Practice Of Pharmaceutical Wastewater Treatment In A Chinese Medicine Enterprise In Gansu Province

With climatic and environmental conditionsvery suitable for the growth of Chinese medicinal materials,Gansu Province is a major province of Chinese medicinal materials in China.However,the Chinese medicine pharmaceutical wastewater has the drawbacks of large water volume,large changes in water quality,complex and variable pollutant composition,high organic content,poor biodegradability,and difficulty in treatment.If discharged directly without treatment,it will inevitably cause damage to local environment and ecology and waste precious water resources.Therefore,the wastewater must be treated and reach the standard before discharging or reusing.Taking a Chinese medicine pharmaceutical company in Gansu Province with a daily wastewateroutput of 200m³/d as the research object,based on the amount of wastewater influent,water quality,and current discharge standards,combined with current specifications,previous engineering experience,and commonly used treatment methods for pharmaceutical wastewater,this article used the comprehensive comparison method for comparison and selection,and then determined the treatment process suitable for this project;On this basis,the design parameters of the main processing unit were analyzed,and the engineering design and operation cost analysis of the process were carried out;Finally,through the actual water quality monitoring data,the engineering operation effect was analyzed and studied.1.Through actual testing and reference to the water quality of similar water plants,and after comprehensive analysis,the designed influent water quality of this traditional Chinese medicine pharmaceutical wastewater was determined COD:5000mg/L,BOD₅:1300mg/L,SS:1500mg/L,ammonia nitrogen 40mg/L,oil:25mg/L,pH:6-8;After treatment,the discharged water needs to meet the"Water Discharge Standard for Traditional Chinese Medicine Pharmaceutical Industry"（GB21906-2008）,and the recycled water needs to meet the"Urban Sewage Recycling and Urban Miscellaneous Water Quality"（GB/T18920-2002）.2.Through a comprehensive comparative analysis of the treatment effects,advantages and disadvantages and applicable conditions of several commonly used pharmaceutical wastewater treatment processes at this stage,the main treatment process of this project was determined as:For discharging water:Adjustment→Coagulation and sedimentation→Hydrolysis acidification→IC reactor→A/O→Vertical flow secondary sedimentation tank→Disinfection→Discharge;For reusing water,on the basis of the above,in-depth treatment was been carried out,namely:Use reclaimed water treatment equipment→reclaimed water tank→reuse（greening and road sprinkling within the plant）3.Through the coagulation experiment of traditional Chinese medicine pharmaceutical wastewater,it was determined to choose PAC as the coagulant and PAM as the coagulant with a dosage of 80mg/L to treat the traditional Chinese medicine wastewater.The removal rate of COD could reach up to 29%.The biochemical method had a good removal effect on COD and ammonia nitrogen.The removal rate of COD and ammonia nitrogen at 18 hours of aeration was 86%and 88%respectively.The experimental results have shown that it is feasible to adopt the coagulation sedimentation and biochemical method as the main treatment process when treating this traditional Chinese medicine wastewater.4.From the perspectives of treatment effect and operating cost,according to the influent water quality and the current relevant regulations,the parameters were analyzed through experiments and reference to the hydraulic retention time of and COD volumetric loading of the structure treatments in similar water plants.The volumetric load of the hydrolysis and acidification tank of the sewage treatment station was determined to be 5.0 kgCOD/（m³·d）,the volumetric load of the IC reactor 8.2 kgCOD/（m³·d）,the hydraulic retention time of the A pool 5.7 hours,and the total hydraulic retention time of the biological contact oxidation tank 18.4 hours,and the volumetric load 0.39kgCOD/（m³·d）etc..On this basis,the design calculation of the main structure was carried out,the size of the main structure was determined,the engineering design of the sewage treatment station was carried out,and the corresponding supporting equipment was selected.5.The monitoring data for more than 3 years after the operation of the sewage treatment station shows that the average removal rates of COD,ammonia nitrogen,turbidity,etc.of the system are respectively:99.12%,88.89%,99.37%,The discharged water has met the"Water Discharge Standard for Traditional Chinese Medicine Pharmaceutical Industry"（GB21906-2008）,and the recycled water has met the"Urban Sewage Recycling Urban Miscellaneous Water Quality"（GB/T 18920-2002）.It is shown that the treatment effect,good operation and stability of the system,the design process have met the requirements of the pharmaceutical plant wastewater treatment,and the design parameters and equipment selection of each wastewater treatment structure have also met the actual requirements.6.The operation cost of the sewage treatment station was analyzed,after which it was found that the cost required for treating 1 cubic meter of sewage was 3.2 yuan.