsequent processes. The two-stage biological aerated filter process could make full use of different microorganisms in different stage with the first stage running in higher loading and the second in lower one, thus the fist stage could decline the loading rapidly and the second guarantee the good effluent quality.Experiment results showed that the start-up of hydrolysis acidification reactor and two-stage biological aerated filter were seeded with sludge from wastewater treatment station, which could shorten the start-up time. HRT had little effect on the hydrolysis acidification of traditional Chinese medicine production wastewater with optimal HRT of over 6h, while the change of COD concentration of influent had also little effect on the COD removal. With the increasing of COD concentration, the removal rate of COD could be enhanced correspondingly when COD concentration was less than 1500mg/L. The HRT and influent loading had some influences on the treatment efficiency of two-stage biological aerated filter; however, the aeration intensity of biological aerated filter had no evident effect on the removal efficiency. Good removal efficiency could be achieved with two-stage biological aerated filter under the HRT, COD and air/water ratio were 12h, 600~800mg/L and 5 : 1 respectively. There was greater difference between the first biological aerated filter and the second one; the treatment efficiency of the first biological aerated filter was better than that of the second one. The quality of effluent could satisfy the first class criteria specified in the Comprehensive Wastewater Emission Standard (GB 8978-1996) under the HRT of process system of 18h and the air/water ratio of 5:1. The experiment also showed that the backwashing of simultaneous air and water met the process requirement for biological aerated...